The Effects of High- and Low-Dose Aspirin on Thermoregulation During and After Acute Cold Exposure.

Objective: To explore the effect of aspirin on the thermoregulatory responses of men during exposure to 12°C air (acute cold exposure) for a period of 120 minutes and recovery in 25°C air (rewarming) for 120 minutes. Methods: Seven male subjects (26.1 ± 2.4 yr) underwent pre-experimental testing to determine peak VO₂ and body composition. Participants underwent 3 trials in which they ingested the following for 1 week prior to each experimental trial: a capsule filled with cellulose (placebo), 81 mg · day⁻¹ of aspirin (low-dose aspirin), or 650 mg · day⁻¹ of aspirin (high-dose aspirin). Each trial consisted of a 30-minute baseline period, 120 minutes of exposure to 12°C air, and 120 minutes of recovery in 25°C air. Mean skin temperature and rectal temperature (T_re) were measured, and heat production was calculated. Results: During both acute cold exposure and rewarming, analysis of variance revealed a main effect for time (P < .05) with respect to T_re, mean skin temperature, and heat production. However, there were no significant differences between the treatments or treatment by time interactions. Conclusions: These data demonstrate that aspirin had no significant effect on the thermal and metabolic responses during acute cold exposure and rewarming. [Copyright &y& Elsevier]