Detecting impaired glucose tolerance or type 2 diabetes mellitus by means of an oral glucose tolerance test in HIV-infected patients

Objective: As a proactive diagnosis of diabetes mellitus (DM) may prevent the onset of severe complications, we used an oral glucose tolerance test (OGTT) to check for impaired glucose tolerance (IGT) and DM in patients with long-standing HIV infection and long durations of exposure to antiretroviral drugs with normal fasting plasma glucose (FPG) levels. Methods: This was a cross-sectional, single-centre study. The homeostatic model assessment for insulin resistance (HOMA-IR) and 2-h post-load glucose levels were used to evaluate patients with known HIV-1 infection since before 1988 and no previous diagnosis of DM for whom data on hepatitis C virus (HCV) and hepatitis B virus (HBV) infection were available. Results: Eighty-four Caucasian patients [67 (80%) male; median age 45.7 years; range 43.8-49.1 years] were able to be evaluated; 65 (77%) were coinfected with HCV, and seven (8%) were coinfected with HBV. Median (interquartile range [IQR]) exposure to antiretrovirals was 12.8 (10.4-16.5) years. Fifteen patients (18%) had a previous AIDS-defining event, 64 (76%) had HIV RNA<50copies/mL, and the median (IQR) CD4 count was 502 (327-628)cells/μL. The median [IQR] FPG was 81mg/dL (4.5mmol/L) [75-87mg/dL (4.2-4.8mmol/L)], and the median (IQR) HOMA-IR was 2.82 (1.89-4.02). After OGTT, nine patients (11%) were diagnosed as having IGT (6) or DM (3). A first multivariable analysis showed that CD4 cell count (P=0.038) and HOMA-IR (P=0.035) were associated with IGT or DM, but a second model including only the variables with a P-value of <0.2 in the univariable analysis (CD4 cell count, HBV coinfection, and HOMA-IR) found that only HOMA-IR independently predicted IGT or DM. Conclusions: In patients with long-standing HIV infection and normal FPG levels, an OGTT can reveal IGT or DM. © 2010 British HIV Association.