Abstract
Determination of serum lipids (TC, TG and HDL-TC) and apolipoprotein (apo A-I, A-III, B, C-I, C-II, C-III and E) levels and disc gel electrophoresis of serum lipoproteins were performed in 46 patients of coronary hearts disease and their 43 roughly-age-matched controls. Coronary heart disease (CHD) group with mean age of 61 years old had 75% or greater stenosis in one or more major coronary arteries. Among them 28 patients were suvivors of acute myocardial infarction which occured not less than 12 months before the study. Controls with mean age of 62 years old showed no evidence of significant stenosis in major vessels on selective arteriography. All female patients experienced menopause at least 5 years before the study.
Serum levels of apo A-I, A-II, B, C-II, C-III and E were determined by electroimmunoassay and apo C-I by radial immunoassay. HDL was isolated by precipitating VLDL and LDL with heparin-manganese chloride and cholesterol (HDL-TC) was measured. Following results were obtained: (1) CHD group showed significantly higher levels of TC, HDL-TC apo A-I, apo C-I, apo C-II and ratio of (TC-HDL-TC)/HDL-TC and apo B/apo A-I than those of control group. (2) midband lipoprotein was detected in 54% of CHD group and 30% of control group; the difference of frequency was statistically significant. Serum lipid and apolipoprotein levels, however, did not correlate with the presence of midband lipoprotein.(3) Levels of apo C-I, C-II, C-III and E showd highly significant correlation with those of TC and TG.(4) In CHD group, survivors of acute myocadial infaction had significantly lower levels of HDL-TC, ratio of (TC-HDL-TC)/HDL-TC and apo B/apo A-I than those who had no history of myocardial infarction which may imply that LDL/HDL ratio was one of the important factor for the development of myocardial infarction.
