NON-INSULIN-DEPENDENT DIABETES-MELLITUS AND FASTING GLUCOSE AND INSULIN CONCENTRATIONS ARE ASSOCIATED WITH ARTERIAL STIFFNESS INDEXES - THEARIC STUDY

Background Cardiovascular diseases are the most common cause of disabi lity and death among subjects with non-insulin-dependent diabetes mell itus (NIDDM). The atherosclerotic process begins during the prediabeti c 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. Methods a nd Results We performed a cross-sectional study of the relation of art erial stiffness indexes with glucose tolerance and serum insulin conce ntrations. Several indexes of common carotid artery stiffness were ass essed with noninvasive ultrasound methods in a biracial sample of 4701 men and women 45 to 64 years of age in the Atherosclerosis Risk in Co mmunities (ARIC) Study. Arterial compliance (AC), stiffness index (SI) , pressure-strain elastic modulus (Ep), and Young's elastic modulus (Y EM) were calculated. YEM includes wall (intima-media) thickness and th us gives an estimate of arterial stiffness controlling for wall thickn ess. All indexes of arterial stiffness were higher with increasing con centrations of fasting glucose. This finding was consistent in both bl ack and white examinees and in both sexes. A 25% increase in fasting g lucose (approximately 1 SD) was associated in nondiabetic white men wi th a 5.8% (95% CI, -9.6% to -1.9%; P=.004) decrease in AC and increase s 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 YE M. In nondiabetic white women, the corresponding predicted changes wer e a decrease of 15.0% (95% CI, -18.2% to -11.7%; P<.001) in AC and inc reases 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 in crease in stiffness indexes. Insulin and triglycerides also had a syne rgistic association with stiffness indexes. Conclusions Our findings a re compatible with the view that persons with NIDDM or borderline gluc ose intolerance have stiffer arteries than their counterparts with nor mal glucose tolerance and that the decreased elasticity is independent of artery wall thickness. The joint effect of elevated glucose, insul in, and triglycerides can have a considerable impact on arterial stiff ness and play an important role in the early pathophysiology of macrov ascular disease in NIDDM.