Japanese Working Population Research Articles

Communication Apprehension in the Workplace: The Role of Position and Facilitation Skills

Communication apprehension (CA) is widely recognized as a significant inhibitor of communication and performance, making its management crucial. This study explored the connections between gender, managerial status, communication frequency, and discussion skills in explaining CA in the Japanese working population ( N = 300). Our findings suggest that facilitation skills explain CA better than personal attributes or communication frequency and that the gender difference in CA was only observed in nonmanagers. We discuss the implications of our findings for research and education.

Clustering of restorative sleep and lifestyle habits in Japanese male working population

Non-restorative sleep (NRS) affects not only individuals’ health, but also company productivity, highlighting the importance of measures in the workplace to improve sleep. This study aimed to examine the clustering of the presence of restorative sleep (RS) and lifestyle habits in a Japanese working population and to explore the characteristics of these clusters. The subjects were 58,150 Japanese working men aged 40−59 years who underwent health check-ups across the country from April 2015 to March 2016. Data for the presence of RS, the frequency and amount of drinking, smoking/exercise habits, and body mass index obtained from health check-ups were clustered with latent class analysis. In addition, the characteristics of each cluster were examined from the perspectives of lifestyle-related disease-associated blood test results obtained from health check-ups and the status of medical treatment at medical institutions as determined from medical claims data. Consequently, RS and lifestyle habits were found to form five clusters. The “NRS, no exercise, drinkers” cluster showed the highest probability of not achieving RS. An “Obese, occasional binge drinkers” cluster with a higher percentage of patients with sleep-apnea syndrome and a “Nondrinkers” cluster with proportions of those taking sleeping pills/anxiolytics and antidepressants/antipsychotics were observed. Furthermore, the “Daily smokers and drinkers” and “RS and drinkers” clusters showed a relatively high probability of achieving RS. These findings suggest that some individuals may not be aware of the sleep disorders caused by their drinking and smoking habits. Measures to improve sleep must be tailored to the characteristics of each cluster.

Meat intake and type 2 diabetes among Japanese workers: a prospective study.

Red meat and processed meat intake has been linked to increased risk of type 2 diabetes; however, evidence from Asia is limited and inconsistent. We prospectively examined the association of intake of total meat and its subtype with type 2 diabetes in a Japanese working population. Participants were 2709 workers aged 18-78 years who reported no history of diabetes when they responded to a health survey for the first time between 2012 and 2019. Dietary intake was assessed using a validated self-administered diet history questionnaire. The incidence of type 2 diabetes was assessed via annual health checkups from baseline through March 2023. Type 2 diabetes was defined as fasting blood glucose ≥ 126 mg/dl, casual blood glucose ≥ 200 mg/dl, HbA1c ≥ 6·5 %, self-report of diabetes or current use of anti-diabetic drugs. Hazard ratios according to tertile of meat intake were estimated using Cox proportional hazards regression. During 16119 person-years of follow-up, 135 (5·0 %) workers developed type 2 diabetes. Intakes of total meat, red meat, processed meat and poultry were not associated with risk of type 2 diabetes. After adjustment for covariates, hazard ratios for the highest v. lowest tertile of meat intake were 1·01 (95 % CI 0·63, 1·62) for total meat, 1·02 (95 % CI 0·66, 1·58) for red meat, 0·99 (95 % CI 0·65, 1·49) for processed meat and 1·13 (95 % CI 0·71, 1·80) for poultry. Our findings suggest that meat intake is not associated with the risk of type 2 diabetes among Japanese workers.

Examination of factors related to problem drinking among the working population: The Japanese civil servants study

Problem drinking affects not only the health of a population but also the productivity of a nation, especially if it is rampant among the working population. This study examines the association between problem drinking and work characteristics, work-family status, and social situations among the Japanese working population. Multivariable logistic regression analysis was performed on the basis of gender on 3136 participants (men: 65.1%, women: 34.9%) adopted from the Japanese Civil Servants Study in 2014 (response rate: 87.8%), to examine the factors related to problem drinking, after adjusting for frequency and quantity of drinking. Problem drinking was assessed using the Cutdown, Annoyed, Guilty, and Eye-opener (CAGE) questionnaire. The presence of problem drinking was found in 24.3% of men and 10.3% of women. The analysis showed that in men, poor work performance (OR: 1.34, 95% CI: 1.00–1.79), high family-to-work conflict (OR: 1.54, 95% CI: 1.14–2.09), and high work-to-family conflict (OR: 1.63, 95% CI: 1.14–2.34) were significantly associated with problem drinking, whereas in women, high work-to-family conflict (OR: 2.45, 95% CI: 1.21–4.95) was significantly associated with problem drinking. Although the number of close friends is negatively associated with problem drinking in women, the significance disappeared in the fully adjusted model. It can be concluded that it is important for both men and women to strike a balance between work and family life. Moreover, owing to gender differences, work performance may be important for men, and the presence of close friends may be important for women, in reducing the risk of problem drinking.

