Limited data suggest that glycated hemoglobin (hemoglobin A1c; A1C) values may not reflect glycemic control accurately in HIV-infected individuals with diabetes.
We evaluated repeated measures of paired fasting glucose and A1C values in 315 HIV-infected and 109 HIV-uninfected diabetic participants in the Women's Interagency HIV Study. Generalized estimating equations used log A1C as the outcome variable, with adjustment for log fasting glucose concentration in all models.
An HIV-infected woman on average had 0.9868 times as much A1C (that is, 1.32% lower; 95% confidence interval 0.9734-0.9904) as an HIV-uninfected woman with the same log fasting glucose concentration. In multivariate analysis, HIV serostatus was not associated, but white, other non-black race, and higher red blood cell mean corpuscular volume (MCV) were statistically associated with lower A1C values. Use of diabetic medication was associated with higher A1C values. In multivariate analysis restricted to HIV-infected women, white and other race, higher MCV, and HCV viremia were associated with lower A1C values whereas older age, use of diabetic medications and higher CD4 cell count were associated with higher A1C values. Use of combination antiretroviral therapy, protease inhibitors, zidovudine, stavudine, or abacavir was not associated with A1C values.
We conclude that A1C values were modestly lower in HIV-infected diabetic women relative to HIV-uninfected diabetic women after adjustment for fasting glucose concentration. The difference was abrogated by adjustment for MCV, race, and diabetic medication use. Our data suggest that in clinical practice A1C gives a reasonably accurate refection of glycemic control in HIV-infected diabetic women.