Identification of risk factors for exertional heat-related illnesses in long-distance cyclists: experience from the California AIDS Ride

Abstract

To identify risk factors for exertional heat-related illnesses and to determine if patients who are afflicted with the human immunodeficiency virus or have acquired immunodeficiency syndrome have an increased risk of exertional heat-related illness. Descriptive, retrospective, matched case-control study. Mobile community of 2,650 participants in the California AIDS Ride 3. Participants included 117 patients presenting for medical care with heat-related illnesses and 234 age-, gender-, and registration site-matched control subjects who did not develop a heat-related illness. Retrospective, matched case-control study utilizing univariate and multivariate conditional logistic regression to determine if human immunodeficiency virus seropositivity, the number of chronic medical illnesses, or the number of current medications known to affect heat dissipation increased the risk of exertional heat-related illnesses. The multivariate model revealed that patients with a greater number of chronic medical illnesses were at a significantly increased risk of a heat-related illness (odds ratio = 1.6, 95% CI = 1.2-2.1). The number of current medications (odds ratio = 1.1, 95% CI = 0.8-1.5) and human immunodeficiency virus seropositivity (odds ratio = 0.7, 95% CI = 0.2-3.1) were not significant predictors of risk for exertional heat-related illness. Those riders suffering from a greater number of chronic medical illnesses were at a greater risk for developing an exertional heat-related illness. Human immunodeficiency virus seropositivity alone was not associated with increased risk of exertional heat-related illness.