EFFECT OF ELECTIVE HOSPITALIZATION ON PLASMA-LIPOPROTEIN CHOLESTEROL AND APOLIPOPROTEIN-A-I, APOLIPOPROTEIN-B AND APOLIPOPROTEIN-LP(A)

Plasma lipoproteins and apolipoproteins are subjects of interest because of their association with coronary artery disease. Elevations of total and low-density lipoprotein (LDL) cholesterol and the main apolipoprotein constituent of LDL, apolipoprotein B, are associated with an increased risk of coronary artery disease. Similarly, elevated plasma levels of Lp(a) are seen more frequently in patients with premature coronary artery disease. Conversely, low levels of high-density lipoprotein (HDL) cholesterol and its major protein constituent, apolipoprotein A-I, are also associated with an increased risk of coronary artery disease.1-5. Many studies linking lipoprotein and apolipoprotein levels are case-controlled where patients are diagnosed by coronary angiography.4,5 Despite technologic advances made in the last 2 decades in noninvasive cardiology, angiography remains the method of choice for the diagnosis of coronary artery disease. We have previously reported data on 88 patients sampled at coronary angiography and in the free-living state and found that HDL cholesterol was significantly lower when sampled in-hospital.6 To extend these findings and examine apolipoproteins A-I, B and Lp(a), we prospectively sampled patients who underwent elective coronary angiography and then returned for blood sampling in the free-living state. Use of certain medications, especially β blockers and diuretics, can alter lipid levels. Major surgery, physical exercise and acute myocardial infarction can alter these levels as well.7,8 We therefore attempted to offset the presence of β blockers and other medications. © 1990.