Association between consumption of small fish and all-cause mortality among Japanese: the Japan Multi-Institutional Collaborative Cohort Study.

OBJECTIVE: Although small fish are an important source of micronutrients, the relationship between their intake and mortality remains unclear. This study aimed to clarify the association between intake of small fish and all-cause and cause-specific mortality. DESIGN: We used the data from a cohort study in Japan. The frequency of the intake of small fish was assessed using a validated FFQ. The hazard ratio (HR) and 95 % confidence interval (CI) for all-cause and cause-specific mortality according to the frequency of the intake of small fish by sex were estimated using a Cox proportional hazard model with adjustments for covariates. SETTING: The Japan Multi-Institutional Collaborative Cohort Study. PARTICIPANTS: A total of 80 802 participants (34 555 males and 46 247 females), aged 35-69 years. RESULTS: During a mean follow-up of 9·0 years, we identified 2482 deaths including 1495 cancer-related deaths. The intake of small fish was statistically significantly and inversely associated with the risk of all-cause and cancer mortality in females. The multivariable-adjusted HR (95 % CI) in females for all-cause mortality according to the intake were 0·68 (0·55, 0·85) for intakes 1-3 times/month, 0·72 (0·57, 0·90) for 1-2 times/week and 0·69 (0·54, 0·88) for ≥ 3 times/week, compared with the rare intake. The corresponding HR (95 % CI) in females for cancer mortality were 0·72 (0·54, 0·96), 0·71 (0·53, 0·96) and 0·64 (0·46, 0·89), respectively. No statistically significant association was observed in males. CONCLUSIONS: Intake of small fish may reduce the risk of all-cause and cancer mortality in Japanese females.

Association between brown sugar intake and decreased risk of cancer in the Amami islands region, Japan.

BACKGROUND AND OBJECTIVES: Although excess white sugar intake imposes various health burdens, brown sugar is high in minerals, polyphenols, and polycosanol. However, few epidemiological studies have assessed brown sugar intake for health benefit. People in the Amami islands region, with a relatively high proportion of individuals with longevity, consume brown sugar as a type of refreshment. This cohort study was conducted in Amami to clarify the association of brown sugar intake with mortality risk and cancer incidence. METHODS AND STUDY DESIGN: Participants were recruited from the general population of Amami as part of the Japan Multi-Institutional Collaborative Cohort Study. The number of eligible participants was 5004 (2057 men and 2947 women). During the median follow-up period of 13.4 years, 274 deaths and 338 cases of cancer were observed. HRs and 95% CIs were estimated using the Cox proportional hazard model, after adjusting for sugar-related and other variables. RESULTS: After adjusting for their related confounding factors, brown sugar intake was associated with decreased HRs and a decreasing trend for all-site and stomach cancer incidence (p = 0.001 and 0.017, respectively) in women and men, and for breast cancer incidence (p = 0.034) in women. Additionally, a decreasing trend in the HRs for lung cancer incidence was observed among never and ex-smokers (p = 0.039). Decreased HRs for overall death, cancer, and cardiovascular disease were not apparent. CONCLUSIONS: Brown sugar intake was associated with decreased risk of all-site, stomach, and breast cancer incidences in the Amami population.

Association between awareness of limiting food intake and all-cause mortality: A cohort study in Japan.

BACKGROUND: Improving diets requires an awareness of the need to limit foods for which excessive consumption is a health problem. Since there are limited reports on the link between this awareness and mortality risk, we examined the association between awareness of limiting food intake (energy, fat, and sweets) and all-cause mortality in a Japanese cohort study. METHODS: Participants comprised 58,772 residents (27,294 men; 31,478 women) aged 35-69 years who completed baseline surveys of the Japan Multi-Institutional Collaborative Cohort Study from 2004 to 2014. Hazard ratios (HRs) for all-cause mortality and 95% confidence intervals (CIs) were estimated by sex using a Cox proportional hazard model, with adjustment for related factors. Mediation analysis with fat intake as a mediator was also conducted. RESULTS: The mean follow-up period was 11 years and 2,516 people died. Estimated energy and fat intakes according to the Food Frequency Questionnaire were lower in those with awareness of limiting food intake than in those without this awareness. Women with awareness of limiting fat intake showed a significant decrease in mortality risk (HR=0.73; 95% CI, 0.55 to 0.94). Mediation analysis revealed that this association was due to the direct effect of the awareness of limiting fat intake and that the total effect was not mediated by actual fat intake. Awareness of limiting energy or sweets intake was not related to mortality risk reduction. CONCLUSION: Awareness of limiting food intake had a limited effect on reducing all-cause mortality risk.

