GWAS meta-analysis of kidney function traits in Japanese populations

BACKGROUND

Genetic epidemiological evidence for the kidney function traits in East Asian population including Japanese remain still relatively unclarified. Especially, the number of GWASs for kidney traits reported still remains limited, and the sample size of each independent study is relatively small. Given the genetic variability between ancestries/ethnicities, implementation of GWAS with sufficiently large sample sizes in specific population of Japanese is considered meaningful.

METHODS

We conducted the GWAS meta-analyses of kidney traits by leveraging the GWAS summary data of the representative large genome cohort studies with about 200,000 Japanese participants (n = 202,406 for estimated glomerular filtration rate [eGFR] and n = 200,845 for serum creatinine [SCr]).

RESULTS

In the present GWAS meta-analysis, we identified 110 loci with 169 variants significantly associated with eGFR (on chromosomes 1-13 and 15-22; p < 5×10-8), whereas we also identified 112 loci with 176 variants significantly associated with SCr (on chromosomes 1-22; p < 5×10-8), of which one locus (more than 1Mb distant from known loci) with one variant (CD36 rs146148222 on chromosome 7) for SCr was considered as the truly novel finding.

CONCLUSIONS

The present GWAS meta-analysis of largest genome cohort studies in Japanese provided some original genomic loci associated with kidney function in Japanese, which may contribute to the possible development of personalized prevention of kidney diseases based on genomic information in the near future.

The Inverse Association between the Frequency of Forest Walking (Shinrin-yoku) and the Prevalence of Insomnia Symptoms in the General Japanese Population: A Japan Multi-Institutional Collaborative Cohort Daiko Study

Since a single forest walk (Shinrin-yoku or forest bathing) session is reported to improve sleep temporarily, occasional forest walks may have a positive effect on daily sleep. Therefore, this study aimed to examine whether more frequent forest walking is associated with better daily sleep conditions. Data from the second survey of the Japan Multi-Institutional Collaborative Cohort (J-MICC) Daiko Study conducted among residents of Nagoya City, Japan, were used. The study design was a cross-sectional study. In total, 2044 participants (529 men and 1515 women; age, mean ± standard deviation: 58.8 ± 9.9 years) were included in the analysis. Frequent forest walks were associated with a low percentage of insomnia symptoms (Insomnia Severity Index ≥10) in women, but not in men. The adjusted odds ratio for the group that rarely took forest walks with reference to the group that engaged in the activity once a month or more often was 2.04 (95% confidence interval: 1.29-3.23) in women. Forest walk frequency was not significantly associated with sleep duration or sleep efficiency as measured by actigraphy in either men or women. In conclusion, the results suggested that increasing the frequency of forest walks or Shinrin-yoku may be effective in preventing insomnia in women.

Evaluation of the usefulness of plasma 4β-hydroxycholesterol concentration normalized by 4α-hydroxycholesterol for accurate CYP3A phenotyping

Plasma 4β-hydroxycholesterol (OHC) has drawn attention as an endogenous substrate indicating CYP3A activity. Plasma 4β-OHC is produced by hydroxylation by CYP3A4 and CYP3A5 and by cholesterol autoxidation. Plasma 4α-OHC is produced by cholesterol autoxidation and not affected by CYP3A activity. This study aimed to evaluate the usefulness of plasma 4β-OHC concentration minus plasma 4α-OHC concentration (4β-OHC-4α-OHC) compared with plasma 4β-OHC concentration and 4β-OHC/total cholesterol (TC) ratio in cross-sectional evaluation of CYP3A activity. Four hundred sixteen general adults were divided into 191 CYP3A5*1 carriers and 225 non-carriers. Twenty-six patients with chronic kidney disease (CKD) with CYP3A5*1 allele were divided into 14 with CKD stage 3 and 12 with stage 4-5D. Area under the receiver operating characteristic curve (AUC) for the three indices were evaluated for predicting presence or absence of CYP3A5*1 allele in general adults, and for predicting CKD stage 3 or stage 4-5D in patients with CKD. There was no significant difference between AUC of 4β-OHC-4α-OHC and AUC of plasma 4β-OHC concentration in general adults and in patients with CKD. AUC of 4β-OHC-4α-OHC was significantly smaller than that of 4β-OHC/TC ratio in general adults (p = 0.025), but the two indices did not differ in patients with CKD. In conclusion, in the present cross-sectional evaluation of CYP3A activity in general adults and in patients with CKD with CYP3A5*1 allele, the usefulness of 4β-OHC-4α-OHC was not different from plasma 4β-OHC concentration or 4β-OHC/TC ratio. However, because of the limitations in study design and subject selection of this research, these findings require verification in further studies.

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 β-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.

Dual decline in subjective gait speed and domain-specific cognition is associated with higher risk of incident dementia in older Japanese adults: A 15-year age-specific cohort study

OBJECTIVES

Dual decline in gait speed and cognition has been found to have higher dementia risk than no decline or pure decline. However, evidence from the Asian population is lacking. Therefore, we aimed to investigate the association of dual decline from age 65 to 70 years with late-life dementia in older Japanese adults with different personal characteristics.

METHODS

Data were collected from an age-specific cohort study conducted in 482 Japanese 65-year-old adults. We investigated participant demographics, medical histories, lifestyles, subjective gait speed, and cognition at both 64/65 and 70/71 years old, and confirmed dementia until age of 85 years. Cox proportion hazard models were used to estimate the risk of dementia, with adjustments for covariates, and death was treated as a competing risk.

RESULTS

After a mean follow-up period of 12.5-years, 111 participants developed dementia. Older adults with dual decline are more likely to have hyperlipidemia, diabetes, and smoking habits. And we found that dual decline in gait speed and domain-specific cognition was associated with a higher risk of dementia compared with no decline in most cognitive tests, with the highest risk observed for gait speed combined with memory (sub-distribution hazard ratio:3.89, 95 %, confidence intervals: [1.68-9.01]). However, significant differences only existed in men after stratification by sex.

CONCLUSIONS

A dual decline in subjective gait speed and cognition may serve as a robust predictor of dementia over a decade prior to its onset, particularly in men. These findings highlighted the importance of screening for dual decline at an early age.

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.

Genetic architecture of alcohol consumption identified by a genotype-stratified GWAS and impact on esophageal cancer risk in Japanese people

An East Asian-specific variant on aldehyde dehydrogenase 2 (ALDH2 rs671, G>A) is the major genetic determinant of alcohol consumption. We performed an rs671 genotype-stratified genome-wide association study meta-analysis of alcohol consumption in 175,672 Japanese individuals to explore gene-gene interactions with rs671 behind drinking behavior. The analysis identified three genome-wide significant loci (GCKR, KLB, and ADH1B) in wild-type homozygotes and six (GCKR, ADH1B, ALDH1B1, ALDH1A1, ALDH2, and GOT2) in heterozygotes, with five showing genome-wide significant interaction with rs671. Genetic correlation analyses revealed ancestry-specific genetic architecture in heterozygotes. Of the discovered loci, four (GCKR, ADH1B, ALDH1A1, and ALDH2) were suggested to interact with rs671 in the risk of esophageal cancer, a representative alcohol-related disease. Our results identify the genotype-specific genetic architecture of alcohol consumption and reveal its potential impact on alcohol-related disease risk.

