Weight gain on tenofovir alafenamide fumarate-based therapy compared to tenofovir disoproxil fumarate- and abacavir-based therapy in children and young people living with HIV in Europe
 Weight gain has emerged as an important concern among people with HIV on antiretroviral therapy (ART), but data in children and young people remain limited. In a study from the European Pregnancy and Paediatric Infections Cohort Collaboration (EPPICC) published in HIV Medicine, Crichton et al. compared changes in BMI-for-age z-score (zBMI) among treatment-experienced children and young people with HIV starting ART containing tenofovir alafenamide (TAF), tenofovir disoproxil fumarate (TDF), or abacavir (ABC).
The study included 765 treatment-experienced children and young people with HIV between 6 and 25 years of age across 12 European countries: of those, 162 received TAF after prior TDF use, 189 received TAF without prior TDF, 270 received TDF, and 144 received ABC. Follow-up extended up to 96 weeks after drug start. The authors compared the incidence of overweight and obesity and assessed changes in zBMI using interval-censored Cox models and mixed models with random time slopes.
By 96 weeks, the incidence of new obesity was 16% for individuals receiving TAF after prior TDF, 13% for those who received TAF without prior TDF, 6% in those who received TDF, and 12% in individuals on ABC-based ART. Compared with children and young people on TAF without prior TDF use, those on TDF were less likely to develop obesity (adjusted hazard ratio 0.42, 95% CI 0.20–0.86), while estimates for TAF with prior TDF (1.33, 95% CI 0.61–2.89) and ABC (0.84, 95% CI 0.46–1.54) did not differ significantly. Over 48 weeks of TAF-based ART, zBMI increased by 0.12 in individuals switching from TDF and 0.17 in those who received TAF without prior TDF. Compared to TAF-based ART, ABC-based ART was associated with similar zBMI increases, whereas TDF led to lower zBMI increases.
In summary, the present study showed more pronounced weight gain and development of obesity among individuals receiving TAF- and ABC-based ART compared to those receiving TDF. These findings confirm a weight-suppressive effect of TDF observed in the adult population, which extends to children and young people with HIV, and highlight the need for monitoring of weight and metabolic health.