Eating behaviors and depressive symptoms among Japanese workers: the Furukawa Nutrition and Health Study.

In addition to the potential effects of nutrients on mood, eating behaviors have been suggested to be associated with depressive symptoms. We investigated the prospective association between the accumulation of unhealthy eating behaviors and depressive symptoms in a Japanese working population. Participants were 914 workers (aged 19-68 years) who did not have depressive symptoms at baseline (April 2012 and May 2013) and attended a 3-year follow-up survey (April 2015 and May 2016). Unhealthy eating behaviors (skipping breakfast, eating dinner just before bedtime, and snacking after dinner) were assessed at baseline. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression (CES-D) scale at follow-up. Multiple logistic regression was used to estimate the odds ratio of depressive symptoms (CES-D score ≥16) at follow-up according to the number of unhealthy eating behaviors. In a model with adjustment of background factors, participants having 2-3 unhealthy eating behaviors at baseline had significantly higher risk of developing depressive symptoms (OR, 2.02; 95% CI, 1.21-3.38) compared with those having no such behaviors. After adjustment for occupational and lifestyle factors, the association was slightly attenuated but remained significant (OR, 1.87; 95% CI, 1.10-3.21). This association was further attenuated and became statistically non-significant after additional adjustment for nutritional factors (OR, 1.67; 95% CI, 0.96-2.90). Our results suggest that the accumulation of unhealthy eating behaviors is associated with an increased risk of depressive symptoms and that this association may be partly ascribed to a lower intake of nutrients with mood-improving effects.

Isoflavone intake and depressive symptoms among workers

Background & AimHigh intake of isoflavones has been reported to be associated with decreased prevalence of depressive symptoms. However, no prospective study has examined this association. We prospectively investigated the association between isoflavone intake and depressive symptoms in a Japanese working population. MethodsParticipants were 1162 workers (1033 men and 129 women aged 18-68 years) without depressive symptoms at baseline. Dietary intake was assessed using a validated self-administered diet history questionnaire. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression (CES-D) scale. Cox proportional hazards regression for interval-censored data was used to estimate the hazard ratio of depressive symptoms (CES-D ≥16) according to the tertile of isoflavone intake with adjustment for covariates. ResultsDuring 5065 person-years of follow-up, 276 (23.8%) workers were newly identified as having depressive symptoms. Isoflavone intake was not associated with risk of depressive symptoms. After adjustment for lifestyle and dietary factors and baseline CES-D score, the multivariable-adjusted hazard ratios (95% confidence interval) for the lowest through highest tertile of isoflavone intake were 1.00 (reference), 0.93 (0.66-1.31), and 0.93 (0.62-1.38) (P for trend = 0.70). ConclusionsOur findings suggest that higher isoflavone intake is not associated with decreased risk of depressive symptoms among Japanese.

Identifying Clusters of Health Behaviors in a Japanese Working Population at Risk for Non-Communicable Diseases: A Latent Class Analysis of 12,168 Individuals

IntroductionNoncommunicable diseases (NCDs) have become a significant global problem. Health behaviors are associated with NCDs, and characterizing populations using a public health approach can help provide specific interventions according to their characteristics. This study aims to examine the formation of clusters of health behavior combinations in the Japanese working population at risk of NCDs, taking into account the influences of age and gender, using latent class analysis. MethodsParticipants were individuals at risk for NCDs but had not previously been diagnosed with any. Latent class analysis (LCA) was used to study clustering based on basic characteristics and health behaviors. All statistical analyses were conducted using R (Version 4.0.4) and the “poLCA” package (Version 1.6.0). ResultsThis study included 12,168 participants. LCA compared models with one to six latent classes. The five-class model was determined to be the most appropriate based on Bayesian Information Criterion, Akaike Information Criterion, and G^2 values, as well as distinguishable cluster characteristics. Cluster 1: “having healthy lifestyles but disliking hospitals”; Cluster 2: “women with healthy lifestyle behaviors”; Cluster 3: “general population”; Cluster 4: “middle-aged group in need of lifestyle improvement”; Cluster 5: “a group receiving treatment for lifestyle-related diseases." ConclusionsThis study reveals discernible health behavior patterns in a sample of the Japanese population using large real-world data, suggesting the effectiveness of distinct approaches when considering a population approach to public health.

