BMI and Cardiometabolic Traits in Japanese: A Mendelian Randomization Study.

BACKGROUND: Although many observational studies have demonstrated significant relationships between obesity and cardiometabolic traits, the causality of these relationships in East Asians remains to be elucidated. METHODS: We conducted individual-level Mendelian randomization (MR) analyses targeting 14,083 participants in the Japan Multi-Institutional Collaborative Cohort Study and two-sample MR analyses using summary statistics based on genome-wide association study data from 173,430 Japanese. Using 83 body mass index (BMI)-related loci, genetic risk scores (GRS) for BMI were calculated, and the effects of BMI on cardiometabolic traits were examined for individual-level MR analyses using the two-stage least squares estimator method. The ß-coefficients and standard errors for the per-allele association of each single-nucleotide polymorphism as well as all outcomes, or odds ratios with 95% confidence intervals were calculated in the two-sample MR analyses. RESULTS: In individual-level MR analyses, the GRS of BMI was not significantly associated with any cardiometabolic traits. In two-sample MR analyses, higher BMI was associated with increased risks of higher blood pressure, triglycerides, and uric acid, as well as lower high-density-lipoprotein cholesterol and eGFR. The associations of BMI with type 2 diabetes in two-sample MR analyses were inconsistent using different methods, including the directions. CONCLUSION: The results of this study suggest that, even among the Japanese, an East Asian population with low levels of obesity, higher BMI could be causally associated with the development of a variety of cardiometabolic traits. Causality in those associations should be clarified in future studies with larger populations, especially those of BMI with type 2 diabetes.

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.

Development, implementation, and evaluation of a local community-based ophthalmology sentinel surveillance system in a remote rural area in Japan.

INTRODUCTION: Solid and sensitive infectious disease surveillance systems need to be developed and implemented to prevent and control epidemics. Although statutory national infectious disease surveillance systems have been developed in many countries, some challenges remain, such as their limited timeliness, representativeness, and sensitivity, as well as the fact that they cannot capture all local outbreaks that occur in small communities. To overcome these limitations, local community-based infectious disease surveillance systems that meet local needs and can operate with constrained resources need to be developed, especially in remote and rural low-resource areas. This study aimed to develop, implement, and evaluate a voluntary and unique local community-based ophthalmology sentinel surveillance system in Isa city (OSSS-Isa), a remote rural area in Japan. METHODS: For the development of OSSS-Isa, one hospital in Isa city assumed a leading role and developed a network with all medical institutions - 20 hospitals and clinics in the local community, including two ophthalmology clinics - as sentinel reporting sites. Surveillance was conducted on a weekly basis from Monday to Sunday. The collection, aggregation, and reporting of the surveillance data were implemented promptly on the same day, Monday, using a paper-based form and fax. For the evaluation of OSSS-Isa, the study followed the updated guidelines for evaluating public health surveillance systems proposed by the Centers for Disease Control and Prevention to select the evaluation criteria and develop a questionnaire. The questionnaires were then distributed to 20 hospitals and clinics, with the responses evaluated on a five-point Likert scale. RESULTS: For the implementation of OSSS-Isa, the system issued alerts twice to the networked hospitals and clinics when signs of an increase in the prevalence of a target infectious eye disease appeared in Isa city. After the alerts, the number of cases decreased in the community. Regarding the evaluation survey, physicians from 18 hospitals and clinics responded to the questionnaire (response rate 90%). In contrast to flexibility, more than 75% of the respondents gave high ratings to simplicity, data quality, acceptability, timeliness, and stability in evaluating OSSS-Isa, with the mean score for these evaluation criteria higher than 3.67. CONCLUSION: The present results indicate that OSSS-Isa has high simplicity, data quality, acceptability, timeliness, and stability, which is highly embedded with the local healthcare providers in Isa city. OSSS-Isa contributed to the early and accurate detection of signs of infectious eye disease outbreaks emerging in a small remote rural local community. The success factors seem to include its simple well-designed implementation methods, good external factors, and active human factors suited to the characteristics of the small remote rural community. The OSSS-Isa initiative appears to be a meaningful practical example of successful health advocacy by healthcare providers by developing a system at the local social level while going beyond the boundaries of routine medical practice. If voluntary small-scale surveillance systems can complement statutory large-scale ones and work together locally, nationally, and internationally, it might be possible to detect small, unusual happenings that occur in the community, such as emerging infectious diseases, and thereby help avert global outbreaks.

