The power of genetic diversity in genome-wide association studies of lipids.

Increased blood lipid levels are heritable risk factors of cardiovascular disease with varied prevalence worldwide owing to different dietary patterns and medication use1. Despite advances in prevention and treatment, in particular through reducing low-density lipoprotein cholesterol levels2, heart disease remains the leading cause of death worldwide3. Genome-wideassociation studies (GWAS) of blood lipid levels have led to important biological and clinical insights, as well as new drug targets, for cardiovascular disease. However, most previous GWAS4-23 have been conducted in European ancestry populations and may have missed genetic variants that contribute to lipid-level variation in other ancestry groups. These include differences in allele frequencies, effect sizes and linkage-disequilibrium patterns24. Here we conduct a multi-ancestry, genome-wide genetic discovery meta-analysis of lipid levels in approximately 1.65 million individuals, including 350,000 of non-European ancestries. We quantify the gain in studying non-European ancestries and provide evidence to support the expansion of recruitment of additional ancestries, even with relatively small sample sizes. We find that increasing diversity rather than studying additional individuals of European ancestry results in substantial improvements in fine-mapping functional variants and portability of polygenic prediction (evaluated in approximately 295,000 individuals from 7 ancestry groupings). Modest gains in the number of discovered loci and ancestry-specific variants were also achieved. As GWAS expand emphasis beyond the identification of genes and fundamental biology towards the use of genetic variants for preventive and precision medicine25, we anticipate that increased diversity of participants will lead to more accurate and equitable26 application of polygenic scores in clinical practice.

A multi-layer functional genomic analysis to understand noncoding genetic variation in lipids.

A major challenge of genome-wide association studies (GWASs) is to translate phenotypic associations into biological insights. Here, we integrate a large GWAS on blood lipids involving 1.6 million individuals from five ancestries with a wide array of functional genomic datasets to discover regulatory mechanisms underlying lipid associations. We first prioritize lipid-associated genes with expression quantitative trait locus (eQTL) colocalizations and then add chromatin interaction data to narrow the search for functional genes. Polygenic enrichment analysis across 697 annotations from a host of tissues and cell types confirms the central role of the liver in lipid levels and highlights the selective enrichment of adipose-specific chromatin marks in high-density lipoprotein cholesterol and triglycerides. Overlapping transcription factor (TF) binding sites with lipid-associated loci identifies TFs relevant in lipid biology. In addition, we present an integrative framework to prioritize causal variants at GWAS loci, producing a comprehensive list of candidate causal genes and variants with multiple layers of functional evidence. We highlight two of the prioritized genes, CREBRF and RRBP1, which show convergent evidence across functional datasets supporting their roles in lipid biology.

A fine-scale genetic map of the Japanese population.

Genetic maps are fundamental resources for linkage and association studies. A fine-scale genetic map can be constructed by inferring historical recombination events from the genome-wide structure of linkage disequilibrium-a non-random association of alleles among loci-by using population-scale sequencing data. We constructed a fine-scale genetic map and identified recombination hotspots from 10 092 551 bi-allelic high-quality autosomal markers segregating among 150 unrelated Japanese individuals whose genotypes were determined by high-coverage (30×) whole-genome sequencing, and the genotype quality was carefully controlled by using their parents' and offspring's genotypes. The pedigree information was also utilized for haplotype phasing. The resulting genome-wide recombination rate profiles were concordant with those of the worldwide population on a broad scale, and the resolution was much improved. We identified 9487 recombination hotspots and confirmed the enrichment of previously known motifs in the hotspots. Moreover, we demonstrated that the Japanese genetic map improved the haplotype phasing and genotype imputation accuracy for the Japanese population. The construction of a population-specific genetic map will help make genetics research more accurate.

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.

Progress report of the Tohoku Medical Megabank Community-Based Cohort Study: Study profile of the repeated center-based survey during second period in Miyagi Prefecture.

