Physiological correlates of HIV-related fatigue.

Our primary aim is to describe the relationship of multiple physiological variables and HIV-related fatigue. We report baseline data collected from 128 human immunodeficiency virus (HIV)-positive individuals. The HIV-Related Fatigue Scale was used to measure several aspects of fatigue. Blood was drawn for the following physiological variables: hepatic function, thyroid function, HIV viral load, immunologic function, gonadal function, hematologic function, serum cortisol, and cellular injury. In bivariable analyses, free testosterone (p=0.03) and CD8 (p=0.07) were negatively correlated with fatigue intensity, and nonlinear relationships were observed between fatigue intensity and total testosterone (p=0.02), thyroxine (p=0.01), hematocrit (p=0.06), and total bilirubin (p=0.06). However, none of these associations persisted in multivariable models. It is possible that fatigue suffered by seropositive people is better predicted by other variables, which must be better understood to develop interventions to successfully ameliorate HIV-related fatigue.