Leptin, adiponectin, and heart rate variability among police officers

Objectives: Police officers have a high prevalence of cardiovascular disease (CVD). Reduced heart rate variability (HRV) is known to increase CVD risk. Leptin and adiponectin may be related to CVD health. Therefore, our objective was to investigate the relationship between these variables and HRV. Methods: Leptin and adiponectin levels were measured in 388 officers from the Buffalo Cardio-Metabolic Occupational Police Stress study. HRV was assessed according to methods published by the Task Force of the European Society of Cardiology and the North American Society of Pacing Electrophysiology for measurement and analysis of HRV. Mean values of high-frequency (HF) and low-frequency (LF) HRV were compared across tertiles of leptin and adiponectin using analysis of variance and analysis of covariance; trends were assessed using linear regression models. Results: Leptin, but not adiponectin, was significantly and inversely associated with HRV. Body mass index (BMI) and percent body fat significantly modified the association between leptin and LF (but not HF) HRV. Among officers with BMI<25 kg/m², leptin was not significantly associated with HRV. However, among officers with BMI≥25 kg/m², leptin was inversely associated with HRV, after adjustment for age, gender, and race/ethnicity; HF HRV, P=0.019 and LF HRV, P<0.0001. Similarly, among officers with percent body fat≥25.5%, leptin and LF HRV showed significant, inverse associations (adjusted P=0.001). Conclusions: Leptin levels were inversely associated with LF HRV, especially among officers with increased adiposity. Increased leptin levels may be associated with CVD-related health problems. Am. J. Hum. Biol. 27:184-191, 2015.