HIV-Infected Women Gain More Weight than HIV-Infected Men Following the Initiation of Antiretroviral Therapy

Background: Obesity is prevalent among HIV-infected individuals on antiretroviral therapy (ART). Cross-sectional studies have suggested that HIV-infected women are more likely to be overweight than men, but observational studies evaluating sex differences in body mass index (BMI) increases following ART initiation are conflicting. Materials and Methods: We pooled data from three randomized clinical trials of ART initiation in persons with HIV in the United States. BMIs were compared between 760 women and 3041 men to test whether BMI changes in the first 96 weeks following initiation of ART differed by sex at birth. Linear regression estimated the relationship between sex and change in BMI from pre-ART initiation to week 96. Results: After 96 weeks, women gained an average of 1.91 kg/m2 (95% confidence interval CI 1.64–2.19), men gained an average of 1.39 kg/m2 (95% CI 1.30–1.48); p for sex difference <0.001; the sex difference persisted within each pre-ART initiation BMI subgroup. After adjusting for pre-ART initiation age, CD4+ count, HIV-1 viral load, race/ethnicity, study, and ART regimen, mean BMI change for women was 0.59 kg/m2 (95% CI 0.37–0.81) more than for men (p < 0.001). Statistical interactions were observed between sex and both pre-ART CD4+ count and HIV-1 viral load and suggest that for subgroups with higher viral load and lower CD4+ at baseline, the estimated BMI changes in women are even larger than the average estimated difference. Conclusions: HIV-1-infected women experienced a significantly greater increase in BMI following ART initiation than men. These differences are a problem of clinical significance to women living with HIV.