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Melatonin, cortisol, and perceived adaptation after working one night shift.

Heemstra, Lydia A.
http://orcid.org/0000-0001-8634-8806
http://rave.ohiolink.edu/etdc/view?acc_num=kent1461153204

Abstract Details

2016, MS, Kent State University, College of Arts and Sciences / Department of Biological Sciences.
Shift work is associated with early death, several types of cancer, and cardiovascular, metabolic, reproductive, and gastrointestinal disorders. Shift work’s disruption of circadian rhythms causes disease. While the increased health risks of long-term shift work are recognized, studies of shorter periods of shift work and rotating shift schedules are less conclusive. Rotating shift schedules are used extensively in emergency services, healthcare, hospitality, manufacturing, and transportation. Shift work schedules affect workers’ performance, and an individual’s perceived adaptation to their shift schedule is associated with improved performance. With more than 100,000 deaths per year in United States hospitals caused by medical error, work performance of nurses is important. More than half of all American nurses work rotating night shifts (at least three nights/month plus days and evenings in that month). Nurses are routinely scheduled to work only one or two night shifts, followed by days off. However most rotating shift work studies focus only on the second – fifth night shifts in a series; the current study investigated the effects of a first night shift. After nurses had worked either a night or day shift, saliva melatonin and cortisol levels were assayed and perceived adaptation was rated, before sleep and on awakening. Assays and ratings were then repeated after each nurse worked the opposite-time shift. This study is also the first to compare the same individuals’ results for these three measures after both night shift and day shifts. Compared to working a day shift, a single night shift lowered melatonin levels on awakening. Cortisol was also lower on awakening, and higher before sleep; perceived adaptation was rated worse. Individual assessments of each participant’s results for melatonin, cortisol, and adaptation suggest that the three measures are associated: individuals whose melatonin and cortisol levels were more disrupted by working a night shift also perceived that their adaptation to the night shift schedule was worse. The specific changes in melatonin and cortisol that occurred after a single night shift can be acutely pathological even in healthy individuals—for example, a high pre-sleep cortisol level prevents normal cellular immune response, increasing susceptibility to most infections including the flu. This study is unique in assessing melatonin and cortisol with perceived adaptation after only one night shift. Working a single night shift significantly disrupted melatonin and cortisol levels and rhythm, and worsened adaptation. Physiological changes that in the long-term increase disease risks also occur after a single night shift—a health concern for rotating shift workers. Perceived adaptation was worse after a single night shift, a potential safety concern for workers and others who could be affected, including hospital patients and drivers sharing the road.
Colleen Novak, PhD (Advisor)
101 p.
Biology
melatonin; cortisol; shiftwork

Recommended Citations

Citations

  • Heemstra, L. A. (2016). Melatonin, cortisol, and perceived adaptation after working one night shift. [Master's thesis, Kent State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=kent1461153204

    APA Style (7th edition)

  • Heemstra, Lydia. Melatonin, cortisol, and perceived adaptation after working one night shift. 2016. Kent State University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=kent1461153204.

    MLA Style (8th edition)

  • Heemstra, Lydia. "Melatonin, cortisol, and perceived adaptation after working one night shift." Master's thesis, Kent State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=kent1461153204

    Chicago Manual of Style (17th edition)

kent1461153204
831
© 2016, all rights reserved.
This open access ETD is published by Kent State University and OhioLINK.