BackgroundWe established a community-based cohort study to assess the long-term impact of the Great East Japan Earthquake on disaster victims and gene-environmental interactions on the incidence of major diseases such as cancer and cardiovascular diseases.MethodsWe asked participants to join our cohort in the health check-up settings and assessment center based settings. Inclusion criteria was 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), for example, carotid echography, calcaneal ultrasound bone mineral density, and so on. All participants agreed to measure genome information and to distribute their information widely.ResultsAs a result, 87,865 gave their informed consent to join our study. Participation rate at health check-up site was about 70%. The participants with Type 1 survey were more likely to have psychological distress than those of 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.ConclusionThis cohort comprised large sample size and it contains information on 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 disaster and also to establish personalized prevention based on genome, metabolome, and other omics information.

Background: Japan became the first country where heat-not-burn tobacco products were sold. Therefore, there was no information for actual status of heat-not-burn tobacco products.The objectives of the study profile are to inform that data can be freely available to external researchers, and to create collaborative research projects in the future.Methods: The Japan “Society and New Tobacco” Internet Survey (JASTIS) is a longitudinal internet cohort study which investigates perception, attitude and use of heat-not-burn tobacco, electronic cigarettes (e-cigarettes) and conventional tobacco products in Japan. The survey also includes demographic, health-related and socioeconomic factors. Participants were randomly selected and invited from internet panellists. The baseline survey was closed when the target number of respondents who had answered the questionnaire was met.Results: The study includes three cohorts (1-3) from the 2015 baseline survey and a cohort (4) from the 2017 baseline survey: cohort 1&4 were recruited based on sex and age: men and women aged 15-69 years (n=8240 for cohort 1 and n=5897 for cohort 4); cohort 2&3 were made by use status-based recruiting: e-cigarette and/or heat-not-burn tobacco ever users (n=2188; cohort 2) and combustible cigarette smokers without e-cigarette/heat-not-burn tobacco experience (n=724; cohort 3). The completion rates were 8.5 to 9.9%. All subjects were followed and assessed annually. Response rates for the follow-up survey were 65.5% in 2016, 55.3% in 2017 and 50.9% in 2018. Because Internet-based responders differ from the representative sample in Japan, we conducted the adjustment to account for “being an internet survey respondent” and reported about the products use in Japan. Recent study reported that prevalence of IQOS current-use among Japanese adults had rapidly increased to 3.6% in 2017.Conclusion: The JASTIS study provides the first estimates for heat-not-burn tobacco use in the world and e-cigarette use in Japan. For information on collaboration, please contact the corresponding author.

Many local workers have been involved in rescue and reconstruction duties since the Great East Japan Earthquake (GEJE) on March 11, 2011. These workers continuously confront diverse stressors as both survivors and relief and reconstruction workers. However, little is known about the psychological sequelae among these workers. Thus, we assessed the prevalence of and personal/workplace risk factors for probable post-traumatic stress disorder (PTSD), probable depression, and high general psychological distress in this population. Participants (N = 1294; overall response rate, 82.9%) were workers (firefighters, n = 327; local municipality workers, n = 610; hospital medical workers, n = 357) in coastal areas of Miyagi prefecture. The study was cross-sectional and conducted 14 months after the GEJE using a self-administered questionnaire which included the PTSD Checklist–Specific Version, the Patient Health Questionnaire-9, and the K6 scale. Significant risk factors from bivariate analysis, such as displacement, dead or missing family member(s), near-death experience, disaster related work, lack of communication, and lack of rest were considered potential factors in probable PTSD, probable depression, and high general psychological distress, and were entered into the multivariable logistic regression model. The prevalence of probable PTSD, probable depression, and high general psychological distress was higher among municipality (6.6%, 15.9%, and 14.9%, respectively) and medical (6.6%, 14.3%, and 14.5%, respectively) workers than among firefighters (1.6%, 3.8%, and 2.6%, respectively). Lack of rest was associated with increased risk of PTSD and depression in municipality and medical workers; lack of communication was linked to increased PTSD risk in medical workers and depression in municipality and medical workers; and involvement in disaster-related work was associated with increased PTSD and depression risk in municipality workers. The present results indicate that at 14 months after the GEJE, mental health consequences differed between occupations. High preparedness, early mental health interventions, and the return of ordinary working conditions might have contributed to the relative mental health resilience of the firefighters. Unlike the direct effects of disasters, workplace risk factors can be modified after disasters; thus, we should develop countermeasures to improve the working conditions of local disaster relief and reconstruction workers.

