A Longitudinal Study on the Effect of Shift Work on Weight Gain in Male Japanese Workers

Abstract

objective: This study compared the effect of alternating shift work and day work on weight gain in Japanese male workers. Methods and Procedures: A longitudinal cohort study was conducted in day workers (n = 4,328) and alternating shift workers (n = 2,926) of a steel company who received annual health checkups over a 14-year period between 1991 and 2005. The association between the type of job schedule and weight gain was investigated using multivariate pooled logistic regression analyses. The endpoints in the study were either a 5, 7.5, or 10% increase in BMI during the period of observation, compared to the BMI at entry. Results: The type of job schedule was significantly associated with all three BMI endpoints (5% increase in BMI; odds ratio (OR) for comparison between alternating shift workers and regular day workers, 1.14; 95% confidence interval (CI), 1.06-1.23): (7.5% increase in BMI; OR, 1.13; 95%CI, 1.03-1.24: 10% increase in BMI; OR, 1.13; 95%CI, 1.00-1.28). BMI at study entry was also positively associated with the 5, 7.5, and 10% increases in BMI during the study. On the other hand, age and drinking habits were negatively associated with 5, 7.5, and 10% increases in BMI. Discussion: Our study revealed that alternating shift work was an independent risk factor for weight gain in male Japanese workers. Efficient health screening and regular checkups, combined with support to control unhealthy lifestyle factors, would be of considerable benefit for maintaining the health of Japanese shift workers.

The relationship of body mass index and waist-hip ratio with shift work among military personnel in 2016

“…Antunes et al investigated the effect of shift work on BMI and WHR concluded the difference was significant in waist circumference and BMI of shift workers than day works, which was consistent with the results of this study (25). The results of this study showed that with increasing age and work experience, rapid changes were observed in BMI and WHR, which was in agreement with the results of the study by Suwazono et al (26). Moreover, the results of the study by Gholami Fesharaki et al showed that with increasing age and work experience, the rates of obesity and BMI also increased that confirms the results of this study (27).…”

Disruption of circadian clocks has ramifications for metabolism, brain, and behavior

“…Long-term experiments in populations showing disrupted sleep/wake patterns are thus necessary to probe these findings further, but a longitudinal study in a nurses cohort of night-shift work has found that exposure to night work can lead to weight gain and obesity (29). More recently, it was found that alternating shift work is an independent risk factor for the development of obesity in a longitudinal (14-y) large cohort of Japanese male shift workers (30). Thus, the ability to model some of these effects in animals may provide methods to intervene and either reverse or protect an individual from the negative physiological ramifications of long-term shift work.…”

Adverse metabolic and mental health outcomes associated with shiftwork in a population-based study of 277,168 workers in UK biobank

“…These studies have utility in avoiding some confounding or effect modification due to sex, work environment and shift patterns, but also generate data that might not be applicable to the general population. [1,2] Large population based studies of the general workforce that adjust for multiple lifestyle and workrelated confounding factors are required to address these challenges of studying the effects of shiftwork on health.…”

“…Keywords circadian depression diabetes neuroticism nightshift obesity shiftwork well being BACKGROUND Shiftwork is associated with detrimental effects on health and wellbeing, including increased risk of diabetes [1][2][3][4][5] and sleep problems, [6][7][8] higher body mass index (BMI) [1,[9][10][11][12], and increased signs of anxiety and depression. [8,13,14] Shiftworkers were once predominantly male, manufacturing sector workers, but this is no longer the case; a recent government survey reported that security services, transport and communications industries were the most common occupation of shiftworkers in the United Kingdom.…”