Clinical and metabolic features of subjects with glucose intolerance and high fasting glucose levels

Abstract

Subjects with glucose intolerance or high fasting glucose levels have a higher cardiovascular risk and frequently become diabetic. To assess clinical and metabolic characteristics of patients with glucose intolerance or high fasting glucose levels. Fasting and post glucose load serum glucose and insulin levels were measured in 1404 people, aged 42,0 +/- 14,2 years (81% women) with high diabetic risk. We categorized subjects in different alterations of blood glucose, according to 2006 American Diabetes Association categories. Insulin resistance (RI), insulin secretion (beta %) and insulin disposition (ID), were calculated using fasting blood glucose and insulin levels, using the homeostasis model assessment (HOMA I and II). Sixty percent of studied subjects had first grade relatives with diabetes mellitus and 1097 (78%) were categorized as normal (N), 45 (3%) as Diabetes Mellitus (DM), 161 (11%) as high fasting glucose levels (GAA) and 103 (7%) as glucose intolerant (ITG). Fifty three of the 106 subjects with GAA (50%), were also glucose intolerant. Subjects with GAA had similar insulin sensitivity and lower beta cell function than N (insulin disposition 58 +/- 12 and 111 +/- 32%, respectively p < 0.01). ITG had less insulin sensitivity than N (HOMA-IR 2.6 +/- 1.50 +/- and 2.0 +/- 1.30, respectively) and only a mild decrease in beta cell function (insulin disposition 96 +/- 26 and 111 +/- 32% respectively, p < 0.01). Patients GAA plus ITG had similar alterations than those with DM (HOMA-IR 3.8 +/- 2.2 and 4.4 +/- 3.7 respectively; insulin disposition 57 +/- 10 and 56.0 +/- 26% respectively. Patients with higher fasting glucose levels behave differently from those with glucose intolerance. High fasting glucose levels are highly prevalent in subjects with high risk of DM and must be considered as risk indicator in preventive programs for diabetes mellitus.