Abstract
Antithrombotic therapy with oral aspirin (ASA) or clopidogrel (CLO) (Plavix®; Bristol-Myers Squibb, Bridgewater, NJ) is associated with an attenuated skin vasodilator response and a greater rate of rise in core temperature in healthy, middle-age individuals during passive heating in a water perfused suit. Purpose: The present double-blind, crossover study examined the functional consequences of 7 d of low-dose ASA (81 mg·d-1) versus CLO (75 mg·d-1) treatment in 14 healthy, middle-age (50-65 yr) men and women during passive heating in air (40 min at 30°C, 40% relative humidity) followed by exercise (60% V̇O2peak). Methods: Oral temperature (Tor) was measured in the antechamber (23.0°C ± 0.1°C) before entering a warm environmental chamber. After 40 min of rest, subjects cycled on a recumbent cycle ergometer for up to 120 min. Esophageal temperature (Tes) and laser Doppler flux were measured continuously, and the latter was normalized to maximal cutaneous vascular conductance (%CVCmax). Results: Before entry into the environmental chamber there were no differences in Tor among treatments; however, after 40 min of rest in the heat, Tes was significantly higher for ASA and CLO versus placebo (37.2°C ± 0.1°C, 37.3°C ± 0.1°C, vs 37.0°C ± 0.1°C, both P < 0.001), a difference that persisted throughout exercise (P < 0.001 vs placebo). The mean body temperature thresholds for the onset of cutaneous vasodilation were shifted to the right for both ASA and CLO during exercise (P < 0.05). Conclusion: ASA and CLO resulted in elevated core temperatures during passive heat stress and shifted the onset of peripheral thermoeffector mechanisms toward higher body temperatures during exercise heat stress.
Original language | English (US) |
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Pages (from-to) | 674-682 |
Number of pages | 9 |
Journal | Medicine and science in sports and exercise |
Volume | 45 |
Issue number | 4 |
DOIs | |
State | Published - 2013 |
All Science Journal Classification (ASJC) codes
- Orthopedics and Sports Medicine
- Physical Therapy, Sports Therapy and Rehabilitation