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.

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.

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

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

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

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

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.

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.

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

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

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

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

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

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

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

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

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

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

Study Profile of the Japan Multi-institutional Collaborative Cohort (J-MICC) Study.

BACKGROUND: The Japan Multi-institutional Collaborative Cohort (J-MICC) study was launched in 2005 to examine gene-environment interactions in lifestyle-related diseases, including cancers, among the Japanese. This report describes the study design and baseline profile of the study participants. METHODS: The participants of the J-MICC Study were individuals aged 35 to 69 years enrolled from respondents to study announcements in specified regions, inhabitants attending health checkup examinations provided by local governments, visitors at health checkup centers, and first-visit patients at a cancer hospital in Japan. At the time of the baseline survey, from 2005 to 2014, we obtained comprehensive information regarding demographics, education, alcohol consumption, smoking, sleeping, exercise, food intake frequency, medication and supplement use, personal and family disease history, psychological stress, and female reproductive history and collected peripheral blood samples. RESULTS: The baseline survey included 92,610 adults (mean age: 55.2 [standard deviation, 9.4] years, 44.1% men) from 14 study regions in 12 prefectures. The participation rate was 33.5%, with participation ranging from 19.7% to 69.8% in different study regions. The largest number of participants was in the age groups of 65-69 years for men and 60-64 years for women. There were differences in body mass index, educational attainment, alcohol consumption, smoking, and sleep duration between men and women. CONCLUSIONS: The J-MICC Study collected lifestyle and clinical data and biospecimens from over 90,000 participants. This cohort is expected to be a valuable resource for the national and international scientific community in providing evidence to support longer healthy lives.

The interaction between ABCA1 polymorphism and physical activity on the HDL-cholesterol levels in a Japanese population.

Few studies have investigated the interactions between HDL-C-related SNPs identified by genome-wide association (GWA) study and physical activity (PA) on HDL-C. First, we conducted a sex-stratified GWA study in a discovery sample (2,231 men and 2,431 women) and replication sample (2,599 men and 3,109 women) to identify SNPs influencing log-transformed HDL-C in Japanese participants in the baseline survey of the Japan Multi-Institutional Collaborative Cohort Study. We also replicated previously reported HDL-C-related SNPs in a combined (discovery plus replication) sample (4,830 men and 5,540 women). We then analyzed the interactions of the HDL-C-related SNPs with PA on HDL-C. The sex-stratified GWA analyses identified 11 and 10 HDL-C-related SNPs in men and women as targets for an interaction analysis. Among these, only one interaction of ABCA1 rs1883025 with PA was statistically significant in men, after Bonferroni correction [P-interaction = 0.001 (α = 0.05/21 = 0.002)]. The per-major-allele (C allele) increase in log-transformed HDL-C was lost in men with low PA (ß = 0.008) compared with those with medium (ß = 0.032) or high PA (ß = 0.034). These findings suggest that the benefit of carrying a C allele of ABCA1 rs1883025 on enhancing HDL-C may be attenuated in inactive men.

Genome-wide association study revealed novel loci which aggravate asymptomatic hyperuricaemia into gout.

OBJECTIVE: The first ever genome-wide association study (GWAS) of clinically defined gout cases and asymptomatic hyperuricaemia (AHUA) controls was performed to identify novel gout loci that aggravate AHUA into gout. METHODS: We carried out a GWAS of 945 clinically defined gout cases and 1003 AHUA controls followed by 2 replication studies. In total, 2860 gout cases and 3149 AHUA controls (all Japanese men) were analysed. We also compared the ORs for each locus in the present GWAS (gout vs AHUA) with those in the previous GWAS (gout vs normouricaemia). RESULTS: This new approach enabled us to identify two novel gout loci (rs7927466 of CNTN5 and rs9952962 of MIR302F) and one suggestive locus (rs12980365 of ZNF724) at the genome-wide significance level (p<5.0×10-8). The present study also identified the loci of ABCG2, ALDH2 and SLC2A9. One of them, rs671 of ALDH2, was identified as a gout locus by GWAS for the first time. Comparing ORs for each locus in the present versus the previous GWAS revealed three 'gout vs AHUA GWAS'-specific loci (CNTN5, MIR302F and ZNF724) to be clearly associated with mechanisms of gout development which distinctly differ from the known gout risk loci that basically elevate serum uric acid level. CONCLUSIONS: This meta-analysis is the first to reveal the loci associated with crystal-induced inflammation, the last step in gout development that aggravates AHUA into gout. Our findings should help to elucidate the molecular mechanisms of gout development and assist the prevention of gout attacks in high-risk AHUA individuals.

Genome-Wide Association Study of Renal Function Traits: Results from the Japan Multi-Institutional Collaborative Cohort Study.