Association Between Nursing Discussions, Resilience, Workplace Social Support and Burnout: A Quantitative Study in Japan.

Background: Although it is known that resilience is negatively associated with burnout, and that certain interventions can effectively increase resilience, little is known about online resilience-enhancing interventions during the COVID-19 crisis. The aim of this study was to identify the association between an online resilience-enhancing intervention and workplace social support, and burnout among nurses working in the mainland and remote islands of Japan during the COVID-19 crisis. Methods: Pretest-posttest was conducted between April 2020 and February 2021, and the questionnaire survey included the bidimensional resilience scale, the Japanese version of Pine's Burnout Measure, and the workplace social support scale. Changes in burnout, resilience, and social support and the associations with nursing discussions as intervention were analyzed. Participants were 98 Nurses with 1 to 10 years of experience from Japan's mainland and remote island hospitals of Kagoshima Prefecture participated in a baseline survey in April 2020. Of these, 76 participated in a secondary survey in September 2020, and 69 participated in the intervention program and a third survey in February 2021. The online intervention over Zoom consisted of small-group nursing discussions based on the broaden-and-build theory. Results: Changes in burnout showed a significant negative association with change in workplace social support (Coef. = -0.019, 95% CI -0.035- -0.003), as did the interaction between change in acquired resilience and intervention (Coef. = -0.088, 95% CI -0.164- -0.011). Conclusion: Change in workplace social support was significantly negatively associated with changes in burnout, as was the interaction of intervention and acquired resilience. Promotion of this intervention and making workplace social support more accessible may contribute to reduce burnout in nurses.

Effects of gene-lifestyle interactions on obesity based on a multi-locus risk score: A cross-sectional analysis.

BACKGROUND: The relationship between lifestyle and obesity is a major focus of research. Personalized nutrition, which utilizes evidence from nutrigenomics, such as gene-environment interactions, has been attracting attention in recent years. However, evidence for gene-environment interactions that can inform treatment strategies is lacking, despite some reported interactions involving dietary intake or physical activity. Utilizing gene-lifestyle interactions in practice could aid in optimizing interventions according to genetic risk. METHODS: This study aimed to elucidate the effects of gene-lifestyle interactions on body mass index (BMI). Cross-sectional data from the Japan Multi-Institutional Collaborative Cohort Study were used. Interactions between a multi-locus genetic risk score (GRS), calculated from 76 ancestry-specific single nucleotide polymorphisms, and nutritional intake or physical activity were assessed using a linear mixed-effect model. RESULTS: The mean (standard deviation) BMI and GRS for all participants (n = 12,918) were 22.9 (3.0) kg/m2 and -0.07 (0.16), respectively. The correlation between GRS and BMI was r(12,916) = 0.13 (95% confidence interval [CI] 0.11-0.15, P < 0.001). An interaction between GRS and saturated fatty acid intake was observed (ß = -0.11, 95% CI -0.21 to -0.02). An interaction between GRS and n-3 polyunsaturated fatty acids was also observed in the females with normal-weight subgroup (ß = -0.12, 95% CI -0.22 to -0.03). CONCLUSION: Our results provide evidence of an interaction effect between GRS and nutritional intake and physical activity. This gene-lifestyle interaction provides a basis for developing prevention or treatment interventions for obesity according to individual genetic predisposition.

Population-Based Impact of Smoking, Drinking, and Genetic Factors on HDL-cholesterol Levels in J-MICC Study Participants.

