Background: Weight loss is comprised of variable proportions of fat and fat-free mass (FFM). HIV-infected patients treated with antiretroviral (ARV) agents may lose subcutaneous fat (lipoatrophy) in the absence of FFM depletion, which could confound the clinical interpretation of weight loss.
Methods: We retrospectively analyzed the results of anthropometric and dual-energy X-ray absorptiometry studies in 196 HIV-infected men and women with documented 10% weight loss (HIV group), and compared them to 29 untreated, HIV-infected men without 10% weight loss (HIV weight-stable), and 109 healthy adults (72 men and 37 women) to evaluate the effect of ARV therapy on the composition of weight loss. The HIV group was divided into four subgroups according to current ARV therapy: treatment-naive (59 men and 26 women), nucleoside reverse transcriptase inhibitor (NRTI) monotherapy (45 men), dual NRTI therapy (28 men) and highly active ARV therapy (HAART) (19 men and 20 women).
Results: Ages and heights were similar in all groups, while body mass index (BMI) and body composition differed significantly. BMI was higher in HIV-infected men and women on HAART than in the other HIV groups, although less than in HIV weight-stable (P=0.36) and healthy controls (P<0.0005). Fat content was lower in all HIV groups than in controls (P<0.001), while FFM was similar in HIV-infected men and women on dual NRTI and HAART and in controls. Comparison with HIV weight-stable gave higher estimates of the contribution of FFM to the differences in weight.
Conclusion: Treatment of HIV infection with ARV may affect the interpretation of 10% weight loss.