Weight change with integrase strand transfer inhibitors among virally suppressed Thai people living with HIV.

BACKGROUND

We compared weight changes in virally suppressed people living with HIV (PLWH) switching to integrase strand transfer inhibitors (INSTIs) with those remaining on an INSTI or non-INSTI regimen.

METHODS

PLWH aged ≥18 years with weight measurements available at baseline between 2001 and 2020 were included. Viral suppression was defined as having had a viral load <400 copies/mL for 6 months. Baseline was defined as the time of switching from a non-INSTI to an INSTI regimen whilst virally suppressed (switch group) or the time that viral suppression was achieved (remain groups). Generalized estimating equations adjusted for age, sex and baseline weight were used to model weight changes 6, 12, 18 and 24 months after baseline.

RESULTS

A total of 1673 PLWH contributed 1952 episodes of viral suppression-143 (7.3%) episodes were among PLWH who had switched from a non-INSTI to an INSTI, 102 (5.2%) episodes were among PLWH who remained on an INSTI and 1707 (87.4%) episodes were among PLWH who remained on a non-INSTI. PLWH in the switch group had significantly greater weight gain than those in the remain groups at 6, 12 and 18 months after achieving viral suppression. By 24 months, weight change on all regimens started to converge. Tenofovir alafenamide use was not significantly associated with weight gain in adjusted models.

CONCLUSIONS

Our findings suggest that the mechanisms of weight gain due to INSTI use go beyond their superior efficacy over other antiretrovirals in controlling HIV or the effect of the 'return-to-health' phenomenon. Further research is needed to understand the mechanisms of such weight gain.