BACKGROUND: Environmental and genetic factors are suggested to exhibit factor-based association with HDL-cholesterol (HDL-C) levels. However, the population-based effects of environmental and genetic factors have not been compared clearly. We conducted a cross-sectional study using data from the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study to evaluate the population-based impact of smoking, drinking, and genetic factors on low HDL-C. METHODS: Data from 11,498 men and women aged 35-69 years were collected for a genome-wide association study (GWAS). Sixty-five HDL-C-related SNPs with genome-wide significance (P < 5 × 10-8) were selected from the GWAS catalog, of which seven representative SNPs were defined, and the population-based impact was estimated using population attributable fraction (PAF). RESULTS: We found that smoking, drinking, daily activity, habitual exercise, egg intake, BMI, age, sex, and the SNPs CETP rs3764261, APOA5 rs662799, LIPC rs1800588, LPL rs328, ABCA1 rs2575876, LIPG rs3786247, and APOE rs429358 were associated with HDL-C levels. The gene-environmental interactions on smoking and drinking were not statistically significant. The PAF for low HDL-C was the highest in men (63.2%) and in rs3764261 (31.5%) of the genetic factors, and the PAFs of smoking and drinking were 23.1% and 41.8%, respectively. CONCLUSION: The present study showed that the population-based impact of genomic factor CETP rs3764261 for low HDL-C was higher than that of smoking and lower than that of drinking.

Sex-specific Relationship Between Stress Coping Strategies and All-cause Mortality: Japan Multi-Institutional Collaborative Cohort Study.

BACKGROUND: Stress coping strategies are related to health outcomes. However, there is no clear evidence for sex differences between stress-coping strategies and mortality. We investigated the relationship between all-cause mortality and stress-coping strategies, focusing on sex differences among Japanese adults. METHODS: A total of 79,580 individuals aged 35-69 years participated in the Japan Multi-Institutional Collaborative Cohort Study between 2004 and 2014 and were followed up for mortality. The frequency of use of the five coping strategies was assessed using a questionnaire. Sex-specific, multivariable-adjusted hazard ratios (HRs) for using each coping strategy ("sometimes," and "often/very often" use versus "very few" use) were computed for all-cause mortality. Furthermore, relationships were analyzed in specific follow-up periods when the proportion assumption was violated. RESULTS: During the follow-up (median: 8.5 years), 1,861 mortalities were recorded. In women, three coping strategies were related to lower total mortality. The HRs for "sometimes" were 0.81 (95% confidence interval [CI], 0.67-0.97) for emotional expression, 0.79 (95% CI, 0.66-0.95) for emotional support-seeking, and 0.80 (95% CI, 0.66-0.98) for disengagement. Men who "sometimes" used emotional expression and sometimes or often used problem-solving and positive reappraisal had a 15-41% lower HRs for all-cause mortality. However, those relationships were dependent on the follow-up period. There was evidence that sex modified the relationships between emotional support-seeking and all-cause mortality (P for interaction = 0.03). CONCLUSION: In a large Japanese sample, selected coping strategies were associated with all-cause mortality. The relationship of emotional support-seeking was different between men and women.

Intake of local vegetables and decreased risk of mortality and cancer incidence in Amami island regions, Japan.

BACKGROUND AND OBJECTIVES: There is emerging scientific evidence of the health benefits of traditional food plants at both molecular and folk remedy levels; however, epidemiological observations are limited. The Amami island region of Japan has a variety of unique traditions conserved till today, where a cohort study was conducted in 2005. The objective of this study was to investigate the associations between the intake of common and local vegetables and the risk of mortality and cancer incidence in Amami. METHODS AND STUDY DESIGN: Participants were enrolled from the general population of Amami as part of the Japan Multi-institutional Collaborative Cohort (J-MICC) Study. In total, 5,015 participants (2,053 men and 2,962 women) aged 35-69 years were enrolled in this study. They were followed up to obtain information on movement, death, and cancer incidence. The hazard ratios (HRs) and 95% CIs were estimated using the Cox proportional hazard model after adjusting for potential confounding factors. RESULTS: A significant inverse association was observed between cabbage intake and the HRs for overall mortality (p for trend=0.046) and lung cancer incidence (p=0.016). Intake of handama and togan as local vegetables was associated with decreased HRs for overall mortality (p=0.019 and 0.036, respectively). CONCLUSIONS: While the molecular and biochemical reasoning and residual confounding factors behind this association remain unclear, the findings of this study suggest that the dietary lifestyle in Amami has a positive impact on the residents, which can significantly decrease mortality risk.

