APOLIPOPROTEIN-B LEVELS AND RELATED FACTORS IN A RURAL WHITE SOUTH-AFRICAN COMMUNITY - THE CORIS STUDY

Objective. In a survey of the Coronary Risk Factor Study (CORIS), apol ipoprotein B (apoB) levels were determined to ascertain their impact o n coronary heart disease (CHD) risk Other CHD risk factors associated with apoB were also identified. Design. Cross-sectional analytical stu dy, which included CHD risk factor and dietary questionnaires, electro cardiography, anthropometric and blood pressure measurements, and a bl ood sample for a lipid profile. Setting and participants. The three di stricts of Riversdale, Robertson and Swellendam in the southwestern Ca pe; a 25% random sample of 1 528 white respondents aged 15-68 years. R esults. Men tended to have higher mean apoe levels than women. Classif ication of CHD risk by apoB levels and total cholesterol (TC) levels d id not correspond, as only 61% of men and 58.5% of women were classifi ed in the same risk categories. Respondents in the highest apoB risk c ategory reported a medical history of hypercholesterolaemia and hypert ension more frequently than those in lower categories. There was a sig nificant increase from the low to the high apoB risk category of TC, l ow-density lipoprotein (LDL) cholesterol, triglyceride levels, body ma ss index and percentage body fat. Using stepwise multiple regression, 84.9% of the variation in apoe of men and 85.8% in apoB of women were accounted for by significantly associated variables. Conclusion. Altho ugh apoB may be a better predictor of CHD than TC or LDL cholesterol c oncentrations, its easy approximation with the formula (TC-HDLC)/2+20, high cost, measurement variability and an approach in management simi lar to that for raised TC discourage its routine use in the screening of patients for CHD.