AORTIC STIFFNESS IN YOUNG-PATIENTS WITH HETEROZYGOUS FAMILIAL HYPERCHOLESTEROLEMIA

Background Dyslipidemia is a primary risk factor for the development o f atherosclerosis. Aortic distensibility is an important determinant o f left ventricular function and coronary blood flow whose possible alt erations in patients with dyslipidemia have not been fully investigate d. Methods To assess the effect of dyslipidemia on the elastic propert ies of the aorta, we studied 60 patients (mean age 37 +/- 11 years) wi th heterozygous familial hypercholesterolemia and no manifest arterial disease and compared them with 20 of their normolipidemic siblings (m ean age 34 +/- 10 years). Two indexes of the aortic elastic properties were measured: aortic distensibility was calculated by use of the for mula: 2 x (AoS-AoD)/PP x AoD, and aortic stiffness index was calculate d by use of the formula: In (SBP/DBP)/(AoS-AoD)/AoD, where AoS and AoD ore aortic root end-systolic and end-diastolic diameters, respectivel y, SEP and DBP are systolic and diastolic arterial pressure, respectiv ely, and PP is pulse pressure. Internal aortic root diameters were mea sured at 3 cm above the aortic valve by use of two-dimensional guided M-mode transthoracic echocardiography, and arterial pressure was measu red simultaneously at the brachial artery by sphygmomanometry. Results The mean aortic systolic and diastolic diameter index did not differ signifficantly between the two groups. In contrast, aortic distensibil ity was found to be significantly reduced in subjects with isolated fa milial hypercholesterolemia compared with that in the control group (2 .15 +/- 1.72 cm(2).dynes.10(-6)vs 3.18 +/- 1.58 cm(2).dynes(-1).10(-6) , p < 0.02), In addition, the mean aortic stiffness index was double i n patients with familial hypercholesterolemia compared with that in no rmolipidemic subjects. Conclusions severe dyslipidemia does not overtl y influence aortic dimensions but leads to impairment of aortic elasti c properties before the occurrence of clinical manifestations of ather osclerotic disease.