Weight gain in antiretroviral therapy-naive HIV-1-infected patients starting a regimen including an integrase strand transfer inhibitor or darunavir/ritonavir

Background: Weight gain after initiation of combination antiretroviral therapy (cART) is a possible side effect of all antiretroviral regimens, but it seems to be more evident in association with integrase strand transfer inhibitors (INSTIs). So, we aimed to evaluate weight change associated with an initial cART including one INSTI or darunavir–ritonavir (DRV/r). Methods: A retrospective, observational, cohort study of antiretroviral therapy-naive adult HIV-positive patients starting an initial cART including raltegravir (RAL), dolutegravir (DTG), elvitegravir–cobicistat (EVG), or DRV/r. We compared changes in weight and body mass index (BMI) across the four groups during a 12-month follow-up. Results: As a whole, 680 patients (470 males, mean age 42.1 years) were enrolled: 196 starting RAL, 174 DTG, 158 EVG/c, and 152 DRV/r. Baseline mean CD4 lymphocyte count was 455 cells/mm3 and 7.3% had an AIDS diagnosis. After 12 months, mean increase in body weight was 1.93 kg in the RAL group, 2.38 kg in the DTG group, 2.14 kg in the EVG group, and 1.85 in the DRV/r group. Mean increase in BMI was 0.71, 0.84, 0.77 and 0.63 kg/m2, respectively (p > 0.05 for each comparison). Therefore, no significant increases in weight and BMI were reported in each group, and no significant differences in weight and BMI changes were described across the four treatment groups. Conclusions: In our study, patients starting an initial cART including one INSTI or DRV/r after 12 months showed a small and comparable, but not significant, increase in body weight, whose long-term clinical consequences are unknown.