Predictive value for coronary heart disease of baseline high-density and low-density lipoprotein cholesterol among Fredrickson type IIa subjects in the Helsinki Heart Study

In the Helsinki Heart Study, 2,590 subjects were identified with Fredricksen type IIa lipid disorder. This is defined as a low-density lipoprotein (LDL) cholesterol level greater than 175 milligrams per deciliter and serum triglycerides less than 177 milligrams per deciliter. (For purposes of comparison, 160 milligrams per deciliter LDL is considered to be borderline and over 190 is considered to be high-risk.) Of these patients, 1,297 were treated with gemfibrozil and 1,293 were given placebo only. For purposes of analysis, the patients were grouped into three similar groups based on serum levels of high-density lipoprotein (HDL) cholesterol. The average measurements of these three groups were less than 44.9, between 44.9 and 53.7, and greater than 53.7 milligrams per deciliter. There was no correlation between the level of LDL and HDL in these patients. For the overall group, which was selected on the basis of high levels of LDL cholesterol, the significant risk factor for development of coronary heart disease was a low level of HDL. Gemfibrozil treatment reduced the risk for coronary artery disease, and the greatest risk reduction, when compared with the corresponding placebo group, was achieved by the subjects with the lowest HDL levels. In this subgroup, the highest risk group included in the study, the reduction in coronary artery disease was 42 percent compared with the control group. The results indicate than even in a group of subjects with elevated levels of LDL cholesterol, increases in HDL cholesterol result in a significant clinical benefit. The findings also indicate that the increase in HDL cholesterol levels achieved with gemfibrozil treatment are of clinical significance for reducing heart attack risk. (Consumer Summary produced by Reliance Medical Information, Inc.)