Associations of metabolic syndrome and metabolically unhealthy obesity with cancer mortality: The Japan Multi-Institutional Collaborative Cohort (J-MICC) study.

PURPOSE: The association between metabolic syndrome (MetS) and the risk of death from cancer is still a controversial issue. The purpose of this study was to examine the associations of MetS and metabolically unhealthy obesity (MUHO) with cancer mortality in a Japanese population. METHODS: We used data from the Japan Multi-Institutional Collaborative Cohort Study. The study population consisted of 28,554 eligible subjects (14,103 men and 14,451 women) aged 35-69 years. MetS was diagnosed based on 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), using the body mass index instead of waist circumference. The Cox proportional hazards analysis was used to estimate adjusted hazard ratios (HR) and 95% confidence intervals (CI) for total cancer mortality in relation to MetS and its components. Additionally, the associations of obesity and the metabolic health status with cancer mortality were examined. RESULTS: During an average 6.9-year follow-up, there were 192 deaths from cancer. The presence of MetS was significantly correlated with increased total cancer mortality when the JASSO criteria were used (HR = 1.51, 95% CI 1.04-2.21), but not when the NCEP-ATP III criteria were used (HR = 1.09, 95% CI 0.78-1.53). Metabolic risk factors, elevated fasting blood glucose, and MUHO were positively associated with cancer mortality (P <0.05). CONCLUSION: MetS diagnosed using the JASSO criteria and MUHO were associated with an increased risk of total cancer mortality in the Japanese population.

The Effects of Resilience and Related Factors on Burnout in Clinical Nurses, Kagoshima, Japan.

Background: Burnout, due to extreme mental and physical fatigue, and emotional exhaustion, leads to decreased nursing quality and turnover. However, not all nurses are observed as burnouts in the same work environment, and resilience and related factors may have effects on the development of burnouts. Therefore, we conducted a cross-sectional study to examine the effects of resilience and related factors on the burnout in clinical nurses, Kagoshima, Japan. Methods: Data for this cross-sectional study involving nurses (n = 98) was collected using the following questionnaire surveys: the Bidimensional Resilience Scale, The Workplace Social Support Scale, and the Japanese version of the Pine's Burnout Scale. Using burnout as a dependent variable, analyses were conducted using one-way analysis of variance and multiple regression analysis after adjusted for related factors. Results: The prevalence of burnouts was 19.6% on the mainland and 36.1% on remote island. Innate resilience, acquired resilience, workplace social support, and burnout showed no significant difference between nurses on the mainland and remote island. In the mainland participants, innate resilience (ß = -0.492, P < 0.001) and acquired resilience (ß = -0.325, P = 0.007) showed a negative association with burnout, and similar associations were observed innate resilience (ß = -0.520, P = 0.004) and acquired resilience (ß = -0.336, P = 0.057) in the remote island participants. For all participants, innate resilience (ß = -0.443, P = 0.001) and workplace social support (ß = -0.204, P = 0.031) showed a negative association with burnout, and turnover intention was positively associated (ß = 0.025, P = 0.021). Conclusion: A negative association between burnout and innate resilience factors was observed in the mainland and remote island. Further evaluation of innate resilience is necessary for burnout prevention in clinical nurses.

A genome-wide association study on adherence to low-carbohydrate diets in Japanese.

