Weight gain following antiretroviral therapy (ART) initiation in ART-naïve people living with HIV in the current treatment era.

OBJECTIVES Evaluate differences in weight change by regimen among people living with HIV (PLWH) initiating antiretroviral therapy (ART) in the current era. METHODS Between 2012-2019, 3232 ART-naive PLWH initiated >3-drug ART regimens in eight Centers for AIDS Research Network of Integrated Clinical Systems (CNICS) sites. We estimated weight change by regimen for 11 regimens in the immediate (first 6-months) and extended (all follow-up on initial regimen) periods using linear mixed models adjusted for time on regimen, interaction between time and regimen, age, sex, race/ethnicity, hepatitis B/C coinfection, nadir CD4, smoking, diabetes, antipsychotic medication, and site. We included more recently approved regimens (e.g. with tenofovir alafenamide fumarate (TAF)) only in the immediate period analyses to ensure comparable follow-up time. RESULTS Mean follow-up was 1.9 years on initial ART regimen. In comparison to efavirenz/tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC), initiating bictegravir/TAF/FTC (3.9kg (95%CI:2.2-5.5)) and dolutegravir/TAF/FTC (4.4kg (95%CI:2.1-6.6)) were associated with the greatest weight gain in the immediate period, followed by darunavir/TDF/FTC (3.7kg (95%CI:2.1-5.2)) and dolutegravir/TDF/FTC (2.6kg (95%CI:1.3-3.9). In the extended period, compared with efavirenz/TDF/FTC, initiating darunavir/TDF/FTC was associated with a 1.0kg (95%CI:0.5-1.5) per 6-months greater weight gain, while dolutegravir/abacavir/FTC was associated with a 0.6kg (95%CI:0.3-0.9) and dolutegravir/TDF/FTC was associated with a 0.6kg (95%CI:0.1-1.1) per 6-months greater gain. Weight gain on dolutegravir/abacavir/FTC and darunavir/TDF/FTC was significantly greater than that for several integrase inhibitor-based regimens. CONCLUSIONS There is heterogeneity between regimens in weight gain following ART initiation among previously ART-naive PLWH; we observed greater gain among PLWH taking newer INSTIs (DTG, BIC) and DRV-based regimens.