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

Abstract

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. 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 A_1c (HbA_1c) through the year after medication initiation, adjusting for baseline HbA_1c level and clinical covariates. A subanalysis using propensity scores was conducted to account for confounding by indication. 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 HbA_1c 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 HbA_1c 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. 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.