Effect Of Aspirin On Thermal And Metabolic Variables After Cold Exposure In Healthy Males

Abstract

INTRODUCTION Aspirin is a common medication currently used as an anti-coagulant (clotting prevention) as well as an anti-pyretic (temperature reducing) agent. Research has demonstrated that there may be a decrease in core temperature during the recovery phase after cold exposure, i.e. afterdrop. Therefore, it is not certain whether the individual who has been fed aspirin for one week is able to maintain core temperature and metabolic heat production in the recovery phase following acute cold exposure. PURPOSE To determine the effect of different doses of aspirin vs. placebo (PLA) during a two hour recovery from exposure to 12°C cold air. METHODS Seven males (26.1±2.4 y) underwent pre-experimental testing to determine VO2max and body composition. Subjects underwent 3 trials in which they were required to ingest for one week prior to all trials: a capsule which was filled with cellulose (PLA), 81 mg · day−1 of aspirin (ASA-L), and 650 mg day−1of aspirin (ASA-H). Each trial consisted of 120 min of exposure to 12°C air and 120 min of recovery in 25°C air. Heat production (HP), mean skin temperature (Tsk), and core temperature (Tre) were measured. Blood samples were taken at 0, 60, and 120 min of recovery and analyzed for epinephrine (EPI) and norepinephrine (NOREPI). Results ANOVA revealed a main effect for time for Tre and HP (p =0.001). However, there was no time × treatment interaction (p > 0.05). EPI and NOREPI concentrations did not reveal a main effect for time (p > 0.05) however NOREPI did demonstrate a main effect for treatment (p=0.049). Conclusion Based on these data, aspirin dosage did demonstrate a differential thermal and metabolic response in the recovery phase of acute cold exposure.