Weight gain following the single substitution of tenofovir disoproxil fumarate by tenofovir alafenamide in HIV-infected people from the French Dat'AIDS cohort: A propensity score-matched analysis.

Objectives: To minimize confounding factors, we aimed to describe the changes in weight and body mass index (BMI) following the single substitution of tenofovir disoproxil fumarate (TDF) by tenofovir alafenamide (TAF) in people living with HIV (PLWH).

Methods: We designed a retrospective study in a large French cohort. We included all HIV-suppressed adults under TDF + emtricitabine + rilpivirine or elvitegravir/cobistat, who experienced a first switch from TDF to TAF, while other antiretrovirals remained unchanged (Switch group). We compared this population to a propensity score-matched Control group (1:1) who stayed on the same TDF-based regimen. Changes were evaluated after 6 (M6) and 12 months (M12).

Results: Some 1260 and 468 PLWH were evaluable per group at M6 and M12, respectively. In the Switch group, there was a mean (95% confidence interval [95% CI]) weight gain of +1014 g (+826 to +1201) at M6 (p < 0.0001) and +1365 g (+910 to +1820) at M12 (p < 0.0001), as compared with baseline. Meanwhile, there was no significant weight gain at M6 (+139 g [-50 to +328]) and M12 (-32 g [-413 to +350]) in the matched Control group. Similarly, mean BMI increased significantly in the Switch group at M6 (+0.35, 95% CI: +0.29 to +0.41, p < 0.0001) and M12 (+0.49, 95% CI: +0.32 to +0.65, p < 0.0001), while it was stable at M6 (+0.05, 95% CI: -0.01 to +0.12, p = 0.11) and M12 (+0.01, 95% CI: -0.12 to +0.14, p = 0.89) in the No Switch group.

Conclusions: Although modest, there is a significant weight gain following the substitution of TDF by TAF. This should be anticipated in certain at-risk populations.