Body mass index variation and nutritional category transitions in people living with HIV on dolutegravir based therapy: a 2 year cohort study

Introduction Dolutegravir (DTG)-based antiretroviral therapy (ART) has been associated with weight gain and increases in body mass index (BMI) among people living with HIV (PLHIV), with higher prevalence of overweight and obesity and potential long-term cardiometabolic consequences. However, the magnitude of these changes and the profile of individuals at greatest risk remain inconsistent across studies, particularly in real-world cohorts from middle-income countries. Methods A cohort study was conducted including 613 PLHIV followed at a specialised clinic, classified by timing of DTG exposure into two groups: initiation of ART with DTG-containing regimens (ART-naïve) or switch from a prior ART regimen to a DTG-based regimen. Baseline BMI and BMI after approximately 2-year follow-up were used to calculate continuous BMI change (ΔBMI, kg/m²) and to define nutritional categories (underweight, normal weight, overweight, obesity) according to World Health Organization (WHO) criteria. The primary outcome was ΔBMI at end of follow-up; secondary outcomes included BMI gain ≥2 kg/m² and transitions between nutritional categories, with focus on recovery from underweight and progression from normal weight/overweight to obesity. Factors associated with BMI gain ≥2 kg/m² were assessed using multivariable logistic regression including sociodemographic, clinical and immunovirological variables. Results Mean BMI change was modest and similar between groups, around 0.7 kg/m² among individuals initiating DTG-based ART and 0.6 kg/m² among those who switched from a previous regimen. Nevertheless, 15.5% of participants experienced a BMI increase ≥2 kg/m², with this clinically relevant weight gain being more frequent in ART-naïve individuals than in those who only switched to DTG (21.1% vs 14.3%). There was a decline in the proportion of underweight participants and an increase in overweight and obesity categories at the end of follow-up, reflecting a mixed pattern of nutritional recovery among initially undernourished individuals and progression from normal weight/overweight to obesity in a smaller, yet clinically relevant, fraction of the cohort, consistent with findings from other DTG-treated populations. In multivariable analyses, male sex, younger age and baseline underweight status were independently associated with a higher likelihood of BMI gain ≥2 kg/m², indicating a subgroup particularly susceptible to weight gain under DTG-based ART. Conclusion In PLHIV receiving DTG-based ART, mean BMI change over 2 years was modest, but a substantial subgroup experienced clinically relevant weight gain, particularly among treatment-naïve, younger male patients with low baseline BMI. This pattern, combining nutritional recovery with an increased prevalence of overweight and obesity, underscores the need for systematic weight monitoring and early lifestyle-focused interventions as integral components of care for PLHIV on DTG-containing regimens.