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.

GWAS of folate metabolism with gene-environment interaction analysis revealed the possible role of lifestyles in the control of blood folate metabolites in Japanese - the J-MICC Study.

BACKGROUND: The present genome-wide association study (GWAS) aimed to reveal the genetic loci associated with folate metabolites as well as to detect related gene-environment interactions in Japanese. METHODS: We conducted the GWAS of plasma homocysteine (Hcy), folic acid (FA), and vitamin B12 (VB12) levels in the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study participants who joined from 2005 to 2012, and also estimated gene-environment interactions. In the replication phase, we used data from the Yakumo Study conducted in 2009. In the discovery phase, data of 2,263 participants from four independent study sites of the J-MICC Study were analyzed. In the replication phase, data of 573 participants from the Yakumo Study were analyzed. RESULTS: For Hcy, MTHFR locus on chr 1, NOX4 on chr 11, CHMP1A on chr 16, and DPEP1 on chr 16 reached genome-wide significance (P < 5×10-8). MTHFR also associated with FA, and FUT2 on chr 19 associated with VB12. We investigated gene-environment interactions in both studies and found significant interactions between MTHFR C677T and ever drinking, current drinking, and physical activity > 33% on Hcy (ß = 0.039, 0.038 and -0.054, P = 0.018, 0.021 and < 0.001, respectively) and the interaction of MTHFR C677T with ever drinking on FA (ß = 0.033, P = 0.048). CONCLUSIONS: The present GWAS revealed the folate metabolism-associated genetic loci and gene-environment interactions with drinking and physical activity in Japanese, suggesting the possibility of future personalized CVD prevention.

Dietary Carbohydrate and Fat Intakes and Risk of Mortality in the Japanese Population: the Japan Multi-Institutional Collaborative Cohort Study.

BACKGROUND: Previous cohort studies have yielded contradictory findings regarding the associations of dietary carbohydrate and fat intakes with risks of mortality. OBJECTIVES: We examined long-term associations of carbohydrate and fat intakes with mortality. METHODS: In this cohort study, 34,893 men and 46,440 women aged 35-69 y (mean body mass index of 23.7 and 22.2 kg/m2, respectively) were followed up from the baseline survey (2004-2014) to the end of 2017 or 2018. Intakes of carbohydrate, fat, and total energy were estimated using a food frequency questionnaire. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated for all-cause and cause-specific mortality according to percentage of energy intakes of carbohydrate and fat. RESULTS: During a mean 8.9-y follow-up, we identified 2783 deaths (1838 men and 945 women). Compared with men who consumed 50% to <55% of energy from carbohydrate, those who consumed <40% carbohydrate energy experienced a significantly higher risk of all-cause mortality (the multivariable-adjusted HR: 1.59; 95% CI: 1.19-2.12; P-trend = 0.002). Among women with 5 y or longer of follow-up, women with high-carbohydrate intake recorded a higher risk of all-cause mortality; the multivariable-adjusted HR (95% CI) was 1.71 (0.93-3.13) for ≥65% of energy from carbohydrate compared with that for 50% to <55% (P-trend = 0.005). Men with high fat intake had a higher risk of cancer-related mortality; the multivariable-adjusted HR (95% CI) for ≥35% was 1.79 (1.11-2.90) compared with that for 20% to <25%. Fat intake was marginally inversely associated with risk of all-cause and cancer-related mortality in women (P-trend = 0.054 and 0.058, respectively). CONCLUSIONS: An unfavorable association with mortality is observed for low-carbohydrate intake in men and for high-carbohydrate intake in women. High fat intake can be associated with a lower mortality risk in women among Japanese adults with a relatively high-carbohydrate intake.

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.

Moderate-to-vigorous Physical Activity and Sedentary Behavior Are Independently Associated With Renal Function: A Cross-sectional Study.

