The Influence of Ethnicity on Thermosensitivity During Cold Water Immersion 2002-01-2410

Purpose: This investigation evaluated the influence of ethnicity, CAU vs. AA, on thermosensitivity and metabolic heat production (HP) during cold-water immersion (20°C) in 15 CAU vs. 7 AA males. Methods: Following a 20 min baseline period (BASE), subjects were immersed in 20°C water until esophageal temperature (Tes) reached 36.5°C or for a maximum pre-occlusion (Pre-OCC) time of 40 min. Arm and thigh cuffs were then inflated to 180 and 220 mmHg, respectively, for 10 min (OCC). Following release of the inflated cuffs (Post-OCC), the slope of the relationship between the decrease in Tes and the increase in HP was used to define thermosensitivity (ß). Results: ANOVA revealed no significant difference in thermosensitivity between CAU and AA. No significant differences (p>0.05) were found for HP. However, a significant (p<0.05) main effect for ethnicity for Tes was observed. Conclusion: These data suggest, despite a differential response in Tes between AA and CAU groups, the ß of HP during cold-water immersion is similar between CAU and AA. Therefore, these data demonstrate that when faced with a cold challenge, there is a similar response in HP between CAU and AA that is accompanied by a differential response in Tes.