Weight and body mass index change after switching to integrase inhibitors or tenofovir alafenamide among women living with HIV.

OBJECTIVE Assess weight and body mass index (BMI) change among women after switch to integrase strand transfer inhibitors (INSTIs) and/or tenofovir alafenamide (TAF). METHODS From 2006-2019, 1458 women living with HIV (WLWH) enrolled in the Women's Interagency HIV Study and on antiretroviral therapy (ART) with ≥1 study visit before and after switching to INSTIs and/or TAF were included. Weight and BMI were compared pre-and post-switch to INSTI (by class and type) and/or TAF using multivariable linear mixed effects models; all models were also stratified by pre-switch presence or absence of obesity (BMI≥30 vs <30kg/m2). RESULTS Mean age pre-switch was 47±6 years, 64% were Black, mean CD4=475±201 cells/mm3, 56% had HIV RNA<200 copies/mL, 36% switched to TAF but not INSTI, 60% to INSTI but not TAF, and 3.5% to TAF+INSTI. Time from pre- to post-switch was 12.8 ±11.8 months. The INSTI-only group but not TAF groups had small but significant increases in weight and BMI: mean 79.2 to 80.6 kg and 30.2 to 30.7 kg/m2, p's<0.001, respectively, with congruent findings by INSTI type (p's<0.01). In stratified (pre-switch BMI) analyses, only non-obese subgroups experienced increases in weight and BMI across all ART treatment groups (p's<0.05). CONCLUSIONS Significant, albeit small-to-medium, increases in weight and BMI occurred among non-obese women who switched to INSTIs and/or TAF over short follow-up. Given long-term health consequences of obesity particularly as a low-grade inflammatory condition, identifying women at highest risk of ART-associated weight gain is imperative.