Investigating the association between glycaemic traits and colorectal cancer in the Japanese population using Mendelian randomisation.


Association of dietary acid load with the prevalence of metabolic syndrome among participants in the baseline survey of the Japan Multi-Institutional Collaborative Cohort Study

The association between dietary acid load and metabolic syndrome (MetS) has not been fully investigated. A cross-sectional study was performed on 14,042 men and 14,105 women (aged 35-69 years) who participated in a baseline survey of the Japan Multi-Institutional Collaborative Cohort study. Dietary acid load was assessed using the net-endogenous-acid-production (NEAP) score that is closely correlated with the rate of renal net acid excretion. MetS was diagnosed according to the Joint Interim Statement Criteria of 2009 using body-mass index instead of waist circumference. After adjusting for potential confounders, higher NEAP scores were associated with a significantly increased odds ratio (OR) of MetS, obesity, high blood pressure, and high fasting blood glucose. These associations remained significant after further adjustment for carbohydrate intake or two nutrient-pattern scores significantly associated with MetS. After adjustment for fiber, iron, potassium, and vitamin pattern scores, the OR of MetS for the highest quartile of NEAP scores, relative to the lowest quartile, was 1.25 (95% confidence interval 1.12-1.39). There was no significant interaction between sex, age, or body-mass index and NEAP. Higher dietary acid load was associated with a higher prevalence of MetS and several of its components, independently of carbohydrate intake or nutrient patterns.


The interaction between ABCA1 polymorphism and physical activity on the HDL-cholesterol levels in a Japanese population.

Few studies have investigated the interactions between HDL-cholesterol (HDL-C)-related single nucleotide polymorphisms (SNPs) identified by genome-wide association (GWA) study and physical activity (PA) on HDL-C. First, we conducted a sex-stratified GWA study in a discovery sample (2,231 men and 2,431 women) and replication sample (2,599 men and 3,109 women) to identify SNPs influencing log-transformed HDL-C in Japanese participants in the baseline survey of Japan Multi-Institutional Collaborative Cohort Study. We also replicated previously reported HDL-C-related SNPs in a combined (discovery plus replication) sample (4,830 men and 5,540 women). We then analyzed the interactions of the HDL-C-related SNPs with PA on HDL-C. The sex-stratified GWA analyses identified 11 and 10 HDL-C-related SNPs in men and women as targets for an interaction analysis. Among these, only 1 interaction of ABCA1 rs1883025 with PA was statistically significant in men, after Bonferroni correction (P-interaction = 0.001 [ = 0.05/21 = 0.002]). The per-major-allele (C) increase in log-transformed HDL-C was lost in men with low PA ( = 0.008) compared with those with medium ( = 0.032) or high PA ( = 0.034). These findings suggest that the benefit of carrying a C allele of ABCA1 rs1883025 on enhancing HDL-C may be attenuated in inactive men.


Genome-wide association study revealed novel loci which aggravate asymptomatic hyperuricaemia into gout.

The first ever genome-wide association study (GWAS) of clinically defined gout cases and asymptomatic hyperuricaemia (AHUA) controls was performed to identify novel gout loci that aggravate AHUA into gout. We carried out a GWAS of 945 clinically defined gout cases and 1003 AHUA controls followed by 2 replication studies. In total, 2860 gout cases and 3149 AHUA controls (all Japanese men) were analysed. We also compared the ORs for each locus in the present GWAS (gout vs AHUA) with those in the previous GWAS (gout vs normouricaemia). This new approach enabled us to identify two novel gout loci (rs7927466 of and rs9952962 of ) and one suggestive locus (rs12980365 of ) at the genome-wide significance level (p<5.0 10). The present study also identified the loci of , and . One of them, rs671 of , was identified as a gout locus by GWAS for the first time. Comparing ORs for each locus in the present versus the previous GWAS revealed three 'gout vs AHUA GWAS'-specific loci (, and ) to be clearly associated with mechanisms of gout development which distinctly differ from the known gout risk loci that basically elevate serum uric acid level. This meta-analysis is the first to reveal the loci associated with crystal-induced inflammation, the last step in gout development that aggravates AHUA into gout. Our findings should help to elucidate the molecular mechanisms of gout development and assist the prevention of gout attacks in high-risk AHUA individuals.


Association of genetic risk score and chronic kidney disease in a Japanese population

Chronic kidney disease (CKD) is a public health problem worldwide including Japan. Recent genome-wide association studies have discovered CKD susceptibility variants. We developed a genetic risk score (GRS) based on CKD-associated variants and assessed a possibility that the GRS can improve the discrimination capability for the prevalence of CKD in a Japanese population. The present study consists of 11 283 participants randomly selected from 12 Japan Multi-Institutional Collaborative Cohort Study sites. Individual GRS was constructed combining 18 single-nucleotide polymorphisms identified in a Japanese population. Participants with eGFR <60 mL/min per 1.73 m was defined as case (stage 3 CKD or higher) in this study. Logistic regression analysis was used to examine the association between the GRS and CKD risk with adjustment for sex, age, hypertension and type 2 diabetes mellitus. The frequency of individuals with CKD was 8.3%, which was relatively low compared with those previously reported in a Japanese population. The odds ratio of having CKD was 1.120 (95% confidence interval: 1.042-1.203) per 10 GRS increment in the fully adjusted model (P = 0.002). The C-statistic was significantly increased in the model with the GRS, comparing with the model without the GRS (0.720 vs 0.719, P = 0.008). Increment of the GRS was associated with increased risk of CKD. Additionally, the GRS significantly improved the discriminatory ability of CKD prevalence in a Japanese population; however, the improvement of discriminatory ability brought about by the GRS seemed to be small compared with that of non-genetic CKD risk factors.


Associations of nutrient patterns with the prevalence of metabolic syndrome: Results from the baseline data of the Japan Multi-Institutional Collaborative Cohort Study

The association between nutrient patterns and metabolic syndrome (MetS) has not been examined in a Japanese population. A cross-sectional study was performed on 30,108 participants (aged 35-69 years) in the baseline survey of the Japan Multi-Institutional Collaborative Cohort Study. Dietary intake was assessed using a 46-item food frequency questionnaire. MetS was diagnosed according to the Joint Interim Statement Criteria of 2009, using body mass index instead of waist circumference. Factor analysis was applied to energy-adjusted intake of 21 nutrients, and three nutrient patterns were extracted: Factor 1 (fiber, potassium and vitamins pattern); Factor 2 (fats and fat-soluble vitamins pattern); and Factor 3 (saturated fatty acids, calcium and vitamin B pattern). In multiple logistic regression analysis adjusted for sex, age, and other potential confounders, Factor 1 scores were associated with a significantly reduced odds ratio (OR) of MetS and all five components. Factor 2 scores were associated with significantly increased prevalence of MetS, obesity, and high blood pressure. Factor 3 scores were significantly associated with lower OR of MetS, high blood pressure, high serum triglycerides and low HDL cholesterol levels. Analysis of nutrient patterns may be useful to assess the overall quality of diet and its association with MetS.


Independent relationships of daily life activity and leisure-time exercise with metabolic syndrome and its traits in the general Japanese population.

Our results suggest that higher daily life activity and higher moderate-intensity exercise may be independently associated with a lower risk of metabolic syndrome in Japanese adults.


Genome-wide association meta-analysis and Mendelian randomization analysis confirm ALDH2 influencing on sleep duration in the Japanese population.

Usual sleep duration has substantial heritability and is associated with various physical and psychiatric conditions as well as mortality. However, for its genetic locus, only PAX8 and VRK2 has been replicated in previous genome-wide association studies (GWAS). We conducted a GWAS meta-analysis of self-reported usual sleep duration using three population-based cohorts totaling 31,230 Japanese individuals. A genome-wide significant locus was identified at 12q24 (P-value < 5.0×10-8). Subsequently, a functional variant in the ALDH2 locus, rs671, was replicated in an independent sample of 5,140 Japanese individuals (P-value = 0.004). The association signal, however, disappeared after adjusting for alcohol consumption, indicating the possibility that the rs671 genotype modifies sleep duration via alcohol consumption. This hypothesis explained a modest genetic correlation observed between sleep duration and alcohol consumption (rG = 0.23). A Mendelian randomization analysis using rs671 and other variants as instrumental variables confirmed this by showing a causal effect of alcohol consumption, but not of coffee consumption on sleep duration. Another genome-wide significant locus was identified at 5q33 after adjusting for drinking frequency. However, this locus was not replicated, nor was the PAX8 and VRK2 . Our study has confirmed a functional ALDH2 variant, rs671, most strongly influencing on usual sleep duration possibly via alcohol consumption in the Japanese population, and presumably in East Asian populations. This highlights the importance of considering the involvement of alcohol consumption in future GWAS of usual sleep duration, even in non-East Asian populations, where rs671 is monomorphic.