Purpose: The present study aimed to examine the association between adherence to the Japanese diet and the subsequent risk of all-cause and cause-specific mortality using a large-scale cohort from settings all over Japan. Methods: We analyzed data from a cohort study of 92,969 Japanese adults aged 45–74 years, covering 11 public health center areas nationwide. We collected dietary information using a validated 147-item food frequency questionnaire. Adherence to the Japanese diet consisting of eight components (high intake of rice, miso soup, seaweeds, pickles, green and yellow vegetables, fish, and green tea; low intake of beef and pork) was assessed using 8-item Japanese Diet Index (JDI8) score, with scores ranging from 0 to 8. The Cox proportional hazards model was used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for all-cause and cause-specific mortality. Results: During a median follow-up of 18.9 years, we documented 20,596 deaths. A higher JDI8 score was significantly associated with a lower risk for all-cause and cardiovascular disease (CVD) mortality. The multivariable-adjusted HR of all-cause and CVD mortality for the highest JDI8 score group (score of 6–8) versus the lowest JDI8 score group (score of 0–2) were 0.86 (95% CI 0.81–0.90, P trend < 0.001), and 0.89 (95% CI 0.80–0.99, P trend = 0.007), respectively. Conclusions: Adhering to the Japanese diet, as assessed by the JDI8, was associated with a decreased risk of all-cause and CVD mortality among adults living in multiple areas across Japan.

Although it has been reported that the Japanese dietary pattern is associated with a lower risk of incident functional disability among older people, the potential benefits of improving adherence to the Japanese diet remain unclear. The aim of the present study was to evaluate the association between 12-year change in adherence to the Japanese diet and the subsequent risk of incident functional disability in older people in Japan. We analyzed 10-year follow-up data from a cohort study of 2923 Japanese older adults (age ≥65 years) in 2006. We collected dietary information using a validated 39-item food frequency questionnaire at two time points (1994 and 2006). Adherence to the Japanese diet (high intake of rice, miso soup, seaweeds, pickles, green and yellow vegetables, fish, green tea; low intake of beef and pork, and coffee) was assessed using the Japanese Diet Index (JDI), which ranges from 0 to 9. Participants were categorized into five groups according to changes in the JDI score at these two time points. Data on incident functional disability from December 2006 to November 2016 were retrieved from the public long-term care insurance database. The Cox proportional hazards model was used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) for incident functional disability. During 22,466 person-years of follow-up, 1093 cases of incident functional disability were documented. Compared with participants in the group with the largest decrease in the JDI score (≤-2), the multivariate-adjusted HR (95% CI) of incident functional disability was 0.77 (0.61-0.98) for those in the largest increase group (≥+2). Improved adherence to the Japanese diet was associated with a significantly lower risk of incident functional disability in older people in Japan.

To investigate the association of smoking status and years since smoking cessation with the risk of incident dementia among elderly Japanese. We conducted a longitudinal analysis of smoking status and smoking cessation with dementia in prospective cohort study of 12,489 Japanese individuals aged ≥ 65 years who were followed up for 5.7 years. Information on smoking status and other lifestyle factors was collected via a questionnaire in 2006. Data on incident dementia were retrieved from the public Long-term Care Insurance Database. The Cox proportional hazards model was used to estimate the multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs) for incident dementia. During 61,613 person-years of follow-up, 1110 cases (8.9%) of incident dementia were documented. Compared with individuals who had never smoked, current smokers showed a higher risk of dementia (HR 1.46, 95% CI 1.17, 1.80). Among ex-smokers, the risk for those who had stopped smoking for ≤ 2 years was still high (HR 1.39, 95% CI 0.96, 2.01), however, quitting smoking for 3 years or longer mitigated the increased risk incurred by smokers; the multivariable HRs (95% CIs) were 1.03 (0.70, 1.53) for those who had stopped smoking for 3–5 years, 1.04 (0.74, 1.45) for 6–10 years, 1.19 (0.84, 1.69) for 11–15 years, and 0.92 (0.73, 1.15) for > 15 years. Our study suggests that the risk of incident dementia among ex-smokers becomes the same level as that of never smokers if they maintain abstinence from smoking for at least 3 years.