Association between meal frequency with others and psychological distress during the COVID-19 pandemic: A cross-sectional study.

Previous studies evaluated the association between eating alone and mental health mainly in older people and adolescents. This study aimed to evaluate the association between dinner frequency with others and psychological distress during the COVID-19 outbreak among the Japanese working population. Data were acquired from a prospective online cohort study (the Employee Cohort Study in the COVID-19 pandemic in Japan) conducted in February 2021 as a cross-sectional design. Dinner frequency with others was categorized into five groups: "almost daily," "4-5 times per week," "2-3 times per week," "once per week," and "less than once per week," setting them as a predictor variable. Modified Poisson regression was performed to calculate the prevalence ratio of psychological distress with multiple imputation for missing data. Global fear and worry about COVID-19 were adjusted as a covariate. A total of 1171 participants completed the questionnaire. Respondents who ate dinner with others "almost daily" had the least psychological distress than those who ate with others "4-5 times," "2-3 times," and "once per week" in the crude model (prevalence ratio (95% CI): 1 [reference], 1.34 [1.08-1.67], 1.40 [1.15-1.69], 1.44 [1.12-1.85], respectively). The association was comparable after adjusting for global fear and worry about COVID-19. Among those who ate dinner with others at least once a week, those who ate with others "almost daily" had the least psychological distress. The association was comparable after adjusting for global fear and worry about COVID-19. Further study is needed on why those who eat with others less than once a week may have a lower prevalence ratio of having mental distress.

Limited social support is associated with depression, anxiety, and insomnia in a Japanese working population.

Lack of social support is associated with depression, anxiety, and insomnia. This study aimed to determine the source of support related to depression, anxiety, and insomnia among Japanese workers. As part of a cohort study, we conducted a questionnaire survey among city government employees in Koka City, Shiga Prefecture, Japan, from September 2021 to March 2022. We used the Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), and Insomnia Severity Index (ISI) to assess depressive symptoms, anxiety symptoms, and insomnia, respectively. We used the Brief Job Stress Questionnaire (BJSQ) to assess job stressors and social support (from supervisors, colleagues, and family). A total of 1,852 Japanese employees (38.4% male, 45.9 ± 12.9 years) participated in the survey, with 15.5, 10.8, and 8.2% of the participants having depressive symptoms (PHQ-9 ≥ 10), anxiety symptoms (GAD-7 ≥ 10), and insomnia (ISI ≥ 15), respectively. The logistic regression analysis suggested that job stressors were associated with depressive symptoms (p < 0.001), anxiety symptoms (p < 0.001), and insomnia (p = 0.009). In contrast, support from co-workers (p = 0.016) and family members (p = 0.001) was associated with decreased depressive symptoms. Support from family members was associated with decreased insomnia (p = 0.005). Social support from co-workers and family may be associated with reduced depressive symptoms, and family support may be associated with reduced insomnia in the Japanese working population. https://clinicaltrials.gov/ct2/show/NCT03276585.

How Sleep Quality Relates to Bodily and Oral Symptoms: An Analysis from Japanese National Statistics.

Sleep is one of the most important health-related factors. This cross-sectional study focused on sleep quality relates to systemic symptoms, including dental symptoms. Resource data were compiled from 7995 men and women aged 30 to 69 years, which is the core of the Japanese working population. The subjects were divided into four groups based on their answers to two questions, one on sleep time and one on sleep sufficiency, and groups were compared with other items in the questionnaire by means of a contingency table analysis (χ2 test). Relationships were found between the sleep groups and basic attributes, the presence of subjective symptoms, and the presence of hospital visits. The items with significant relationships included 14 symptoms, such as lower back pain (p &lt; 0.01) and four diseases, including high blood pressure (p &lt; 0.01). A multinomial logistic regression was conducted with the sleep groups as objective variables. In the poor sleep group, significant odds ratios were found for four items, including hours of work (odds ratio: 2.53) and feeling listless (2.01). The results allowed multiple symptoms and diseases related to sleep quality to be identified, and different trends in the response rates of the groups were found. These results suggest that the useful classification of sleep quality groups according to health problems contributes to understanding the effects of different symptoms.

