Journal Article

Shift Work in Nurses: Contribution of Phenotypes and Genotypes to Adaptation

Hicks, Jennifer, Hida, Akiko, Summar, Marshall L., Motsinger-Reif, Alison A., Borsetti, Hugo M., Hamilton, Nalo, McMahon, Douglas G., Servick, Stein V., Johnson, Carl Hirschie, Robbins, Sam, Carver, Krista, Wells, Nancy, Ciarleglio, Christopher M., Gamble, Karen L.

2011

Overview

Daily cycles of sleep/wake, hormones, and physiological processes are often misaligned with behavioral patterns during shift work, leading to an increased risk of developing cardiovascular/metabolic/gastrointestinal disorders, some types of cancer, and mental disorders including depression and anxiety. It is unclear how sleep timing, chronotype, and circadian clock gene variation contribute to adaptation to shift work. Newly defined sleep strategies, chronotype, and genotype for polymorphisms in circadian clock genes were assessed in 388 hospital day- and night-shift nurses. Night-shift nurses who used sleep deprivation as a means to switch to and from diurnal sleep on work days (∼25%) were the most poorly adapted to their work schedule. Chronotype also influenced efficacy of adaptation. In addition, polymorphisms in CLOCK, NPAS2, PER2, and PER3 were significantly associated with outcomes such as alcohol/caffeine consumption and sleepiness, as well as sleep phase, inertia and duration in both single- and multi-locus models. Many of these results were specific to shift type suggesting an interaction between genotype and environment (in this case, shift work). Sleep strategy, chronotype, and genotype contribute to the adaptation of the circadian system to an environment that switches frequently and/or irregularly between different schedules of the light-dark cycle and social/workplace time. This study of shift work nurses illustrates how an environmental \"stress\" to the temporal organization of physiology and metabolism can have behavioral and health-related consequences. Because nurses are a key component of health care, these findings could have important implications for health-care policy.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Adaptation / Adaptation, Physiological / Adaptation, Psychological / Alcohol use / Alcoholic beverages / Analysis / Anxiety / Behavior / Biological clocks / Biology / Body temperature / Caffeine / Cancer / Cardiovascular diseases / Circadian Rhythm / Circadian rhythms / Clock gene / Colorectal cancer / Depression (Mood disorder) / Diurnal / Emotional disorders / Gastrointestinal diseases / Gene expression / Genes / Genetic aspects / Genetic polymorphisms / Genotype / Genotypes / Health care / Health policy / Health risks / Hormones / Humans / Insomnia / Light effects / Medical personnel / Medicine / Mental depression / Mental disorders / Metabolic syndrome / Metabolism / Neurosciences / Night / NPAS2 protein / Nurses / Nursing research / Nursing schools / Nursing Staff - psychology / Occupational health / Period 2 protein / Period 3 protein / Phenotype / Physiological aspects / Physiology / Polymorphism, Genetic / Psychiatry / Psychological stress / Risk taking / Schedules / Shift work / Sleep / Sleep and wakefulness / Sleep deprivation / Sleep disorders / Sleepiness / Switches / Work hours / Work Schedule Tolerance / Working conditions / Working hours / Young adults