BACKGROUND: The purpose of this study was to report the basic profile of the Miyagi Prefecture part of a repeated center-based survey during the second period (2nd period survey) of the Tohoku Medical Megabank Community-Based Cohort Study (TMM CommCohort Study), as well as the participants' characteristics based on their participation type in the baseline survey. METHODS: The 2nd period survey, conducted from June 2017 to March 2021, included participants of the TMM CommCohort Study (May 2013 to March 2016). In addition to the questionnaire, blood, urine, and physiological function tests were performed during the 2nd period survey. There were three main ways of participation in the baseline survey: Type 1, Type 1 additional, or Type 2 survey. The 2nd period survey was conducted in the same manner as the Type 2 survey, which was based on the community support center (CSC). RESULTS: In Miyagi Prefecture, 29,383 (57.7%) of 50,967 participants participated in the 2nd period survey. The participation rate among individuals who had visited the CSC was approximately 80%. Although some factors differed depending on the participation type in the baseline survey, the 2nd period survey respondents in the Type 1 and Type 2 survey groups at baseline had similar traits. CONCLUSIONS: The 2nd period survey of the TMM CommCohort Study provided detailed follow-up information. Following up on the health conditions of the participants will clarify the long-term effects of disasters and contribute to personalized prevention.

Genome-wide association study of the risk of chronic kidney disease and kidney-related traits in the Japanese population: J-Kidney-Biobank.

Chronic kidney disease (CKD) is a syndrome characterized by a gradual loss of kidney function with decreased estimated glomerular filtration rate (eGFR), which may be accompanied by an increase in the urine albumin-to-creatinine ratio (UACR). Although trans-ethnic genome-wide association studies (GWASs) have been conducted for kidney-related traits, there have been few analyses in the Japanese population, especially for the UACR trait. In this study, we conducted a GWAS to identify loci related to multiple kidney-related traits in Japanese individuals. First, to detect loci associated with CKD, eGFR, and UACR, we performed separate GWASs with the following two datasets: 475 cases of CKD diagnosed at seven university hospitals and 3471 healthy subjects (dataset 1) and 3664 cases of CKD-suspected individuals with eGFR <60 ml/min/1.73 m2 or urinary protein ≥ 1+ and 5952 healthy subjects (dataset 2). Second, we performed a meta-analysis between these two datasets and detected the following associated loci: 10 loci for CKD, 9 loci for eGFR, and 22 loci for UACR. Among the loci detected, 22 have never been reported previously. Half of the significant loci for CKD were shared with those for eGFR, whereas most of the loci associated with UACR were different from those associated with CKD or eGFR. The GWAS of the Japanese population identified novel genetic components that were not previously detected. The results also suggest that the group primarily characterized by increased UACR possessed genetically different features from the group characterized by decreased eGFR.

Combined Associations of Liver Enzymes and Obesity With Diabetes Mellitus Prevalence: The Tohoku Medical Megabank Community-based Cohort Study.

BACKGROUND: Alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT) are enzymes associated with diabetes mellitus (DM) prevalence. However, limited information is available regarding the association of liver enzymes and DM consistently present in obese and non-obese individuals. We examined whether the combination of ALT and GGT enzymes is associated with the prevalence of DM, regardless of obesity, in a general Japanese population. METHODS: We conducted a cross-sectional study of 62,786 participants aged ≥20 years who lived in Miyagi and Iwate, Japan. We divided all the participants into eight groups according to the ALT level (low: <30 IU/L and high: ≥30 IU/L), GGT level (low: <50 IU/L and high: ≥50 IU/L), and the presence of obesity. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) using multivariable logistic regression analysis, adjusting for potential confounders, to determine associations of the combination of ALT and GGT levels and obesity with DM prevalence. RESULTS: Overall, 6,008 participants (9.6%) had DM. Compared to non-obese individuals with low ALT and GGT levels, the participants with high ALT and GGT levels had high ORs for DM in both obese (OR 4.06; 95% CI, 3.61-4.56) and non-obese groups (OR 2.19; 95% CI, 1.89-2.52). The obese group had high ORs for DM, even at low ALT and GGT levels. CONCLUSION: High ALT and GGT levels are associated with DM prevalence in obese and non-obese participants. This finding suggests that correcting ALT and GGT levels and controlling obesity are important for the prevention of DM.

Body mass index and colorectal cancer risk: A Mendelian randomization study.