Prolonged Sleep Latency and Reduced REM Latency Are Associated with Depressive Symptoms in a Japanese Working Population.

Background: Examining the relationship between sleep and depression may be important for understanding the aetiology of affective disorders. Most studies that use electroencephalography (EEG) to objectively assess sleep have been conducted using polysomnography in the laboratory. Impaired sleep continuity, including prolonged sleep latency and changes in rapid eye movement (REM) sleep, have been reported to be associated with depression in clinical settings. Here, we aimed to use home EEG to analyse the association between sleep and depressive symptoms. Methods: We performed a cross-sectional epidemiological study in a large Japanese working population to identify the EEG parameters associated with depressive symptoms based on the results of a questionnaire survey and home EEG measurements using 1-channel (1-Ch) EEG. Results: The study included 650 Japanese patients (41.2% male, 44.7 ± 11.5 years) who underwent home EEG monitoring along with the Patient Health Questionnaire-9 (PHQ-9) to assess depressive symptoms. Logistic regression analysis revealed that depressive symptoms (PHQ-9 ≥ 10) were associated with sleep latency (odds ratio (OR) 1.02; 95% confidence interval (CI): 1.00–1.04) and REM latency (OR, 0.99; 95% CI: 0.99–1.00). Conclusions: Our results suggest that depressive symptoms are associated with prolonged sleep latency and reduced REM latency in a Japanese working population. The 1-Ch EEG may be a useful tool to monitor sleep and screen depression/depressive symptoms in non-clinical settings.

Incidence of out-of-hospital cardiac arrests and survival rates after 1 month among the Japanese working population: a cohort study

ObjectivesThe prevention and improvement of the prognosis of out-of-hospital cardiac arrests (OHCAs) are important issues especially with respect to their social and economic significance in working populations. The age distribution...

Fraction and Number of Unemployed Associated with Self-Reported Low Back Pain: A Nation-Wide Cross-Sectional Study in Japan.

This study examined a cross-sectional association between self-reported low back pain (LBP) and unemployment among working-age people, and estimated the impact of self-reported LBP on unemployment. We used anonymized data from a nationally representative survey (24,854 men and 26,549 women aged 20–64 years). The generalized estimating equations of the multivariable Poisson regression models stratified by gender were used to estimate the adjusted prevalence ratio (PR) and 95% confidence interval (CI) for unemployment. The population attributable fraction (PAF) was calculated using Levin’s method, with the substitution method for 95% CI estimation. The prevalence of self-reported LBP was 9.0% in men and 11.1% in women. The prevalence of unemployment was 9.3% in men and 31.7% in women. After adjusting for age, socio-economic status, lifestyle habits, and comorbidities, the PR (95% CI) for the unemployment of the LBP group was 1.32 (1.19–1.47) in men and 1.01 (0.96–1.07) in women, compared with the respective non-LBP group. The PAF (95% CI) of unemployment associated with self-reported LBP was 2.8% (1.6%, 4.2%) in men. Because the total population of Japanese men aged 20–64 in 2013 was 36,851 thousand, it was estimated that unemployment in 1037 thousand of the Japanese male working population was LBP-related.

Prospective study on the association between serum amino acid profiles and depressive symptoms among the Japanese working population

ObjectiveAccumulating evidence suggests that amino acids, particularly tryptophan and glutamate, play an important role in the pathology of depression, but prospective epidemiologic data on this issue is scarce. We examined the association between circulating amino acids and the risk of depressive symptoms in a Japanese working population.MethodsParticipants were 841 workers who were free from depressive symptoms and provided blood at baseline and completed 3-yr follow-up survey. 30 varieties of amino acid concentrations in serum were measured using liquid chromatography/mass spectrometry. Depressive symptoms were defined using the Center for Epidemiologic Studies Depression Scale. Logistic regression was used to calculate the odds ratios of depressive symptoms according to serum amino acids with adjustment for lifestyle factors.ResultsA total of 151 (18.0%) workers were newly identified as having depressive symptoms at the follow-up. Baseline tryptophan and glutamate concentrations in serum were not appreciably associated with the risk of depressive symptoms. Risk of depressive symptoms tended to increase with increasing arginine concentrations; the multivariable-adjusted odds ratio for the highest versus lowest tertile of serum arginine was 1.65 (95% confidence interval: 0.96–2.83; P for trend = 0.07). No clear association was found for other amino acids.ConclusionsResults of the present study do not support a significant role of circulating amino acids in the development of depressive symptoms among Japanese.

