Application of Latent Class Growth Analysis in Identifying Body Weight Gain Trajectories Among ART-Naïve and Experienced Patients on DTG Based Regimen

Background: Weight gain among people living with HIV (PLHIV) on antiretroviral therapy (ART) is an emerging concern, especially with increased use of Dolutegravir (DTG)-based regimens. This study identified and characterized distinct body weight gain trajectories among PLHIV, comparing DTG treatment-naïve and treatment-experienced individuals. Methods: A retrospective longitudinal analysis of 3,525 PLHIV on DTG-based ART was conducted using 24-month body weight data. Latent Class Growth Analysis (LCGA) identified subgroups with distinct weight trajectories based on baseline weight (intercept) and rate of change (slope). Model selection was guided by Akaike Information Criterion (AIC), Bayesian Information Criterion (BIC), and clinical interpretability. Weight gain trajectories were compared by treatment status, sex, and age. Results: Participants had a mean age of 33.5 years (SD = 12.8); 62.6% were female. Mean baseline weight was 52.7 kg (SD = 11.7), higher among treatment-naïve individuals (54.5 kg) than experienced ones (49.6 kg). Four weight gain trajectories emerged: Class 3 (Minimal/No Change, 84.3%), Class 1 (Moderate Gain, 8.9%), Class 2 (Rapid Gain, 5.9%), and Class 4 (Unique, 0.9%). The four-class model provided the best fit (AIC = 41,786.47; BIC = 41,866.65), with Class 4 showing highest classification accuracy (AvePP = 0.96). Conclusion: Considerable heterogeneity exists in weight gain among PLHIV on DTG-based ART, with 15.7% showing moderate to rapid gain. Treatment-naïve status and higher baseline weight predicted upward trajectories. Early metabolic screening and targeted counselling, especially for males and younger clients, are recommended to mitigate obesity-related risks and improve outcomes.