Changes in body mass index in children and adolescents living with HIV in Europe and Thailand starting dolutegravir

Background: Excess weight gain has been reported in some adults on dolutegravir (DTG), but data in children/adolescents living with HIV (CALHIV) are limited. // Methods: CALHIV aged 2-<18 years (yrs) at DTG start from 15 observational cohorts across Europe and Thailand were included. Mixed-models described changes in body mass index-for-age z-score(zBMI). We assessed (i) zBMI change 48 weeks(wks) before versus after DTG start; (ii) zBMI change up to 96wks on DTG and associated factors; and (iii) zBMI changes over 96wks in CALHIV aged 6-<18yrs at start of DTG versus protease inhibitor(PI)-based regimens using propensity score weighting. // Results: Of 948 CALHIV on DTG, 50% were female, median[IQR] age 13.7[11.1,15.6] years, zBMI 0.31[-0.64,1.19], 48% Black, 30% overweight or obese at DTG start. Among 741 with zBMI available pre/post DTG start, zBMI (95% CI) increased by 0.07(0.03,0.11) versus 0.13(0.09,0.16) (p=0.087), in the 48wks before and after DTG start, respectively. Mean zBMI change by 96wks on DTG was 0.20(0.14,0.27). In multivariable models, greatest increases in zBMI were in those aged 6-<12yrs at DTG start (0.34(0.23,0.44)), males of ‘Other’ ethnicity(0.39(0.10,0.68)), Black females(0.27(0.15,0.39)), and those on tenofovir alafenamide(TAF) (0.39(0.17,0.61)). There was no difference in mean zBMI change at 96wks among those on DTG versus PI-based regimens (0.21(0.13,0.30) vs 0.30(0.13,0.48), p=0.354). // Conclusions: CALHIV experienced zBMI increases on DTG with largest gains in children aged 6-<12yrs, on TAF, with low baseline zBMI, and some variation by sex and ethnicity. However, zBMI changes over 96 weeks were comparable between those on DTG and PI-based regimens.