Traditional observational studies have reported a positive association between higher body mass index (BMI) and the risk of colorectal cancer (CRC). However, evidence from other approaches to pursue the causal relationship between BMI and CRC is sparse. A two-sample Mendelian randomization (MR) study was undertaken using 68 single nucleotide polymorphisms (SNPs) from the Japanese genome-wide association study (GWAS) and 654 SNPs from the GWAS catalogue for BMI as sets of instrumental variables. For the analysis of SNP-BMI associations, we undertook a meta-analysis with 36 303 participants in the Japanese Consortium of Genetic Epidemiology studies (J-CGE), comprising normal populations. For the analysis of SNP-CRC associations, we utilized 7636 CRC cases and 37 141 controls from five studies in Japan, and undertook a meta-analysis. Mendelian randomization analysis of inverse-variance weighted method indicated that a one-unit (kg/m2 ) increase in genetically predicted BMI was associated with an odds ratio of 1.13 (95% confidence interval, 1.06-1.20; P value <.001) for CRC using the set of 68 SNPs, and an odds ratio of 1.07 (1.03-1.11, 0.001) for CRC using the set of 654 SNPs. Sensitivity analyses robustly showed increased odds ratios for CRC for every one-unit increase in genetically predicted BMI. Our MR analyses strongly support the evidence that higher BMI influences the risk of CRC. Although Asians are generally leaner than Europeans and North Americans, avoiding higher BMI seems to be important for the prevention of CRC in Asian populations.

Artificial intelligence powered statistical genetics in biobanks.

Large-scale, sometimes nationwide, prospective genomic cohorts biobanking rich biological specimens such as blood, urine and tissues, have been established and released their vast amount of data in several countries. These genetic and epidemiological resources are expected to allow investigators to disentangle genetic and environmental components conferring common complex diseases. There are, however, two major challenges to statistical genetics for this goal: small sample size-high dimensionality and multilayered-heterogenous endophenotypes. Rather counterintuitively, biobank data generally have small sample size relative to their data dimensionality consisting of genomic variation, lifestyle questionnaire, and sometimes their interaction. This is a widely acknowledged difficulty in data analysis, so-called "p¼n problem" in statistics or "curse of dimensionality" in machine-learning field. On the other hand, we have too many measurements of individual health status, which are endophenotypes, such as health check-up data, images, psychological test scores in addition to metabolomics and proteomics data. These endophenotypes are rich but not so tractable because of their worsen dimensionality, and substantial correlation, sometimes confusing causation among them. We have tried to overcome the problems inherent to biobank data, using statistical machine-learning and deep-learning technologies.

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

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

Relationship Between Calcium Intake and Impaired Activities of Daily Living in a Japanese Population: NIPPON DATA90.

BACKGROUND: Major reasons for long-term care insurance certification in Japan are stroke, dementia, and fracture. These diseases are reported to be associated with calcium intake. This study examined the association between calcium intake and impaired activities of daily living (ADL) using the data from NIPPON DATA90, consisting of representative sample of the Japanese population. METHODS: A population-based nested case-control study was performed. A baseline survey was conducted in 1990, followed by ADL surveys of individuals ≥65 years old in 2000. Individuals with impaired ADL and selected age- and sex-matched controls were then identified. We obtained 132 pairs. Calcium intake was energy-adjusted using the residual method. The association between calcium intake and impaired ADL was examined using conditional logistic regression models. To assess the accuracy of the estimates, we conducted bootstrap analyses. RESULTS: The adjusted odds ratios (ORs) for impaired ADL compared with the group with a calcium intake of <476 mg/day were 0.72 (95% confidence interval [CI], 0.37-1.40) for the 476-606 mg/day group and 0.44 (95% CI, 0.21-0.94) for the ≥607 mg/day group in 2000 (P for linear trend = 0.03). After the bootstrap analyses, the inverse relationship unchanged (median OR per 100-mg rise in calcium intake, 0.87 [1,000 resamplings]; 95% CI, 0.76-0.97). CONCLUSIONS: After bootstrap analyses, calcium intake was inversely associated with impaired ADL 10 years after the baseline survey.