Genomewide Association Study of Leisure-Time Exercise Behavior in Japanese Adults

Although several genetic factors may play a role in leisure-time exercise behavior, there is currently no evidence of a significant genomewide association, and candidate gene replication studies have produced inconsistent results. We conducted a two-stage genomewide association study and candidate single-nucleotide polymorphisms (SNP) association study on leisure-time exercise behavior using 13,980 discovery samples from the Japan Multi-Institutional Collaborative Cohort (J-MICC) study, and 2036 replication samples from the Hospital-based Epidemiologic Research Program at Aichi Cancer Center-2 study. Leisure-time physical activity was measured using a self-administered questionnaire that inquired about the type, frequency and duration of exercise. Participants with ≥4 MET·h·wk of leisure-time physical activity were defined as exhibiting leisure-time exercise behavior. Association testing using mixed linear regression models was performed on the discovery and replication samples, after which the results were combined in a meta-analysis. In addition, we tested six candidate genetic variants derived from previous genomewide association study. We found that one novel SNP (rs10252228) located in the intergenic region between NPSR1 and DPY19L1 was significantly associated with leisure-time exercise behavior in discovery samples. This association was also significant in replication samples (combined P value by meta-analysis = 2.2 × 10). Several SNP linked with rs10252228 were significantly associated with gene expression of DPY19L1 and DP19L2P1 in skeletal muscle, heart, whole blood, and the nervous system. Among the candidate SNP, rs12612420 in DNAPTP6 demonstrated nominal significance in discovery samples but not in replication samples. We identified a novel genetic variant associated with regular leisure-time exercise behavior. Further functional studies are required to validate the role of these variants in exercise behavior.

Medicine and Science in Sports and Exercise


Association of exposure level to passive smoking with hypertension among lifetime nonsmokers in Japan: a cross-sectional study

.Japan Multi-Institutional Collaborative Cohort (J-MICC) Study

Brief exposure to passive smoking immediately elevates blood pressure. However, little is known about the association between exposure to passive smoking and chronic hypertension. We aimed to examine this association in a cross-sectional study, after controlling multiple potential confounders.Participants included 32,098 lifetime nonsmokers (7,216 men and 24,882 women) enrolled in the Japan Multi-Institutional Collaborative Cohort Study. Passive smoking was assessed using a self-administered questionnaire. The single question about exposure to passive smoking had five response options: "sometimes or almost never," "almost every day, 2 hours/day or less," "almost every day, 2 to 4 hours/day," "almost every day, 4 to 6 hours/day," and "almost every day, 6 hours/day or longer." Hypertension was defined as any of the following: systolic blood pressure ≥140 mmHg, diastolic blood pressure ≥90 mmHg, or use of antihypertensive medication. Multivariate-adjusted odds ratio (OR) and 95% confidence interval (CI) for hypertension were estimated by exposure level to passive smoking using unconditional logistic regression models.The multivariate-adjusted OR for hypertension in those exposed almost every day was 1.11 (95% CI: 1.03-1.20) compared with those exposed sometimes or almost never. The OR for a 1-hour per day increase in exposure was 1.03 (95% CI: 1.01-1.06, Pfor trend = .006). This association was stronger in men than in women; the ORs were 1.08 (95% CI: 1.01-1.15, Pfor trend = .036) and 1.03 (95% CI: 1.00-1.05, Pfor trend = .055), respectively.Our findings suggest importance of tobacco smoke control for preventing hypertension.


Inverse association between soy food consumption, especially fermented soy products intake and soy isoflavone, and arterial stiffness in Japanese men.

Studies on the associations between soy food consumption and arterial stiffness are rare. The aim of the present study was to evaluate their associations in Japanese men. A total of 652 eligible men, aged 35-69 years, who underwent the measurement of brachial-ankle pulse wave velocity (baPWV) as an index of arterial stiffness were evaluated in this cross-sectional study. Information on their lifestyle characteristics, including dietary behavior, was obtained from a structured self-administered questionnaire. The frequency of total soy products as well as fermented and non-fermented soy products intakes was calculated, and the amounts of soy protein and soy isoflavone intakes were also estimated; these were then divided into tertiles and their associations with baPWV values were evaluated using general linear models. Higher frequency of fermented soy products intake was associated with decreased baPWV after adjusting for the multivariable covariates (P value for trend was 0.002, in Model 3). This association did not alter after further adjustment with a biomarker of systemic inflammation (serum high-sensitivity C-reactive protein (hs-CRP)) (P value for trend was 0.001, in Model 4). Total soy isoflavone consumption was also inversely associated with baPWV even after adjusting for multivariable covariates including serum hs-CRP (P value for trend was 0.043, in Model 4); however total soy protein consumption was not. These results demonstrated that greater consumption of soy food, especially fermented soy products and soy isoflavone was associated with reduced arterial stiffness, independent of systemic inflammation, in Japanese men.


Nutrient-derived dietary patterns and their association with metabolic syndrome in a Japanese population

Nutrients have been proposed to be related to metabolic syndrome (MetS). The aims of this study were to identify dietary patterns that correlated with several nutrients using reduced rank regression (RRR) and to examine the association between extracted dietary patterns and prevalence of MetS in a Japanese population. The study population comprised 1,092 Japanese men and women (35-69 years old) who had participated in the baseline survey of the Japan Multi-Institutional Collaborative Cohort Study in Tokushima Prefecture. Dietary patterns were derived with RRR using 46 food items as predictors and six established nutrients (potassium, calcium, vitamin D, vitamin C, insoluble dietary fiber, and carotene) as response variables. Associations between extracted dietary patterns and MetS were then examined with logistic regression models. Among the six dietary patterns, dietary pattern 1 (DP1) explained the largest proportion (60.1%) of variance in the six nutrients. Therefore, only DP1 was selected for further analysis. DP1 was characterized by high intake frequency of vegetables, fruits, fish and small fish, natto (fermented soybeans), and deep-fried tofu. After adjustment for potential confounders, significant inverse associations were found between DP1 score and MetS (odds ratio [OR] for each quartile: 1.00, 0.58, 0.60, 0.52; P = 0.02); DP1 and high blood pressure (P = 0.0002); and DP1 and high blood glucose (P = 0.02). A dietary pattern characterized by high intake of vegetables, fruits, fish and small fish, natto, and deep-fried tofu was associated with reduced prevalence of MetS in a Japanese population.


A genome-wide association study in the Japanese population idetifies the 12q24 locus for habitual coffee consumption: the J-MICC Study

Coffee is one of the most widely consumed beverages worldwide, and its role in human health has received much attention. Although genome-wide association studies (GWASs) have investigated genetic variants associated with coffee consumption in European populations, no such study has yet been conducted in an Asian population. Here, we conducted a GWAS to identify common genetic variations that affected coffee consumption in a Japanese population of 11,261 participants recruited as a part of the Japan Multi-Institutional Collaborative Cohort (J-MICC) study. Coffee consumption was collected using a self-administered questionnaire, and converted from categories to cups/day. In the discovery stage (n = 6,312), we found 2 independent loci (12q24.12-13 and 5q33.3) that met suggestive significance (P < 1 × 10). In the replication stage (n = 4,949), the lead variant for the 12q24.12-13 locus (rs2074356) was significantly associated with habitual coffee consumption (P = 2.2 × 10), whereas the lead variant for the 5q33.3 locus (rs1957553) was not (P = 0.53). A meta-analysis of the discovery and replication populations, and the combined analysis using all subjects, revealed that rs2074356 achieved genome-wide significance (P = 2.2 × 10 for a meta-analysis). These findings indicate that the 12q24.12-13 locus is associated with coffee consumption among a Japanese population.


Dietary calcium intake is associated with serum high-sensitivity C-reactive protein level in the general Japanese population

The beneficial effects of dietary calcium intake on high-sensitivity C-reactive protein levels, a risk factor of cardiovascular disease, have not been fully elucidated. This study investigated the associations between dietary calcium intake and serum high-sensitivity C-reactive protein levels in the general Japanese population. We analyzed the data of 2,019 subjects (1,194 men and 825 women) aged 35 to 69 years in a cross-sectional study of the Japan Multi-Institutional Collaborative Cohort Study. Nutrients intake including calcium were estimated using a validated food-frequency questionnaire. Analysis using a general linear model revealed that dietary calcium intake was inversely associated with serum high-sensitivity C-reactive protein levels ( for trend <0.001) after adjustment for age, sex, research group, leisure-time physical activity, smoking habit, drinking habit, dietary intakes (energy, dietary fiber, saturated fatty acids and vitamin D) and menopausal status. The association was slightly attenuated after additional adjustment for body mass index; however, remained significant ( for trend = 0.008). There were no significant interactions between dietary calcium intakes and sex, body mass index, or vitamin D intake for high-sensitivity C-reactive protein levels. This study have demonstrated that dietary calcium intake was inversely associated with serum high-sensitivity C-reactive protein levels in the general population.

Journal of Clinical Biochemistry and Nutrition


A Genome-wide Association Study in the Diabetic Patients Finds the 13q35.43-35.46 Locus Associated with Estimated Glomerular Filtration Rate: The Japan Multi-Institutional Collaborative Cohort Study


Genetic Variants of RAMP2 and CLR are Associated with Stroke.

