Aspirin and clopidogrel alter core temperature and skin blood flow during heat stress

Med Sci Sports Exerc. 2013 Apr;45(4):674-82. doi: 10.1249/MSS.0b013e31827981dc.

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) versus CLO (75 mg·d) 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% V˙O2peak).

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.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Aspirin / pharmacology*
  • Body Temperature Regulation / drug effects*
  • Clopidogrel
  • Cross-Over Studies
  • Double-Blind Method
  • Exercise Test / instrumentation
  • Exercise Test / methods
  • Female
  • Heat Stress Disorders / physiopathology
  • Heat Stress Disorders / prevention & control*
  • Humans
  • Laser-Doppler Flowmetry
  • Male
  • Middle Aged
  • Pennsylvania
  • Platelet Aggregation Inhibitors / pharmacology*
  • Regional Blood Flow / drug effects
  • Regional Blood Flow / physiology
  • Skin / blood supply*
  • Thermography / methods
  • Ticlopidine / analogs & derivatives*
  • Ticlopidine / pharmacology

Substances

  • Platelet Aggregation Inhibitors
  • Clopidogrel
  • Ticlopidine
  • Aspirin