BACKGROUND: Little is known about whether insufficient moderate-to-vigorous physical activity (MVPA) and longer sedentary behavior (SB) are independently associated with estimated glomerular filtration rate (eGFR) and chronic kidney disease (CKD), whether they interact with known risk factors for CKD, and the effect of replacing sedentary time with an equivalent duration of physical activity on kidney function. METHODS: We examined the cross-sectional association of MVPA and SB with eGFR and CKD in 66,603 Japanese cohort study in 14 areas from 2004 to 2013. MVPA and SB were estimated using a self-reported questionnaire, and CKD was defined as eGFR <60 mL/min/1.73 m2. Multiple linear regression analyses, logistic regression analyses, and an isotemporal substitution model were applied. RESULTS: After adjusting for potential confounders, higher MVPA and longer SB were independently associated with higher eGFR (P for trend MVPA <0.0001) and lower eGFR (P for trend SB <0.0001), and a lower odds ratio (OR) of CKD (adjusted OR of MVPA ≥20 MET·h/day, 0.76; 95% confidence interval [CI], 0.68-0.85 compared to MVPA <5 MET·h/day) and a higher OR of CKD (adjusted OR of SB ≥16 h/day, 1.81; 95% CI, 1.52-2.15 compared to SB <7 h/day), respectively. The negative association between MVPA and CKD was stronger in men, and significant interactions between sex and MVPA were detected. Replacing 1 hour of SB with 1 hour of physical activity was associated with about 3 to 4% lower OR of CKD. CONCLUSION: These findings indicate that replacing SB with physical activity may benefit kidney function, especially in men, adding to the possible evidence on CKD prevention.

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.

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.

Irregular sleep and all-cause mortality: A large prospective cohort study.

OBJECTIVES: Previous studies using objective parameters have shown that irregular sleep is associated with the disease incidence, progression, or mortality. This study aimed to determine the association between subjective sleep duration and sleep regularity, with mortality in a large population. METHODS: Participants were from the Japan Multi-Institutional Collaborative Cohort study. We obtained information from each participant on sleep duration, sleep regularity, and demographics and overall lifestyle using self-administered questionnaires. We defined sleep regularity according to participants' subjective assessment of sleep/wake time regularity. Participants (n = 81,382, mean age: 58.1 ± 9.1years, males: 44.2%) were classified into 6 groups according to sleep duration and sleep regularity. Hazard ratios (HR) for time-to-event of death were calculated using the Cox proportional hazards model. RESULTS: The mean follow-up period was 9.1 years and the mean sleep duration was 6.6 h/day. Irregular sleep significantly increased the risk of all-cause mortality in all models compared with regular sleep (HR 1.30, 95% confidence interval; CI, 1.18-1.44), regardless of sleep duration. Multivariable analysis of the 6 groups by sleep pattern (sleep regularity and duration) showed irregular sleep and sleep durations of <6 h/day, 6 to <8 h/day, or ≥8 h/day were associated with a 1.2-1.5-fold increases in mortality, compared to regular sleep and sleep duration of 6 to <8 h/day. CONCLUSIONS: Our study shows an association between sleep irregularity and all-cause mortality in a large Japanese population. Our findings provide further confirmation of the need to consider not only sleep duration, but also the regularity aspect of sleep schedules.

Genetic polymorphism of pleiotrophin is associated with pain experience in Japanese adults: Case-control study.

Genetic factors play a role in individual differences in pain experience. Here, we performed a genome-wide association study (GWAS) to identify novel loci regulating pain processing. We conducted a 2-stage GWAS and the candidate single-nucleotide polymorphisms (SNPs) association study on pain experience using an exploratory cohort of patients with cancer pain. The confirmatory cohort comprised of participants from the general population with and without habitual use of analgesic medication. In the exploratory cohort, we evaluated pain intensity using a numerical rating scale, recorded daily opioid dosages, and calculated pain reduction rate. In the confirmatory cohort, pain experience was defined as habitual nonsteroidal anti-inflammatory drug usage. Using linear regression models, we identified candidate SNP in the exploratory samples, and tested the association between phenotype and experienced pain in the confirmatory samples. We found 1 novel SNP (rs11764598)-located on the gene encoding for pleiotrophin on chromosome 7-that passed the genome-wide suggestive significance at 20% false discovery rate (FDR) correction in the exploratory samples of patients with cancer pain (P = 1.31 × 10-7, FDR = 0.101). We confirmed its significant association with daily analgesic usage in the confirmatory cohort (P = .028), although the minor allele affected pain experience in an opposite manner. We identified a novel genetic variant associated with pain experience. Further studies are required to validate the role of pleiotrophin in pain processing.