Stroke is associated closely with vascular homeostasis, and several complex processes and interacting pathways, which involve various genetic and environmental factors, contribute to the risk of stroke. Although adrenomedullin (ADM) has a number of physiological and vasoprotective functions, there are few studies of the ADM receptor system in humans. The ADM receptor comprises a calcitonin-receptor-like receptor (CLR) and receptor activity-modifying proteins (RAMPs). We analyzed single nucleotide polymorphisms (SNPs) in the RAMP2 and CLR genes to determine their association with stroke in the light of gene-environment interactions. Using cross-sectional data from the Japan Multi-Institutional Collaborative Cohort Study in the baseline surveys, 14,087 participants from 12 research areas were genotyped. We conducted a hypothesis-based association between stroke prevalence and SNPs in the RAMP2 and CLR genes based on data abstracted from two SNPs in RAMP2 and 369 SNPs in CLR. We selected five SNPs from among the CLR variants (rs77035639, rs3815524, rs75380157, rs574603859, and rs147565266) and one RAMP2 SNP (rs753152), which were associated with stroke, for analysis. Five of the SNPs (rs77035639, rs3815524, rs75380157, rs147565266, and rs753152) showed no significant association with obesity, ischemic heart disease, hypertension, dyslipidemia, and diabetes. In the logistic regression analysis, rs574603859 had a lower odds ratio (0.238; 95% confidence interval, 0.076-0.745, adjusted for age, sex, and research area) and the other SNPs had higher odds ratios for association with stroke. This was the first study to investigate the relationships between ADM receptor genes (RAMP2 and CLR) and stroke in the light of gene-environment interactions in human.

Journal of Atherosclerosis and Thrombosis


Comparison of weighed food record procedures for the reference methods in two validation studies of food frequency questionnaires.

Our comparison of WFR procedures in two independent studies revealed several differences. Notwithstanding these procedural differences, however, the subsequent outcomes were similar.


Association between Dietary Patterns and Serum Adiponectin: A Cross-Sectional Study in a Japanese Population

The aim of this study was to evaluate the associations between dietary pattern, adiponectin and insulin resistance. The study population consisted of 612 men and women aged 35-69 years old who had participated in the baseline survey of Japan Multi-Institutional Collaborative Cohort (J-MICC) Study in Tokushima Prefecture. Diets and lifestyle related variables were assessed by questionnaires. Multiple regression analyses were used to analyse the relations between dietary patterns and high molecular weight (HMW) adiponectin. For further analysis, path analysis was used to test the hypothesised model of association between dietary pattern, serum adiponectin and insulin resistance. The result showed that higher score of bread and dairy pattern was directly associated with increased serum level of adiponectin in women, which was inversely related to homeostasis model assessment of insulin resistance (HOMA-IR). In conclusion, higher consumption of bread and dairy products, and low intake of rice may be associated with increased serum adiponectin in women.

International Journal of Food Sciences and Nutrition


Relationships of serum high-sensitivity C-reactive protein and body size with insulin resistance in a Japanese cohort.

Impacts of chronic systemic inflammation and body size and their interaction effect on insulin resistance in Asian populations, in whom obesity is less common, are not fully understood. This study evaluated combined relationships of systemic inflammation and body size with insulin resistance in a Japanese cohort. We analyzed cross-sectional data from 1,074 eligible subjects (536 men and 538 women) aged 35-69 years who participated in the baseline survey of a cohort study in Tokushima Prefecture, Japan. Systemic inflammation level was assessed by serum high-sensitivity C-reactive protein (hs-CRP), and the degree of insulin resistance and beta-cell function were evaluated by the homeostasis model assessment insulin resistance (HOMA-IR) and beta-cell function (HOMA- ), respectively. Overweight and obesity were defined as a body mass index (BMI) of 23.0-24.9 kg/m2 and ·25.0 kg/m2, respectively. Associations between serum hs-CRP (assessed as quartiles and additionally continuous values after log-transformation) and indices of glucose homeostasis were analysed adjusting for probable covariates, including BMI (quartiles). Combined associations of serum hs-CRP ( median, >median) and body size (normal, overweight, obese) with insulin resistance as well as their interaction effect on insulin resistance were also evaluated. Serum hs-CRP was dose-dependently associated with HOMA-IR, but not HOMA- , after adjustment for probable covariates, including BMI. Subjects with obesity and elevated serum hs-CRP (>median) showed a high multivariable-adjusted HOMA-IR value of 1.32 (95% confidence interval (CI) 1.23, 1.41) compared with subjects with normal BMI and low serum hs-CRP ( median) whose multivariable-adjusted HOMA-IR value was 1.14 (95% CI 1.06, 1.21). The interaction effect between body size (normal, overweight, obese) and serum hs-CRP ( median, >median) on HOMA-IR was significant (P for interaction <0.001). Our study suggests that elevated systemic inflammation is dose-dependently associated with increased insulin resistance, independent of the known risk factors, in a Japanese population. Concomitant obesity and elevated systemic inflammation may synergistically contribute to increased insulin resistance.


Matrix metalloproteinase 9 gene polymorphisms are associated with a multiple family history of gastric cancer

The Japan Multi-institutional Collaborative Cohort Study Group

A family history of gastric cancer (GC) is a well-known risk factor of GC. Genetic variations in genes of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) have been related to the risk of GC, but their association with familial background is not clear. We investigated whether individuals with a multiple family history of GC have more risk genotypes of MMP/TIMP genes. We genotyped ten common functional polymorphisms of MMP/TIMP genes in 4427 individuals aged 35-69 years without a history of GC who were enrolled in the Japan Multi-institutional Collaborative Cohort Study. Individuals who have two or more first-degree relatives (parents and siblings) with GC were categorized as having a multiple family history. Odds ratios (ORs) for multiple family history compared with no family history were calculated. MMP9 279QQ (rs17576) was more frequently observed in individuals whose both parents had a history of GC (n = 23) and in individuals for whom one parent and their sibling(s) had a history of GC (n = 36) compared with those with no family history (n = 3816) [30.4 % vs 11.6 %, OR 4.34, 95 % confidence interval (CI) 1.45-13.03 and 16.7 % vs 11.6 %, OR 2.26, 95 % CI 0.81-6.27 after adjustment for age, sex, and current smoking]. The population attributable fraction was 38.1 %. The haplotype MMP9-1562C/279Q/668Q was more frequently observed in individuals whose both parents had a history of GC and in individuals for whom one parent and their sibling(s) had a history of GC compared with those with no family history (OR 3.35, 95 % CI 0.75-14.96 and OR 3.51, 95 % CI 1.35-9.15 respectively). MMP9 polymorphisms were associated with a multiple family history of GC. Screening for these genotypes together with familial background may help us to identify individuals at an increased risk of GC.


Systemic inflammation and family history in relation to the prevalence of type 2 diabetes based on an alternating decision tree

To investigate unknown patterns associated with type 2 diabetes in the Japanese population, we first used an alternating decision tree (ADTree) algorithm, a powerful classification algorithm from data mining, for the data from 1,102 subjects aged 35-69 years. On the basis of the investigated patterns, we then evaluated the associations of serum high-sensitivity C-reactive protein (hs-CRP) as a biomarker of systemic inflammation and family history of diabetes (negative, positive or unknown) with the prevalence of type 2 diabetes because their detailed associations have been scarcely reported. Elevated serum hs-CRP levels were proportionally associated with the increased prevalence of type 2 diabetes after adjusting for probable covariates, including body mass index and family history of diabetes (P for trend = 0.016). Stratified analyses revealed that elevated serum hs-CRP levels were proportionally associated with increased prevalence of diabetes in subjects without a family history of diabetes (P for trend = 0.020) but not in those with a family history or with an unknown family history of diabetes. Our study demonstrates that systemic inflammation was proportionally associated with increased prevalence of type 2 diabetes even after adjusting for body mass index, especially in subjects without a family history of diabetes.


Changes in foot function, disease activity, and disability after forefoot resection arthroplasty in patients with rheumatoid arthritis

The purpose of this study was to investigate the changes in foot function, disease activity, and disability in patients with RA after resection arthroplasty of the forefoot (arthroplasty). Arthroplasty was performed on 11 patients with RA. All study patients underwent clinical assessment to measure disease activity (Disease Activity Score in 28 Joints-C-reactive protein, DAS28-CRP), disability (Health Assessment Questionnaire-Disability Index, HAQ-DI) and foot function (Foot Function Index, FFI) at the following stages: preoperatively and 1, 3, and 12 months after surgery. Following arthroplasty, foot function improved significantly, as assessed by FFI total and subscales (pain, disability, and limitation of activity) (P<0.001, P<0.001, P<0.001, and P=0.002, respectively). Disease activity was significantly improved in relation to DAS28-CRP and its subscales of number of swollen joints and patient global assessment (PtGA) (P=0.033, P=0.008, and P=0.038, respectively). There was no significant difference in disability, as assessed by the HAQ-DI and its subscale, HAQ-walking (P=0.150 and P=0.597, respectively). Foot function improved significantly after arthroplasty, and was maintained at 12 months postoperatively. Additionally, our study showed that disease activity and its subscale PtGA improved after arthroplasty.

