Norepinephrine response in early HIV infection.

Norepinephrine response to a cold pressor test was investigated in 95 homosexual men in a longitudinal study of human immunodeficiency virus (HIV) infection. The baseline data obtained from 76 HIV+ and 19 HIV- subjects are included in this report. After the insertion of a venicatheter and following a 30 min rest, subjects immersed one of their hands in ice water for 2 min, and serial blood samples were obtained for the determination of catecholamine levels. The results show that the norepinephrine response in HIV+ subjects compared to that of HIV- subjects was blunted. Examination of the responses using linear and quadratic orthogonal polynomials suggested that these differences between the two groups were primarily a function of their rate of increase in norepinephrine levels. It was observed also that in HIV+ subjects, norepinephrine level peaked earlier than that in HIV- subjects. The data suggest that autonomic dysfunction is present in the early stages of HIV infection.