Levels of circulating cortisol and cytokines in members of the Canadian Armed Forces: associations with age, sex, and anthropometry

Objective: To assess blood levels of cortisol and cytokines (inflammatory and non-inflammatory) in members of the regular Canadian Armed Forces (CAF), and examine the associations between sex, age and adiposity and circulating levels of cortisol as well as pro- and anti-inflammatory cytokines. Methods: As part of a larger ranging project, 331 blood samples were collected from a representative population of the total CAF, which included officers and non-commissioned women and men from the Air Force, Navy and Army. The blood samples were analyzed for levels of cortisol, C-Reactive Protein, adiponectin and 20 cytokines (that included interleukins, interferons and Tumor Necrosis Factors). Results: Higher levels of adiponectin were found in women compared to men (median and IQR; 16.71 (7.68-25.32) vs 5.81 (3.52-13.19) µg/ml), and higher levels of IL-18 in men compared to women (89.25 (84.03-94.48) vs 75.91 (69.70-82.13) pg/ml). An association between age and levels of stress and inflammatory cytokines was obse...