BACKGROUND/OBJECTIVES: Low-carbohydrate diets (LCD) are useful for weight reduction, and 50-55% carbohydrate consumption is associated with minimal risk. Genetic differences were related to nutritional consumption, food preferences, and dietary patterns, but whether particular genetic differences in individuals influence LCD adherence is unknown. SUBJECTS/METHODS: We conducted a GWAS on adherence to LCD utilizing 14,076 participants from the Japan Multi-Institutional Collaborative Cohort study. We used a previously validated semiquantitative food frequency questionnaire to estimate food consumption. Association of the imputed variants with the LCD score by Halton et al. we used linear regression analysis adjusting for sex, age, total dietary energy consumption, and components 1 to 10 by principal component analysis. We repeated the analysis with adjustment for alcohol consumption (g/day) in addition to the above-described variables. RESULTS: Men and women combined analysis without adjustment for alcohol consumption; we found 395 variants on chromosome 12 associated with the LCD score having P values <5 × 10-8. A conditional analysis with the addition of the dosage data of rs671 on chromosome 12 as a covariate, P values for all 395 SNPs on chromosome 12 turned out to be insignificant. In the analysis with additional adjustment for alcohol consumption, we did not identify any SNPs associated with the LCD score. CONCLUSION: We found rs671 was inversely associated with adherence to LCD, but that was strongly confounded by alcohol consumption.

Association of perceived stress and coping strategies with the renal function in middle-aged and older Japanese men and women.

Elucidating the risk factors for chronic kidney disease is important for preventing end-stage renal disease and reducing mortality. However, little is known about the roles of psychosocial stress and stress coping behaviors in deterioration of the renal function, as measured by the estimated glomerular filtration rate (eGFR). This cross-sectional study of middle-aged and older Japanese men (n = 31,703) and women (n = 38,939) investigated whether perceived stress and coping strategies (emotional expression, emotional support seeking, positive reappraisal, problem solving, and disengagement) were related to the eGFR, with mutual interactions. In multiple linear regression analyses adjusted for age, area, lifestyle factors, and psychosocial variables, we found a significant inverse association between perceived stress and the eGFR in men (Ptrend = 0.02), but not women. This male-specific inverse association was slightly attenuated after adjustment for the history of hypertension and diabetes and was more evident in lower levels of emotional expression (Pinteraction = 0.003). Unexpectedly, problem solving in men (Ptrend < 0.001) and positive reappraisal in women (Ptrend = 0.002) also showed an inverse association with the eGFR. Perceived stress may affect the eGFR, partly through the development of hypertension and diabetes. The unexpected findings regarding coping strategies require the clarification of the underlying mechanisms, including the hormonal and immunological aspects.

Association between the Perception of Behavior Change and Habitual Exercise during COVID-19: A Cross-Sectional Online Survey in Japan.

In general, the perception of behavior change may be associated with habitual exercise. However, this association might not be well-understood due to the state of emergency of the COVID-19 pandemic. This study collected data from 1499 internet users aged 20-86 years living in Japan who participated in the online survey from 26 to 27 February 2021. Having a perception of behavior change was defined as preparation, action, and maintenance of the transtheoretical model. The habitual exercise was defined as 600 metabolic equivalent min/week or more based on the International Physical Activity Questionnaire. Multivariate logistic regression analysis was used to calculate the odds ratio of habitual exercise and a 95% confidence interval was estimated after adjusting for related factors. We found that perception of behavior change was positively associated with habitual exercise (adjusted odds ratio = 2.41, 95%CI = 1.89-3.08), and similar associations were found in states of emergency (2.69, 1.97-3.69) and non-emergency (2.01, 1.34-3.01). Moreover, women were negatively associated in all analyses with habitual exercise compared to men (0.63, 0.49-0.80; 0.65, 0.44-0.96; 0.62, and 0.45-0.84, respectively). Thus, the perception of behavior change may be involved in the implementation of habitual exercise, suggesting that women face difficulties in engaging in habitual exercise.

Association between Regular Exercise and Self-Rated Health and Sleep Quality among Adults in Japan during the COVID-19 Pandemic.

Regular exercise may be associated with better self-rated health and sleep status. However, this correlation among various age groups, such as young, middle-aged, and older people, as well as during the COVID-19 pandemic, has not been examined. This study examined the correlation between regular exercise and self-rated health and sleep quality among adults in Japan during the COVID-19 pandemic. Data were collected using an online survey conducted between February 26 and 27, 2021. A total of 1410 adults in Japan (age range, 20-86 years) completed the online survey. Regular exercise was divided into: (1) more than 30 min of moderate exercise a day, (2) more than 2 days per week, and (3) continuous for 1 year or longer. Self-rated health and sleep quality were assessed using the Likert scale. After adjusting for multiple confounders, regular exercise was correlated with decreased poor self-rated health and poor sleep quality in middle-aged adults; however, no significant correlation was observed among young and older adults. The promotion of regular exercise among middle-aged people during the COVID-19 pandemic may contribute to better self-rated health and sleep quality status.

