The association between living alone and depressive symptoms and the role of pet ownership among Japanese workers.

BACKGROUND: Living alone has been positively associated with the prevalence of depressive symptoms. We examined how a combination of living alone and pet ownership relates to depressive symptoms. METHODS: As part of the Japan Epidemiology Collaboration on Occupational Health Study, we conducted a survey on health-related lifestyles, including living arrangements and pet ownership, among 12,763 employees of five companies in 2018-2021. Depressive symptoms were assessed using the 11-item Center for Epidemiological Studies-Depression Scale (cutoff score ≥ 9). A Poisson regression model with a robust variance estimator was used to calculate prevalence ratio and 95% confidence interval (CI) while adjusting for covariates. RESULTS: Among the participants, 30.9% were depressed, 17.7% had pets, and 29.1% lived alone. Compared to individuals living with others but not with a pet, those living alone and not with a pet had a 1.17 times higher prevalence ratio of depressive symptoms (95% CI: 1.08-1.26). The corresponding figures were 1.03 (95% CI: 0.95-1.11) for those living with others and pet(s) and 1.42 (95% CI: 1.18-1.69) for those living alone but with pet(s). CONCLUSION: Living alone was significantly associated with a higher prevalence of depressive symptoms. The association was rather stronger among individuals with vs. without pets. Pet ownership may not be associated with decreased depressive symptoms.

Heated tobacco product use and abnormal glucose metabolism: a working population-based study.

AIMS: We aimed to assess the cross-sectional association of heated tobacco product (HTP) use with prediabetes and diabetes. METHODS: The present analysis included 8950 workers from 5 companies (Study I) and 31,341 workers from another large company (Study II), who participated in the Japan Epidemiology Collaboration on Occupational Health Study. The participants were divided into five groups: never smokers, past smokers, exclusive HTP users, dual users of cigarettes and HTPs, and exclusive cigarette smokers. Diabetes and prediabetes were defined according to the fasting blood glucose and HbA1c levels and self-reported diabetes treatment, using the American Diabetes Association criteria. We analyzed the data of Study I and II separately, and then pooled these estimates using the fixed-effect models, with adjustment for a wide range of covariates. RESULTS: In this study that included 40,291 participants (mean age, 46.6 years; men, 84.3%), about half of the current tobacco-related product users reported using HTPs. Exclusive HTP users had higher odds of prediabetes (pooled odds ratio 1.36; 95% CI 1.25-1.47) and diabetes (1.68; 95% CI 1.45-1.94) than never smokers. Similarly, dual users also had increased odds of prediabetes (pooled odds ratio, 1.26; 95% CI 1.13-1.39) and diabetes (1.93; 95% CI 1.63-2.29). The strength of these associations was comparable to that of cigarette smokers. We observed significantly higher HbA1c and fasting blood glucose levels among both exclusive HTP users and dual users compared to never smokers. CONCLUSION: HTP use was associated with an increased likelihood of prediabetes and diabetes. Prospective studies are warranted to confirm the cross-sectional association.

Heated tobacco products and circulating high-density lipoprotein cholesterol concentrations.