Five-year changes of social activity and incident long-term care needs among depressed older adults: A 15-year follow up

OBJECTIVES

To examine the effects of changes in individual/multiple social activities between 65 and 70 years of age on incident long-term care (LTC) needs between 70 and 80 in older adults with depressive symptoms.

METHODS

Participants were recruited from the New Integrated Suburban Seniority Investigation Project, an ongoing prospective cohort study. A total of 525 older adults with depressive symptoms were included. The validated 15-item Geriatric Depression Scale was used to assess depressive symptoms. A self-report questionnaire was used to measure social activities (social-related, learning, and personal). LTC needs was defined according to Japan's Long-term Care Insurance System. A competing risk model and a Laplace regression model were used to estimate the hazard ratios of LTC needs incidence and the 25th percentile difference in LTC-needs-free survival time and their 95% confidence intervals.

RESULTS

Out of 4314 person-years of mild LTC needs, 108 individuals developed it. Participants who increased their frequency of learning activities have a lower risk of developing mild LTC needs. Increasing the frequency could also prolong LTC-needs-free survival time by approximately 2.61 years. Out of 4535 person-years for severe LTC needs, 54 individuals developed it. Participants with a continuous regular frequency of learning activities had a lower risk of developing severe LTC needs. However, the association between this frequency and LTC-needs-free survival time for severe LTC needs was insignificant in the multivariable models.

CONCLUSIONS

Increased frequency of learning activities reduced the risk of LTC needs among older adults with depressive symptoms and prolonged their LTC-needs-free survival time.

Association of serum superoxide dismutase activity and the incidence of colorectal cancer in a nested case-control study

BACKGROUND

Superoxide dismutase (SOD) is an antioxidant enzyme that degrades superoxide, a major causative factor in carcinogenesis. We assessed associations between serum SOD activities and incidence of colorectal carcinoma (CRC) in a case-control study nested in the Japan Collaborative Cohort (JACC) study.

METHODS

At baseline, 39,242 subjects donated serum samples. Participants diagnosed with CRC during follow-up were regarded as cases. Odds ratios (ORs) for CRC incidence associated with SOD were evaluated with conditional logistic regression models. In the current study, 176 cases and 524 controls were analyzed.

RESULTS

For the overall cohort, a decreasing trend in risk of CRC with increasing SOD was observed (P for trend=0.054) and the fourth quartile of SOD level showed the lowest risk compared to the first (OR=0.52, 95% confidence interval [CI]=0.29-0.93). This was significant in men (P for trend=0.001), with the fourth quartile of SOD level showing the lowest risk compared to the first (OR, 0.23; 95%CI, 0.09-0.60). It was also exclusively observed for rectal cancer and left-sided CRC (P for trend, 0.037 and 0.020, respectively), with the fourth quartile again showing the lowest risk compared to the first (OR, 0.28 and 0.38; 95%CI, 0.09-0.84 and 0.16-0.91, respectively). Limiting subjects to those followed-up over 2 years, all trends remained unchanged.

CONCLUSIONS

Our findings suggest that serum SOD activity correlates inversely with risk of CRC, particularly in men and individuals with rectal cancer/left-sided CRC.

Association between total fat and fatty acid intake and the risk of type 2 diabetes mellitus among Japanese adults: Analysis based on the JACC study

BACKGROUND

We prospectively examined the association between total fat and fatty acid intake and type 2 diabetes (T2D) among Japanese adults.

METHODS

This study was conducted using data from the Japan Collaborative Cohort Study for Evaluation of Cancer Risk (JACC). A validated food frequency questionnaire evaluated the intake of total fat and fatty acids. Diabetes was assessed using self-reported data. Multivariable logistic regression analysis was performed to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) of incident T2D across quintiles of total fat and fatty acid intake after adjusting for potential confounders.

RESULTS

A total of 19,088 non-diabetic participants (age range, 40-79 years) enrolled in the JACC between 1988 and 1990 were included in this study. During the five-year study period, 494 the participants developed T2D. The OR of T2D for the highest versus lowest quintiles was 0.58 (95% CI, 0.37-0.90) for total fat, 0.78 (95% CI, 0.51-1.20) for saturated fatty acid (SFA), 0.55 (95% CI, 0.35-0.86) for monounsaturated fatty acids (MUFA), 0.61 (95% CI, 0.39-0.96) for polyunsaturated fatty acids (PUFA), 0.64 (95% CI, 0.42-0.99) for n-3 PUFA, and 0.70 (95% CI, 0.45-1.09) for n-6 PUFA. Total fat and fatty acid (except SFA and n-6 PUFA) intake were inversely associated with T2D in men. Total fat and fatty acid intake were not associated with T2D in women.

CONCLUSION

Higher intakes of total fats, MUFA, PUFA, and n-3 PUFA were inversely associated with T2D among Japanese men.

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.

Effects of oral health-related quality of life on total mortality: a prospective cohort study

BACKGROUND

The effects of oral health on mortality have been reported; however, the association between mortality and Oral Health-Related Quality of Life (OHQOL) is unknown. We investigated the effect of OHQOL on total mortality in a cohort consisting of dentists.

METHODS

In this cohort study, we analyzed data from the Longitudinal Evaluation of Multi-phasic, Odonatological and Nutritional Associations in Dentists study. We conducted a baseline survey of general and oral health factors. We called for 31,178 participants and collected responses from 10,256 participants. We followed up with 10,114 participants (mean age ± standard deviation, 52.4 ± 12.1 years; females, 8.9%) for 7.7 years, until March 2014, to determine the average total mortality. OHQOL was assessed using the General Oral Health Assessment Index (GOHAI). The total score was divided into quartiles (Q1 ≤ 51.6, Q2 = 51.7-56.7, Q3 = 56.8-59.9, and Q4 = 60.0), with higher GOHAI scores indicating better OHQOL (score range, 12-60). The association between OHQOL and total mortality was analyzed using the Cox proportional hazards model.

RESULTS

We documented 460 deaths. Males with low GOHAI scores possessed a remarkably high risk of total mortality. The multivariate adjusted-hazard ratios (aHRs), were 1.93 (95% confidence interval [CI], 1.07 - 3.48) for Q1, 1.69 (95% CI, 0.90 - 3.17) for Q2, and 0.65 (95% CI, 0.29 - 1.46) for Q3, relative to Q4 (trend p = 0.001). The aHRs in the multivariate model with all background variables were 1.69 (95% CI, 1.15-2.46) for Q1, 1.53 (95% CI, 1.04-2.27) for Q2, and 1.09 (95% CI, 0.71-1.70) for Q3, relative to Q4 (trend p = 0.001). In females, there was no significant association between the quartiles, in both the multivariate-adjusted model (trend p = 0.52) and multivariate-adjusted model with all background variables (trend p = 0.79).