The Journal of Medical Investigation : JMI


Association between brain-muscle-ARNT-like protein-2 (BMAL2) gene polymorphism and type 2 diabetes mellitus in obese Japanese individuals: A cross-sectional analysis of the Japan Multi-Institutional Collaborative Cohort Study

Brain-muscle-Arnt-like protein-1 (BMAL1) and BMAL2 genes are essential components of the circadian clock, and are considered to be involved in glucose homeostasis. We examined whether single nucleotide polymorphisms (SNPs) of BMAL1 and BMAL2 were associated with the prevalence of type 2 diabetes (T2DM) in the general Japanese population. We studied 2467 subjects (1232 men and 1235 women, 35-69 years old), including 105 men and 57 women with T2DM, from the participants of the Japan Multi-institutional Collaborative Cohort Study. The association between SNPs in the BMAL1 (rs11022775 and rs2290035) and BMAL2 (rs7958822) genes and T2DM were analyzed by multiple logistic regression after adjustment for potential confounders. Analysis was also performed after stratification by body mass index (≥25kg/m(2) and <25kg/m(2)) to investigate an interaction between genotypes and obesity. The A/G and A/A genotypes of BMAL2 rs7958822 showed significantly higher adjusted odds ratios (OR) for T2DM than the G/G genotype among obese men (OR=2.2, 95% confidence intervals [CI] 1.1, 4.6, P for interaction=0.0495) and obese women (OR=2.7, 95% CI 1.1, 6.7, P for interaction=0.199). There were no significant associations between BMAL1 rs11022775 or rs2290035 genotypes and T2DM. To the best of our knowledge, this is the first study to show the significant association between BMAL2 rs7958822 genotype and T2DM among obese subjects.


A variant of the CLOCK gene and related haplotypes are associated with the prevalence of type 2 diabetes in the Japanese population.

Circadian rhythm disruption is recognized as the cause of various health disorders. This study evaluated associations between single nucleotide polymorphisms in the core circadian gene, CLOCK, and prevalent type 2 diabetes in the Japanese population. We analyzed cross-sectional data from 2,485 subjects (1,243 men and 1,242 women; age, 35-69 years) who were enrolled in the baseline surveys of the Japan Multi-institutional Collaborative Cohort (J-MICC) Study. Associations between 3 CLOCK gene polymorphisms (rs1801260, rs3736544, and rs4864548) and prevalent obesity (BMI ≥25 kg/m(2) ), overweight (BMI ≥23 kg/m(2) ), and diabetes were evaluated by logistic regression analyses; haplotype analysis and stratified analyses for prevalent diabetes were also conducted. Compared to those who were homozygous for the respective major alleles, subjects with the rs1801260 minor allele C showed a significantly higher odds ratio (95% CI) of 1.5 (1.1-2.1) for prevalent diabetes, after adjustment for potential confounding factors, including BMI. When stratified by overweight, the associations between rs1801260 and prevalent diabetes were marked and significant in non-overweight subjects but were not significant in overweight subjects. The TGA (rs1801260 - rs3736544 - rs4864548) haplotype was associated with lower prevalence of diabetes, and the CGG haplotype was associated with higher prevalence of diabetes. CLOCK gene variants and related haplotypes are associated with prevalent type 2 diabetes in the Japanese population in whom obesity is less common, and the association between a CLOCK gene variants at rs1801260 and prevalent diabetes is enhanced in normal-build subjects.


Polymorphisms in CYP19A1, HSD17B1 and HSD17B2 genes and serum sex hormone level among postmenopausal Japanese women

Extraovarian sex hormone production plays an important role in estrogen biosynthesis in postmenopausal women. We examined possible associations between serum sex hormone level and polymorphisms in CYP19A1, HSD17B1, and HSD17B2. We also assessed possible interaction between these polymorphisms and current overweight. We conducted a cross-sectional study. 785 Japanese natural postmenopausal women were randomly selected from the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study database. Information on lifestyle factors was obtained from a self-administered questionnaire. Serum estrogens and androgens levels were measured by liquid chromatography-tandem mass spectrometry. Four tag SNPs (single nucleotide polymorphisms) of CYP19A1, one missense SNP of HSD17B1 and three tag SNPs of HSD17B2 were examined by Invader assay. A trend test was conducted using linear regression. After adjustment for multiple comparisons, we found that rs4441215 and rs936306 in CYP19A1 and rs4888202 and rs2955160 in HSD17B2 were associated with differences in serum estrone level. Further, rs4441215 and rs936306 were associated with differences in serum estradiol level. None of these polymorphisms showed a significant interaction with current body mass index (BMI). Our findings suggested that CYP19A1 and HSD17B2 polymorphisms might be associated with circulating sex hormone levels in Japanese postmenopausal women, independent of current BMI.


Inverse association between soy food consumption and insulin resistance in Japanese adults

The purpose of the present study was to examine the association between soya food consumption and insulin resistance using baseline data of the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study in Tokushima, Japan. This cross-sectional study included 1274 subjects, aged 34-70 years at baseline, living in Tokushima Prefecture between 2008 and 2013. Fasting blood samples were collected and information on lifestyle characteristics including soya food intake and medical history were obtained using a structured self-administered questionnaire. The homeostasis model assessment of insulin resistance (HOMA-IR) was measured and those with HOMA-IR ≥ 2.5 were defined as having insulin resistance. Multiple logistic regression models were used to analyse the association between soya product intake and the prevalence of insulin resistance. Rural communities located in Tokushima Prefecture, Japan, between 2008 and 2013. A total of 1148 adults (565 men and 583 women), aged 34-70 years. The frequency of intake of miso soup, total non-fried soya products and total soya products showed significant inverse dose-response relationships with insulin resistance, after adjustments for potential confounders. When soya product intake was calculated as soya protein and isoflavone, the odds ratios of insulin resistance decreased significantly as the estimated intake of soya protein increased. Furthermore, significant inverse dose-response relationships were observed for total non-fried soya products and total soya products, after adjustment for total vegetable or total fibre consumption. The present results indicate that the intake of soya products and non-fried soya products is associated with reduced insulin resistance in the Japanese population.


Relationships of elevated levels of serum hepatic enzymes and alcohol intake with arterial stiffness in men.

The present study aimed to evaluate the relationships between elevated serum levels of hepatic enzymes and arterial stiffness and to investigate whether alcohol intake had a modifying effect on these relationships in Japanese men. A total of 647 eligible men aged 35-69 years who underwent measurement of brachial-ankle pulse wave velocity (baPWV) as an index of arterial stiffness were evaluated. Information on their lifestyle characteristics were obtained from a structured self-administered questionnaire. Serum biochemical factors, including alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT), were determined. The serum ALT and GGT levels were divided into tertiles, and their associations with baPWV values were evaluated using general linear models adjusted for potential confounding factors. The interaction effects between serum hepatic enzymes and alcohol intake on baPWV were further evaluated. Elevated serum ALT and GGT levels were proportionally associated with increased baPWV after adjusting for the multivariable covariates (P values for trend, 0.004 and 0.003, respectively). Further analyses revealed that the proportional associations between serum levels of hepatic enzymes and baPWV were striking in the subjects without alcohol intake but not in those with alcohol intake. The interaction effect between serum GGT level and alcohol intake on baPWV was significant (P for interaction, 0.042). These results demonstrate that elevated serum ALT and GGT levels are associated with increased arterial stiffness, independent of the classical atherosclerotic risk factors in Japanese men, and that the association of elevated serum GGT level with arterial stiffness differs according to alcohol intake.


Family history of stroke is potentially associated with arterial stiffness in the Japanese population.

Studies on the association between family history of cardiovascular disease and arterial stiffness are rare. This study evaluated the possible relationship between family history of cardiovascular disease and arterial stiffness in the Japanese population, by measuring brachial-ankle pulse wave velocity (ba-PWV). A total of 1004 eligible subjects (664 men and 340 women) aged 35-69 years, who were enrolled in the baseline survey of a cohort study in Tokushima Prefecture (Japan) and who underwent ba-PWV measurement, were analysed. Information about their lifestyle characteristics and first-degree family histories of ischaemic heart disease (i.e. myocardial infarction or angina pectoris), stroke or hypertension were obtained from a structural self-administered questionnaire. Subjects of both sexes with a family history of stroke showed significantly higher multivariable-adjusted means of ba-PWV than those without that trait (P values were 0.001 in men and 0.002 in women), while those with a family history of ischaemic heart disease did not. Subjects of both sexes with a family history of hypertension showed significantly higher age-adjusted means of ba-PWV than those without that trait, although these differences disappeared after further adjusting for blood pressure or multivariable covariates. When family histories of these diseases were inserted simultaneously into the same model, these results did not alter substantially. A family history of stroke might be associated with increased arterial stiffness, independent of other known atherosclerotic risk factors, including hypertensive elements, in both sexes in the Japanese population.


Association between dietary calcium intake and arterial stiffness according to dietary vitamin D intake in men.

Studies on the associations of dietary Ca and vitamin D intakes with arterial stiffness are scarce. In the present study, these associations were evaluated in Japanese men. Data from a total of 535 eligible men, aged 35-69 years, who participated in the baseline survey of a cohort study in Tokushima Prefecture, Japan, and underwent brachial-ankle pulse wave velocity (ba-PWV) measurements were analysed. ba-PWV is a measure of arterial stiffness and is recognised as a marker of atherosclerotic vascular damage. Information regarding the cohort's lifestyle characteristics including dietary behaviour over the past year was obtained from a structured self-administered questionnaire. Dietary Ca and vitamin D intakes were adjusted for total energy intake using the residual method and divided into quartiles; the highest quartile was used as the reference. General linear models were used to evaluate the associations between dietary Ca and vitamin D intakes and ba-PWV values adjusted for probable covariates. The association between dietary Ca intake and ba-PWV was further evaluated using similar general linear models stratified by dietary vitamin D intake (median or below/above median). Dietary Ca intake was found to be significantly inversely associated with ba-PWV after adjusting for probable covariates (P for trend = 0·020). However, no such association was observed between dietary vitamin D intake and ba-PWV. The inverse association between dietary Ca intake and ba-PWV was striking in subjects with higher dietary vitamin D intake. However, no association was found in subjects with lower dietary vitamin D intake. These results indicate that adequate dietary Ca and vitamin D intakes may be protective against the development of arterial stiffness in Japanese men.


