(C-037) Hospitalization Risk in Persons with and without HIV Initiating Metformin for Type 2 Diabetes

Background: Despite antiretroviral therapy, hospitalization risk remains higher for persons with HIV (PWH) than for the general population. Type 2 diabetes mellitus (T2DM) prevalence is high and increasing in PWH, and T2DM complications could contribute to PWH’s elevated hospitalization risk.

Objectives: To compare hospitalization risk, among persons initiating first-line T2DM treatment, between PWH versus persons without HIV (PWoH).

Methods: We included patients in MarketScan Commercial Claims and Encounters with a T2DM diagnosis code who had a first outpatient metformin dispensation between 2016 and 2022 with no hospitalization in the prior 6 months. We excluded those initiating multiple T2DM medications, as they were more likely to have had unobserved previous treatment episodes. HIV status at metformin initiation (baseline) was defined as a history of HIV diagnosis and antiretroviral dispensation. We used Kaplan-Meier methods to estimate 1-year all-cause hospitalization risk differences (RD) comparing PWH and PWoH. We adjusted for baseline age and sex using stabilized standardized morbidity ratio (SMR) weights and used a non-parametric bootstrap to estimate 95% confidence intervals (CI).

Results: PWH (N=1162) were more likely than PWoH (N=329,855) to be male (76% vs. 53%), reside in the South (63% vs. 51%), and have longer time between first T2DM diagnosis code and metformin dispensation (median 5 [IQR 0-15] vs 1 month [0-10]). Median age at metformin initiation was similar for PWH and PWoH (53 [46-57] and 52 years [45-58], respectively). After metformin initiation, PWH experienced 210 hospitalizations over 2153 person-years (PY) of follow-up, a rate of 9.8 per 100 PY (95% CI 8.5, 11.2), compared with 49,811 hospitalizations over 639,150 PY for PWoH, a rate of 7.8 per 100 PY (7.7, 7.9). The unadjusted 1-year risk of hospitalization after metformin initiation was 9.0% (7.2%, 10.8%) for PWH and 6.2% (6.1%, 6.3%) for PWoH, an RD of 2.8% (0.9%, 4.5%). After adjusting to the age and sex distribution of PWoH, the 1-year risk of hospitalization among PWH was 8.5% (6.6%, 10.3%), yielding an adjusted RD of 2.3% (0.3%, 4.1%).

Conclusions: In this US cohort of commercially insured persons with T2DM, PWH had a greater hospitalization risk than PWoH in the first year after metformin initiation. Further research should elucidate potential drivers of this disparity, such as differences in glycemic control, comorbidity burden, social determinants of health, or time from T2DM diagnosis to treatment initiation.