CONCLUSIONS

A lower OHQOL indicated an increased risk of total mortality in dentists. OHQOL may be used as an indicator for selecting treatment plans and personalized care interventions, thus contributing to increased healthy life expectancy.

TRIAL REGISTRATION

Aichi Cancer Center, Nagoya University Graduate School of Medicine, and Hiroshima University (Approval numbers: 33, 632-3, 8-21, and E2019-1603).

Association between Dietary Patterns and Serum Low Density Lipoprotein Cholesterol in Japanese Women and Men: The Japan Multi-Institutional Collaborative Cohort (J-MICC) Study

AIMS

The association between dietary patterns and serum low density lipoprotein (LDL) cholesterol would be changing in recent dietary habits in Japan. We investigated the relationship between dietary patterns and serum LDL cholesterol in a large general population.

METHODS

From the baseline survey of Japan Multi-Institutional Collaborative Cohort Study between 2005 and 2013, 27,237 participants (13,994 were women) aged 35-69 years were cross-sectionally analyzed. Using a semi-quantitative food frequency questionnaire, five major sex-specific dietary patterns were identified using factor analysis. We assessed serum LDL cholesterol by quintiles of dietary pattern factor score.

RESULTS

We identified dietary patterns; "vegetable rich pattern" , "meat and fried food rich pattern" and "high bread and low rice pattern" in women and men; "fish and shellfish rich pattern" and "high confectioneries and low alcohol pattern" in men; "healthy Japanese diet pattern" and "high alcohol and low rice pattern" in women. Serum LDL cholesterol in men was associated with "high bread and low rice pattern" score (Q5 was 4.2 mg/dL higher than Q1, p for trend ＜0.001) and "high confectioneries and low alcohol pattern" scores (Q5 was 9.5 mg/dL higher than Q1, p for trend ＜0.001). In women, serum LDL cholesterol was associated with "high bread and low rice pattern" score (Q5 was 7.1 mg/dL higher than Q1, p for trend ＜0.001).

CONCLUSION

Some recent dietary patterns in Japan were associated with serum LDL cholesterol. Serum LDL cholesterol was associated with high bread and low rice pattern in both sex, and high confectioneries and low alcohol pattern in men.

Multi-ancestry genome-wide analysis identifies shared genetic effects and common genetic variants for self-reported sleep duration

Both short (≤6 h per night) and long sleep duration (≥9 h per night) are associated with increased risk of chronic diseases. Despite evidence linking habitual sleep duration and risk of disease, the genetic determinants of sleep duration in the general population are poorly understood, especially outside of European (EUR) populations. Here, we report that a polygenic score of 78 European ancestry sleep duration single-nucleotide polymorphisms (SNPs) is associated with sleep duration in an African (n = 7288; P = 0.003), an East Asian (n = 13 618; P = 6 × 10-4) and a South Asian (n = 7485; P = 0.025) genetic ancestry cohort, but not in a Hispanic/Latino cohort (n = 8726; P = 0.71). Furthermore, in a pan-ancestry (N = 483 235) meta-analysis of genome-wide association studies (GWAS) for habitual sleep duration, 73 loci are associated with genome-wide statistical significance. Follow-up of five loci (near HACD2, COG5, PRR12, SH3RF1 and KCNQ5) identified expression-quantitative trait loci for PRR12 and COG5 in brain tissues and pleiotropic associations with cardiovascular and neuropsychiatric traits. Overall, our results suggest that the genetic basis of sleep duration is at least partially shared across diverse ancestry groups.

Integration of methylation quantitative trait loci (mQTL) on dietary intake on DNA methylation levels: an example of n-3 PUFA and ABCA1 gene

BACKGROUND

Epigenetic studies have reported relationships between dietary nutrient intake and methylation levels. However, genetic variants that may affect DNA methylation (DNAm) pattern, called methylation quantitative loci (mQTL), are usually overlooked in these analyses. We investigated whether mQTL change the relationship between dietary nutrient intake and leukocyte DNAm levels with an example of estimated fatty acid intake and ATP-binding cassette transporter A1 (ABCA1).

METHODS

A cross-sectional study on 231 participants (108 men, mean age: 62.7 y) without clinical history of cancer and no prescriptions for dyslipidemia. We measured leukocyte DNAm levels of 8 CpG sites within ABCA1 gene by pyrosequencing method and used mean methylation levels for statistical analysis. TaqMan assay was used for genotyping a genetic variant of ABCA1 (rs1800976). Dietary fatty acid intake was estimated with a validated food frequency questionnaire and adjusted for total energy intake by using residual methods.

RESULTS

Mean ABCA1 DNAm levels were 5% lower with the number of minor alleles in rs1800976 (CC, 40.6%; CG, 35.9%; GG, 30.6%). Higher dietary n-3 PUFA intake was associated with lower ABCA1 DNAm levels (1st (ref) vs. 4th, β [95% CI]: -2.52 [-4.77, -0.28]). After controlling for rs180076, the association between dietary n-3 PUFA intake and ABCA1 DNAm levels was attenuated, but still showed an independent association (1st (ref) vs. 4th, β [95% CI]: -2.00 [-3.84, -0.18]). The interaction of mQTL and dietary n-3 PUFA intake on DNAm levels was not significant.

CONCLUSIONS

This result suggested that dietary n-3 PUFA intake would be an independent predictor of DNAm levels in ABCA1 gene after adjusting for individual genetic background. Considering mQTL need to broaden into other genes and nutrients for deeper understanding of DNA methylation, which can contribute to personalized nutritional intervention.

Elevated arsenic level in fasting serum via ingestion of fish meat increased the risk of hypertension in humans and mice

Aims

There has been a shortage of human studies to elucidate the association between serum arsenic levels and the prevalence of hypertension. This study multidirectionally investigated associations among arsenic exposure, dietary ingestion, and the risk of hypertension by combined human epidemiological and mouse experimental studies.

Methods and results

This study focused on the total arsenic level in fasting serum, a biomarker of arsenic exposure. Associations among ingestion frequencies of 54 diet items of Japanese food separated into six categories, total arsenic level in fasting serum, and the prevalence of hypertension were investigated in 2709 general people in Japan. Logistic regression analysis demonstrated a dose-dependent association between serum arsenic level and hypertension and a positive association between the ingestion of fish meat and hypertension. Further analysis showed that the latter association was fully mediated by increased fasting serum arsenic levels in humans. Similarly, oral exposure to the putative human-equivalent dose of arsenic species mixture with the same ratios in a common fish meat in Japan increased systolic blood pressure and arsenic levels in fasting serum in mice.

Conclusion

This interdisciplinary approach suggests that fish-meat ingestion is a potential risk factor for arsenic-mediated hypertension. Because the increased consumption of fish meat is a recent global trend, health risks of the increased ingestion of arsenic via fish meat should be further investigated.

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.

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 (β = 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 (β = 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.