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.

Application of objective structured clinical examination (OSCE) for the evaluation of Kampo medicine training.

BACKGROUND: The purpose of this study was to develop an objective, content-valid, and reliable assessment method for Kampo medicine using an objective structured clinical examination (OSCE) for the assessment of clinical competence in Kampo medicine. METHODS: We developed a blueprint followed by a list of 47 assessment items and three task scenarios related to clinical competence in Kampo medicine. An eight-member test committee checked the relevance of the assessment items on a Likert scale. We calculated a content validity index and content validity ratio, and used the Angoff method to set the passing threshold. We trained a total of nine simulated patients with three assigned to each scenario. We conducted an OSCE for 11 candidates with varying medical abilities, and conducted three stations per person, which were evaluated by one evaluator in one room by direct observation. We used video recordings to test the inter-rater reliability of the three raters. We used the test results to verify the reliability of the assessment chart. RESULTS: The inter-rater reliability (intraclass correlation coefficient [2,1]) was 0.973. The reliability of the assessment chart for each scenario (Cronbach's α) was 0.86, 0.89, and 0.85 for Scenarios 1, 2, and 3, respectively. The reliability of the assessment chart for the whole OSCE (Cronbach's α) was 0.90. CONCLUSIONS: We developed a content-valid new OSCE assessment method for Kampo medicine and obtained high inter-rater and test reliabilities. Our findings suggest that this is one of the most reliable evaluation methods for assessing clinical competence in Kampo medicine.

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.

Effect of the interaction between physical activity and estimated macronutrient intake on HbA1c: population-based cross-sectional and longitudinal studies.

INTRODUCTION: Healthy diet and physical activity (PA) are essential for preventing type 2 diabetes, particularly, a combination of diet and PA. However, reports on interaction between PA and diet, especially from large epidemiological studies, are limited. We investigated the effect of interaction between PA and macronutrient intake on hemoglobin A1c (HbA1c) levels in the general population. RESEARCH DESIGN AND METHODS: We conducted a cross-sectional study of 55 469 men and women without diabetes who participated in the baseline survey of the Japan Multi-Institutional Collaborative Cohort Study. A self-administered questionnaire ascertained PA and macronutrient intake (carbohydrate, fat, and protein). Multiple linear regression analyses were performed to adjust for confounding variables and examine the interactions. In addition, we conducted a longitudinal study during a 5-year period within a subcohort (n=6881) with accelerometer-assessed PA data. RESULTS: Overall, PA had a weak inverse association (ß=-0.00033, p=0.049) and carbohydrate intake had a strong positive association (ß=0.00393, p<0.001) with HbA1c. We observed a tendency of interactions between PA and carbohydrate or fat intake, but not protein intake, on HbA1c levels after adjusting for age, sex, study area, total energy intake, alcohol consumption, smoking, and medication for hypertension or hypercholesterolemia (Pinteraction=0.054, 0.006, and 0.156, respectively). The inverse associations between PA and HbA1c level were more evident in participants with high-carbohydrate (or low-fat) intake than in participants with low-carbohydrate (or high-fat) intake. Although further adjustment for body mass index slightly attenuated the above interactions (Pinteraction=0.098 for carbohydrate and 0.068 for fat), the associations between PA and HbA1c level in stratified analyses remained unchanged. Similar associations and interactions were reproduced in the longitudinal study. CONCLUSIONS: The present results suggest that the effect of PA on HbA1c levels is modified by intake of macronutrient composition.

Assessing the Relationship Between High-sensitivity C-reactive Protein and Kidney Function Employing Mendelian Randomization in the Japanese Community-based J-MICC Study.

