['Fatty acid concentrations are increased in patients with HIV and fat redistribution and may contribute to insulin resistance in this population.', 'We determined the effects of acute inhibition of lipolysis on insulin sensitivity in HIV-infected patients with fat redistribution who were receiving a protease inhibitor.', 'Seven HIV-infected men [age: 45 +/- 2 y; body mass index (in kg/m(2)): 28.8 +/- 1.9] with a fasting insulin concentration > or= 104 pmol/L (15 micro IU/mL), combined visceral adiposity and peripheral lipoatrophy, and receiving a protease inhibitor were studied. Tolbutamide-modified frequently sampled intravenous-glucose-tolerance tests (FSIGTTs) were performed after randomized double-blind administration of acipimox (500 mg at -90 and 0 min), a potent inhibitor of lipolysis, and placebo. The subjects completed 2 FSIGTTs separated by 3-7 d.', 'At baseline, fasting insulin and fatty acid concentrations were 27.6 +/- 5.0 micro IU/mL and 0.83 +/- 0.08 mmol/L (normal range: 0.1-0.6 mmol/L), respectively. Fatty acid concentrations were significantly reduced after acipimox compared with placebo (fatty acid area under the curve: acipimox = 73 +/- 8 compared with placebo = 122 +/- 12 mmol x 270 min/L, P = 0.002). Acipimox treatment resulted in a significant increase in the insulin sensitivity index (acipimox = 1.63 +/- 0.5 compared with placebo = 0.88 +/- 0.3 x 10(-4) x min(-1) x micro IU/mL, P = 0.015).'] Does inhibition of lipolysis improve insulin sensitivity in protease inhibitor-treated HIV-infected men with fat redistribution?