Increased carotid intima-media thickness in the physiologic range is associated with impaired postprandial glucose metabolism, insulin resistance and beta cell dysfunction

Background: Carotid Intima-Media Thickness (C-IMT) is a reliable predictor of cardiovascular events. We examined if increased C-IMT was associated with defects in glucose metabolism in non-diabetic subjects independently of age.Methods: In 366 Caucasian non-diabetic subjects of the CARAMERIS study, we measured glucose response during a 75 g-Oral Glucose Tolerance Test (OGTT), insulin sensitivity index (ISI, by Matsuda Index), Liver Insulin Resistance Index (Liver-IR), insulin secretion by Delta AUC Ins(0-120)/Glu(0-120) (Delta I/Delta G) and beta cell function (Disposition Index, DI).Results: Subjects were divided in two groups according to the median age (AGE1 <= 45 y; AGE2 > 45 y). Only 5 subjects in AGE1 and 32 in AGE2 had C-IMT > 0.9 mm. Compared to AGE1, AGE2 had a worse cardio-metabolic profile, increased cholesterol, glucose and insulin concentrations, blood pressure and C-IMT. Both Delta I/Delta G ratio and DI were significantly reduced in AGE2. By considering tertiles of C-IMT in each AGE group (G1-G3, where G3 comprised the highest C-IMT), we found that G3 showed increased OGTT glucose profiles and Liver IR, decreased ISI and DI, compared to G1 in each AGE group.Conclusions: Increased C-IMT, but within normal ranges, is associated independently of age with altered postprandial glucose profile, increased peripheral and hepatic insulin resistance, decreased b-cell function. C-IMT measurement should become a routine analysis even in younger subjects to predict the risk of cardio-metabolic disease. (C) 2013 Elsevier Ireland Ltd. All rights reserved.