Prospective association of confectionery intake with depressive symptoms among Japanese workers: the Furukawa Nutrition and Health Study.

High intake of sweet foods such as cakes, cookies, chocolate and ice cream has been reported to be associated with depressive symptoms. However, prospective studies are scarce and no study has been conducted in Asian populations. We prospectively investigated the association between confectionery intake and depressive symptoms in a Japanese working population. Participants were 911 workers (812 men and 99 women; aged 19-68 years) without depressive symptoms at baseline who completed a 3-year follow-up survey. Dietary intake was assessed using a validated self-administered diet history questionnaire. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression (CES-D) scale. Multiple logistic regression was used to estimate the OR of depressive symptoms according to tertile of confectionery intake with adjustment for covariates. At the time of the 3-year follow-up survey, 153 (16·8 %) workers were newly identified as having depressive symptoms (CES-D score ≥ 16). Confectionery intake was significantly associated with increased odds of developing depressive symptoms. The multivariable-adjusted OR of depressive symptoms for the highest v. lowest tertile of confectionery intake was 1·72 (95 % CI 1·03, 2·86) after adjustment for covariates including dietary factors such as folate, vitamin B6, vitamin B12, n-3 PUFA, Mg, Zn and soft drink (Pfor trend = 0·012). Our results suggest that confectionery intake is associated with a higher risk of depressive symptoms in a Japanese working population predominantly comprised of men.

Visit-to-visit variability of blood pressure and cardiovascular events among the working-age population in Japan: findings from the Japan Epidemiology Collaboration on Occupational Health Study.

Increased visit-to-visit variability (VVV) of blood pressure, which is calculated based on several readings, has been suggested to be a significant predictor of cardiovascular events and mortality, independent of mean blood pressure. This study examined associations between the VVV of systolic blood pressure (SBP) measured annually and cardiovascular disease (CVD) events among 72,617 Japanese subjects. Data were obtained from the Japan Epidemiology Collaboration on Occupational Health Study, which is an ongoing epidemiological survey of workers in Japan. VVV was calculated as the coefficient of variation of SBP readings from 2008 to 2011; information on fatal and nonfatal CVD events was collected from registries of specific outcomes between April 2012 and March 2019. A Cox proportional hazards model was applied to investigate associations after adjusting for mean SBP between 2008 and 2011 and covariates. During the 7-year follow-up period, there were 63 CVD fatalities and 314 CVD events (combining fatal and nonfatal events). The results showed that a one-standard deviation increase in VVV was associated with a significant increase in the risk of CVD mortality (hazard ratio [HR] = 1.42; 95% confidence interval [CI] = 1.32-1.54); those in the highest tertile had a 3.20 times (95% CI = 1.26-8.17) higher risk of CVD mortality than those in the lowest tertile. We found less pronounced associations regarding CVD events (HR = 1.08, 95% CI = 1.02-1.15). In conclusion, VVV was significantly associated with CVD mortality in our Japanese working population.

Association of weekday-to-weekend sleep differences and stress response among a Japanese working population: a cross-sectional study

ObjectivesTo investigate the relationship between differences in weekday-to-weekend sleep habits and stress responses in a working population. MethodsThis cross-sectional study used data from university workers on sleep habits, differences in sleep duration between weekdays and weekends, and each midpoint of the sleep phase on weekdays and weekends. Social jetlag was defined as the difference in the midpoint of the sleep phase between weekdays and weekends. In addition, the Brief Job Stress Questionnaire assessed stress responses and stress-related factors. To examine sleep-related factors affecting stress responses, regression analysis was performed with adjustments for age, sex, and stress-related factors. ResultsAnalyzed were 2,739 participants. Sleep duration differences obtained by subtracting sleep duration on weekdays from that on weekends, social jetlag, and weekday sleep duration were significantly associated with an increased risk of stress responses in a univariate linear regression model. Adjusting for age, sex, job stressors, and stressor buffering factors did not change this trend. However, when additionally adjusting for all sleep parameters, only sleep duration differences and weekday sleep duration were significantly associated with stress responses (β 0.67 [95% CI 0.24, 1.10], p = 0.002), (−0.66 [-1.20, −0.13], p = 0.015). ConclusionsThis study provided further evidence that weekday sleep duration and weekday-to-weekend sleep duration differences were independently associated with stress responses even when considering stress-related factors. However, social jetlag was not clearly associated with stress responses. Our findings highlighted the necessity of securing sufficient sleep for stress management and mental health promotion in a working population.

