Relation of parental history of early myocardial infarction to the level of apoprotein B in men

The relations between parental history of early myocardial infarction and plasma lipids and apoproteins have been examined in a population of 4045 middle-aged (20 to 60 years old) working men at the initial examination of the Paris Prospective Study 2. Subjects with a history of myocardial infarction, angina pectoris, or peripheral arterial disease or those treated with hypolipidemic drugs were excluded from the analysis. The numbers of subjects with a paternal or maternal history of early myocardial infarction were 123 and 30, respectively. After adjustment for age, cigarette consumption, alcohol consumption, and body mass index, subjects with parental history of myocardial infarction had higher levels of total cholesterol (p less than .01), low-density lipoprotein (LDL) cholesterol (p less than .01), and apoprotein B (APOB) (p less than .0001) and a lower level of high-density lipoprotein (HDL) cholesterol (p less than .05) than subjects with no parental history of myocardial infarction. On the other hand, apoprotein A1 (APOA1) and triglyceride levels were not different between the two groups. The ratios of HDL/total cholesterol and APOA1/APOB were also lower in presence of parental myocardial infarction (p less than .001 and p less than .01, respectively). When a discriminant analysis was performed, only APOB level was related to parental myocardial infarction. The results for paternal and maternal history were very similar and were grouped for the analysis. We conclude that part of the known relationship between parental history of myocardial infarction and coronary heart disease could be mediated by an increased APOB level.