Plasma lipids as collateral risk factors in coronary artery disease-A study of 371 males with chest pain

A group of 371 males with chest pain was studied to ascertain the way in which the risk of coronary artery disease depends on the joint variation of plasma lipid concentrations. Patients were divided into two groups: one called diseased in which one or more major coronary vessels was shown on angiography to have at least a 25% stenosis; and the second called normal. For both groups, advanced techniques were used to estimate the joint probability density function which represents the way in which the two lipid concentrations vary jointly. With these density functions, we analyzed the risk of coronary artery disease as a function of plasma triglyceride concentration for fixed plasma cholesterol concentrations. We found that in general this risk increases markedly with increasing plasma triglyceride concentration, and this effect is more pronounced at higher cholesterol levels. These results suggest an association between elevated plasma triglyceride and the risk of coronary artery disease independent of that implied by the co-existing plasma cholesterol concentration. Our analytical approach can be used in other investigations of risk factors in coronary artery disease.