INSTI-associated weight gain has been described among ART-naïve persons initiating INSTI-containing ART, but not among virally suppressed (VS) persons whose first INSTI exposure is via a switch regimen. We evaluated changes in weight (CW) among such persons in the HIV Outpatient Study (HOPS).
We analyzed medical record data of patients from nine United States HIV clinics who were INSTI-naive and VS for >1 year on non-INSTI-based ART, and switched to INSTI-based ART and remained VS. Participants received INSTI-based ART for >6 months, had >2 weights recorded in the year prior to switch and >1 after. We evaluated CW over time, overall and stratified by demographics, pre-switch body mass index (BMI) and ART use, CD4 at ART start, and INSTI received. We used multivariable random regression mixed model to estimate factors associated with CW.
Among 437 patients (median age 51 years, interquartile range 44.5, 57.5), 86 (19.6%) were women, 107 (24.5%) were non-Hispanic Black (NHB). Pre-INSTI regimens often included an NNRTI (193 [44.1%]) or PI (185 [42.0%]) with >1 NRTI (402 [91.5%]). INSTI regimens included raltegravir (236 [54.0%]), elvitegravir (89 [20.4%]), or dolutegravir (112 [25.6%]). Mean CW in the year prior to INSTI was -0.2 kg (95% confidence interval [CI]: -0.6, 0.2). Mean duration of INSTI use was 2.9 years (max=9.7 years). Mean CW on INSTI was 1.2 kg (CI 0.6, 1.9), did not differ by INSTI drug used (p>0.2) and was greater for persons with pre-INSTI BMI < 25 (2.2 kg, CI 1.5, 3.0) than 25-29.9 (0.5 kg, CI -0.5, 1.4) or >30 (0.4 kg, CI -1.7, 2.6), p=0.03; NHB than Non-Hispanic whites, 2.7 kg (CI 1.3, 4.1) vs 1.0 kg (CI 0.2, 1.7), p=0.02; and persons whose pre-INSTI ART did not include an NRTI vs those whose did, 4.5 kg (CI 1.8, 7.3) vs. 0.9 kg (CI 0.3, 1.6), p<0.01. Duration of INSTI use was not associated with CW: mean 1.0 kg (CI 0.5, 1.4) for 6-<12 months (mos), 1.2 kg (CI -0.5, 2.9) for 12-<24 mos, 1.3 kg (CI 0.7, 1.9) for 24-<60 mos, 1.2 kg (CI 0.5, 2.0) for ≥60 mos, p=0.7. In multivariable models NHB race, and no pre-INSTI NRTI use remained associated with greater percent change in weight (p<0.05) while lower pre-INSTI BMI was borderline significant, p=0.08.
We observed weight gain among VS persons who switched to INSTI-based ART that was associated with NHB race, no pre-INSTI NRTI use, and lower pre-INSTI BMI .These findings of differential risk for INSTI-related weight gain require further evaluation.