Carbohydrate score and rice intake for breakfast, lunch, and dinner and impaired glucose metabolism in a working population: A cross-sectional study.

Few studies have examined the association between carbohydrate intake and diabetes with consideration to time of eating. We investigated the association of carbohydrate score and rice intake for breakfast, lunch, and dinner with impaired glucose metabolism in a Japanese working population. Participants were 1416 workers (aged 18-69 years) without a history of diabetes or serious disease who participated in a health survey. Intakes of rice, bread, and noodles at each meal were ascertained using a questionnaire, and carbohydrate score was calculated from these intakes. Impaired glucose metabolism was defined by fasting blood glucose ≥110mg/dl or HbA1c≥6.0% Logistic regression analysis was used to estimate the odds ratios of impaired glucose metabolism for quartile of carbohydrate score or rice intake for each meal with adjustment for covariates. Carbohydrate score and rice intake for each meal were not significantly associated with impaired glucose metabolism. However, among non-obese participants (BMI <25kg/m2), a higher intake of rice at dinner was associated with an increased odds of having impaired glucose metabolism (P for trend=0.02), with a multivariable-adjusted odds ratio for the highest versus lowest quartile of rice intake at dinner of 3.43 (95% confidence interval 1.22-9.70). In contrast, no such association was observed among obese participants (BMI ≥25kg/m2) (P for interaction=0.097). Our results suggest that carbohydrate score and rice intake for each meal are not associated with impaired glucose metabolism. The increased odds of having impaired glucose metabolism associated with higher rice intake at dinner among non-obese participants requires further investigation.

Health-Related Quality of Life during COVID-19 Pandemic: Assessing Impacts of Job Loss and Financial Support Programs in Japan.

This cross-sectional study examined the association between job loss during the coronavirus disease 2019 (COVID-19) pandemic and health-related quality of life (HRQOL) in the Japanese working population and whether universal financial support program has a protective influence on the HRQOL. Two self-reported internet surveys were used to determine job loss during the pandemic: one was conducted between February and March 2020, just before the COVID-19 emergency declaration by the Japanese government (April 2020), and the other was conducted between August and September 2020. For the dependent variable, we used the EQ-5D-5L utility score (QOL utility score), which was assessed between August and September 2020. The independent variables were job loss after the state of emergency was declared and two types of government financial support (either universal support or support targeting child-raising households). The Tobit regression model was applied, adjusting for covariates. Job loss during the pandemic was negatively associated with the QOL utility score in the fully adjusted model; the coefficient (95% confidence interval [CI]) for job loss during the pandemic was −0.07 (−0.11 to −0.03). For the government financial support variables, the universal financial support program was associated with a better QOL utility score of the coefficient (95% CI), 0.05 (0.03 to 0.08). Job loss during the COVID-19 pandemic is negatively associated with HRQOL, while universal financial support is positively associated with HRQOL. Our study results imply that universal financial support during the COVID-19 era has a protective influence on an individual’s HRQOL.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11482-021-09918-6.

Eating alone and depressive symptoms among the Japanese working population: The Furukawa nutrition and health study

The aim of this study was to determine the cross-sectional associations between frequency of eating with others and depressive symptoms in Japanese employees while accounting for lifestyle and dietary factors. We also examined the relationship with stratification by living arrangement. Participants were 1876 workers aged 18–74 years who participated in a health survey at a periodic checkup. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression scale. Frequency of eating with others was categorized into ranges between daily and <1 day/week. Associations between frequency of eating with others and depressive symptoms were assessed using logistic regression analysis, with adjustment for lifestyle and dietary factors. The prevalence of depressive symptoms was 32.9%. The prevalence of depressive symptoms tended to increase with decreasing frequency of eating with others, with multivariate-adjusted odds ratios (95% confidence intervals) for the highest through lowest frequency groups of eating meals with others being 1.00 (reference), 1.27 (0.92–1.74), 1.56 (1.11–2.21), 1.86 (1.29–2.67), and 2.22 (1.53–3.22), respectively (P for trend<0.001). In analysis stratified by living arrangement, a significant association was found with those living with others but not those living alone (P for interaction <0.001). Lower frequency of eating with others may be associated with higher odds of depressive symptoms among Japanese workers living with others, even after controlling for lifestyle and dietary factors.