Abstract
Purpose: Alterations in the level of inflammatory markers due to poor or short sleep may increase the risk of adverse health outcomes such as cardiovascular disease. Methods: C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor- alpha, fibrinogen, intercellular adhesion molecule 1, and white blood cell count were measured using standardized methods in 387 police officers. Sleep data were collected via The Pittsburgh Sleep Quality Index. Linear regression models and ANCOVA were used to assess the relationship between levels of inflammatory markers and indicators of sleep quality. Reported means were adjusted for age, race, gender, smoking and alcohol. Results: Mean CRP levels were higher in officers who reported higher sleep latency (2.16mg/l vs. 1.78 mg/l, p= 0.05) and day time dysfunction (2.91 mg/l vs. 1.92 mg/l, p=0.04). Mean IL-6 levels were also higher in officers who reported higher sleep latency (2.15 pg/ml vs. 1.69 pg/ml; p=0.04). Fibrinogen levels were lower in officers with poor overall sleep quality compared to those with good sleep quality (2.90 mg/dl vs. 3.10 mg/dl; p=0.01). No other associations were observed. Conclusion: Mean levels of CRP and IL-6 were independently associated with sleep latency while fibrinogen was found to be associated with poor overall sleep. Further research examining these relationships prospectively may be warranted.
