INSULIN-RESISTANCE AS AN INDEPENDENT RISK FACTOR FOR CAROTID WALL THICKENING

It has been reported that insulin resistance is associated with essent ial hypertension and that an aggregation of risk factors-hypertension, dyslipidemia, and glucose intolerance-together with insulin resistanc e leads to the more frequent appearance of coronary artery disease. We examined the relation between early asymptomatic atherosclerosis and these risk factors in 72 nondiabetic subjects with essential hypertens ion (41 men, 31 women) aged 50 to 59 years. Intima-media thickness and plaque formation of the carotid artery were assessed by B-mode ultras onography, and insulin sensitivity was measured by the steady-state pl asma glucose method. Lipoprotein profile was analyzed by ultracentrifu gation. The intima-media thickness of the common carotid artery signif icantly correlated with systolic pressure; mean blood pressure; steady -state plasma glucose, indicating insulin resistance; fasting insulin; area under the curve of plasma insulin and glucose; body mass index; apolipoprotein B; apolipoprotein B in low-density lipoprotein; lower r atio of cholesterol to apolipoprotein B of low-density lipoprotein; an d decreased high-density lipoprotein cholesterol. By multiple regressi on analysis, steady-state plasma glucose was the strongest risk, follo wed by lower high-density lipoprotein and systolic pressure. These thr ee factors accounted for 54.9% of all the risk for increased intima-me dia thickness of the common carotid artery. In conclusion, insulin res istance was the strongest risk factor for carotid intima-media thickne ss, followed by lower high-density lipoprotein cholesterol and hyperte nsion. An effort to maintain normal insulin sensitivity is essential f or the prevention of early atheromatous lesions in essential hypertens ion.