Effect of acquired immune deficiency syndrome wasting on the protein metabolic response to acute exercise

Wasting is a major complication of human immunodeficiency virus (HIV) infection, which remains prevalent even in the era of highly-active antiretroviral therapy. We have previously shown that progressive resistance exercise can increase lean body mass (LBM) significantly in patients with wasting, and that exercise does not increase circulating HIV RNA concentrations. We examined the effect of 1 bout of moderately difficult exercise on whole body protein kinetics in 10 patients with HIV wasting and 12 patients with HIV infection without wasting. At baseline, there were no differences between the groups in whole body leucine flux, oxidation, or nonoxidative leucine disposal (NOLD, a measure of whole body protein synthesis). Six days after exercise, NOLD was significantly higher in the wasted patients compared with the nonwasted ones (82.2 +/- 16.7 v 66.5 +/- 15.2 micromol/kg LBM/h, P <.03). The change in NOLD between baseline and day 6 was significantly different between the 2 groups (+9.0 +/- 9.2 v -3.3 +/- 5.7 micromol/kg LBM/h, P <.02). These data indicate that the ability to respond to exercise with protein synthesis is maintained in HIV wasting.