Associations of night shift work with weight gain among female nurses in The Netherlands: results of a prospective cohort study

• Published in: Scandinavian journal of work, environment & health Vol. 50; no. 7; pp. 536 - 544
• Main Authors: van Duijne, Henriëtte M, Berentzen, Nina E, Vermeulen, Roel CH, Vlaanderen, Jelle J, Kromhout, Hans, Jóźwiak, Katarzyna, Pijpe, Anouk, Rookus, Matti A, van Leeuwen, Flora E, Schaapveld, Michael
• Format: Journal Article
• Language: English
• Published: Finland Scandinavian Journal of Work, Environment & Health 01.10.2024; Nordic Association of Occupational Safety and Health; Nordic Association of Occupational Safety and Health (NOROSH)
• Subjects: Adult; bmi; Body Mass Index; Body size; Body weight; Body weight gain; circadian rhythm; Cohort analysis; Female; Females; Health promotion; Humans; menopausal status; Middle Aged; Netherlands - epidemiology; night shift; Night shifts; night work; Nighttime; nurse; Nurses; Nurses - statistics & numerical data; nursing; Obesity; Obesity - epidemiology; occupational environment; occupational health; Original; Overweight; Overweight - epidemiology; Post-menopause; prospective cohort study; Prospective Studies; Risk assessment; Risk Factors; Shift work; Shift Work Schedule - adverse effects; Statistical analysis; Surveys and Questionnaires; the netherlands; Weight Gain; Work Schedule Tolerance - physiology; Working conditions; Netherlands; Europe
• ISSN: 0355-3140; 1795-990X; 1795-990X
• DOI: 10.5271/sjweh.4185

OBJECTIVE: This study aimed to prospectively investigate associations of working night shifts with weight gain in the Nightingale Study, a large cohort of female nurses. METHODS: This study included 36 273 registered nurses, who completed questionnaires in 2011 and 2017. Cumulative number of nights, mean number of nights/month and consecutive number of nights/month in 2007–2011 were assessed. We used Poisson regression to estimate multivariable-adjusted incidence rate ratios (IRR) of >5% weight gain from 2011 to 2017 among all participants and assess risk of development of overweight/obesity (BMI≥25 kg/m 2 ) among women with healthy baseline body mass index. The reference group consisted of women who never worked nights. RESULTS: Overall, working night shifts in 2007–2011 was associated with >5% weight gain [IRR 1.07, 95% confidence interval (CI) 1.01–1.13]. Associations differed by menopausal status in 2011, with an increased risk of gaining >5% weight limited to postmenopausal women who worked nights (IRR 1.23, 95% CI 1.10–1.38). Postmenopausal women had an increased risk of >5% weight gain when they worked on average ≥4 nights/month (4–5: IRR 1.29, 95% CI 1.09–1.52, ≥6: IRR 1.27, 95% CI 1.11–1.47) or ≥4 consecutive nights/month (IRR 1.37, 95% CI 1.19–1.58), compared to postmenopausal women who never worked nights. For postmenopausal women with healthy weight at baseline, night shift work was associated with an increased risk of overweight/obesity at follow-up (IRR 1.24, 95% CI 1.03–1.50). CONCLUSIONS: Working night shifts was associated with a slightly increased risk of weight gain and overweight/obesity development among women who were postmenopausal at study inclusion. Our findings emphasize the importance of health promotion to maintain a healthy weight among (postmenopausal) night workers.