Coffee and metabolic phenotypes: A cross-sectional analysis of the Japan multi-institutional collaborative cohort (J-MICC) study.

BACKGROUND AND AIMS: To date, the relationship between coffee consumption and metabolic phenotypes has hardly been investigated and remains controversial. Therefore, the aim of this cross-sectional study is to examine the associations between coffee consumption and metabolic phenotypes in a Japanese population. METHODS AND RESULTS: We analyzed the data of 26,363 subjects (aged 35-69 years) in the baseline survey of the Japan Multi-Institutional Collaborative Cohort Study. Coffee consumption was assessed using a questionnaire. Metabolic Syndrome (MetS) was defined according to the Joint Interim Statement Criteria of 2009, using body mass index (BMI) instead of waist circumference. Subjects stratified by the presence or absence of obesity (normal weight: BMI <25 kg/m2; obesity: BMI ≥25 kg/m2) were classified by the number of MetS components (metabolically healthy: no components; metabolically unhealthy: one or more components) other than BMI. In multiple logistic regression analyses adjusted for sex, age, and other potential confounders, high coffee consumption (≥3 cups/day) was associated with a lower prevalence of MetS and metabolically unhealthy phenotypes both in normal weight (OR 0.83, 95% CI 0.76-0.90) and obese subjects (OR 0.83, 95% CI 0.69-0.99). Filtered/instant coffee consumption was inversely associated with the prevalence of MetS and metabolically unhealthy phenotypes, whereas canned/bottled/packed coffee consumption was not. CONCLUSION: The present results suggest that high coffee consumption, particularly filtered/instant coffee, is inversely associated with the prevalence of metabolically unhealthy phenotypes in both normal weight and obese Japanese adults.

Daily Consumption of Coffee and Eating Bread at Breakfast Time Is Associated with Lower Visceral Adipose Tissue and with Lower Prevalence of Both Visceral Obesity and Metabolic Syndrome in Japanese Populations: A Cross-Sectional Study.

BACKGROUND: The study aimed to investigate the association between daily consumption of coffee or green tea, with and without habitual bread consumption for breakfast, and components and prevalence of metabolic syndrome in Japanese populations. METHODS: The study population consisted of 3539 participants (1239 males and 2300 females). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression analyses to evaluate the associations of daily coffee and green tea consumption with the prevalence of obesity, visceral obesity, and metabolic syndrome. RESULTS: Coffee consumption was associated with significantly lower proportions of visceral obesity (OR: 0.746, CI: 0.588-0.947) and metabolic syndrome (OR: 0.706, CI: 0.565-0.882). On the other hand, green tea was not associated with visceral obesity (OR: 1.105, CI: 0.885-1.380) or metabolic syndrome (OR: 0.980, CI: 0.796-1.206). The combination of daily drinking coffee and eating bread at breakfast time was associated with significantly lower proportions of obesity (OR: 0.613, CI: 0.500-0.751) (p = 0.911 for interaction), visceral obesity (OR: 0.549, CI: 0.425-0.710) (p = 0.991 for interaction), and metabolic syndrome (OR: 0.586, CI: 0.464-0.741) (p = 0.792 for interaction). CONCLUSION: Coffee consumption was significantly associated with lower visceral adipose tissue and lower proportions of visceral obesity, but the same was not true for green tea consumption. Furthermore, in combination with coffee consumption, the addition of eating bread at breakfast time significantly lowered proportions of visceral obesity and metabolic syndrome, although there was no interaction between coffee and bread.

Genome-wide association meta-analysis and Mendelian randomization analysis confirm the influence of ALDH2 on sleep durationin 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 have 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 5140 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 that a functional ALDH2 variant, rs671, most strongly influences 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.

Japanese female Kendo practitioners are associated with high radial bone mineral density.

Osteopenia is a condition in which bone mineral density (BMD) is lower than normal. Exercise increases BMD in both the young and adults. This study aimed to compare the radial apparent BMD (aBMD) in Japanese females who are Kendo practitioners (KPs) and those with no regular exercise habits (no-REH). The analysis participants consisted of 45 KPs (mean age: 49.4 years old) and 110 no-REH (mean age: 48.8 years old). Radial aBMD was measured using an ultrasonic bone densitometry system. Radial aBMD in KPs was 196.1 ± 33.9 mg/cm3, and was 182.9 ± 45.3 mg/cm3 in no-REH participants. KPs had significantly higher BMD than no-REH participants. In KPs, left radial aBMD was 196.1 ± 33.9 mg/cm3, and right radial aBMD was 184.5 ± 37.7 mg/cm3. The left radius was also significantly higher than the right radius with respect to aBMD in KPs. After adjusting for age, body mass index, menstrual status, parous women and frequency of milk and dairy intake, the odds ratio (OR) of osteopenia associated with no-REH was 6.58 (95% confidence interval (CI): 1.72-25.1) and the prevalence ratio (PR) of osteopenia associated with no-REH was 4.12 (95% CI: 1.23-13.7). Therefore, the Kendo practice may have a protective efficacy for osteopenia in women.