Associations of dietary patterns with metabolic syndrome and insulin resistance: a cross-sectional study in a Japanese population

The associations of dietary patterns with metabolic syndrome (MetS) and insulin resistance have not been fully investigated in the Japanese population. A cross-sectional study was performed on 513 subjects without treatment for diabetes who had participated in the baseline survey of a cohort study in Tokushima Prefecture, Japan. Frequencies of consumption of 46 foods and beverages were assessed using a questionnaire. MetS was diagnosed using the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) criteria. Logistic and linear regression analyses were used to examine the associations of the dietary patterns with the prevalence of MetS, its components, and the Homeostasis Model of Assessment-Insulin Resistance (HOMA-IR). Using principal component analysis, four dietary patterns were extracted: prudent diet (high intake of vegetables and fruits); high fat/Western (high intake of fried foods, fried dishes and meat); bread and dairy products; and seafood patterns. After adjustment for sex, age, and other potential confounders, prudent diet pattern scores were inversely correlated with the prevalence of reduced serum high-density lipoprotein cholesterol (P=0.04) and high blood pressure (P=0.05), and bread and dairy products pattern scores were correlated with a lower prevalence of abdominal obesity (P=0.04) and high plasma glucose (P=0.04). The high fat/Western pattern was positively correlated with HOMA-IR (P=0.04). Prudent dietary pattern and bread and dairy products pattern may be correlated with a lower prevalence of some components of MetS. A high fat/Western dietary pattern may be positively associated with insulin resistance in the Japanese population.

The Journal of Medical Investigation : JMI


A polymorphism near MC4R gene (rs17782313) is associated with serum triglyceride levels in the general Japanese population: the J-MICC Study

Previously reported associations of a common polymorphism near melanocortin-4 receptor (MC4R) gene (rs17782313) with BMI/obesity were inconsistent, especially in East Asia, and the associations of the polymorphism with serum lipid levels have not been fully elucidated. This study evaluated the association between rs17782313 and obesity-related traits and serum lipid levels in the general Japanese population. A total of 2,035 subjects (aged 35-69 years, 1,024 males and 1,011 females) enrolled in the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study. We examined the associations between near MC4R polymorphism (rs17782313) and obesity-related traits [height, weight, body mass index (BMI), weight change from 20 years old], serum lipid levels (triglycerides, total and HDL-cholesterol), and intake of nutrients (total energy and macronutrients). Polymorphism of rs17782313 (minor C allele) was positively associated with serum triglyceride levels (P for trend = 0.020) adjusted for age and sex. Analysis using a general linear model revealed that the number of minor C alleles was positively associated with serum triglyceride levels after adjustment for age, sex, and potential confounders (P for trend = 0.004). Statistical significance did not change after further adjustment for total energy intake and BMI. There was no significant association between rs17782313 and obesity-related traits including BMI. Interactions between rs17782313 and sex, BMI, or total energy intake for triglyceride levels were not significant. To our knowledge, this study demonstrated for the first time that rs17782313 was associated with serum triglyceride levels in Asian population. Further studies are needed to confirm this result.


Serum hepatic enzyme activity and alcohol drinking status in relation to the prevalence of metabolic syndrome in the general Japanese population.

Studies on the combined associations of elevated serum hepatic enzyme activity and alcohol drinking with metabolic syndrome are rare. Our objectives were to evaluate the associations of elevated serum hepatic enzyme activity with the prevalence of metabolic syndrome in the general Japanese population and whether alcohol drinking had a modifying effect on these associations. We conducted a cross-sectional study with 1,027 men and 1,152 women throughout Japan during 2002-2010. Biochemical factors including alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT) were determined in overnight fasting blood, and a survey on lifestyle was conducted by questionnaire. Serum ALT and GGT levels were divided into tertiles in men and women, and their associations with the prevalence of metabolic syndrome were evaluated by logistic regressions. Elevated serum ALT and GGT, even within the reference range, were independently associated with increased metabolic syndrome prevalence and were associated with most of its components in both sexes, except for the association between GGT and low high-density lipoprotein (HDL) cholesterol in men. Stratified analyses by alcohol drinking status revealed that within the same tertile category of serum ALT and GGT, subjects classified as alcohol abstainers showed higher adjusted odds ratios for metabolic syndrome prevalence than those classified as regular alcohol drinkers in both sexes. The interaction effects of serum GGT with alcohol drinking status on metabolic syndrome prevalence were significant in both sexes. These results suggest that elevated serum ALT and GGT, even within the reference range, are independently associated with increased metabolic syndrome prevalence, especially in alcohol abstainers, in Japanese men and women.


GCK, GCKR polymorphisms and risk of chronic kidney disease in Japanese individuals: data from the J-MICC Study

Chronic kidney disease (CKD) is well known as a strong risk factor for both of end-stage renal disease and cardiovascular disease. To clarify the association of glucokinase and glucokinase regulatory protein (GCKR) polymorphisms with the risk of CKD in Japan, we examined this association among Japanese individuals using cross-sectional data. The subjects for this analysis were 3,314 consecutively selected participants from the Japan Multi-Institutional Collaborative Cohort Study. Age- and sex- adjusted odds ratios (aORs) of CKD stages 3-5 were calculated for each genotype by logistic regression and the effects of genotype on estimated glomerular filtration rate were evaluated by linear regression. Gene-environment interaction was also investigated based on questionnaire information. When subjects with GCKR rs780094 G/A and G/G, or GCKR rs1260326 T/C and C/C were combined together and compared with the references (GCKR rs780094 A/A or GCKR rs1260326 T/T), the aORs were 0.84 (0.69-1.02) or 0.81 (0.67-0.99) (p = 0.075 or 0.037), respectively. A significant OR for interaction between GCKR rs1260326 T/T and current smoking (OR = 1.79, p = 0.041) was also observed. The present study suggests a possible association of the T/T genotype of GCKR rs1260326 polymorphism with elevated risk of CKD and its interaction with current smoking, which may support the possibility of performing risk evaluation and prevention of this potentially life-threatening disease based on genetic traits in the near future.


Association between blood levels of PCDDs/PCDFs/dioxin-like PCBs and history of allergic and other diseases in the Japanese population.

Previous studies reported that exposure to dioxins was associated with an increased risk of various diseases in general populations. The aim of this study was to examine the association between levels of dioxins in blood and allergic and other diseases. We conducted a cross-sectional study on 1,063 men and 1,201 women (aged 15-76 years), who were living throughout Japan and not occupationally exposed to dioxins, during 2002-2010. In fasting blood samples, polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like PCBs (DL-PCBs) were analyzed by isotope dilution high-resolution gas chromatography/mass spectrometry. We obtained information on life style and self-reported history of diseases using a questionnaire. Blood pressure, blood levels of hemoglobin A1c, and serum lipids were also measured. Multiple logistic regression models were used to analyze the association between dioxin levels in blood and various diseases. Toxic equivalents of PCDDs/PCDFs and total dioxins showed significant inverse dose-response relationships with atopic dermatitis, after adjustments for potential confounders. The highest quartile for total dioxins had an adjusted odds ratio of 0.26 (95 % confidence interval 0.08-0.70) compared to the reference group (first quartile). The odds ratios for hypertension, diabetes mellitus, hyperlipidemia, gout in men, and gynecologic diseases in women significantly increased with increasing toxic equivalents of PCDDs/PCDFs, DL-PCBs, and total dioxins in blood. The present findings suggest that background exposure to dioxins was associated with reduced risk of atopic dermatitis. The results also support the idea that low-level exposure to dioxins is associated with an increased risk of diabetes, hypertension, and hyperlipidemia.

International Archives of Occupational and Environmental Health


Chronic academic stress increases a group of microRNAs in peripheral blood

MicroRNAs (miRNAs) play key roles in regulation of cellular processes in response to changes in environment. In this study, we examined alterations in miRNA profiles in peripheral blood from 25 male medical students two months and two days before the National Examination for Medical Practitioners. Blood obtained one month after the examination were used as baseline controls. Levels of seven miRNAs (miR-16, -20b, -26b, -29a, -126, -144 and -144*) were significantly elevated during the pre-examination period in association with significant down-regulation of their target mRNAs (WNT4, CCM2, MAK, and FGFR1 mRNAs) two days before the examination. State anxiety assessed two months before the examination was positively and negatively correlated with miR-16 and its target WNT4 mRNA levels, respectively. Fold changes in miR-16 levels from two days before to one month after the examination were inversely correlated with those in WNT4 mRNA levels over the same time points. We also confirmed the interaction between miR-16 and WNT4 3'UTR in HEK293T cells overexpressing FLAG-tagged WNT4 3'UTR and miR-16. Thus, a distinct group of miRNAs in periheral blood may participate in the integrated response to chronic academic stress in healthy young men.