We aimed to assess the association between heated tobacco product (HTP) use and high-density lipoprotein cholesterol (HDL-C) concentration. Our study included 12,268 workers from five companies (Study I) and 36,503 workers from another large company (Study II). Participants were categorized into five groups: never smokers, past smokers, exclusive HTP users, dual users of cigarettes and HTPs, and exclusive cigarette smokers. We analyzed the data of Studies I and II separately and then pooled these estimates using a fixed-effect model. Of the 48,771 participants, 9.3% were exclusive HTP users, and 6.0% were dual users. Exclusive HTP users had modestly but significantly lower concentrations of HDL-C than never smokers, with the pooled mean difference being - 1.1 (95% CI - 1.5 to - 0.6) mg/dL. Dual users showed a further reduction (mean difference - 3.7 (- 4.2 to - 3.2) mg/dL), which was comparable to that of exclusive cigarette smokers versus never smokers (mean difference - 4.3 (- 4.7 to - 3.9) mg/dL). The pooled odds ratios (95% CIs) of having low HDL-C (< 40 mg/dL for men and 50 mg/dL for women) were 1, 0.99 (0.90-1.11), 1.25 (1.09-1.43), 2.02 (1.76-2.32), and 2.09 (1.88-2.32) for never smokers, past smokers, exclusive HTP users, dual users, and exclusive cigarette smokers, respectively. In conclusion, exclusive HTP users had lower HDL-C concentrations than never smokers, although higher than exclusive cigarette smokers. Moreover, dual users had HDL-C concentrations similar to those in exclusive cigarette smokers.

Effect of circadian rhythm type on serum lipid levels in shift workers: A 5-year cohort study.

We investigated how differences in circadian rhythm type affect the health of workers engaged in shift work. Employees, who were newly hired in a steel company between 2007 and 2011, received the Morningness-Eveningness Questionnaire (MEQ) survey. The target participants were 153 male shift workers who were not being treated with any antihyperlipidemic drugs and underwent periodic physical examinations including blood tests at least twice. According to the score of the MEQ at the time of joining the company, we classified the subjects into five types. Longitudinal changes in serum lipid level were estimated among the circadian rhythm types adjusted for age, BMI, and other covariates using a linear mixed model. The regression coefficient of total cholesterol level in the "definitely and moderately morning" group was -17.83 (95% confidence interval (CI): -33.42 to -2.23), and in the "intermediate 'group' was -16.84 [95% CI: -30.40 to -3.28], compared to the moderate evening type." The total cholesterol level was higher in the moderately evening type than in any of the other groups. Between the Morningness-Eveningness (ME) type and Low-density lipoprotein (LDL) cholesterol levels, compared with the "moderately evening type" group, the regression coefficient in the "intermediate type" group was -16.08 (95% CI: -28.79 to -3.37), and in the "definitely and moderately morning type" group was -17.50 [95% CI: -32.11 to -2.88]. The "moderately evening type" group had a higher LDL cholesterol level than any of the other groups. Evening-type circadian rhythm type shift workers are more prone to elevated serum lipid levels.

Age-, sex-, and diagnosis-specific incidence rate of medically certified long-term sick leave among private sector employees: The Japan Epidemiology Collaboration on Occupational Health (J-ECOH) study.

BACKGROUND: Long-term sick-leave is a major public health problem, but data on its incidence in Japan are scarce. We aimed to present reference data for long-term sick-leave among private sector employees in Japan. METHODS: The study population comprised employees of 12 companies that participated in the Japan Epidemiology Collaboration on Occupational Health Study. Details on medically certified sick-leave lasting ≥30 days were collected from each company. Age- and sex-specific incidence rate of sick-leave was calculated for the period of April 2012 to March 2014. RESULTS: A total of 1422 spells in men and 289 in women occurred during 162,989 and 30,645 person-years of observation, respectively. The three leading causes of sick-leave (percentage of total spells) were mental disorders (52%), neoplasms (12%), and injury (8%) for men; and mental disorders (35%), neoplasms (20%), and pregnancy-related disease (14%) for women. Incidence rate of sick-leave due to mental disorders was relatively high among men in their 20s-40s but tended to decrease with age among women. Incidence rate of sick-leave due to neoplasms started to increase after age 50 in men and after age 40 in women, making neoplasms the leading cause of sick-leave after age 50 for women and after age 60 for men and the second leading cause after age 40 for women and after age 50 for men. Pregnancy-related disease was the second leading cause of sick-leave among women aged 20-39 years. CONCLUSIONS: These results suggest that mental disorder, neoplasms, and pregnancy-related disease are the major causes of long-term sick-leave among private sector employees in Japan.