['Cardiovascular diseases are the most common cause of disability and death among subjects with non-insulin-dependent diabetes mellitus (NIDDM). The atherosclerotic process begins during the prediabetic phase characterized by impaired glucose tolerance, hyperinsulinemia, and insulin resistance. In vitro studies have suggested that glucose and insulin can substantially alter the structure and function of the arterial wall and affect the development of atherosclerosis.', "We performed a cross-sectional study of the relation of arterial stiffness indexes with glucose tolerance and serum insulin concentrations. Several indexes of common carotid artery stiffness were assessed with noninvasive ultrasound methods in a biracial sample of 4701 men and women 45 to 64 years of age in the Atherosclerosis Risk in Communities (ARIC) Study. Arterial compliance (AC), stiffness index (SI), pressure-strain elastic modulus (Ep), and Young's elastic modulus (YEM) were calculated. YEM includes wall (intima-media) thickness and thus gives an estimate of arterial stiffness controlling for wall thickness. All indexes of arterial stiffness were higher with increasing concentrations of fasting glucose. This finding was consistent in both black and white examines and in both sexes. A 25% increase in fasting glucose (approximately 1 SD) was associated in nondiabetic white men with a 5.8% (95% CI, -9.6% to -1.9%; P = .004) decrease in AC and increases of 5.8% (95% CI, 2.0% to 9.7%; P = .002) in SI, 11.3% (95% CI, 6.9% to 15.9%; P < .001) in Ep, and 11.2% (95% CI, 6.2% to 16.6%; P < .001) in YEM. In nondiabetic white women, the corresponding predicted changes were a decrease of 15.0% (95% CI, -18.2% to -11.7%; P < .001) in AC and increases of 16.6% (95% CI, 12.5% to 20.8%; P < .001) in SI, 23.2% (95% CI, 18.4% to 28.2%; P < .001) in Ep, and 19.2% (95% CI, 14.0% to 24.7%; P < .001) in YEM. Glucose and insulin contributed synergistically to the increase in stiffness indexes. Insulin and triglycerides also had a synergistic association with stiffness indexes."] Are non-insulin-dependent diabetes mellitus and fasting glucose and insulin concentrations associated with arterial stiffness indexes . The ARIC Study . Atherosclerosis Risk in Communities Study?