Genome-wide association study of serum prostate-specific antigen levels based on 1000 Genomes imputed data in Japanese: the Japan Multi-Institutional Collaborative Cohort Study.

Prostate cancer is emerging as a significant global public health burden. The incidence and prevalence of prostate cancer has increased in Japan, as westernized lifestyles become more popular. Recent advances in genetic epidemiology, including genome-wide association studies (GWASs), have identified considerable numbers of human genetic factors associated with diseases. Several GWASs have reported significant loci associated with serum prostate-specific antigen (PSA) levels. One GWAS, which was based on classic GWAS microarray measurements, has been reported for Japanese so far. In the present study, we conducted a GWAS of serum PSA using 1000Genomes imputed GWAS data (n =1,216) from the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study, to detect candidate novel genetic loci that influence serum PSA levels in Japanese. The association of SNPs/genetic variants with serum PSA as a continuous variable was tested using the linear Wald test. SNP rs10000006 in SGMS2 (sphingomyelin synthase 2) on chromosome 4 had genome-wide significance (P <5×10-8), and eight variants on three chromosomes (chromosomes 12, 14, 15) had genome-wide suggestive levels of significance (P <1×10-6). With an independent data set from the J-MICC Shizuoka Study (n = 2,447), the association of the SGMS2 SNP with blood PSA levels was not replicated. Although our GWAS failed to detect novel loci associated with serum PSA levels in the Japanese cohort, it confirmed the significant effects of previously reported genetic loci on PSA levels in Japanese. Importantly, our results confirmed the significance of KLK3 SNPs also in Japanese, implying that consideration of individual genetic information in prostate cancer diagnosis may be possible in the future.

A genome-wide association study on confection consumption in a Japanese population: the Japan Multi-Institutional Collaborative Cohort Study.

Differences in individual eating habits may be influenced by genetic factors, in addition to cultural, social or environmental factors. Previous studies suggested that genetic variants within sweet taste receptor genes family were associated with sweet taste perception and the intake of sweet foods. The aim of this study was to conduct a genome-wide association study (GWAS) to find genetic variations that affect confection consumption in a Japanese population. We analysed GWAS data on confection consumption using 14 073 participants from the Japan Multi-Institutional Collaborative Cohort study. We used a semi-quantitative FFQ to estimate food intake that was validated previously. Association of the imputed variants with confection consumption was performed by linear regression analysis with adjustments for age, sex, total energy intake and principal component analysis components 1-3. Furthermore, the analysis was repeated adjusting for alcohol intake (g/d) in addition to the above-described variables. We found 418 SNP located in 12q24 that were associated with confection consumption. SNP with the ten lowest P-values were located on nine genes including at the BRAP, ACAD10 and aldehyde dehydrogenase 2 regions on 12q24.12-13. After adjustment for alcohol intake, no variant was associated with confections intake with genome-wide significance. In conclusion, we found a significant number of SNP located on 12q24 genes that were associated with confections intake before adjustment for alcohol intake. However, all of them lost statistical significance after adjustment for alcohol intake.

A genome-wide association study in Japanese identified one variant associated with a preference for a Japanese dietary pattern.

BACKGROUND/OBJECTIVES: Individual eating habits may be influenced by genetic factors, in addition to environmental factors. Previous studies suggested that adherence to Japanese food patterns was associated with a decreased risk of all-cause and cardiovascular disease mortality. We conducted a genome-wide association study (GWAS) in a Japanese population to find genetic variations that affect adherence to a Japanese food pattern. SUBJECTS/METHODS: We analyzed GWAS data using 14,079 participants from the Japan Multi-Institutional Collaborative Cohort study. We made a Japanese food score based on six food groups. Association of the imputed variants with the Japanese food score was performed by linear regression analysis with adjustments for age, sex, total energy intake, alcohol intake (g/day), and principal components 1-10 omitting variants in the major histocompatibility region. RESULTS: We found one SNP in the 14q11.2 locus that was significantly associated with the Japanese food score with P values <5 × 10-8. Functional annotation revealed that the expression levels of two genes (BCL2L2, SLC22A17) were significantly inversely associated with this SNP. These genes are known to be related to olfaction and obesity. CONCLUSION: We found a new SNP that was associated with the Japanese food score in a Japanese population. This SNP is inversely associated with genes link to olfaction and obesity.

