Weight and metabolic changes after switching from tenofovir disoproxil fumarate to tenofovir alafenamide in people living with HIV. Annals of Internal Medicine.
Surial and Mugglin et al. evaluated the impact of switching from Tenofovir disoproxil fumarate (TDF) to Tenofovir alafenamide (TAF) on weight, the development of obesity and other metabolic outcomes among participants on stable antiretroviral therapy.
Authors analyzed data from all individuals who received a TDF-containing therapy for 6 months or longer and compared weight trajectories and changes in lipid levels over 18 months between individuals who switched from TDF to TAF and those who continued TDF.
The study population included 4375 individuals; the median age was 50 years (IQR 43–56), 26% were women, and 52% had a normal body mass index. Overall, 3484 (79.6%) switched to TAF and 891 (20.4%) continued TDF. After 18 months, participants who switched to TAF experienced a mean weight increase of 1.7 kg (95% CI 1.5–2.0), compared with 0.7 kg (CI 0.4–1.0) with the continued use of TDF (between group difference 1.1 kg, CI 0.7–1.4). The difference between both groups was largest among women of African (1.5 kg) and non-African origin (1.4 kg), and among individuals who received integrase inhibitors (1.7 kg), but weight increases were greater with TAF than TDF with all third drugs used. Among individuals with a normal BMI, 13.8% who switched to TAF became overweight or obese, compared with 8.4% who remained on TDF. In a sensitivity analysis, patients who switched from abacavir (ABC)-containing regimens to TAF also experienced larger weight increases compared with those who continued ABC. Finally, the use of TAF was associated with greater increases in levels of total cholesterol, low-density lipoprotein cholesterol, and triglycerides compared with the continued use of TDF.
This study highlights that replacing TDF with TAF is associated with adverse metabolic changes, including weight increase, the development of obesity and worsening of blood lipid values. The increases in weight observed after switching from TDF and ABC to TAF further show that weight changes cannot only be explained by stopping TDF. Taken together, these findings underscore the need of a balanced evaluation of the advantages and potential harms when recommending TAF over TDF.