THE 2ND ATHEROGENIC PHENOTYPE OR THE ROLE OF INSULIN-RESISTANCE IN VASCULAR RISK

LDL cholesterol is the principal vascular risk factor but it is not th e only one. Paradoxically, the atherogenic role of triglycerides or th at of metabolic abnormalities of triglyceride-rich lipoproteins has be en underestimated. It is convenient to use the term ''second atherogen ic phenotype '' for those phenotypes associating a hypertriglyceridaem ia, a low HDL-cholesterol, a moderate increase in LDL cholesterol comp osition (the small dense LDL). Insulin resistance could be the common denominator of these different abnormalities, increasing the productio n of triglyceride-rich lipoproteins and decreasing their catabolism. I n this concept wich remains hypothetical, insulin resistance would app ear to be a vascular risk factor. its role could be direct or indirect by the many risk factors described in the syndrome X. The taking into account of this second atherogenic phenotype of hyperlipidaemia has o bvious therapeutic implications because of the choice of diet and trea tment. Though statins represent the treatment of choice of high LDL ch olesterol, the fibrates are useful in the treatment of hypertriglyceri daemia, low HDL-cholesterol and small and dense LDL. Therapeutic trial s comparing the efficacy of statins and fibrates with respect to cardi ovascular and global mortality should provide future information in th is debate.