CAROTID ATHEROSCLEROSIS IN SUBJECTS WITH DIFFERENT HYPERLIPIDEMIA PHENOTYPES

Objective. To evaluate the presence of carotid plaque and/or stenosis in patients with different phenotype of hyperlipidaemia. Experimental design. Case-control study. Setting. Outpatients metabolic clinic. Pat ients. Sixty type IIa, 50 type IIb and 40 type IV hyperlipidaemic subj ects were compared with 50 normolipidaemic controls, matched for sex a nd age. Interventions. Blood lipid analysis for phenotype classificati on was performed after two months of diet. Blood pressure was measured by a zero-random sphygmomanometer. CHD risk factors, smoking habit, p revious and ongoing drug therapy were assessed by a self-administered questionnaire. Echo-Doppler examination of the extracranial arteries ( common, internal and external carotid artery and bulb) was done by a M ultigon Angioview 600 provided with a 7.5 MHz probe for B-mode and 5 M Hz for pulsed Doppler. Subjects were classified as having carotid athe rosclerosis when a plaque and/or a stenosis was found in at least one of the examined segments and as normal when no atherosclerotic lesions were detected. Results. There were more hypertensives among type IV s ubjects whereas the prevalence of smokers and diabetics was similar in all four groups. The prevalence of carotid atherosclerosis was higher in type IIb and IIa subjects than in controls (58% and 38% respective ly vs 14%, p < 0.01) while in type TV subjects it was comparable to th at of controls (25%). Conclusions. The present findings show that hype rcholesterolaemia and mixed hyperlipidaemia are frequently associated with carotid atherosclerosis, whereas hypertriglyceridaemia is not. Th e role of hypertriglyceridaemia in the development of atherosclerosis seems mediated by mechanisms other than plaque formation.