Plasma lipoprotein patterns in patients hospitalized for coronary artery bypass surgery.

Preoperative plasma samples from coronary artery bypass surgery patients were analyzed for relative levels of high-density lipoproteins (HDL) and low-density lipoproteins (LDL) in order to assess the HDL:LDL ratio as an indicator of risk for coronary heart disease. Fasting blood samples were drawn from bypass patients prior to surgery, and bypass patient mean plasma lipid data were compared with values from three other groups: randomly selected, newly admitted hospitalized patients; acutely ill student outpatients; and healthy hospital employees. Sudan Black B prestained plasma samples were electrophoresed on polyacrylamide gels, and HDL:LDL ratios were determined by densitometric gel scan and automatic peak integration. Of the four study groups, the bypass patient group had the lowest mean HDL:LDL ratio; the low ratios were due particularly to reduced levels of HDL2. Chemical analyses indicated that the bypass patient group also had lower mean HDL-cholesterol and higher mean total cholesterol and triglyceride levels than the other groups. When group age and sex differences were taken into account, the bypass group, especially males, also had low ratios. The results also strongly indicated that stresses involved with illness and hospitalization unrelated to clinical coronary heart disease (CHD) can adversely affect lipoprotein patterns.