Background:
Weight gain is common during first-line ARV treatment, especially among women and those of black race. Use of TDF or EFV can suppress weight gain. People with lower baseline CD4 count show greater weight gains, but this might be from regaining weight lost during advanced disease.
Methods:
Data were pooled from three clinical trials: ADVANCE (n=1053), NAMSAL (n=624), and WHRI001 (n=536). These randomised trials evaluated first-line ARV regimens (TAF/XTC/DTG, TDF/XTC/DTG, and TDF/XTC/EFV) in Cameroon and South Africa. BMI over 96 weeks was analysed, stratified by baseline CD4 count as a marker for disease stage (<100, 100-200, 200-350, ≥350 cells/uL). Multivariate models at week 96 assessed factors associated with BMI and clinical obesity (BMI ≥30), adjusting for baseline CD4 category, age, sex, TDF, EFV, and clinical trial.
Results:
At baseline, mean age was 34.5 (SD 8.9), 60% were female, 14% had CD4 <100 cells/uL, and 31% had CD4 ≥350. Lower baseline BMI was strongly correlated with lower baseline CD4 count (p<0.001). At week 96, mean unadjusted BMI change was highest in the <100 CD4 group (+3.2 kg/m2; SD 3.1) and lowest in the CD4≥350 group (+1.1; SD 2.4). Individuals with advanced disease on TAF-based regimens experienced greater BMI increases compared to those on TDF-based regimens (Figure 1). For participants on TAF-based treatment (ADVANCE only), increases in BMI to Week 96 were significantly higher in people with CD4<100 (+5.0; SD 3.1) compared to the ≥350 group (1.6; SD 2.2). In the adjusted model, for people taking TAF/FTC/DTG, BMI at Week 96 was significantly higher for people with baseline CD4<100 (28.4 [95%CI 26.7-30.1]) compared to CD4≥350 (25.3 [95%CI 24.4-26.3]; p=0.001). However, on TDF or EFV-based regimens, there was no difference in BMI across the CD4 categories. Analyses using clinical obesity (BMI >30 kg/m2) showed consistent results: people taking TAF/FTC/DTG with CD4<100 were significantly more likely to become obese after 96 weeks of first-line treatment.
Conclusions:
For people taking TAF/FTC/DTG, baseline CD4<100 cells/uL at treatment initiation was associated with significantly higher BMI and clinical obesity at Week 96. Weight continued to rise over time for people with low CD4 counts taking TAF/FTC/DTG, above the levels seen with higher baseline CD4 counts. Use of TDF and EFV were associated with smaller rises in weight. Effective weight management is required with current regimens to avoid complications associated with significant weight increases.
