332. Exploring the Prevalence and Characteristics of Weight Gain and other Metabolic Changes in Patients with HIV Infection Switching to Integrase Inhibitor Containing ART

BACKGROUND: Excessive weight gain in patients living with HIV (PLWH) can have considerable health-related consequences. Recent observational studies suggest that patients initiating or switching to integrase strand transfer inhibitor (INSTI)-based antiretroviral therapy (ART) may experience weight gain. The prevalence and extent of weight gain as well as the presence of other metabolic changes following switches to INSTI-based ART remain unclear. METHODS: This retrospective study evaluated changes in weight, body mass index (BMI), cholesterol and hemoglobin A1C in virologically suppressed PLWH who switched from non-INSTI to INSTI-based ART at a single academic medical center from May 2015 to December 2017. Adult patients on non-INSTI-based ART for ≥1 year before switching to INSTI-based regimens were included. Body weight, BMI, cholesterol and A1C values were collected for the year prior to and 18 months following the switch. The unadjusted distributions of pre- and post-switch values were compared with the Wilcoxon signed-rank test and predictors of weight gain were determined with simple linear regression. RESULTS: A total of 90 patients met criteria for analysis (Table 1). In unadjusted analyses, there were significant increases in weight and BMI (each P ≤ 0.001, Table 2), but not cholesterol or A1C values following switches to INSTI-based ART (Table 3). On average, patient weight increased by 2.2 kg after switching, though 26% of patients gained ≥4.5 kg. Patients switching from non-nucleoside reverse transcriptase inhibitors vs. protease inhibitors had numerically greater mean increases in weight (Table 3). A similar trend occurred for those switching to elvitegravir as opposed to dolutegravir. In the linear regression model, neither pre-switch nor post-switch ART components were identified as predictors for weight gain. This was also true for differences in gender, race, and pre-switch BMI. Increasing age was protective against weight gain in the model. CONCLUSION: Weight gain in patients switching to INSTI-based ART observed in this analysis did not correspond to changes in cholesterol or glycemic control. Some patients receiving INSTIs in this sample gained substantial amounts of weight. The mechanisms and risk factors for substantial weight gain require further study. [Image: see text] [Image: see text] [Image: see text] DISCLOSURES: All authors: No reported disclosures.