This study assessed glucose tolerance, insulin sensitivity and lipid parameters in HIV-infected patients presenting with lipodystrophy during HAART including protease inhibitors. Fourteen consecutive patients from Rothschild Hospital treated with HAART and presenting with marked facial lipoatrophy were evaluated. A 75 g oral glucose tolerance test (OGTT) with measurement of plasma glucose, insulin, proinsulin and free fatty acids at T0, 30, 60, 90 and 120 min was performed. Lipid parameters (triglycerides, cholesterol, apolipoproteins A1 and B) were studied as well as nutritional and inflammatory markers (albumin, prealbumin, transferrin, haptoglobin, orosomucoid, C-reactive protein), endocrine and cytokine parameters (thyrotropin, cortisol, leptin, interleukin-6), HIV viral load and CD4-lymphocyte count. These patients were compared with 20 non-lipodystrophic protease inhibitor-treated patients. The measurements performed during OGTT showed that among the 14 lipodystrophic patients, 11 (79%) presented with diabetes (5 patients) or normal glucose tolerance but with insulin resistance (6 patients). This frequency was strikingly different in the group of nonlipodystrophic patients, which included only 4 (20%) presenting with diabetes (1 patient), or impaired glucose tolerance (2 patients), or normal glucose tolerance but with insulin resistance (1 patient). Hypertriglyceridaemia was present in 11 lipodystrophic (79%) versus 7 nonlipodystrophic patients (35%). Nutritional and endocrine measurements were normal. An abnormal processing of proinsulin to insulin was excluded. Thus, lipodystrophy during HAART was associated with diabetes, insulin resistance and hypertriglyceridaemia. Diabetes, diagnosed by basal and/or 120 min-OGTT glycaemia, seems more frequent than previously described. The therapeutic consequences of these results deserve evaluation in clinical trials.