SMALL DENSE, LOW-DENSITY LIPOPROTEINS OF YOUNG ADULTS WITH FAMILY HISTORY OF ACUTE MYOCARDIAL INFARCTION: PREDECTIVE VALUE AND RELATED RISK FACTORS

Abstract

Background Although growing evidence suggests that small, low density lipoprotein-cholesterol (Sd, LDL-ch) is strong predictors of coronary artery disease in the general population, epidemiological data among young adults with family history of acute myocardial infarction are limitedObjective To evaluate the Sd, LDL-ch and related risk factors of young adults with a positive family history of acute myocardial infarction and compared them with controls in order to identify risk indicators for atherosclerosis.Subjects and methods A group of 200 young adults aged 20-40 years with a positive family history of acute myocardial infarction were evaluated for serum concentrations of total cholesterol (Tch), low-density lipoprotein cholesterol (LDL-ch), high density lipoprotein cholesterol (HDL-ch), small dense, low density lipoprotein cholesterol (Sd, LDL-ch), triglycerides (TG), oxidized lipoproteins, C-reactive protein(C-RP) and malonyldialdehyde (MDA).These values were compared with the levels of a control group of 100 adults of comparable age. Results In young adults with positive family history of acute myocardial infarction, increased serum Sd, LDL-ch was more frequent than in controls (65.5 versus 10.0%, p<0.001). Among these young adults, 66(33%), 68(34%), and 63(31.5%) had hypercholesterolemia, hypertriglyceridemia and metabolic syndrome. In addition, those young adults had significantly higher concentrations of Tch, TG, LDL-ch, Sd, LDL-ch, oxidized lipoproteins, MDA, C-RP and glucose and lower concentrations of HDL-ch compared with controls. Significant differences were also noted in the values of waist circumference, and blood pressure between positive family history group and controls. The serum Sd, LDL-ch and related risk factors being frequently positively correlated. In a ROC curve analysis, the area under curve was 0.894(95% CI 0.802-0.886), suggesting a good discrimination between the young adults with and without family history for myocardial infarction. Conclusions In young adults, positive family history group is characterized by a higher prevalence of increased Sd, LDL-ch and metabolic abnormalities. This finding may have clinical implications due to the increased risk of future coronary artery disease.