Study Profile of the Tohoku Medical Megabank Community-Based Cohort Study.

BACKGROUND: We established a community-based cohort study to assess the long-term impact of the Great East Japan Earthquake on disaster victims and gene-environment interactions on the incidence of major diseases, such as cancer and cardiovascular diseases. METHODS: We asked participants to join our cohort in the health check-up settings and assessment center based settings. Inclusion criteria were aged 20 years or over and living in Miyagi or Iwate Prefecture. We obtained information on lifestyle, effect of disaster, blood, and urine information (Type 1 survey), and some detailed measurements (Type 2 survey), such as carotid echography and calcaneal ultrasound bone mineral density. All participants agreed to measure genome information and to distribute their information widely. RESULTS: As a result, 87,865 gave their informed consent to join our study. Participation rate at health check-up site was about 70%. The participants in the Type 1 survey were more likely to have psychological distress than those in the Type 2 survey, and women were more likely to have psychological distress than men. Additionally, coastal residents were more likely to have higher degrees of psychological distress than inland residents, regardless of sex. CONCLUSION: This cohort comprised a large sample size and it contains information on the natural disaster, genome information, and metabolome information. This cohort also had several detailed measurements. Using this cohort enabled us to clarify the long-term effect of the disaster and also to establish personalized prevention based on genome, metabolome, and other omics information.

Association between the social isolation and depressive symptoms after the great East Japan earthquake: findings from the baseline survey of the TMM CommCohort study.

BACKGROUND: Social isolation and mental health issues have become a severe problem in disaster areas in the Great East Japan Earthquake. This study examined whether the combination of the house damage and social isolation or the combination of the death of family members and social isolation is associated with depressive symptoms among survivors using the baseline study data of the Tohoku Medical Megabank Project Community-Based Cohort Study (TMM CommCohort Study). METHODS: We used cross-sectional data from a baseline survey of 48,958 participants (18,423 males, 30,535 females; aged 60.1 ± 11.2 years) to examine the association between social isolation measured by the Lubben social network scale 6 (LSNS-6) and depressive symptoms measured by the Center for Epidemiological Studies-Depressive Scale (CES-D). The presence of social isolation and depressive symptoms was defined by an LSNS-6 score of < 12 and a CES-D score of ≥16, respectively. We performed a logistic regression analysis to determine the multivariable-adjusted odds ratio (95% confidence interval) [AOR (95% CI)] for depressive symptoms according to sex in the social isolation in comparison to without social isolation, and the associations of the combination of the house damage or the death of family members and social isolation and depressive symptoms. RESULTS: Social isolation was significantly associated with depressive symptoms (males: OR = 1.87; 95% CI = 1.72-2.04, females: OR = 2.13; 95% CI = 2.00-2.26). Both males and females respondents with severe house damage and social isolation had a greater risk of depressive symptoms in comparison to those with an undamaged house and without social isolation (males: OR = 3.40; 95% CI = 2.73-4.24, females: OR = 2.92; 95% CI = 2.46-3.46). The risk of depressive symptoms was also higher in both males and females respondents with the death of family members and social isolation in comparison to those without the death of family members and without social isolation (males: OR = 2.18; 95% CI = 1.90-2.50, females: OR = 2.60; 95% CI = 2.35-2.88). CONCLUSION: The findings suggested that a combination of social isolation and severe house damage and the death of family members caused by a large-scale natural disaster was associated with a higher risk of depressive symptoms although the interaction was not statistically significant.

Association between the combined fat mass and fat-free mass index and hypertension: The Tohoku Medical Megabank Community-based Cohort Study.

