Association of Rotating Night Shift Work with BMI and Abdominal Obesity among Nurses and Midwives

Abstract

BackgroundMounting epidemiological evidence suggests that night shift work may contribute to the etiology of increased body weight. The present study aimed to examine association between rotating night shift work and body mass index (BMI), and abdominal adiposity respectively among nurses and midwives.MethodsA cross-sectional study was conducted among 724 female nurses and midwives, aged 40-60 years (354 rotating night shift and 370 daytime workers) in Łódź, Poland, between 2008 and 2011. Information about occupational history and potential confounders was collected during personal interviews. Anthropometric measurements of body weight, height, waist (WC) and hip (HC) circumference were made, and body mass index (BMI), waist to hip ratio (WHR) and waist to height ratio (WHtR) were calculated. GLM regression models and multinomial logit regression models were fitted to explore the association between night shift work and anthropometric parameters, with adjustment for age, body silhouette at age 20, current smoking status, packyears, marital status, and menopausal hormone therapy use.ResultsCumulative night shift work showed significant associations with BMI, WC, HC and WHtR, with BMI increasing by 0.477 kg/m2 per 1000 night duties and by 0.432 kg/m2 per 10000 night shift hours, WC increasing respectively by 1.089 cm and 0.99 cm, and HC by 0.72 cm and WHtR by 0.007 cm for both metrics. Both current and cumulative night work was associated with obesity (BMI≥30kg/m2), with OR=3.9 (95%CI:1.5-9.9), in women reporting eight or more night shifts per month.ConclusionThe results of the study support the previously reported relations between night shift work and development of obesity.

Jet Lag and Shift Work Disorder

“…62 Shift work itself is associated with numerous poor health outcomes similar to those seen with sleep loss and circadian misalignment, such as diabetes, obesity, hypertension, impaired reproductive health, cognitive function, and cancer. 40,61,[63][64][65][66] It is likely that duration of shift work exposure, the number of night shifts worked per month, and the age at which a person started shift work also play a role in the development of poor health outcomes. For example, shift work is associated with poor cognitive function that is related to the duration of shift work exposure particularly when exposure was more than 10 years.…”

“…67 Nurses who work more than 8 night shifts per month are 3.9 times more likely to be obese. 65 Using the Nurses' Health Study II, Ramin and colleagues 68 found that ever working shift work was associated with obesity, greater caloric intake, and short sleep duration. These associations were impacted by age at which shift work was performed and if shift work was performed before age 25 this was associated with fewer risk factors than shift work later in life.…”

Night shift work and other determinants of estradiol, testosterone, and dehydroepiandrosterone sulfate among middle-aged nurses and midwives

“…Moreover, night workers were more likely than day workers to become obese (14,15) and to have unhealthy lifestyle (16) such as smoking (17), unhealthy diet (16) or low physical activity (18), which may contribute to the risk of cancer and affect hormonal milieu and sex hormone metabolism (19,20).…”

Keeping Up With the Clock

“…Cross-sectional and prospective studies identify shift work as an independent predictor of excess body weight, 35-37 and indicate that abdominal obesity, the obesity phenotype carrying the greatest risk, is prominent. 36 These harmful effects of shift work are conceivably a function of circadian disruption. Due to nocturnal lighting exposure, levels of urinary 6-sulfatoxymelatonin, the main melatonin metabolite, are lower in rotating night shift workers 38 than daytime workers.…”