Weight and body mass index (BMI) change was assessed among women after switch to integrase inhibitors (INSTIs) and/or tenofovir alafenamide (TAF). From 2006 to 2019, 1,458 women living with HIV 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 postswitch to INSTI (by class and type) and/or TAF using multivariable linear mixed effects models; all models were also stratified by preswitch presence or absence of obesity (BMI ≥30 vs. <30 kg/m2). Mean age preswitch 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 postswitch was 12.8 ± 11.8 months. The INSTI-only group but not TAF groups had small but significant increases in weight and BMI: mean 79.2-80.6 kg and 30.2-30.7 kg/m2, p's < .001, respectively, with congruent findings by INSTI type (p's ≤ .01). In stratified (preswitch BMI) analyses, only nonobese subgroups experienced increases in weight and BMI across all ART treatment groups (p's < .05). Significant, although small-to-medium, increases in weight and BMI occurred among nonobese 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.
Keywords: HIV; body mass index; body weight; integrase inhibitors; tenofovir alafenamide; women.