Association of daily physical activity and leisure-time exercise with dysphagia risk in community-dwelling older adults: a cross-sectional study

This study aimed to clarify the association of daily physical activity and leisure-time exercise with the risk of dysphagia in community-dwelling Japanese older adults using a questionnaire-based survey. We analyzed 3070 participants (1657 men, 1413 women; age 66 ± 4 years [mean ± SD]) of the Shizuoka and Daiko studies within the Japanese Multi-Institutional Collaborative Cohort study. We used the Dysphagia Risk Assessment for the Community-dwelling Elderly questionnaire to assess dysphagia risk and the International Physical Activity Questionnaire to assess daily physical activity and leisure-time exercise. Logistic regression analyses were used to evaluate the independent association of the amount of physical activity and leisure-time exercise with dysphagia risk. The proportion of participants with dysphagia risk was 27.5% (n = 844) and the risk was significantly higher in women (29.8%, n = 421) than in men (25.5%, n = 423; P = 0.008). Daily physical activity was not associated with dysphagia risk. A greater amount of leisure-time exercise was associated with lower dysphagia risk (P for trend = 0.003) and individuals in the highest leisure-time exercise quartile had a significantly lower odds ratio (0.68, 95% CI 0.52-0.89) than those in the lowest quartile, even after adjusting for the covariates.

Genome-wide association study of lung adenocarcinoma in East Asia and comparison with a European population

Lung adenocarcinoma is the most common type of lung cancer. Known risk variants explain only a small fraction of lung adenocarcinoma heritability. Here, we conducted a two-stage genome-wide association study of lung adenocarcinoma of East Asian ancestry (21,658 cases and 150,676 controls; 54.5% never-smokers) and identified 12 novel susceptibility variants, bringing the total number to 28 at 25 independent loci. Transcriptome-wide association analyses together with colocalization studies using a Taiwanese lung expression quantitative trait loci dataset (n = 115) identified novel candidate genes, including FADS1 at 11q12 and ELF5 at 11p13. In a multi-ancestry meta-analysis of East Asian and European studies, four loci were identified at 2p11, 4q32, 16q23, and 18q12. At the same time, most of our findings in East Asian populations showed no evidence of association in European populations. In our studies drawn from East Asian populations, a polygenic risk score based on the 25 loci had a stronger association in never-smokers vs. individuals with a history of smoking (Pinteraction = 0.0058). These findings provide new insights into the etiology of lung adenocarcinoma in individuals from East Asian populations, which could be important in developing translational applications.

Association of kidney function with cancer incidence and its influence on cancer risk of smoking: The Japan Multi-Institutional Collaborative Cohort Study

The association between kidney function and cancer incidence is inconsistent among previous reports, and data on the Japanese population are lacking. It is unknown whether kidney function modifies the cancer risk of other factors. We aimed to evaluate the association of estimated glomerular filtration rate (eGFR) with cancer incidence and mortality in 55 242 participants (median age, 57 years; 55% women) from the Japan Multi-Institutional Collaborative Cohort Study. We also investigated differences in cancer risk factors between individuals with and without kidney dysfunction. During a median 9.3-year follow-up period, 4278 (7.7%) subjects developed cancer. Moderately low and high eGFRs were associated with higher cancer incidence; compared with eGFR of 60-74 ml/min/1.73 m² , the adjusted hazard ratios (HRs) (95% confidence intervals [CIs]) for eGFRs of ≥90, 75-89, 45-59, 30-44 and 10-29 ml/min/1.73 m² were 1.18 (1.07-1.29), 1.09 (1.01-1.17), 0.93 (0.83-1.04), 1.36 (1.00-1.84) and 1.12 (0.55-2.26), respectively. High eGFR was associated with higher cancer mortality, while low eGFR was not; the adjusted subdistribution HRs (95% CIs) for eGFRs of ≥90 and 75-89 ml/min/1.73 m² were 1.58 (1.29-1.94) and 1.27 (1.08-1.50), respectively. Subgroup analyses of participants with eGFRs ≥60 and <60 ml/min/1.73 m² revealed elevated cancer risks of smoking and family history of cancer in those with eGFR <60 ml/min/1.73 m² , with significant interactions. Our findings suggest that the relationship between eGFR and cancer incidence was U-shaped. Only high eGFR was associated with cancer mortality. Kidney dysfunction enhanced cancer risk from smoking.

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

Observational studies suggest that abnormal glucose metabolism and insulin resistance contribute to colorectal cancer; however, the causal association remains unknown, particularly in Asian populations. A two-sample Mendelian randomisation analysis was performed to determine the causal association between genetic variants associated with elevated fasting glucose, haemoglobin A1c (HbA1c), and fasting C-peptide and colorectal cancer risk. In the single nucleotide polymorphism (SNP)-exposure analysis, we meta-analysed study-level genome-wide associations of fasting glucose (~ 17,289 individuals), HbA1c (~ 52,802 individuals), and fasting C-peptide (1,666 individuals) levels from the Japanese Consortium of Genetic Epidemiology studies. The odds ratios of colorectal cancer were 1.01 (95% confidence interval [CI], 0.99-1.04, P = 0.34) for fasting glucose (per 1 mg/dL increment), 1.02 (95% CI, 0.60-1.73, P = 0.95) for HbA1c (per 1% increment), and 1.47 (95% CI, 0.97-2.24, P = 0.06) for fasting C-peptide (per 1 log increment). Sensitivity analyses, including Mendelian randomisation-Egger and weighted-median approaches, revealed no significant association between glycaemic characteristics and colorectal cancer (P > 0.20). In this study, genetically predicted glycaemic characteristics were not significantly related to colorectal cancer risk. The potential association between insulin resistance and colorectal cancer should be validated in further studies.

Mediation analysis unveils a carcinogenic effect of ADH1B rs1229984 through mechanisms other than change in drinking intensity: oesophageal cancer case-control study

BACKGROUND

Ingested alcohol is predominantly oxidized to acetaldehyde by alcohol dehydrogenase 1B (ADH1B), and acetaldehyde is further oxidized to acetate mainly by aldehyde dehydrogenase 2 (ALDH2). Although alcohol consumption is a convincing risk factor for oesophageal cancer, the role of ADH1B rs1229984 (His48Arg), the single-nucleotide polymorphism associated with slow alcohol metabolism, in oesophageal cancer development is unclear. Because this single-nucleotide polymorphism is associated with both increased risk of oesophageal cancer and drinking intensity, its association with oesophageal cancer might operate either through a direct pathway independently of drinking intensity, via an indirect pathway mediated by drinking intensity, or both.

METHODS

To disentangle these different pathways, we applied a mediation analysis to an oesophageal cancer case-control study (600 cases and 865 controls) by defining the ADH1B Arg allele and alcohol consumption as exposure and mediator, respectively, and decomposed the total-effect odds ratio of the ADH1B Arg allele into direct- and indirect-effect odds ratio.

