Comparative Effectiveness of Diabetic Oral Medications Among HIV-Infected and HIV-Uninfected Veterans

Abstract

OBJECTIVE Type 2 diabetes is increasingly common in HIV-infected individuals. The objective of this study was to compare the glycemic effectiveness of oral diabetic medications among patients with and without HIV infection. RESEARCH DESIGN AND METHODS A longitudinal cohort study was conducted among HIV-infected and uninfected veterans with type 2 diabetes initiating diabetic medications between 1999 and 2010. Generalized estimating equations were used to compare changes in hemoglobin A1c (HbA1c) through the year after medication initiation, adjusting for baseline HbA1c level and clinical covariates. A subanalysis using propensity scores was conducted to account for confounding by indication. RESULTS A total of 2,454 HIV-infected patients and 8,892 HIV-uninfected patients initiated diabetic medications during the study period. The most commonly prescribed medication was metformin (n = 5,647, 50%), followed by a sulfonylurea (n = 5,554, 49%) and a thiazolidinedione (n = 145, 1%). After adjustment for potential confounders, there was no significant difference in the change in HbA1c level among the three groups of new users. HIV infection was not significantly associated with glycemic response (P = 0.24). Black and Hispanic patients had a poorer response to therapy compared with white patients, with a relative increase in HbA1c level of 0.16% (95% CI 0.08, 0.24) [1.7 mmol/mol (0.9, 2.6)] (P < 0.001) and 0.25% (0.11, 0.39) [2.7 mmol/mol (1.2, 4.3)] (P = 0.001), respectively. CONCLUSIONS We found that glycemic response was independent of the initial class of diabetic medication prescribed among HIV-uninfected and HIV-infected adults with type 2 diabetes. The mechanisms leading to poorer response among black and Hispanic patients, who make up a substantial proportion of those with HIV infection and type 2 diabetes, require further investigation.