OBJECTIVES: To analyze weight changes associated with dolutegravir- versus efavirenz-based antiretroviral therapy (ART) in people with HIV (PWH) in rural Tanzania, where undernutrition is prevalent. DESIGN: Longitudinal, observational study of the prospective Kilombero and Ulanga Antiretroviral Cohort (KIULARCO). METHODS: We included adult, ART-naïve, nonpregnant PWH initiating efavirenz-based ART 12/2016-02/2019 or dolutegravir-based ART 03/2019-12/2022. We used multivariable linear mixed-effects models to assess adjusted weight changes during 18 months after ART start and Cox regression models to assess factors associated with incident obesity, weight gain ≥10% and hypertension. RESULTS: Of 1205 PWH at ART start [median age 40 years (interquartile range (IQR) 32-48)
719 (59.7%) females], 166 (13.8%) individuals were underweight and 317 (26.3%) overweight/obese
621 (51.5%) initiated efavirenz-based and 584 (48.5%) dolutegravir-based ART. After 18 months, estimated weight gain was 5.1 kg [95% confidence interval (CI) 4.7-5.5] in the dolutegravir versus 4.0 kg (95% CI 3.7-4.4) in the efavirenz group. The weight gain difference between treatment groups was high in men (1.7 kg (95% CI 0.8-2.6
P <
0.002)), in those aged 30-49 years (1.5 kg (0.8-2.1)
P <
0.002) and those with CD4 + cell count ≥500/ul (2.5 kg (1.4-3.7), P <
0.002)). Cumulative obesity incidence at 18 months was 10.9% (95% CI 8.3-14.0) in the dolutegravir and 5.1% (95% CI 3.6-7.1) in the efavirenz group. Associated factors were dolutegravir and a pre-ART body mass index (BMI) of 25-29 kg/m 2 . Dolutegravir and age, but not weight gain were associated with incident of hypertension. CONCLUSIONS: Dolutegravir-based ART was associated with more weight gain, higher obesity and hypertension - especially in those with a higher pre-ART BMI compared to efavirenz-based regimens.