RESULTS

The ADH1B Arg allele was associated with oesophageal cancer risk through pathways other than change in drinking intensity (direct-effect odds ratio, 2.03; 95% confidence interval, 1.41-2.92), in addition to the indirect pathway mediated by drinking intensity (indirect-effect odds ratio, 1.27; 95% confidence interval, 1.05-1.53). Further analyses by stratifying genotypes of ALDH2 rs671 (Glu504Lys), the functional single-nucleotide polymorphism that strongly attenuates the enzymatic activity, showed significant direct-effect odds ratio within each stratum.

CONCLUSIONS

These results indicate that ADH1B Arg allele contributes to oesophageal cancer risk by slowing alcohol breakdown, in addition to its effect on the amount of alcohol consumed.

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.

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.

Association of 25-hydroxyvitamin D with risk of overall and colorectal cancer among Japanese using a Mendelian randomization approach

The association between vitamin D and total and colorectal cancer risk was inconsistent in observational studies. We conducted Mendelian randomization approach in which the effect of confounding might be reduced. 110 single nucleotide polymorphisms (SNPs) associated with 25-hydroxyvitamin D concentrations were systematically selected according to the "GWAS Catalog" from all ethnic populations. For the SNP-vitamin D concentration association, 3978 individuals from two Japanese cohorts were included. Regarding SNP-total and colorectal cancer association, 4543 cancer cases and 14,224 controls and 7936 colorectal cancer cases and 38,042 controls, respectively were included from the Japanese Consortium of Genetic Epidemiology and other studies in Japan. There was no significant association between the genetically predicted plasma 25-hydroxyvitamin D concentration and total or colorectal cancer in any of the MR analyses. Odds ratios per doubling in vitamin D concentration were 0.83 (95% confidence interval [CI] 0.63-1.09) for total cancer and 1.00 (95% CI 0.80-1.24) for colorectal cancer in inverse variance weighted method, 0.83 (95% CI 0.57-1.19) for total cancer and 1.01 (95% CI 0.75-1.37) for colorectal cancer in MR-Egger method. Consistent with previous MR analyses among European ancestries, there was no significant association identified between 25-hydroxyvitamin D levels and total or colorectal cancer among Asians.

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 (β = -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 (β = -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.

Serum Soluble Fas Levels and Incidence of Liver Cancer in Nested Case-Control Study

BACKGROUND

Soluble Fas (sFas) plays various roles in carcinogenesis and tumor dissemination by preventing apoptosis via binding to Fas ligand. We analyzed associations of serum sFas levels with the incidence of liver cancer in a prospective case-control study nested in the Japan Collaborative Cohort Study.

METHODS

A baseline survey was conducted from 1988, with blood samples obtained from 39,242 subjects. Patients diagnosed with liver cancer were regarded as cases. Two or three controls were selected and matched for sex, age, and geographic area. Conditional logistic regression was used to estimate ORs for cancer incidence associated with sFas.

RESULTS

This study contained 86 cases and 249 controls. After controlling for alcohol intake, body mass index, smoking, and hepatitis viral infection, participants with high sFas showed elevated risk of cancer (Ptrend = 0.003) and the third tertile of sFas showed a higher risk compared with the first tertile [OR, 3.53; 95% confidence interval (CI), 1.28-9.69]. In hepatocellular carcinoma, high sFas was associated with elevated risk (Ptrend < 0.001). In men and the elderly, subjects in the highest tertiles showed higher cancer risk. Limiting subjects to those followed for 3 years, high sFas was related to liver cancer risk (Ptrend = 0.033) and the third tertile showed a higher risk compared with the first (OR, 2.94; 95% CI, 0.94-9.14).

CONCLUSIONS

High serum sFas may be related to future risk of liver cancer.

IMPACT

Our findings highlight this biomarker for further analysis in pooled investigations with different/larger prospective cohorts.

Temporal change in the association between life satisfaction and functional decline with gender differences: an age-specific prospective cohort study

BACKGROUND

Although life satisfaction (LS) has been shown to predict mortality, research studying the relationship between LS and functional decline is scarce. This study examined the association between LS and functional decline across four time points in young-old Japanese adults.

METHODS

We analysed 1,899 community-dwelling 65-year-olds in this age-specific cohort study conducted between 2000 and 2005. The Life Satisfaction Index K was used to evaluate LS and was classified into quartiles. Functional decline was determined using the Japanese Long-Term Care Insurance (LTCI) system: 1) mild disability; 2) severe disability; 3) all-cause mortality; 4) mild or severe disability; 5) severe disability or death; 6) mild or severe disability, or death. Adjusted hazard ratios (HR) with 95% confidence intervals (CI) were calculated using the Cox proportional hazard model. The analyses were conducted in the 8^th, 10^th, 12^th, and 14^th years to assess the effect of LS on functional decline across time points.

RESULTS

The impact of LS gradually weakened over time. In the 8^th year (aged 72-73), a higher LS was associated with a lower risk of mild or severe disability among the women participants (adjusted HR [95% CI] = 0.30 [0.11-0.81]). However, the effect disappeared gradually (adjusted HR [95% CI] = 0.55 [0.27-1.14]) in the 10^th year (aged 74-75), 0.72 (0.41-1.26) in the 12^th year (aged 76-77), and 0.68 (0.41-1.14) in the 14^th year (aged 78-79). This trend continued in severe disability or death (adjusted HR [95% CI] = 0.24 [0.06-0.70], 0.31 [0.11-0.76], 0.57 [0.28-1.14], and 0.60 [0.32-1.12]) and mild or severe disability, or death (adjusted HR [95% CI] = 0.30 [0.14-0.68], 0.46 [0.24-0.87], 0.67 [0.41-1.10], and 0.65 [0.42-1.02]) in the 8^th, 10^th, 12^th, and 14^th years, respectively. No statistically significant association was found among men at any time points or in any classification of outcomes.

CONCLUSIONS

Higher LS scores in 65-year-old women were associated with a lower risk for functional decline in any combination of mild disability, severe disability, or death. Additionally, the effect of LS was observed to weaken over time.

TRIAL REGISTRATION

This is not an intervention survey and does not require registration.

Anti-Helicobacter pylori antibody status is associated with cancer mortality: A longitudinal analysis from the Japanese DAIKO prospective cohort study

Paradoxically, patients with advanced stomach cancer who are Helicobacter pylori-positive (HP+) have a higher survival rate than those who are HP-. This finding suggests that HP infection has beneficial effects for cancer treatment. The present study examines whether HP+ individuals have a lower likelihood of death from cancer than those who are HP-. Prospective cohort data (n = 4,982 subjects enrolled in the DAIKO study between 2008-2010) were used to assess whether anti-HP antibody status was associated with cancer incidence. The median age in the primary registry was 53 years-old (range 35-69 years-old). Over the 8-year observation period there were 234 (4.7%) cancer cases in the cohort and 88 (1.8%) all-cause deaths. Urine anti-HP antibody data was available for all but one participant (n = 4,981; 99.98%). The number of HP+ and HP- individuals was 1,825 (37%) and 3,156 (63%), respectively. Anti-HP antibody distribution per birth year revealed that earlier birth year was associated with higher HP+ rates. With a birth year-matched cohort (n = 3,376), all-cancer incidence was significantly higher in HP+ individuals than those who were HP- (p = 0.00328), whereas there was no significant difference in the cancer death rate between HP+ and HP- individuals (p = 0.888). Cox regression analysis for prognostic factors revealed that the hazards ratio of HP+ was 1.59-fold (95%CI 1.17-2.26) higher than HP- in all-cancer incidence. Potential systemic effects of HP+ status may contribute to reduced likelihood of death for patients after an initial diagnosis of cancer.

