From the Guidelines
Yes, TAF causes more weight gain than TDF.
Key Points
- Tenofovir alafenamide (TAF) is associated with greater weight gain than tenofovir disoproxil fumarate (TDF) 1.
- The exact mechanisms of this weight gain difference are unknown, but it may be related to the effects of TDF on lipid levels and metabolism 1.
- Regimens that include TAF, as well as integrase strand transfer inhibitors (InSTIs) like dolutegravir and bictegravir, are associated with greater weight gain than comparator regimens 1.
- Patients should be counseled about the potential for weight gain and provided with information on diet, exercise, and behavior modifications to minimize this issue 1.
- A placebo-controlled study of pre-exposure prophylaxis (PrEP) suggested that TDF may inhibit weight gain, which could partially explain the excess weight gain observed with TAF compared to TDF 1.
From the Research
Weight Gain Comparison between TAF and TDF
- The study 2 found that switching from TDF to TAF was associated with pronounced weight gain immediately after the switch, regardless of the core class or core agent.
- Another study 3 reported that patients initiating TAF 25 mg had greater weight or BMI increase compared to patients initiating TAF 10 mg, TDF, or non-TAF/TDF regimens.
- A study 4 observed significant weight gain and BMI increase during the first year after initiation of TAF-containing ART regimens in both groups of patients who switched from TDF to TAF.
- The analysis 5 showed a statistically significant correlation in weight after changing from a TDF to a TAF containing antiretroviral regimen, with patients showing a mean percentual weight increase of 3.17% after 360 days of initiating TAF.
- A comparison study 6 found that weight gain was associated with both switching HIV regimens from non INSTI- to INSTI-based ART and TDF- to TAF-based ART, with no statistical difference in weight gain between the two switch groups.
Key Findings
- TAF is associated with more weight gain than TDF, as reported in studies 2, 3, 4, 5, 6.
- The weight gain associated with TAF tends to slow down or plateau approximately nine months after the switch, as observed in study 2.
- The effect of TAF on weight gain is independent of the core class or core agent, as suggested by study 2.