Abundant daily non-sedentary activity is associated with reduced prevalence of metabolic syndrome and insulin resistance.

Background: Non-exercise activity thermogenesis (NEAT) has recently drawn attention because of its potential to prevent weight gain. Aim: This study evaluated the relationships between the duration of daily non-sedentary activities and the prevalence of metabolic syndrome and insulin resistance in the Japanese population. Material/Subjects and Methods: A total of 518 eligible subjects (380 men and 138 women) who attended the Tokushima Prefectural General Health Checkup Center and participated in the baseline survey of a cohort study conducted in Tokushima Prefecture, Japan were analyzed. Information about lifestyle characteristics including leisure-time exercise and daily non-exercise activities was obtained from a questionnaire. Logistic and multiple linear regression analyses were performed to evaluate the associations between the duration of daily non-exercise non-sedentary activities (beyond sitting) and prevalence of metabolic syndrome (and its components) and insulin resistance. Results: Subjects with longer duration of daily non-sedentary activities had significantly lower adjusted odds ratios for metabolic syndrome (P for trend = 0.024), abdominal obesity (P for trend = 0.023), and low HDL-cholesterol levels (P for trend = 0.002), after adjustment for sex, age, and other probable covariates including leisure-time exercise. Longer duration of daily non-sedentary activities was further associated with lower Homeostasis Model of Assessment-Insulin Resistance (HOMA-IR) values (P for trend = 0.009). Conclusions: Our results suggest that abundant daily non-sedentary activity might be associated with a lower prevalence of metabolic syndrome, especially for the components of central obesity and low HDL-cholesterol levels, and with a lower prevalence of insulin resistance, independent of leisure-time exercise.

Journal of Endocrinological Investigation


Consumption of coffee, not green tea, is inversely associated with arterial stiffness in Japanese men.

Background/Objectives:Studies on the associations between coffee and green tea consumption and arterial stiffness are rare. This study evaluated the possible relationships between coffee and green tea consumption and brachial-ankle pulse wave velocity (ba-PWV) values in Japanese men.Subjects/Methods:In total, 540 eligible men who enrolled in the baseline survey of a cohort study in Tokushima Prefecture, Japan, and who underwent ba-PWV measurement were analyzed. Information about lifestyle characteristics including coffee and green tea intake were obtained from a structural self-administered questionnaire. Multiple linear regression analyses were used to evaluate the associations between coffee and green tea consumption and ba-PWV.Results:Subjects with greater coffee consumption were younger and showed higher proportions of current smoking and alcohol consumption. Subjects with greater green tea consumption were older and showed lower proportions of current smoking and alcohol consumption. Greater coffee consumption was significantly inversely associated with ba-PWV after the adjustment for probable covariates, including serum low-density lipoprotein cholesterol and high-density lipoprotein cholesterol (P for trend =0.031). After additional adjustment for serum triglycerides, this inverse association persisted, but was somewhat attenuated (P for trend =0.050). In contrast, green tea consumption was not associated with ba-PWV.Conclusions:Coffee consumption was inversely associated with arterial stiffness independent of known atherosclerotic risk factors, and this association was partly mediated by reduced circulating triglycerides. Further prospective or interventional studies are needed to confirm the causal association.European Journal of Clinical Nutrition advance online publication, 17 July 2013; doi:10.1038/ejcn.2013.132.


MTHFR, MTR and MTRR polymorphisms and risk of chronic kidney disease in Japanese: cross-sectional data from the J-MICC Study.

PURPOSE: Chronic kidney disease (CKD) is well known as a strong risk factor for both of end-stage renal disease and cardiovascular disease. To clarify the associations of MTHFR, MTR, and MTRR polymorphisms with the risk of CKD in Japanese, we examined this association among Japanese subjects using cross-sectional data. METHODS: The subjects for this analysis were 3,318 participants consecutively selected from the Japan Multi-institutional Collaborative Cohort (J-MICC) Study. The polymorphisms were genotyped by a multiplex polymerase chain reaction-based Invader assay. Age- and sex-adjusted odds ratio (aOR) of CKD with stage 3-5 was calculated for each genotype. RESULTS: When those with MTHFR C677T C/C were defined as references, those with MTHFR C677T C/T and T/T demonstrated the aORs for CKD of 1.14 (95 % CI 0.93-1.40) and 1.39 (1.06-1.82), respectively. Marginally significantly decreased risk of CKD with increasing number of MTR A2756G G allele (p = 0.058) was observed. Stratified analyses by plasma folate low (<7.4 ng/ml) or high (≥7.4 ng/ml) suggested significantly higher OR of CKD for those with MTHFR C677T T/T and low serum folate with the aOR of 2.07 (95 % CI 1.30-3.31) compared with that for those with MTHFR C677T T/T and high serum folate. CONCLUSIONS: The present study found a significant association between the subjects with the T/T genotype of MTHFR C677T polymorphism and the elevated risk of CKD, which may suggest the possibility of the risk evaluation and prevention of this potentially life-threatening disease based on genetic traits in the near future.


Consumption of seafood, serum liver enzymes, and blood levels of PFOS and PFOA in the Japanese population.

Perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) have been shown to accumulate in the human body. The purpose of the present study was to examine the factors associated with the blood levels of PFOS and PFOA. A cross-sectional study was performed on 307 men and 301 women (aged 16-76 years) living in 15 prefectures in Japan. Blood levels of PFOS and PFOA were measured by liquid chromatography-mass spectrometry. Hepatic enzymes (-GTP, GOT, and GPT) and -3 polyunsaturated fatty acids (DHA and EPA) levels in serum were also measured. Associations between the levels of PFOS and PFOA in blood and the intake frequency of 41 kinds of dishes, foods and beverages and the serum levels of liver enzymes and -3 polyunsaturated fatty acids were examined using rank correlations. Frequency of intake of boiled fish in broth, sliced raw fish and coastal fish showed significant positive correlations with PFOS concentrations in blood after adjustments for potential confounders. Serum levels of GOT, GPT, DHA and EPA showed significant positive correlations with PFOS and PFOA in blood. There was also a significant regional difference in the blood levels of PFOS and 2013PFOA, with medians being highest in the Tokai/Hokuriku/Kinki region. These findings suggest that the concentrations of PFOS in blood were mainly associated with fish consumption and that the levels of PFOS and PFOA were associated with the serum levels of liver enzymes in Japanese populations. Further investigations are required to clarify the reason for the regional differences in blood levels of PFOS and PFOA in Japan.


Significant interaction between RETN -420 G/G genotype and lower BMI on decreased risk of type 2 diabetes mellitus (T2DM) in Japanese--the J-MICC Study.

We examined the association of the RETN (resistin) -420 C>G polymorphism (rs1862513) with risk of diabetes mellitus (DM), considering lifestyle factors, in Japanese. Subjects were participants of J-MICC Study, where 2,651 participants aged 35-69 years provided their blood for genotyping and lifestyle data after informed consent. Odds ratio (OR) of DM for RETN-420 G/G genotype was estimated using unconditional logistic regression model. Statistically significant interaction on risk of DM was observed between RETN-420 G/G genotype and BMI<25 (OR for interaction = 0.12; P = 0.046), and when subjects with RETN-420 C/C+C/G and BMI 25 (n = 69 for DM and 544 for non-DM) were defined as the reference, the adjusted ORs for subjects with RETN-420 G/G genotype and BMI>25 (n = 10 for DM and 111 for non-DM), RETN-420 C/C+C/G and BMI<25 (n = 81 for DM and 1,605 for non-DM), and RETN-420 G/G and BMI<25 (n = 1 for DM and 230 for non-DM) were demonstrated to be 0.72 (95% confidence interval: 0.36-1.46), 0.40 (0.28-0.56) and 0.03 (0.005-0.25), respectively. The present study revealed the significant interaction of RETN-420 G/G genotype with lower BMI on the decreased risk of DM, but the direction was opposite to the reported ones in Japanese. We should be careful in interpretation of the present study results because of the limited sample sizes. Further investigation of this association as well as of the actual biological roles of RETN in the genesis of human metabolic disorders including DM will be required.


Inverse Correlation between Coffee Consumption and Prevalence of Metabolic Syndrome: Baseline Survey of the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study in Tokushima, Japan

It is unclear whether consumption of coffee and green tea is associated with metabolic syndrome. This cross-sectional study enrolled 554 adults who had participated in the baseline survey of the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study in Tokushima Prefecture, Japan. Consumption of coffee and green tea was assessed using a questionnaire. Metabolic syndrome was diagnosed using the criteria of the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) and the Japan Society for the Study of Obesity (JASSO). Logistic regression analysis was used to examine the association between consumption of coffee and green tea and prevalence of metabolic syndrome and its components. After adjustment for sex, age, and other potential confounders, greater coffee consumption was associated with a significantly lower prevalence of metabolic syndrome, as defined by NCEP ATP III criteria (P for trend = 0.03). Participants who drank more coffee had a lower odds ratio (OR) for high serum triglycerides (P for trend = 0.02), but not for increased waist circumference or high blood pressure. Using JASSO criteria, moderate coffee consumption (1.5 to <3 cups/day) was associated with a significantly lower OR for high plasma glucose (OR = 0.51, 95% CI 0.28-0.93). Green tea consumption was not associated with the prevalence of metabolic syndrome or any of its components. Coffee consumption was inversely correlated with metabolic syndrome diagnosed using NCEP ATP III criteria, mainly because it was associated with lower serum triglyceride levels. This association highlights the need for further prospective studies of the causality of these relationships.