BACKGROUND: A  higher body fat percentage is associated with hypertension, even in non-obese individuals. The difference in body composition may be related to hypertension. The fat mass index (FMI) and fat-free mass index (FFMI) are proposed indicators of body composition. This study aimed to examine the relationship of a combination of FMI and FFMI with hypertension. METHODS: We conducted a cross-sectional study of 5,058 men and 11,842 women aged ≥ 20 years in the Miyagi Prefecture, northeastern Japan. The FMI and FFMI were calculated as the fat mass and fat-free mass divided by the height squared, respectively. The indices were classified into quartiles and combined into 16 groups. Hypertension was defined as casual blood pressure ≥ 140/90 mmHg and/or self-reported treatment for hypertension. Multivariable logistic regression models, adjusted for potential confounders, were used to assess the relationship of a combination of FMI and FFMI with hypertension. RESULTS: Higher FMI was associated with hypertension in most of the FFMI subgroups. Similarly, a higher FFMI was associated with hypertension in most of FMI subgroups. For men, the association between FFMI and hypertension in the lowest FMI group was not significant. CONCLUSIONS: Reducing the FMI and FFMI may be important in preventing hypertension. For men, the relationship between the FFMI and hypertension in the lowest FMI group might be weak.

Dietary Inflammatory Index Positively Associated With High-Sensitivity C-Reactive Protein Level in Japanese From NIPPON DATA2010.

BACKGROUND: It has been reported that chronic inflammation may play an important role in the pathogenesis of several serious diseases and could be modulated by diet. Recently, the Dietary Inflammatory Index (DII®) was developed to assess the inflammatory potential of the overall diet. The DII has been reported as relevant to various diseases but has not been validated in Japanese. Thus, in the present study, we analyzed the relationship between DII scores and high-sensitivity C-reactive protein (hs-CRP) levels in a Japanese population. METHODS: Data of the National Integrated Project for Prospective Observation of Non-communicable Disease and its Trends in the Aged 2010 (NIPPON DATA2010), which contained 2,898 participants aged 20 years or older from the National Health and Nutrition Survey of Japan (NHNS2010), were analyzed. Nutrient intakes derived from 1-day semi-weighing dietary records were used to calculate DII scores. Energy was adjusted using the residual method. Levels of hs-CRP were evaluated using nephelometric immunoassay. Multiple linear regression analyses were performed. RESULTS: After adjusting for age, sex, smoking status, BMI, and physical activity, a significant association was observed between DII scores and log(CRP+1) (standard regression coefficient = 0.05, P < 0.01). Although it was not statistically significant, the positive association was consistently observed in almost all age-sex subgroups and the non-smoker subgroup. CONCLUSIONS: The current study confirmed that DII score was positively associated with hs-CRP in Japanese.

Use of a multilayer perceptron to create a prediction model for dressing independence in a small sample at a single facility.

[Purpose] This study aimed to assess the accuracy of a prediction model for dressing independence created with a multilayer perceptron in a small sample at a single facility. [Participants and Methods] This retrospective observational study included 82 first-stroke patients. The prediction models for dressing independence at hospital discharge were created using a multilayer perceptron, logistic regression, and a decision tree, and compared for predictive accuracy. Age, dressing performance, trunk function, visuospatial perception, balance, and cognitive function at admission were used as variables. [Results] The area under the receiver operating characteristic curve, classification accuracy, sensitivity, specificity, positive-predictive value, and negative-predictive value for training data were highest with the multilayer perceptron model. Cochran's Q and multiple comparison tests revealed a significant difference between logistic regression and multilayer perceptron models. Testing of data in 10-fold cross-validation yielded the same results, except for sensitivity. [Conclusion] The present study suggested that higher accuracy could be expected with a multilayer perceptron than with logistic regression and a decision tree when creating a prediction model for independence of activities of daily living in a small sample of stroke patients.

[Association between mild physical injury and psychological distress: Shichigahama Health Promotion Project].

