Help Me Make it Through the Night (Shift)

Laura A. Stokowski, RN, MS


January 24, 2012

In This Article

The Night Shift

Few nurses seem to really love working the night shift. Sure, we all know nurses who thrive on the night shift or who choose it for personal reasons. Some prefer to work when the ambience is quieter, there are no visitors, rules are less strictly enforced, and interruptions are fewer. Some work nights for family reasons -- perhaps they have young children at home and working the night shift allows them to share caretaking responsibilities with husbands/partners who work conventional daytime hours. For some, the night-shift differential is incentive enough to choose nights. However, many nurses work nights not out of choice but because they are required to do so. Usually, these nurses are farther down on the seniority list, and most will gravitate to the day shift as soon as they get the chance.

Of course, nurses are not the only night workers. It is estimated that 15%-20% of workers in industrialized countries work nontraditional hours. Intolerance to working nights even has its own label -- shift work disorder. People who have this often undiagnosed and undertreated problem have trouble getting to sleep and waking up and often experience excessive sleepiness during their shifts. Chronic fatigue in these individuals can impair productivity, safety, health, and quality of life.[1]

A Hazard to Your Health?

The health of the night-working population has not been ignored in epidemiologic research. Numerous studies have investigated the possible health consequences of working the night shift. Judging by the number of studies alone, it seems that these health consequences are significant and could represent a huge public health problem in our increasingly 24-hour society. Some of the health problems found to be associated with working nights include the following:

  • Increased risk for breast cancer[2,3] and colorectal cancer[4];

  • Increase in inflammatory markers (IL-6, C-reactive protein, white blood cells, neutrophils, lymphocytes, and platelets)[5];

  • Irregular menstrual cycles[6]and reduced fertility[7];

  • Increased risk for ischemic stroke[8;]

  • Increased wrist and hip fractures[9];

  • Pronounced insulin response to eating[10];

  • Increased development of the metabolic syndrome[11];

  • Increase in type 2 diabetes[12];

  • Increased blood pressure[13];

  • Increased cardiovascular disease[14]; and

  • Increased risk for mental health disorders, including anxiety and depression.[15]

It's a miracle that anyone is willing to work nights. The night shift does pay a little more, but can you put a price on your health?

Of course, observational studies that have linked serious health effects with working nights do not establish causation. Furthermore, a publication bias prevalent in the health literature can mean that studies with positive findings make it into print, whereas those finding no association may not. Yet, many of the negative health outcomes associated with working nights are considered biologically plausible. This plausibility, combined with evidence for one of the most serious shiftwork-related health effects -- cancer -- although limited in humans, prompted the International Agency for Research on Cancer to declare that "shiftwork that involves circadian disruption is probably carcinogenic in humans."[16]

A phrase that jumps out here is "circadian disruption," because this is the putative link, and possibly the critical exposure variable, in the chain of causation.[17]What constitutes circadian disruption, and is it an inevitable consequence of working nights?


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