Polygenic risk score for blood pressure and lifestyle factors with overall and CVD mortality: a prospective cohort study in a Japanese population.

Although previous polygenic risk score (PRS) studies for cardiovascular disease (CVD) focused on incidence, few studies addressed CVD mortality and quantified risks by environmental exposures in different genetic liability groups. This prospective study aimed to examine the associations of blood pressure PRS with all-cause and CVD mortality and to quantify the attributable risk by modifiable lifestyles across different PRS strata. 9,296 participants in the Japan Multi-Institutional Collaborative Cohort Study without hypertension at baseline were analyzed in this analysis. PRS for systolic blood pressure and diastolic blood pressure (PRSSBP and PRSDBP) were developed using publicly available Biobank Japan GWAS summary statistics. CVD-related mortality was defined by the International Classification of Diseases 10th version (I00-I99). Cox-proportional hazard model was used to examine associations of PRSs and lifestyle variables (smoking, drinking, and dietary sodium intake) with mortality. During a median 12.6-year follow-up period, we observed 273 all-cause and 41 CVD mortality cases. Compared to the middle PRS group (20-80th percentile), adjusted hazard ratios for CVD mortality at the top PRS group ( > 90th percentile) were 3.67 for PRSSBP and 2.92 for PRSDBP. Attributable risks of CVD mortality by modifiable lifestyles were higher in the high PRS group ( > 80th percentile) compared with the low PRS group (0-80th percentile). In summary, blood pressure PRS is associated with CVD mortality in the general Japanese population. Our study implies that integrating PRS with lifestyle could contribute to identify target populations for lifestyle intervention even though improvement of discriminatory ability by PRS alone is limited.

Risk Factors for Heart Failure and Coronary Artery Disease Mortality Based on the National Vital Statistics During a 25-Year Follow-up in Japan　- NIPPON DATA90.

BACKGROUND: Prevention of heart failure (HF) is a public health issue. Using the National Vital Statistics, we explored risk factors for HF and coronary artery disease (CAD) mortality. METHODS AND RESULTS: Altogether, 7,556 Japanese individuals aged ≥30 years in 1990 were followed over 25 years; of these, 139 and 154 died from HF and CAD, respectively. In multivariable Cox proportional hazard analysis, common risk factors for CAD and HF mortality were hypertension (hazard ratio [HR] 1.48 [95% confidence interval {CI} 1.00-2.20] and 2.31 [95% CI 1.48-3.61], respectively), diabetes (HR 2.52 [95% CI 1.63-3.90] and 2.07 [95% CI 1.23-3.50], respectively), and current smoking (HR 2.05 [95% CI 1.27-3.31) and 1.86 [95% CI 1.10-3.15], respectively). Specific risk factors for CAD were male sex, chronic kidney disease, history of cardiovascular disease, and both abnormal T and Q waves, with HRs (95% CIs) of 1.75 (1.05-2.92), 1.78 (1.19-2.66), 2.50 (1.62-3.88), and 11.4 (3.64-36.0), respectively. Specific factors for HF were current drinking (HR 0.43; 95% CI 0.24-0.78) and non-high-density lipoprotein cholesterol (non-HDL-C; HR 0.81; 95% CI 0.67-0.98). There was an inverse association between non-HDL-C and HF in those aged ≥65 years (HR 0.71; 95% CI 0.56-0.90), but not in those aged <65 years. CONCLUSIONS: We identified common risk factors for HF and CAD deaths; a history of cardiovascular disease was a specific risk for CAD.

Inter-prefectural and urban-rural regional disparities in lung cancer surgery: a Japanese nationwide population-based cohort study from 2017 to 2019.

PURPOSE: To investigate regional disparities in lung cancer surgery in Japan. METHODS: The annual incidence of lung cancer, lung cancer surgery, and the number of board-certified thoracic surgeons in Japan during 2014-2019 were investigated using a national open database. Lung cancer surgeries were categorized by procedure (wedge resection, segmentectomy, lobectomy, pneumonectomy) and approach (open, thoracoscopic). Disparities in 47 prefectures and urban-rural disparities during 2017-2019 were evaluated using the Gini coefficient and an unpaired t-test. Correlation was assessed using Pearson's correlation method. RESULTS: The national annual average incidences of lung cancer and lung cancer surgery were 121,106 and 50,959, respectively, in 2014-2019. The use of the thoracoscopic approach increased over time in all procedures, except pneumonectomies. The Gini coefficients of lung cancer, thoracoscopic surgery, and board-certified thoracic surgeons indicated low inequality across prefectures; however, those of open surgery indicated high inequality. Open surgery was more common in urban areas than in rural areas. The number of thoracoscopic surgeries and board-certified thoracic surgeons by prefecture were moderately correlated. CONCLUSION: The thoracoscopic approach is becoming more common in lung cancer surgery, with little inter-prefectural regional disparity in the incidence of lung cancer, thoracoscopic surgeries, or the number of board-certified thoracic surgeons.