Blood Lipids and the Risk of Colorectal Cancer: Mendelian Randomization Analyses in the Japanese Consortium of Genetic Epidemiology Studies

The associations between blood lipids, including total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), triglycerides, and low-density lipoprotein cholesterol (LDL-C), and colorectal cancer risk are controversial. We evaluated potential causal relationships between blood lipids and colorectal cancer risk. Using the baseline data from the Japanese Consortium of Genetic Epidemiology studies, we estimated the single-nucleotide polymorphism (SNP)-exposure associations (n = 34,546 for TC, n = 50,290 for HDL-C, n = 51,307 for triglycerides, and n = 30,305 for LDL-C). We also estimated the SNP-outcome associations in another Japanese dataset (n = 7,936 colorectal cancer cases and n = 38,042 controls). We conducted Mendelian randomization (MR) analyses for the association between each blood lipid type and the risk of colorectal cancer using an inverse variance-weighted method. The total variances explained by the selected SNPs in TC (68 SNPs), HDL-C (50 SNPs), log-transformed triglycerides (26 SNPs), and LDL-C (35 SNPs) were 7.0%, 10.0%, 6.2%, and 5.7%, respectively. The odds ratios for colorectal cancer were 1.15 [95% confidence interval (CI), 1.01-1.32] per 1 standard deviation (SD; 33.3 mg/dL) increase in TC, 1.11 (95% CI, 0.98-1.26) per 1 SD (15.4 mg/dL) increase in HDL-C, 1.06 (95% CI, 0.90-1.26) per 1 SD (0.5 log-mg/dL) increase in log-transformed triglycerides, and 1.17 (95% CI, 0.91-1.50) per 1 SD (29.6 mg/dL) increase in LDL-C. Sensitivity analyses consistently suggested the positive association between TC and colorectal cancer, whereas results of each lipid component were inconsistent. In conclusion, this large MR study of a Japanese population showed a potentially causal association between high TC and colorectal cancer risk, although the association between each lipid component and colorectal cancer remained inconclusive.

PREVENTION RELEVANCE

In this large MR analysis of a Japanese population, a positive association was found between genetically predicted high total cholesterol (TC) levels and an increased risk of colorectal cancer. Therefore, lowering TC levels by lifestyle modifications or medications may be justified for the purpose of preventing colorectal cancer.

Association between daily sleep duration and the risk of incident dementia according to the presence or absence of diseases among older Japanese individuals in the New Integrated Suburban Seniority Investigation (NISSIN) project

OBJECTIVE

This study aimed to investigate the association between daily sleep duration and incident dementia among physically and socially independent older people with/without diseases (hypertension, diabetes mellitus, cardiovascular diseases) in a Japanese age-specific cohort.

METHODS

We carried out a prospective cohort study including 1954 (1006 men and 948 women) Japanese individuals aged 64/65 years. Information on daily sleep duration, medical status, demographics, and lifestyle characteristics was collected by a baseline questionnaire survey and health checkup (2000-2005). Dates of incident dementia were confirmed using the nationally standardized dementia scale proposed by the Ministry of Health, Labor, and Welfare. A competing risk model was used to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs) for incident dementia. We treated censored cases due to death as competing events.

RESULTS

During a median of 15.6 years of follow-up, 260 participants reported incident dementia. Compared with participants without diseases and who slept 6-7.9 h/day, those with a shorter daily sleep duration of <6 h/day, presence of disease and shorter, moderate, or longer daily sleep duration ≥8 h/day had an increased risk of incident dementia (HR 1.73; 95% CI 1.04-2.88, HR 1.98; 95% CI 1.14-3.44, HR 1.44; 95% CI 1.03-2.00, and HR 2.09; 95% CI 1.41-3.09, respectively) with a significant interaction between the presence of diseases and sleep duration (p < 0.001).

CONCLUSIONS

The present findings suggest that habitual sleep duration predicts future risk of dementia.

Sex- and age-specific all-cause mortality in insomnia with hypnotics: Findings from Japan multi-institutional Collaborative Cohort Study

OBJECTIVE

Findings on the increased mortality risk in individuals with insomnia are inconsistent across studies. Rather than improving insomnia by sleep control, hypnotic use may be one factor in the increased risk of death; however, the effects of hypnotics on mortality remains unclear. This study aimed to examine the association between all-cause mortality and hypnotic use in a large sample, while adjusting for the effects of comorbidities.

METHODS

Overall, 92,527 individuals aged 35-69 years were followed up for mortality in the Japan Multi-Institutional Collaborative Cohort Study. Regular use of hypnotics was assessed using a self-administered questionnaire. Since cancer history carries a substantial risk of death and is associated with the treatment of insomnia with hypnotics, participants with a cancer history were excluded. The hazard ratio (HR) and 95% confidence interval (CI) for all-cause mortality related to hypnotic use were estimated using a Cox proportional hazard model with adjustments for covariates including sleeping hours and comorbidities (body mass index, ischemic heart disease, stroke, and diabetes).

RESULTS

During the follow-up (mean, 8.4 ± 2.5 years), 1,492 mortalities were recorded, and the prevalence of taking hypnotics was 4.2%. Hypnotic use was associated with significantly greater risk of all-cause mortality, even after adjustment for the covariates (HR, 1.32; 95% CI, 1.07-1.63). The association between hypnotic use and all-cause mortality was robust in males (HR, 1.51; 95% CI, 1.15-1.96), and participants aged <60 years (HR, 1.75; 95% CI, 1.21-2.54).

CONCLUSIONS

Our study revealed sex-age specific associations between hypnotic use and all-cause mortality.

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.

