"Short and Long-term Body Weight Change Following the Switch to or the Addition of Integrase Inhibitors in Persons with HIV Differs by Sex".

Background: Sex-specific, long-term, body weight change in persons with HIV (PWH) following switch to regimens containing integrase strand-transfer inhibitors (INSTIs) is unknown.

Methods: We compared PWH enrolled in the MACS/WIHS Combined Cohort Study (2007-2020) who switched/added an INSTI to their antiretroviral therapy (ART) to those remaining on non-INSTI ART and to people without HIV (PWOH), by sex. Follow-up time was time since switch visit (or comparable visit in controls). Linear regression mixed effect models assessed the effects of sex, group (INSTI, non-INSTI, PWOH), and time upon weight and anthropometric measurements (waist, hip, thigh).

Results: Of 3464 participants included, women (411 INSTI, 709 Non-INSTI, 818 PWOH) compared to men (223 INSTI, 412 Non-INSTI, 891 PWOH) were younger (47.2 years vs 54.5), majority non-Hispanic Black (65 vs 23%), and had higher mean BMI (31.5 kg/m2 vs 26.9), respectively. Women switching to INSTIs experienced greater absolute and % weight gain compared to men at 5 years: +3.0 kg (95% CI 2.1-3.9) vs +1.8 kg (0.7-2.9) and +4.6% (3.5-5.7) vs +2.3% (1.0-3.6), respectively, [sex*time*study group interaction, p<0.01]. Compared to men, women switching to INSTIs experienced greater hip and thigh circumference gain at 5 years: +2.6 cm (95% CI 1.6-3.6) vs +1.2 cm (0.3-2.1) and +1.5 cm (0.7-2.2) vs -0.2 cm (-0.9, 0.5), respectively, but there were no significant sex differences in waist circumference or waist-hip ratio.

Conclusions: Weight change among PWH over 5 years after switch to INSTI was 2-fold higher in women than men. The cardio-metabolic implications of this difference in weight gain remain unknown.