Replacing TDF with tenofovir alafenamide leads to obesity in adults living with HIV

Switching from tenofovir disoproxil fumarate (TDF) to tenofovir alafenamide (TAF) in people living with HIV results in adverse metabolic changes such as weight increase, obesity, and worsening of serum lipid levels, a study has found.

This cohort study included 4,375 adults living with HIV who received TDF-containing antiretroviral therapy for ≥6 months from five hospitals and private physicians in Switzerland. Mixed-effect models were used to assess changes in weight and lipid levels. Two-proportions Z tests were performed to calculate differences in proportions of newly overweight/obese participants.

Of the patients (median age 50 years, interquartile range 43–56 years, 25.9 percent female) followed between 1 January 2016 and 31 July 2019, more than half (51.7 percent) had a normal body mass index (BMI), and 3,484 (79.6 percent) switched to TAF while the rest (n=894; 20. 4 percent) continued TDF.

Switching to TAF correlated with an adjusted mean weight increase of 1.7 kg (95 percent confidence interval [CI], 1.5–2.0), compared with 0.7 kg (95 percent CI, 0.4–1.0) with continued TDF use, after 18 months (between-group difference, 1.1 kg, 95 percent CI, 0.7–1.4).

In addition, 13.8 percent of individuals with a normal BMI who switched to TAF became overweight or obese compared with 8.4 percent of those who continued using TDF (difference, 5.4 percentage points, 95 percent CI, 2.1–8.8).

After 18 months, switching to TAF resulted in increases in adjusted mean levels of total cholesterol (0.25 mmol/L), high-density lipoprotein cholesterol (0.05 mmol/L), low-density lipoprotein cholesterol (0.12 mmol/L), and triglyceride (0.18 mmol/L).

This study was limited by its short follow-up, small subgroup analyses, and potential residual confounding, according to the authors.