Genetic loci and prioritization of genes for kidney function decline derived from a meta-analysis of 62 longitudinal genome-wide association studies

Estimated glomerular filtration rate (eGFR) reflects kidney function. Progressive eGFR-decline can lead to kidney failure, necessitating dialysis or transplantation. Hundreds of loci from genome-wide association studies (GWAS) for eGFR help explain population cross section variability. Since the contribution of these or other loci to eGFR-decline remains largely unknown, we derived GWAS for annual eGFR-decline and meta-analyzed 62 longitudinal studies with eGFR assessed twice over time in all 343,339 individuals and in high-risk groups. We also explored different covariate adjustment. Twelve genome-wide significant independent variants for eGFR-decline unadjusted or adjusted for eGFR-baseline (11 novel, one known for this phenotype), including nine variants robustly associated across models were identified. All loci for eGFR-decline were known for cross-sectional eGFR and thus distinguished a subgroup of eGFR loci. Seven of the nine variants showed variant-by-age interaction on eGFR cross section (further about 350,000 individuals), which linked genetic associations for eGFR-decline with age-dependency of genetic cross-section associations. Clinically important were two to four-fold greater genetic effects on eGFR-decline in high-risk subgroups. Five variants associated also with chronic kidney disease progression mapped to genes with functional in-silico evidence (UMOD, SPATA7, GALNTL5, TPPP). An unfavorable versus favorable nine-variant genetic profile showed increased risk odds ratios of 1.35 for kidney failure (95% confidence intervals 1.03-1.77) and 1.27 for acute kidney injury (95% confidence intervals 1.08-1.50) in over 2000 cases each, with matched controls). Thus, we provide a large data resource, genetic loci, and prioritized genes for kidney function decline, which help inform drug development pipelines revealing important insights into the age-dependency of kidney function genetics.

Changes in behavioral activities and transition of depressive symptoms among younger-old community-dwelling adults during 6 years: An age-specific prospective cohort study

OBJECTIVE

Regular engagement in behavioral activities plays a crucial role against depressive symptoms in older adults. This study aims to explore the relationship between behavioral activities and the temporal evolution of depressive symptoms.

METHODS

We included community-dwelling Japanese adults aged 64 or 65 years with and without depressive symptoms enrolled in the New Integrated Suburban Seniority Investigation (NISSIN) project. Depressive symptoms at baseline and follow-up were assessed using the 15-item Geriatric Depression Scale. Behavioral activities were measured by self-reported questions. Risk ratios and 95% confidence intervals were calculated using modified Poisson regression, adjusting for relevant sociodemographic variables and health-related confounders.

RESULTS

During the 6 year follow-up period, 139 (10.1%) without depressive symptoms at baseline developed such symptoms over time, while 174 (51.6%) with depressive symptoms improved to the point of these symptoms being absent. The participants without depressive symptoms at baseline and those who engaged in social activity or daily walking at a continued regular frequency (CRF) or an increased frequency (IF) and exercise habits at CRF were the least likely to have depressive symptoms onset at follow-up. There was no significant difference between the changes in behavioral activities and the improvement of depressive symptoms after controlling for confounders. Participants engaging in a greater variety of behavioral activities at CRF were less likely to experience a new onset of depressive symptoms.

CONCLUSIONS

Consistent and regular participation in one or more behavioral activities was significantly associated with the onset of depressive symptoms in Japanese community-dwelling older adults.

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.

Associations of Genome-Wide Polygenic Risk Score and Risk Factors With Hypertension in a Japanese Population

Background:

Although many polygenic risk scores (PRS) for cardiovascular traits have been developed in European populations, it is an urgent task to construct a PRS and to evaluate its ability in non-European populations. We developed a genome-wide PRS for blood pressure in a Japanese population and examined the associations between this PRS and hypertension prevalence.

Methods:

We performed a cross-sectional study in 11 252 Japanese individuals who participated in the J-MICC (Japan Multi-Institutional Collaborative Cohort) study. Using publicly available GWAS summary statistics from Biobank Japan, we developed the PRS in the target data (n=7876). With >30 000 single nucleotide polymorphisms, we evaluated PRS performance in the test data (n=3376). Hypertension was defined as systolic blood pressure of 130 mm Hg or more, or diastolic blood pressure of 85 mm Hg or more, or taking an antihypertensive drug.

Results:

Compared with the middle PRS quintile, the prevalence of hypertension at the top PRS quintile was higher independently from traditional risk factors (odds ratio, 1.73 [95% CI, 1.32–2.27]). The difference of mean systolic blood pressure and diastolic blood pressure between the middle and the top PRS quintile was 4.55 (95% CI, 2.26–6.85) and 2.32 (95% CI, 0.86–3.78) mm Hg, respectively. Subgroups reflecting combinations of Japanese PRS and modifiable lifestyles and factors (smoking, alcohol intake, sedentary time, and obesity) were associated with the prevalence of hypertension. A European-derived PRS was not associated with hypertension in our participants.

Conclusions:

A PRS for blood pressure was significantly associated with hypertension and BP traits in a general Japanese population. Our findings also highlighted the importance of a combination of PRS and risk factors for identifying high-risk subgroups.

Association between serum carotenoids and premature mortality in a population-based case-control study

Carotenoids are abundant pigments mainly contained in vegetables and fruits, and show antioxidant properties by quenching free radicals in human body. Few studies have investigated associations between serum carotenoid levels and premature mortality. The objective of this study was to investigate the association between serum carotenoid level and premature mortality in a Japanese population. This study included 446 Japanese adults (174 men, aged of 40-64) recruited as participants in the Japan Collaborative Cohort (JACC) Study. Serum carotenoid level was measured by high-performance liquid chromatography. Premature mortality was defined as death before 65 years old during the follow-up period. Premature mortality was ascertained in 60 men (34.5%) and 65 women (23.9%). In men, compared to the 1^st tertile of serum β-cryptoxanthin and provitamin A, those who were in the 3^rd tertile had lower risks of premature all-cause mortality (OR, 95% CI: 0.19, 0.07-0.47 for β-cryptoxanthin, and 0.24, 0.09-0.61 for provitamin A). In women, compared to the 1^st tertile of serum β-cryptoxanthin, those who were in the 3^rd tertile had higher risks of premature all-cause mortality (OR, 95% CI: 1.94, 1.00-4.03). These significant associations were observed in analyses for premature cancer mortality. We found significant associations between higher levels of serum β-cryptoxanthin and provitamin A and lower risks of premature mortality among Japanese men, while a different directional association was found in women. Although these findings suggest roles of serum carotenoids on premature mortality, further studies are needed to validate this association in other populations.

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.

Secondhand Smoke Exposure During Childhood and Cancer Mortality in Adulthood Among Never Smokers: The Japan Collaborative Cohort Study for Evaluation of Cancer Risk

We examined whether secondhand smoke exposure during childhood was associated with cancer mortality in adulthood among never smokers. In the Japan Collaborative Cohort Study for Evaluation of Cancer Risk, we analyzed data from 45,722 Japanese lifetime nonsmokers aged 40-79 years with no history of cancer at baseline (1988-1990) who had completed a lifestyle questionnaire, including information on the number of family members who had smoked at home during their childhood (0, 1, 2, or ≥3 family members). A Cox proportional hazards model and competing-risks regression were used to calculate multivariable hazard ratios and subdistribution hazard ratios with 95% confidence intervals for overall and site-specific cancer mortality according to the number of family members who smoked during the participant's childhood, after adjusting for potentially confounding factors. During a median follow-up period of 19.2 years, a total of 2,356 cancer deaths were documented. Secondhand smoke exposure was positively associated with the risk of mortality from pancreatic cancer in adulthood; the multivariable hazard ratio for having 3 or more family members who smoked (as compared with none) was 2.32 (95% confidence interval: 1.14, 4.72). Associations were not evident for total cancer risk or risk of other types of smoking-related cancer. In this study, secondhand smoke exposure during childhood was associated with an increased risk of pancreatic cancer mortality in adulthood.