BACKGROUND: Inflammation is thought to be a risk factor for kidney disease. However, whether inflammatory status is either a cause or an outcome of chronic kidney disease remains controversial. We aimed to investigate the causal relationship between high-sensitivity C-reactive protein (hs-CRP) and estimated glomerular filtration rate (eGFR) using Mendelian randomization (MR) approaches. METHODS: A total of 10,521 participants of the Japan Multi-institutional Collaborative Cohort Study was analyzed in this study. We used two-sample MR approaches (the inverse-variance weighted (IVW), the weighted median (WM), and the MR-Egger method) to estimate the effect of genetically determined hs-CRP on kidney function. We selected four and three hs-CRP associated single nucleotide polymorphisms (SNPs) as two instrumental variables (IV): IVCRP and IVAsian, based on SNPs previously identified in European and Asian populations. IVCRP and IVAsian explained 3.4% and 3.9% of the variation in hs-CRP, respectively. RESULTS: Using the IVCRP, genetically determined hs-CRP was not significantly associated with eGFR in the IVW and the WM methods (estimate per 1 unit increase in ln(hs-CRP), 0.000; 95% confidence interval [CI], -0.019 to 0.020 and -0.003; 95% CI, -0.019 to 0.014, respectively). For IVAsian, we found similar results using the IVW and the WM methods (estimate, 0.005; 95% CI, -0.020 to 0.010 and -0.004; 95% CI, -0.020 to 0.012, respectively). The MR-Egger method also showed no causal relationships between hs-CRP and eGFR (IVCRP: -0.008; 95% CI, -0.058 to 0.042; IVAsian: 0.001; 95% CI, -0.036 to 0.036). CONCLUSION: Our two-sample MR analyses with different IVs did not support a causal effect of hs-CRP on eGFR.

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

Recent genome-wide association studies (GWAS) on the dietary habits of the Japanese population have shown that an effect rs671 allele was inversely associated with fish consumption, whereas it was directly associated with coffee consumption. Although meat is a major source of protein and fat in the diet, whether genetic factors that influence meat-eating habits in healthy populations are unknown. This study aimed to conduct a GWAS to find genetic variations that affect meat consumption in a Japanese population. We analysed GWAS data using 14 076 participants from the Japan Multi-Institutional Collaborative Cohort (J-MICC) study. We used a semi-quantitative food frequency questionnaire to estimate food intake that was validated previously. Association of the imputed variants with total meat consumption per 1000 kcal energy was performed by linear regression analysis with adjustments for age, sex, and principal component analysis components 1-10. We found that no genetic variant, including rs671, was associated with meat consumption. The previously reported single nucleotide polymorphisms that were associated with meat consumption in samples of European ancestry could not be replicated in our J-MICC data. In conclusion, significant genetic factors that affect meat consumption were not observed in a Japanese population.

A Proposal for Practical Diagnosis of Renal Hypouricemia: Evidenced from Genetic Studies of Nonfunctional Variants of URAT1/SLC22A12 among 30,685 Japanese Individuals.

BACKGROUND: Renal hypouricemia (RHUC) is characterized by a low serum uric acid (SUA) level and high fractional excretion of uric acid (FEUA). Further studies on FEUA in hypouricemic individuals are needed for a more accurate diagnosis of RHUC. METHODS: In 30,685 Japanese health-examination participants, we genotyped the two most common nonfunctional variants of URAT1 (NFV-URAT1), W258X (rs121907892) and R90H (rs121907896), in 1040 hypouricemic individuals (SUA ≤ 3.0 mg/dL) and 2240 individuals with FEUA data. The effects of NFV-URAT1 on FEUA and SUA were also investigated using linear and multiple regression analyses. RESULTS: Frequency of hypouricemic individuals (SUA ≤ 3.0 mg/dL) was 0.97% (male) and 6.94% (female) among 30,685 participants. High frequencies of those having at least one allele of NFV-URAT1 were observed in 1040 hypouricemic individuals. Furthermore, NFV-URAT1 significantly increased FEUA and decreased SUA, enabling FEUA and SUA levels to be estimated. Conversely, FEUA and SUA data of hypouricemic individuals are revealed to be useful to predict the number of NFV-URAT1. CONCLUSIONS: Our findings reveal that specific patterns of FEUA and SUA data assist with predicting the number of nonfunctional variants of causative genes for RHUC, and can also be useful for practical diagnosis of RHUC even before genetic tests.