Assessment of factors associated with pre-diabetes in HCV infection including direct and dynamic measurements of insulin action

Abstract

Although hepatitis C (HCV) is associated with diabetes, few studies have examined pre-diabetes in this population. We aimed to evaluate factors associated with pre-diabetes in HCV-infected patients, including direct measurement of insulin action. Ninety-seven non-cirrhotic, non-diabetic and HCV-infected patients underwent clinical evaluation and oral glucose tolerance testing (OGTT). Insulin sensitivity was measured directly by steady-state plasma glucose (SSPG) concentration during insulin suppression test. Early phase and total insulin secretion were determined using OGTT. Rates of pre-diabetes were as follows: 21% impaired fasting glucose (IFG), 7% impaired glucose tolerance (IGT) and 9% combined IFG/IGT. Twelve percent of Caucasians, 50% of African Americans and 70% of Latinos had pre-diabetes (P = 0.002). Patient characteristics among the glucose metabolism categories were similar except those with combined IFG/IGT had a higher body mass index (BMI) vs normal glucose tolerance (NGT) (30 vs 26 kg/m(2), P = 0.007) and lower LDL vs NGT and IGT (74, 104 and 112 mg/dL, respectively, P ≤ 0.01). On multivariable analysis, non-Caucasian race (OR 23.1, P = 0.003), BMI (OR 3.4, P = 0.02) and greater liver inflammation (OR 7.9, P = 0.03) predicted IFG, whereas non-Caucasian race (OR 14.8, P = 0.01) and SSPG (OR 1.1 per 10 units, P = 0.01) predicted IGT. Early and total insulin secretion adjusted for the degree of insulin resistance was decreased in pre-diabetes compared with NGT (P = 0.01 and P = 0.02, respectively). Pre-diabetes is highly prevalent among HCV-infected patients, and in some instances, coincides with host responses to the virus. In most cases, however, factors that are associated with pre-diabetes in HCV-infected patients are similar to those observed in the non-HCV population.

Conflict of interest statement

Conflict of Interest: No conflicts of interest exist.

© 2011 Blackwell Publishing Ltd.

Figures

Figure 1

A. Plasma glucose responses to oral glucose during OGTT in subjects with normal glucose tolerance (NGT), impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and combined IFG/IGT. Values represent mean plasma glucose concentrations (± SE) measured during OGTT for N=97 patients. B. Plasma insulin responses to oral glucose during OGTT in subjects with normal glucose tolerance (NGT), impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and combined IFG/IGT. Values represent mean plasma insulin concentrations (± SE) measured during OGTT for N=97 patients.

Figure 1

A. Plasma glucose responses to oral glucose during OGTT in subjects with normal glucose tolerance (NGT), impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and combined IFG/IGT. Values represent mean plasma glucose concentrations (± SE) measured during OGTT for N=97 patients. B. Plasma insulin responses to oral glucose during OGTT in subjects with normal glucose tolerance (NGT), impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and combined IFG/IGT. Values represent mean plasma insulin concentrations (± SE) measured during OGTT for N=97 patients.

Figure 2. Insulin resistance (SSPG) by glucose metabolism categories

Box plots illustrate median and range of SSPG concentrations for all four groups of subjects, with boundaries of the box representing upper and lower quartiles. • Outliers with values between 1.5 and 3 box lengths from the boundaries of the box.