Objective　Although a number of previous studies have investigated the association between natural disaster-related physical injury and mental health, very few have focused on mild physical injury. The aim of this study was to evaluate the association between natural disaster-related mild physical injury and psychological distress in a cross-sectional study.Method　This study is a part of the Shichigahama Health Promotion Project, which was conducted in cooperation with the Tohoku University and Shichigahama Town, Miyagi Prefecture, after the Great East Japan Earthquake (GEJE). We conducted the research about one year after the GEJE, and performed logistic regression analyses using 3,844 participants (1,821 males/2,023 females) aged 20 years or older, who answered all the questions on physical injuries and the Kessler 6 scale (K6), after adjusting for gender, age, social factors, and lifestyles. Psychological distress was defined as a K6 score ≥ 13 out of 24 points. We also investigated the effect of other disaster situations on the association between mild physical injury and psychological distress by stratifying the dataset by bereavement, witnessing someone's death, and house damage.Results　The participants with physical injury were at a significantly higher risk of psychological distress, with an adjusted odds ratio (aOR) of 2.05 and 95% confidence interval (CI) of 1.26-3.34, than those uninjured. Additionally, the participants with mild physical injury were at a significantly higher risk of psychological distress (aOR=2.18, 95% CI=1.32-3.59). In the subgroup of participants with small-scale house damage, mild physical injury was significantly associated with psychological distress with an aOR of 4.01 and 95% CI of 2.03-7.93, whereas not in the subgroup of those with large-scale house damage, and a significant interaction was detected between mild physical injury and house damage.Conclusion　We investigated the association between natural disaster-related physical injury and psychological distress in a cohort of approximately 4,000 residents in an area devastated by the GEJE. In this study, natural disaster-related physical injury was positively associated with psychological distress. The finding indicates that even mild physical injury can be an indicator of high risk for psychological distress.

Impact of social capital on psychological distress and interaction with house destruction and displacement after the Great East Japan Earthquake of 2011.

AIM: Social capital has been considered an important factor affecting mental-health outcomes, such as psychological distress in post-disaster settings. Although disaster-related house condition and displacement could affect both social capital and psychological distress, limited studies have investigated interactions. This study aimed to examine the association between social capital and psychological distress, taking into consideration the interaction of disaster-related house condition after the Great East Japan Earthquake of 2011. METHODS: Using data from 3793 adults living in Shichigahama, Miyagi Prefecture, Japan, we examined the association between social capital measured by generalized trust and psychological distress measured by the Kessler 6 scale. We conducted stratified analysis to investigate an interaction of house destruction and displacement. Multivariate analyses taking into consideration the interaction were performed. RESULTS: In the crude analysis, low social capital (odds ratio [OR] 4.46; 95% confidence interval [CI], 3.27-6.07) and large-scale house destruction (OR 1.96; 95%CI, 1.47-2.62) were significantly associated with psychological distress. Stratified analyses detected an interaction with house destruction and displacement (P for interaction = 0.04). Multivariate analysis with interaction term revealed that individuals with low social capital, large-scale house damage, and displacement were at greater risk of psychological distress, corresponding to adjusted OR of 5.78 (95%CI, 3.48-9.60). CONCLUSION: In the post-disaster setting, low social capital increased the risk of psychological distress, especially among individuals who had large-scale house destruction. Among the participants with severe disaster damage, high social capital would play an important role in protecting mental health.

Partners' Ongoing Treatment for Chronic Disease and the Risk of Psychological Distress after the Great East Japan Earthquake.

Several studies have reported that not only patients with chronic diseases but also their partners are likely to face major psychosocial problems. This study examined the association between a partner's ongoing treatment for chronic disease and the risk of psychological distress after the Great East Japan Earthquake (GEJE). In 2012, a questionnaire was distributed as part of a cross-sectional study of participants aged 20 years or older living in a municipality that had been severely inundated by the tsunami following the GEJE. We identified couples using the household numbers of the municipality and collected self-reported information on ongoing chronic disease treatment for stroke, cancer, myocardial infarction, and angina. Psychological distress was evaluated using the Kessler 6 scale (K6) and was defined as a score ≥ 5/24 points. Among 1,246 couples (2,492 participants) thus identified, 2,369 completed the K6. The number of participants whose partners were under treatment for chronic diseases was 209 (9%). Overall, participants with partners who were receiving treatment for chronic diseases (odds ratio [OR] = 1.3, 95% confidence interval [CI] = 0.95-1.8, P = 0.09) did not show a significantly higher risk of psychological distress using logistic regression analysis. Women, but not men, whose partners were receiving treatment for chronic diseases, had a higher risk of psychological distress (women: OR = 1.6, P = 0.02; men: OR = 1.0, P = 0.92). After the GEJE, only in women the presence of partners under treatment for chronic diseases appears to be a risk factor for psychological distress.