Differential Effect of Polymorphisms on Body Mass Index Across the Life Course of Japanese: The Japan Multi-Institutional Collaborative Cohort Study.

BACKGROUND: Obesity is a reported risk factor for various health problems. Genome-wide association studies (GWASs) have identified numerous independent loci associated with body mass index (BMI). However, most of these have been focused on Europeans, and little evidence is available on the genetic effects across the life course of other ethnicities. METHODS: We conducted a cross-sectional study to examine the associations of 282 GWAS-identified single nucleotide polymorphisms with three BMI-related traits, current BMI, BMI at 20 years old (BMI at 20), and change in BMI (BMI change), among 11,586 Japanese individuals enrolled in the Japan Multi-Institutional Collaborative Cohort study. Associations were examined using multivariable linear regression models. RESULTS: We found a significant association (P < 0.05/282 = 1.77 × 10-4) between BMI and 11 polymorphisms in or near FTO, BDNF, TMEM18, HS6ST3, and BORCS7. The trend was similar between current BMI and BMI change, but differed from that of the BMI at 20. Among the significant variants, those on FTO were associated with all BMI traits, whereas those on TMEM18 and HS6SR3 were only associated with BMI at 20. The association of FTO loci with BMI remained, even after additional adjustment for dietary energy intake. CONCLUSIONS: Previously reported BMI-associated loci discovered in Europeans were also identified in the Japanese population. Additionally, our results suggest that the effects of each loci on BMI may vary across the life course and that this variation may be caused by the differential effects of individual genes on BMI via different pathways.

Association between alcohol intake pattern and metabolic syndrome components and simulated change by alcohol intake reduction: A cross-sectional study from the Japan Multi-Institutional Collaborative Cohort Study.

To investigate the association between alcohol intake pattern in amount and frequency and metabolic syndrome (Mets) components, we simulated the change in the prevalence of Mets components by intake reduction. In order to manage Mets, alcohol intake reduction with moderation of intake pattern is required. However, evidence investigating the comparative impact of alcohol intake reduction in amount and frequency for Mets components is limited. We conducted a large-scale cross-sectional study in the general Japanese population. The study subjects included 37,371 non-drinkers and current drinkers recruited in the Japan Multi-Institutional Collaborative Cohort Study. Odds ratios (ORs) for Mets components according to alcohol intake amount and frequency were estimated using a multiple logistic regression model. The prevalence of Mets components was estimated after assumed alcohol intake reduction of a) none, b) 10 g/day (men) or 5 g/day (women), c) 20 g/day (men) or 10 g/day (women), d) less than 20 g/day (men) or 10 g/day (women) for moderate-to-heavy drinkers, e) 1-2 times/week, and f) 3-4 times/week. The ORs with alcohol intake amount and frequency increased with high blood pressure while decreasing with dyslipidemia. A J-shaped association was observed between intake amount and Mets. The estimated prevalence (%) of high blood pressure and dyslipidemia in men were a) 45.2, b) 43.0, c) 41.4, d) 40.4, e) 42.9, and f) 42.0; and a) 50.3, b) 51.8, c) 52.9, d) 50.2, e) 52.7, and f) 53.4 in women. The estimated prevalence of high blood pressure in women did not evidently decrease. Simulated alcohol intake reduction showed decreased prevalence for high blood pressure and increased prevalence for dyslipidemia in men after reduced intake amount and frequency. The largest decreased prevalence for high blood pressure was observed in men when all moderate-to-heavy drinkers reduced their alcohol intake amount to less than 20 g/day.

Association of Dietary Acid Load with the Prevalence of Metabolic Syndrome among Participants in 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.