Investigation of miRNA expression profiles using cohort samples reveals potential early detectability of colorectal cancers by serum miR-26a-5p before clinical diagnosis

Previous studies have investigated the usefulness of microRNA (miRNA/miR) expression data for the early detection of colorectal cancer (CRC). However, limited data are available regarding miRNAs that detect CRC before clinical diagnoses. Accordingly, the present study investigated the early detectability of CRC by miRNAs using the preserved serum samples of the cohort participants affected with CRC within 2 years of study enrollment. First, the significant miRNAs were revealed using clinical CRC samples for a (seven early CRCs and seven controls) microarray analysis based on significance analysis of microarrays. Next, replicability was verified by reverse transcription-quantitative (RT-q)PCR (eight early CRCs and eight controls, together with 12 CRCs and 12 controls). Finally, early detectability was tested using the cohort samples of Japan Multi-Institutional Collaborative Cohort Study (17 CRCs and 17 controls) to reveal how a certain number of patients developed CRC within 2 years after participation. In the discovery phase, miRNA expression measurements were conducted using a 3D-Gene Human miRNA Oligo Chip for 2,555 miRNAs, and RT-qPCR analyses were performed to validate the replicability. In the first validation set with eight CRCs with early clinical stage and eight age- and gender-matched controls, miR-26a-5p and miR-223-3p demonstrated the highest diagnostic accuracy of area under the curve (AUC)=1.000 (sensitivity and specificity 100%). In an examination of the predictability of CRC incidence using pre-clinical cohort samples, miR-26a-5p demonstrated good predictability of advanced CRC incidence with an AUC of 0.840. Overall, the present study revealed serum miR-26a-5p as a potential early detection marker for CRC.

Nutritional Influences on Locomotive Syndrome

Healthy dietary habits are important to prevent locomotive syndrome (LS). We investigated the relationship between LS and nutritional intake using community health checkup data. We included 368 participants who underwent LS staging, blood sampling, and nutritional intake assessments. Participants (163 adults < 65: 205 older adults ≥ 65) were divided into normal (N; LS stage 0) and LS (L; LS stage 1–2) groups, and blood sample data and nutritional intake were compared between groups. Among adults (N group, 71; L group, 92), low-density lipoprotein cholesterol (LDL-C) was significantly lower, and Vitamin B₁ intake was significantly higher in the L than in the N group; LDL-C, p = 0.033; Vitamin B1, 0.029. Among older adults (N group, 85; L group, 120), hemoglobin (Hb), albumin, and calcium levels were significantly lower, and sodium, monounsaturated fatty acids (MUFA), and n-6 polyunsaturated fatty acids (n-6 PUFA) were significantly higher in the L than the N group; Hb, p = 0.036; albumin, 0.030; calcium, 0.025; sodium; 0.029; MUFA; 0.047, n-6 PUFA; 0.0233). Logistic regression analysis indicated that sodium was the risk factor for the L group (exp (B) 1.001, 95% CI: 1–1.001, p = 0.032). In conclusion, salt intake was associated with LS.

Associations of breastfeeding history with metabolic syndrome and cardiovascular risk factors in community-dwelling parous women: The Japan Multi-Institutional Collaborative Cohort Study

OBJECTIVE

The aim of the present study was to investigate the associations between breastfeeding and the prevalence of metabolic syndrome in community-dwelling parous women and to clarify whether the associations depend on age.

METHODS

The present cross-sectional study included 11,118 women, aged 35-69 years. Participants' longest breastfeeding duration for one child and their number of breastfed children were assessed using a self-administered questionnaire, and their total breastfeeding duration was approximated as a product of the number of breastfed children and the longest breastfeeding duration. The longest and the total breastfeeding durations were categorized into none and tertiles above 0 months. Metabolic syndrome and cardiovascular risk factors (obesity, hypertension, dyslipidemia, and hyperglycemia) were defined as primary and secondary outcomes, respectively. Associations between breastfeeding history and metabolic syndrome or each cardiovascular risk factor were assessed using multivariable unconditional logistic regression analysis.

RESULTS

Among a total of 11,118 women, 10,432 (93.8%) had ever breastfed, and 1,236 (11.1%) had metabolic syndrome. In participants aged <55 years, an inverse dose-response relationship was found between the number of breastfed children and the prevalence of metabolic syndrome; multivariable-adjusted odds ratios for 1, 2, 3, and ≥4 breastfed children were 0.60 (95% confidence interval [CI]: 0.31 to 1.17), 0.50 (95% CI: 0.29 to 0.87), 0.44 (95% CI: 0.24 to 0.84), and 0.35 (95% CI: 0.14 to 0.89), respectively. The longest and total breastfeeding durations of longer than 0 months were also associated with lower odds of metabolic syndrome relative to no breastfeeding history in participants aged <55 years. In contrast, all measures of breastfeeding history were not significantly associated with metabolic syndrome and cardiovascular risk factors in participants aged ≥55 years old.

CONCLUSIONS

Breastfeeding history may be related to lower prevalence of metabolic syndrome in middle-aged parous women.

Plasma angiopoietin-like protein 2 levels and mortality risk among younger-old Japanese people: a population-based case-cohort study

Aging is important medical and social problem. Excessive angiopoietin-like protein (ANGPTL)-2 signaling causes chronic tissue inflammation, promoting development and progression of aging-related diseases. Moreover, circulating ANGPTL2 levels reportedly predict risk of some aging-related diseases and subsequent death. However, there are as yet no reports of whether circulating ANGPTL2 levels predict vital prognosis in younger-old, community-dwelling populations. This study investigated associations between plasma ANGPTL2 levels and all-cause and specific-cause mortality in this population. The case-cohort study was abstracted from an on-going, age-specific prospective cohort study: the New Integrated Suburban Seniority Investigation Project. This project enrolled 3073 participants aged 64 years at the beginning of the investigation from 1996 through 2005. A sub-cohort of 714 randomly sampled participants plus 387 cases representing deceased participants followed through 2015 underwent survival analysis. Plasma ANGPTL2 concentrations were positively associated with >80% and 100% higher risk of all-cause mortality and cancer mortality, respectively, after adjustment for gender, smoking, alcohol consumption, walking time, sleep duration, caloric intake, medical status, disease history, BMI, and triglyceride, creatinine, uric acid, and high sensitivity C-reactive protein levels. More robust association between ANGPTL2 levels and all-cause and cancer mortality was seen in subjects with either frailties or with lifestyles of heavier drinking or current smoking. Elevated plasma ANGPTL2 levels are associated with high all-cause and cancer mortality in a community-dwelling sample of younger-old adults. These findings expand our knowledge of human aging and associated diseases.

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 (P_trend = 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 (P_interaction = 0.003). Unexpectedly, problem solving in men (P_trend < 0.001) and positive reappraisal in women (P_trend = 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.