Relationship of dietary factors and habits with sleep-wake regularity.

The purpose of this study was to evaluate the associations between dietary factors and sleep-wake regularity in the Japanese population. We analyzed 1368 eligible subjects (931 men and 437 women) aged 35-69 years who had participated in the baseline survey of a cohort study in Tokushima Prefecture, Japan. Information on individual lifestyle characteristics, including dietary habits and sleep-wake regularity, was obtained by a selfadministrated questionnaire. Logistic regression analyses were performed to evaluate adjusted associations of the intake energy ratios of macronutrients, as well as intake frequency, and the amount of staple foods with sleepwake regularity. The lowest quartile of protein intake as well as the highest quartile of carbohydrates showed significantly higher multivariable-adjusted odds ratios of 2.1 (95% confidence interval, 1.3-3.3) and 2.1 (1.3-3.5), respectively, for poor sleep-wake regularity compared with the respective second quartile that is thought to be moderate intake. Regarding intake of staple foods, low weekly intake frequency at breakfast (<5 times/week), the lowest intake amount (<1 bowl or slice/roll) at breakfast, and the highest intake amount (>=2 bowls or slices/ rolls) at lunch and dinner exhibited significantly high adjusted odds ratios for poor sleep-wake regularity. Additionally adjusting for sleep duration, these results did not substantially alter. Our results suggested that low intake energy ratio of proteins and high intake energy ratio of carbohydrates, skipping intake of the staple foods at breakfast, and excessive intake amount of the staple foods at lunch and dinner may be associated with poor sleep-wake regularity.

Asia Pacific Journal of Clinical Nutrition


Evaluation of the Sugar Content in the Side Dishes Served in Elementary School Lunches

小学校給食の副食に含まれる糖質量の検討

Kuroda et al. proposed a simple method for calculating the carbohydrate content based on a food exchange list (Shokuhin Koukanhyou), with a sugar content of dietary staples of 40 % for rice, 50 % for bread, and 20 % for boiled noodles and a side dish containing 20 g sugar. This study focused on the sugar content in in school lunches, which have a nutrient composition that is different from diabetic meals. The total energy content of school lunches and the sugar content in their side dishes were investigated in 42 school lunches served in elementary school. The average energy intake in the total lunch increased depending on the school grade (670±44 to 752±50 kcal; means±standard deviation). On the other hand, the sugar content of side dishes increased from 29.7±7.5 g in the 1st-2nd grade to 31.2±8.1 g in the 5th-6th grade, thus it could be estimated to be 30 g regardless of the energy intake. Two hundred milliliters of milk containing approximately 10 g of carbohydrate was served in every school lunch, which accounted for the 10 g increase in comparison to hospital lunches. These results indicate that the sugar content in the side dishes of elementary school lunches can be estimated to be 30 g regardless of the energy intake.

「食品交換表に基づく新たなカーボカウント法」(黒田ら，糖尿病2010)に基づいて糖尿病食1食に含まれる糖質量を算出する場合，1食を主食と副食にわけ，副食は一律20 gと概算する．しかし，小児期は必要エネルギー量や栄養素バランスが食品交換表とは異なる．よって本研究では，小児期の副食糖質量を検討することを目的とした．学校給食摂取基準に基づく学校給食42食分を小学校の学年別に検討した．その結果，1食のエネルギーは670±44∼752±50(平均値±標準偏差)kcalと学年が上がるに従い増加したが，副食糖質量は29.7±7.5∼31.2±8.1 gであり，エネルギー量にかかわらず副食糖質量を約30 gに概算できた．学校給食では糖質約10 gの牛乳が毎食提供されるため糖尿病食や病院普通食に比較して副食糖質量が10 g増加すると考えられた．以上より，小学校給食では副食糖質量を30 gとしてカーボカウントを指導できることが明らかとなった．<br>

Journal of the The Japan Diabetes Society


Circulating cytokine signatures in healthy medical students exposed to academic examination stress.

Stress-induced production of proinflammatory cytokines in the brain and periphery is associated with mental distress. In this study, we measured changes in levels of salivary cortisol and 50 circulating immune mediators in 28 4th-grade medical students (19 males and 9 females) 7 weeks before, 1 day before, immediately after, and 1 week after an authorized nationwide examination for promotion. Repeated measures ANOVA with multiple testing correction and post hoc tests revealed that the examination significantly increased levels of proinflammatory cytokines (granulocyte colony-stimulating factor, interferon-, interleukin (IL)-1, and tumor necrosis factor-), Th2 cytokines (IL-4, IL-5, and IL-13), and -nerve growth factor in association with significant decreases in salivary cortisol levels and anxiety after the examination. These mediators may have a negative impact on the mental state of healthy young adults exposed to naturalistic stressors.


MicroRNAs miR-144/144* and miR-16 in peripheral blood are potential biomarkers for naturalistic stress in healthy Japanese medical students.

Non-coding microRNAs (miRNAs) are suggested to serve fundamental roles in cellular stress responses and in coping with sudden environmental changes in experimental animals. We examined whether naturalistic stressor-responsive miRNAs were detectable in whole blood. Blood and saliva were collected between 16:00 and 17:00 from 10 healthy medical students (5 males and 5 females; aged 22.4±0.8 years, mean±SD) 7 weeks before, one day before, immediately after, and one week after a nationally administered examination for academic promotion. Samples obtained one week after the examination were used as baseline controls. State anxiety and salivary cortisol levels reached maximum levels the day before the examination. Eleven candidate miRNAs (miR-144, -144*, -16, -15a, -19a, -19b, -26b, -30b, -106b, -126, and -142-3p) were extracted using a human miRNA microarray, and quantitative real-time reverse transcription PCR confirmed significant elevation of miR-144/144* and miR-16 levels immediately after finishing the examination. miR-16 levels in individual students were positively correlated with those of serum tumor necrosis factor (TNF)- measured immediately after the examination. Percentage changes in miR-144* and miR-16 levels from immediately after to one week after the examination were significantly correlated with percentage changes in circulating interferon- and/or TNF- levels over the same time points. Our results suggest that miR-144/144* and miR-16 may constitute a part of an integrated response to naturalistic stressors in healthy young adults.


Autism-associated gene expression in peripheral leucocytes commonly observed between subjects with autism and healthy women having autistic children.

Autism spectrum disorder (ASD) is a severe neuropsychiatric disorder which has complex pathobiology with profound influences of genetic factors in its development. Although the numerous autism susceptible genes were identified, the etiology of autism is not fully explained. Using DNA microarray, we examined gene expression profiling in peripheral blood from 21 individuals in each of the four groups; young adults with ASD, age- and gender-matched healthy subjects (ASD control), healthy mothers having children with ASD (asdMO), and asdMO control. There was no blood relationship between ASD and asdMO. Comparing the ASD group with control, 19 genes were found to be significantly changed. These genes were mainly involved in cell morphology, cellular assembly and organization, and nerve system development and function. In addition, the asdMO group possessed a unique gene expression signature shown as significant alterations of protein synthesis despite of their nonautistic diagnostic status. Moreover, an ASD-associated gene expression signature was commonly observed in both individuals with ASD and asdMO. This unique gene expression profiling detected in peripheral leukocytes from affected subjects with ASD and unaffected mothers having ASD children suggest that a genetic predisposition to ASD may be detectable even in peripheral cells. Altered expression of several autism candidate genes such as FMR-1 and MECP2, could be detected in leukocytes. Taken together, these findings suggest that the ASD-associated genes identified in leukocytes are informative to explore the genetic, epigenetic, and environmental background of ASD and might become potential tools to assess the crucial factors related to the clinical onset of the disorder.


Circulating vascular endothelial growth factor is independently and negatively associated with trait anxiety and depressive mood in healthy Japanese university students.

Anxiety and depressive mood are sometimes accompanied by modulation of neuroendocrine and immune functions. The aim of this study was to identify circulating immune mediators reflecting anxiety and depressive mood in healthy young adults. Anxiety and depressive mood in 209 healthy medical students (125 males and 84 females, aged 20.7±2.7years (mean±SD)) were assessed by the Spielberger state-trait anxiety inventory (STAI) and the Zung self-rating depression scale (Zung-SDS), respectively. Cortisol and chromogranin A (CgA) levels in saliva were measured using enzyme immunoassay kits, and 50 different mediators in sera were measured by a multiplex-suspension array system. The level of statistical significance was set at =0.05. Forty-four mediators were measurable in sera, and each mediator showed substantial individual variations. After determining Pearson correlation coefficients, we selected candidate cytokines whose levels were associated with STAI-state (2 cytokines), STAI-trait (8 cytokines), or SDS scores (8 cytokines). The candidate cytokines plus interleukin (IL)-1, IL-6, tumor necrosis factor-, and macrophage migration inhibitory factor were then subjected to multiple regression analysis adjusted for gender, BMI, and salivary concentrations of cortisol and CgA. Vascular endothelial growth factor (VEGF) was independently and negatively associated with both trait anxiety (p<0.05) and depressive mood (p<0.01). IL-1 showed independently positive association with depressive mood (p<0.05). Interactions between these two cytokines and gender or BMI were not observed. Besides IL-1, circulating VEGF may be a potential biomarker for negative mood states in healthy young adults.

