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.