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.

Seven-plus hours of daily sedentary time and the subsequent risk of breast cancer: Japan Multi-Institutional Collaborative Cohort Study.

This study aimed to investigate the association between daily sedentary time and the risk of breast cancer (BC) in a large Japanese population. The participants were 36,023 women aged 35-69 years from the Japan Multi-Institutional Collaborative Cohort Study. Cox proportional hazards analysis was used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for BC incidence in relation to time spent sedentarily (categorical variables: <7 and ≥7 hours/day [h/d]). Additionally, the associations of BC incidence to the joint effect of sedentary time with each component of physical activity, such as leisure-time metabolic equivalents (METs), frequency of leisure-time physical activity, and daily walking time, were examined. During 315,189 person-years of follow-up, 554 incident cases of BC were identified. When compared to participants who spent <7 h/d sedentary, those who spent ≥7 h/d sedentary have a significantly higher risk of BC (HR, 1.36; 95% CI, 1.07-1.71). The corresponding HRs among participants who spent ≥7 h/d sedentary with more physical activity, such as ≥1 h/d for leisure-time METs, ≥3 days/week of leisure-time physical activity, and ≥1 h/d of daily walking were 1.58 (95% CI, 1.11-2.25), 1.77 (95% CI, 1.20-2.61), and 1.42 (95% CI, 1.10-1.83), respectively, compared with those who spent <7 h/d sedentary. This study found that spending ≥7 h/d of sedentary time is associated with the risk of BC. Neither leisure-time physical activity nor walking had a BC-preventive effect in those with ≥7 h/d of sedentary time.

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.

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.

Epidemiology of Acute Aortic Dissection in a General Population of 1.4 Million People in Japan　- Shiga Stroke and Heart Attack Registry.

BACKGROUND: Acute aortic dissection (AAD) is a life-threatening cardiovascular disease, with a reported incidence rate ranging from 2.5 to 7.2 per 100,000 person-years in several population-based registries in Western countries, but epidemiological data are lacking in Japan.Methods and Results: The Shiga Stroke and Heart Attack Registry is an ongoing multicenter population-based registry of cerebro-cardiovascular diseases. We enrolled patients who developed AAD, defined by any imaging examination method from 2014 to 2015 in Shiga Prefecture. Death certificates were used to identify cases that were not registered at acute care hospitals. The incidence rates of AAD were calculated by age categories and adjusted using standard populations for comparison. We evaluated differences in patient characteristics between Stanford type A-AAD and type B-AAD subtypes. A total of 402 incident cases with AAD were analyzed. The age-adjusted incidence rates using the 2015 Japanese population and the 2013 European Standard Population were 15.8 and 12.2 per 100,000 person-years, respectively. Compared with cases of type B-AAD, those with type A-AAD were older (75.0 vs. 69.9 years, P=0.001) and more likely to be women (62.3% vs. 28.6%, P<0.001). CONCLUSIONS: Population-based incidence rates of AAD in Japan appear to be higher than in previous reports from Western countries. Incident cases with type A-AAD were older and female predominance.

Comparison of the loci associated with HbA1c and blood glucose levels identified by a genome-wide association study in the Japanese population.

Aims: Hemoglobin A1c (HbA1c) levels are widely employed to diagnose diabetes. However, estimates of the heritability of HbA1c and glucose levels are different. Therefore, we explored HbA1c- and blood glucose-associated loci in a non-diabetic Japanese population. Methods: We conducted a two-stage genome-wide association study (GWAS) on variants associated with HbA1c and blood glucose levels in a Japanese population. In the initial stage, data of 4911 participants of the Japan Multi-Institutional Collaborative Cohort (J-MICC) were subjected to discovery analysis. In the second stage, two datasets from the Tohoku Medical Megabank project, with 8175 and 40,519 participants, were used for the replication study. Association of the imputed variants with HbA1c and blood glucose levels was determined via linear regression analyses adjusted for age, sex, body mass index (BMI), smoking, and genetic principal components (PC1-PC10). Moreover, we performed a BMI-stratified GWAS on HbA1c levels in the J-MICC. The discovery analysis and BMI-stratified GWAS results were validated with re-analyses of normalized HbA1c levels adjusted for site in addition to the above, and blood glucose adjusted for fasting time as an additional covariate. Results: Genetic variants associated with HbA1c levels were identified in KCNQ1 and TMC6. None of the genetic variants associated with blood glucose levels in the discovery analysis were replicated. Association of rs2299620 in KCNQ1 with HbA1c levels showed heterogeneity between individuals with BMI ≥ 25 kg/m2 and BMI < 25 kg/m2. Conclusions: The variant rs2299620 in KCNQ1 might affect HbA1c levels differentially based on BMI grouping in the Japanese population. Supplementary Information: The online version contains supplementary material available at 10.1007/s13340-023-00618-0.