Shiftwork Can Affect Your Health

Workers with nontraditional schedules are burdened by sleep-related health problems and poor metabolic health, according to new report in Sleep Health

New York, NY, May 18 2015

Shiftwork is an occupational health risk of growing significance because it is becoming more common and because of its potential influence on health outcomes, possibly increasing health differences between workers of higher vs lower socioeconomic status. A new study from the University of Wisconsin School of Medicine and Public Health determined that employees who work shifts outside of a 9-to-5 schedule are more likely to be overweight and experience sleep problems, and possibly more likely to develop metabolic disorders, such as diabetes, compared to workers following traditional work schedules. The study is published in Sleep Health, Journal of the National Sleep Foundation.

“Shiftwork employees are particularly vulnerable to experiencing sleep problems as their jobs require them to work night, flex, extended, or rotating shifts,” explained lead investigator Marjory Givens, PhD, an ‎Associate Scientist with the University of Wisconsin School of Medicine and Public Health. “Shiftworkers are more commonly men, minorities, and individuals with lower educational attainment and typically work in hospital settings, production, or shipping industries.”

The investigators used cross-sectional data from the Survey of the Health of Wisconsin (SHOW) collected from 2008-2012. SHOW is a population-based health examination survey that includes home- and clinic-based interviews and physical examinations. In this analysis, 1593 participants were assessed using measures from the physical examination to calculate body mass index and determine obesity or overweight status. Type-2 diabetes (T2D) was assessed in 1400 subjects using either self-report of physician-diagnosed T2D or glycated hemoglobin (HbA1c) equal to or greater than 6.5% as determined from a blood sample obtained at the physical examination.

Shiftworkers were significantly more likely than traditional schedule workers to be overweight (47.9% vs. 34.7%). They also experienced more sleep problems such as insomnia (23.6% vs. 16.3%), insufficient sleep (53.0% vs. 42.9%), or excessive wake-time sleepiness (31.8% vs. 24.4%). Since shiftwork and sleep problems have both been implicated in poor metabolic health, this study asked whether sleep problems may play a role in shiftworker health disparities. Dr. Givens and her colleagues found that experiencing sleep problems was positively associated with being overweight/obese or diabetic. Moreover, even though sleep problems did not fully explain the relation between shiftwork and overweight or diabetes, these association appear to be stronger among shiftworkers who were not able to obtain sufficient sleep (less than seven hours per day), suggesting that the adverse metabolic consequences of shiftwork could be partially alleviated by sufficient sleep.

Two particular strengths of this study are that it draws from a general population sample and primary outcomes (overweight and diabetes status) were defined according to objective markers (measured weight, height, and HbA1c). Potential limitations include unmeasured confounding factors, the potential for systematic biases in self-reports of sleep duration and sleep quality, and an inability to determine a causal relationship due to the cross-sectional nature of the study.

According to Dr. Givens, “This study adds to a growing body of literature calling attention to the metabolic health burden commonly experienced by shiftworkers and suggests that obtaining sufficient sleep could lessen this burden. More research in this area could inform workplace wellness or healthcare provider interventions on the role of sleep in addressing shiftworker health disparities.”


Notes for Editors
“Shiftwork, sleep habits, and metabolic disparities: results from the Survey of the Health of Wisconsin,” by Marjory L. Givens, PhD, Kristen C. Malecki, PhD, Paul E. Peppard, PhD, Mari Palta, PhD, Adnan Said, MD, Corinne D. Engelman, PhD, Matthew C. Walsh, PhD, and F. Javier Nieto, MD, PhD. It is published in Sleep Health, Volume 1, Issue 2 (June 2015), DOI: It is openly available at

Full text of the article is available to credentialed journalists upon request; contact Jennifer Williams at +1 202 631 1205 or Journalists wishing to interview the authors should contact Javier Nieto, MD, PhD ( or Marjory Givens, PhD (

The project was supported by award number T32HD049302 from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, USA. This project was also supported through the SHOW funded by the National Institutes of Health; National Heart, Lung, and Blood Institute (1RC2HL101468-01); the UW Wisconsin Partnership (Madison, WI) (06012009); and the UW Institute for Clinical and Translational Research (Madison, WI) (KL2 RR025012). Dr. Nieto's contributions were partially supported by the UW Helfaer Endowed Chair (Madison, WI).

About Sleep Health
Sleep Health: Journal of the National Sleep Foundation is the premier, multidisciplinary journal that explores sleep's role in population health and elucidates the social science perspective on sleep and health. Aligned with the National Sleep Foundation's global authoritative, evidence-based voice for sleep health, the Journal aims to serve as the foremost publication for manuscripts that advance the sleep health of all members of society. The scope of the Journal extends across diverse sleep-related fields, including anthropology, education, health services research, human development, international health, law, mental health, nursing, nutrition, psychology, public health, public policy, fatigue management, transportation, social work, and sociology.

About The National Sleep Foundation
The National Sleep Foundation is dedicated to improving health and well-being through sleep education and advocacy. It is well known for its annual Sleep in America® poll. The Foundation is a charitable, educational and scientific not-for-profit organization located in Washington, DC. Its membership includes researchers and clinicians focused on sleep medicine, health professionals, patients, families affected by drowsy driving and more than 900 healthcare facilities.

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Media contact
Jennifer Williams
The National Sleep Foundation
+1 202 631 1205