Extracoronary atherosclerosis and genetic variants of apolipoprotein AI-CIII cluster in myocardial infarction survivors from southern Italy.

The relationships between some genetic markers, as evaluated by DNA analysis, and ultrasound evidence of extracoronary athero-sclerosis, as detected by ultrasound methods, were evaluated in 39 myocardial infarction survivors of middle age and in 40 healthy controls of comparable age. Coronary heart disease (CHD) patients showed higher levels of triglycerides (P = 0.01) and greater number of exsmokers (P = 0.004). Carotid stenoses (> 15%) were detected in ten CHD patients and in two controls; iliac stenoses (> 15%) or abnormal ankle/arm ratio (< 0.97) were found in ten CHD patients and in one control; the scores of vascular disease severity in the myocardial infarction survivors were higher (Mann-Whitney test) than in controls (P < 0.01). Molecular genetic analysis of SstI restriction fragment length polymorphism (RFLP) of the apolipoprotein (apo) AI-CIII cluster and of the apo B gene demonstrated a higher frequency of the S2 allele (SstI RFLP) in coronary patients than in controls (P = 0.04) and no significant differences in the frequencies of XbaI RFLP of the apo B gene between patients and controls. The relative risk of myocardial infarction associated with an abnormal vascular score (> 8) or with the presence of the rare allele S2 (SstI apo AI-CIII polymorphism) was estimated by odds ratios. The lower 95% limits of odds ratios were above 1 (indicating significant increase in the relative risk of myocardial infarction) both in the case of vascular score and that of SstI RFLP. These associations were independent of one another and of triglyceride levels. SstI RFLP association with CHD disappeared after adjustment for smoking habits.(ABSTRACT TRUNCATED AT 250 WORDS)