Increased levels of resistin in rotating shift workers: A potential mediator of cardiovascular risk associated with circadian misalignment

Objective: Shift work schedule has been associated with several health problems, including deleterious effects on the cardiovascular system. The present study aimed to evaluate the circulating levels of four biomarkers of atherosclerosis (soluble CD40 ligand [sCD40L], monocyte chemoattractant protein-1 [MCP-1], resistin, and plasminogen activator inhibitor-1 [PAI-1]) in a population-based sample of young adult men exposed to rotating shift work schedule in comparison with day workers. Design and participants: A total of 439 men aged 34.4 +/- 8.6 years were included in a cross-sectional study comparing 255 day workers with 184 rotating shift workers. Circulating levels of the biomarkers were measured in duplicate by ELISA using monoclonal specific antibodies. Results: Rotating shift workers had elevated (6440 +/- 4510 pg/mL) (mean +/- SD) circulating levels of resistin in comparison with day workers (5450 +/- 3780 pg/mL), and significance remains after adjusting for age and blood leukocyte count (p < 0.045, ANCOVA). Shift work schedule explains 1% of the proportion of the total variation in the circulating resistin levels. Multiple regression analysis showed that resistin levels significantly correlate with rotating shift work (p < 0.04) and blood leukocyte count (p < 0.00003) independently of age, BMI, waist-hip ratio, HOMA, and cardiovascular risk %. Circulating levels of sCD40L, MCP-1, and PAI-1 did not significantly differ between day workers and shift workers. Conclusion: Shift work schedule was significantly associated with elevated plasma resistin levels. Resistin, which is probably produced by leukocytes, may play an important role in the pathogenesis of early metabolic syndrome components in young men chronically exposed to circadian misalignment. (c) 2009 Elsevier Ireland Ltd. All rights reserved.