Shiftwork and decline in endothelial function among police officers

BackgroundOur objective was to assess the influence of shiftwork on change in endothelial function. MethodsThis longitudinal study was conducted in 188 police officers (78.2% men). Shiftwork status (day, afternoon, night) was assessed objectively using daily Buffalo, NY payroll work history records. Brachial artery flow-mediated dilation (FMD) was assessed using ultrasound. Mean change in FMD% between 2004-2009 and 2010-2015 was compared across shiftwork using analysis of variance/covariance. ResultsOverall, mean FMD% decreased from 5.742.83 to 3.88 +/- 2.11 over an average of 7 years among all officers; P<0.0001. Effect modification by gender was significant. Among men (but not women), those who worked day shifts had a smaller mean (+/- SE) decrease in FMD% (-0.89 +/- 0.35) compared with those who worked the afternoon (-2.69 +/- 0.39; P=0.001) or night shifts (-2.31 +/- 0.45; P=0.020) after risk factor adjustment. ConclusionsLarger declines in endothelial function were observed among men who worked afternoon or night shifts. Further investigation is warranted. Am. J. Ind. Med. 59:1001-1008, 2016. Published 2016. This article is a U.S. Government work and is in the public domain in the USA