Variation in sweating patterns

In Brief Objective: The literature of sweat physiology and population variation in response to heat stress suggests that variation in sweating patterns may affect the measurement of hot flashes. This study examined variation in sweating patterns in Puebla, Mexico, and Amherst, MA, and compared the levels of concordance between subjective and objective measures of hot flashes. Design: Thirteen women in Puebla, Mexico, and 15 women in Amherst, MA, aged 45 to 61, completed surveys, body diagrams of heat flow during a hot flash, anthropometric measures, and the measurement of hot flashes through skin conductance monitoring. Hot flashes were measured through sternal (Mexico and Massachusetts) and nuchal (Mexico only) skin conductance. Results: Mexican women were significantly more likely to describe the heat of hot flashes on the back of their neck (100% vs 40%) and on their arms and/or hands (85% vs 40%) compared with women in Massachusetts. Hot flashes in the midback were associated with concordance between nuchal, but not sternal, measures of skin conductance and subjective report in Mexico. In comparing average scores for concordance between subjective and sternal measures of hot flashes, there was a higher mean score for true positives in Mexico (61% vs 29%, P = 0.06) and a significantly higher mean score for false-negative measures in Massachusetts (57% vs 21%, P = 0.04). Conclusions: Variation in rates of concordance between subjective and objective measures were not adequately explained by sweating patterns. Future studies should consider population variation in acclimatization and assess variation in the amount of sweat produced during a hot flash. Women in Puebla, Mexico demonstrated a higher rate of concordance between subjective and objective (sternal) measures of hot flashes and a significantly lower mean score for false negative measures compared to women in Amherst, Massachusetts. Although women in Mexico were more likely to describe hot flashes on the back of their neck, the addition of nuchal monitoring did not increase the rate of concordance between subjective and objective measures within the Mexican sample.