Association between glycosylated hemoglobin, left ventricular mass and aortic function in nondiabetic individuals with insulin resistance

Abstract

An association between glycosylated hemoglobin (GHb) and cardiovascular mortality in nondiabetic individuals has recently been reported. Prompt detection of nondiabetic individuals with high-normal GHb and early cardiovascular involvement may be of value for preventive strategies. In this investigation, a possible relationship between GHb, aortic function and left ventricular (LV) mass in nondiabetic individuals has been studied. A total of 263 nondiabetic African-Americans, aged 22-63 (mean 42 +/- 8) years were studied. All individuals were first degree relatives of diabetic patients, had normal oral glucose tolerance test (2-h OGTT) and decreased peripheral action of insulin. LV diameters and mass (echocardiography); ascending and abdominal aortic distensibility (echocardiography, arterial pressure); pulse wave velocity (PWV; electrocardiography, Doppler); fasting glucose; GHb; insulin sensitivity index (S(I)) and 2-h OGTT were measured. Multiple linear and logistic regression analyses were used to identify significant independent associations of fasting glucose; GHb; S(I) and 2-h OGTT with aortic function and LV mass. In fully adjusted multivariate logistic regression analysis, GHb predicted lower values of aortic distensibility (odds ratio (OR) 1.67 95% CI (1.04-2.75), P=0.04); higher PWV (OR 1.79 95% CI (1.09-2.93), P=0.022); and higher values of LV mass (OR 1.56 95% CI (1.08-2.88), P=0.029). Fasting glucose, S(I), and 2 h OGTT were not associated with aortic function and LV mass. Higher GHb concentrations, even within 'normal' range, are independently associated with stiffer aorta and increased LV mass and thus may detect nondiabetic individuals at increased cardiovascular risk.