International Journal of Psychophysiology


Effects of chronic academic stress on mental state and expression of glucocorticoid receptor α and β isoforms in healthy Japanese medical students.

Chronic academic stress responses were assessed by measuring mental state, salivary cortisol levels, and the glucocorticoid receptor (GR) gene expression in healthy Japanese medical students challenging the national medical license examination. Mental states of 17 male and 9 female medical undergraduates, aged 25.0 ± 1.2 years (mean ± SD), were assessed by the State and Trait Anxiety Inventory (STAI) and the Self-Rating Depression Scale (SDS) 2 months before, 2 days before, and 1 month after the examination. At the same time points, saliva and blood were collected. STAI-state scores peaked 2 days before the examination. Scores on STAI-trait and SDS, and salivary cortisol levels were consistently higher during the pre-examination period. One month after the examination, all these measures had significantly decreased to baseline levels. Real-time reverse transcription PCR showed that this chronic anxious state did not change the expression of the functional GRα mRNA isoform in peripheral leukocytes, while it resulted in reduced expression of the GRβ isoform 2 days before the examination. Our results replicate and extend a significant impact of chronic academic stressors on the mental state of healthy Japanese medical students and suggest a possible association of GRβ gene in response to psychological stress.


A novel biomental tool for assessing psychological stress response

メンタルヘルスを支える新たなストレスバイオマーカー (特集 職場のメンタルストレスの新しい視点--ストレス社会を生き抜く)

Stress plays an important role in both mental and physical problems. Stressful life events initiate a coordinated physiological process that is produced by interactions between the hypothalamuspituitary- adrenal axis, sympathetic nervous system, and immune system. The response to psychological stress varies considerably and depends on a wide range of environmental and genetic factors. Establishment of a new biomental tool for objectively assessing stress response is required. We focus on high-throughput analysis of gene expression using microarray system to study the complex stress responses. Alternative splicing(AS)regulates the gene expression program in response to surrounding environment. However, acute psychological stress-initiated AS events have not been documented yet. Academic examinations are one of the brief naturalistic stressors and have been shown to change gene expression in peripheral leukocytes, which is postulated to be involved in the psychological response. Using the GeneChip human exon1．0ST array, AS events of 27 genes with splicing indices >1．0could be detected immediately after the examination among healthy university students. Real-time reverse transcription PCR validated the stress-initiated skipping of exon 63 of SMG -1 that encodes a phosphatidylinositol 3-kinase-related protein kinase crucial for activations of p 53-dependent pathways and mRNA decay system. These results indicate that AS mediated regulation of gene expression in response to brief naturalistic stressors in peripheral leukocytes, and suggest the SMG -1 splice variant as a potential biomarker for acute psychological stress.


Interleukin-18 deficiency reduces neuropeptide gene expressions in the mouse amygdala related with behavioral change.

In this study, we examined the effects of IL-18 deficiency on behaviors and gene expression profiles in 6 brain regions. IL-18(-/-) mice reduced depressive-like behavior and changed gene expressions predominantly in the amygdala compared with wild-type mice. Pathway analysis of the differentially expressed genes ranked behavior as the top-scored biological function. Of note, the absence of IL-18 decreased Avp, Hcrt, Oxt, and Pmch mRNA levels and the number of arginine vasopressin- and oxytocin-positive cells in the amygdala, but not in the hypothalamus. Our results suggest that IL-18-dependent vasopressinergic and oxytocinergic circuitry in the amygdala may regulate depressive-like behaviors in mice.


Brief naturalistic stress induces an alternative splice variant of SMG-1 lacking exon 63 in peripheral leukocytes.

Alternative splicing (AS) not only regulates the gene expression program in response to surrounding environment, but also produces protein isoforms with unique properties under stressful conditions. However, acute psychological stress-initiated AS events have not been documented in human studies. After assessments of changes in salivary cortisol levels and anxiety among 28 fourth-grade medical students 7 weeks prior to, 1 day before, immediately after, and 1 week after an examination for promotion, we selected 5 male students, who showed a typical stress response, and screened AS events in their circulating leukocytes using the GeneChip human exon 1.0 ST array. AS events of 27 genes with splicing indices >1.0 could be detected between immediately after and either 7 weeks before, 1 day before, or 1 week after the examination. The examination stress preferentially caused skipping rather than inclusion: 21 out of the 27 pre-mRNAs underwent skipping of exons, and skipping in 3'UTR was observed in 8 genes. Among the candidate genes, real-time reverse transcription PCR validated the stress-initiated skipping of exon 63 of SMG-1 that encodes a phosphatidylinositol 3-kinase-related protein kinase crucial for activations of p53-dependent pathways and nonsense-mediated mRNA decay. Our results indicate a significant impact of brief naturalistic stressors on AS-mediated regulation of gene expression in peripheral leukocytes, and suggest the SMG-1 splice variant as a potential biomarker for acute psychological stress.


High-throughput screening of brief naturalistic stress-responsive cytokines in university students taking examinations.

This study was designed to prospectively examine the impact of a brief naturalistic stressor (academic examination) on salivary/serum cortisol, measures of anxiety and depressive mood, and 50 circulating immune mediators assessed 7 days before, the first day of, and 2 days after the first term examination period (5 days) among 20 male and 6 female medical students (19.7+/-3.1 years, mean+/-SD). Of 42 serum factors detected, repeated measures ANOVA and Bonferroni post hoc testing indicated that concentrations of macrophage migration inhibitory factor (MIF), monocyte chemoattractant protein (MCP)-3, and beta-nerve growth factor (beta-NGF) were significantly decreased 2 days after finishing examinations, compared with the levels on the first day of examinations (p<0.05) in association with a concomitant post-examination decreases (p<0.05) in anxiety and salivary cortisol levels. In contrast, interleukin (IL)-16 was reciprocally increased between the two time points (p<0.05). However, after correction for multiple comparisons, only changes in MIF were significant (p<0.05/42=0.00119), and MIF levels peaked on the first day of examinations was significantly higher than those measured both 7 days before and 2 days after the examination. The present high-throughput analysis with multiplex cytokine panels reconfirms the impact of brief naturalistic stressors on immune outcomes, and suggests a potential role of MIF in the acute stress response.


beta-Carotene and beta-cryptoxanthin but not lutein evoke redox and immune changes in RAW264 murine macrophages.

The mechanism of immunological benefits induced by carotenoids has not been fully elucidated. Here, we investigated some of the immunity-related properties of beta-carotene and two other carotenoids, beta-cryptoxanthin, and lutein, on the murine macrophages cell line RAW264. beta-Carotene added to the culture medium accumulated in the cells in a time- and dose-dependent manner. The accumulation was positively correlated with cellular lipid peroxidation, demonstrating the pro-oxidative activity of beta-carotene, and also with the synthesis of glutathione, an intracellular antioxidant. Conversely, accumulation of beta-carotene was negatively correlated with the transcription of immune-active molecules, such as IL-1beta, IL-6, and IL-12 p40, in cells stimulated by LPS and INF-gamma. The transcription of the pro-inflammatory cytokines IL-1beta and IL-6 was more sensitive to the accumulation of beta-carotene than was IL-12 p40. The accumulation of beta-cryptoxanthin in cells resulted in effects similar to those of beta-carotene. However, lutein accumulated minimally and did not significantly affect the cells. These results demonstrate that beta-carotene, and beta-cryptoxanthin as well, can accumulate in RAW264 cells and induce changes in intracellular redox status, which in turn regulate the immune function of macrophages.


Changes in behavior and gene expression induced by caloric restriction in C57BL/6 mice.

Caloric restriction (CR) is an effective method for prevention of age-associated diseases as well as overweight and obesity; however, there is controversy regarding the effects of dieting regimens on behavior. In this study, we investigated two different dieting regimens: repeated fasting and refeeding (RFR) and daily feeding of half the amount of food consumed by RFR mice (CR). CR and RFR mice had an approximate 20% reduction in food intake compared with control mice. Open field, light-dark transition, elevated plus maze, and forced swimming tests indicated that CR, but not RFR, reduced anxiety- and depressive-like behaviors, with a reduction peak on day 8. Using a mouse whole genome microarray, we analyzed gene expression in the prefrontal cortex, amygdala, and hypothalamus. In addition to the CR-responsive genes commonly modified by RFR and CR, each regimen differentially changed the expression of distinct genes in each region. The most profound change was observed in the amygdalas of CR mice: 884 genes were specifically upregulated. Ingenuity pathway analysis revealed that these 884 genes significantly modified nine canonical pathways in the amygdala. alpha-Adrenergic and dopamine receptor signalings were the two top-scoring pathways. Quantitative RT-PCR confirmed the upregulation of six genes in these pathways. Western blotting confirmed that CR specifically increased dopamine- and cAMP-regulated phosphoprotein (Darpp-32), a key regulator of dopamine receptor signaling, in the amygdala. Our results suggest that CR may change behavior through altered gene expression.