POLYMORPHISMS AT THE 5'-END OF THE APOLIPOPROTEIN AI GENE AND SEVERITY OF CORONARY-ARTERY DISEASE

Elevated HDL-cholesterol (C) and apo AI are associated with decreased coronary artery disease (CAD) risk, We determined distributions of two MspI polymorphisms of the apo At gene, associated in other studies wi th increased HDL-C, among 644 patients aged less than or equal to 65 y ears in relation to circulating lipids and CAD severity assessed angio graphically, The rare allele distributions at both sites were in Hardy -Weinberg equilibrium in these patients but the base changes were not associated with HDL-C and apo Al levels, However, patients homozygous for the -75 bp substitution were more likely to have one or more signi ficantly diseased vessels (> 50% luminal obstruction)(OR 4.75, 95%CI: 1.10-20.46) as also were patients with the rare +83 bp alleles (OR: 2. 56, 95%CI: 1.13-5.81), While there was an additive effect of the two p olymorphisms to have severe CAD (OR: 6.33, 95%CI: 1.33-30.02), the pol ymorphism at +83 bp remained significant in predicting CAD severity af ter adjusting for other variables in a logistic regression analysis (O R: 2.95, 95%CI: 1.26-6.90), which was also strongly associated with th e positive family CAD history (P = 0.009), We conclude that patients w ith these base changes in this Australian coronary population do not h ave increased HDL-C and apo At levels but do have more severe CAD.