BACKGROUND: Chronic kidney disease (CKD) is a rapidly growing, worldwide public health problem. Recent advances in genome-wide-association studies (GWAS) revealed several genetic loci associated with renal function traits worldwide. METHODS: We investigated the association of genetic factors with the levels of serum creatinine (SCr) and the estimated glomerular filtration rate (eGFR) in Japanese population-based cohorts analyzing the GWAS imputed data with 11,221 subjects and 12,617,569 variants, and replicated the findings with the 148,829 hospital-based Japanese subjects. RESULTS: In the discovery phase, 28 variants within 4 loci (chromosome [chr] 2 with 8 variants including rs3770636 in the LDL receptor related protein 2 gene locus, on chr 5 with 2 variants including rs270184, chr 17 with 15 variants including rs3785837 in the BCAS3 gene locus, and chr 18 with 3 variants including rs74183647 in the nuclear factor of -activated T-cells 1 gene locus) reached the suggestive level of p < 1 × 10-6 in association with eGFR and SCr, and 2 variants on chr 4 (including rs78351985 in the microsomal triglyceride transfer protein gene locus) fulfilled the suggestive level in association with the risk of CKD. In the replication phase, 25 variants within 3 loci (chr 2 with 7 variants, chr 17 with 15 variants and chr 18 with 3 variants) in association with eGFR and SCr, and 2 variants on chr 4 associated with the risk of CKD became nominally statistically significant after Bonferroni correction, among which 15 variants on chr 17 and 3 variants on chr 18 reached genome-wide significance of p < 5 × 10-8 in the combined study meta-analysis. The associations of the loci on chr 2 and 18 with eGFR and SCr as well as that on chr 4 with CKD risk have not been previously reported in the Japanese and East Asian populations. CONCLUSION: Although the present GWAS of renal function traits included the largest sample of Japanese participants to date, we did not identify novel loci for renal traits. However, we identified the novel associations of the genetic loci on chr 2, 4, and 18 with renal function traits in the Japanese population, suggesting these are transethnic loci. Further investigations of these associations are expected to further validate our findings for the potential establishment of personalized prevention of renal disease in the Japanese and East Asian populations.

Interactions between inflammatory gene polymorphisms and HTLV-I infection for total death, incidence of cancer, and atherosclerosis-related diseases among the Japanese population.

BACKGROUND: An increased risk of total death owing to human T-lymphotropic virus type-I (HTLV-I) infection has been reported. However, its etiology and protective factors are unclear. Various studies reported fluctuations in immune-inflammatory status among HTLV-I carriers. We conducted a matched cohort study among the general population in an HTLV-I-endemic region of Japan to investigate the interaction between inflammatory gene polymorphisms and HTLV-I infection for total death, incidence of cancer, and atherosclerosis-related diseases. METHOD: We selected 2180 sub-cohort subjects aged 35-69 years from the cohort population, after matching for age, sex, and region with HTLV-I seropositives. They were followed up for a maximum of 10 years. Inflammatory gene polymorphisms were selected from TNF-α, IL-10, and NF-κB1. A Cox proportional hazard model was used to estimate the hazard ratio (HR) and the interaction between gene polymorphisms and HTLV-I for risk of total death and incidence of cancer and atherosclerosis-related diseases. RESULTS: HTLV-I seropositivity rate was 6.4% in the cohort population. The interaction between TNF-α 1031T/C and HTLV-I for atherosclerosis-related disease incidence was statistically significant (p = 0.020). No significant interaction was observed between IL-10 819T/C or NF-κB1 94ATTG ins/del and HTLV-I. An increased HR for total death was observed in the Amami island region, after adjustment of various factors with gene polymorphisms (HR 3.03; 95% confidence interval, 1.18-7.77). CONCLUSION: The present study found the interaction between TNF-α 1031T/C and HTLV-I to be a risk factor for atherosclerosis-related disease. Further follow-up is warranted to investigate protective factors against developing diseases among susceptible HTLV-I carriers.

Transgenic expression of human neutrophil peptide-1 enhances hepatic fibrosis in mice fed a choline-deficient, L-amino acid-defined diet.

BACKGROUND: Neutrophils infiltrate the livers of patients with nonalcoholic steatohepatitis (NASH). Human neutrophil peptides (HNPs) induce cytokine and chemokine production under inflammatory conditions, which may contribute to the progression of NASH. In this study, we focused on the effects of HNP-1 on hepatic steatosis and fibrosis in a mouse model of NASH induced by a choline-deficient, L-amino acid-defined (CDAA) diet. MATERIALS & METHODS: We generated transgenic mice expressing HNP-1 under the control of a ß-actin-based promoter. HNP-1 transgenic and wild-type C57BL/6N mice were fed a CDAA diet for 16 weeks to induce hepatic steatosis and fibrosis. Serological and histological features were examined, and the effects of HNP-1 on hepatic stellate cell lines were assessed. RESULTS: HNP-1 transgenic and wild-type mice fed the CDAA diet showed no significant differences in serum alanine aminotransferase levels or the degree of hepatic steatosis based on Oil red O staining and hepatic triglyceride content. In contrast, Sirius Red and Azan staining showed significantly more severe hepatic fibrosis in HNP-1 transgenic mice compared with wild-type mice. In addition, significantly more α-smooth muscle actin-positive hepatic stellate cells were observed in the transgenic mice than in the wild-type mice. Finally, the proliferation of the LI90 hepatic stellate cell line increased in response to HNP-1. CONCLUSION: Our data indicate that HNP-1 enhances hepatic fibrosis in fatty liver by inducing hepatic stellate cell proliferation. Thus, neutrophil-derived HNP-1 may contribute to the progression of NASH.

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

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

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

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