Comparison of fasting and postprandial plasma lipoproteins in subjects with and without coronary heart disease

Plasma lipoprotein levels, including remnant-like particle (RLP) cholestero l and RLP triglycerides, were assessed in fasting (12 hours) and postprandi al (PP) (4 hours after a fat-rich meal) states in 88 patients with coronary heart disease (CHD) and 88 controls. All lipoproteins were assessed by dir ect methods. We hypothesized that patients with CHD would have greater perc ent increases in their triglyceride levels, RLP cholesterol, and RLP trigly cerides, in response to a fat-rich meal. In the fasting state, triglyceride s, RLP cholesterol, RLP triglycerides, and low-density lipoprotein (LDL) ch olesterol levels were all significantly higher in cases versus controls by 51%, 35%, 39%, and 40%, respectively. These levels were 57%, 37%, 64%, and 37% higher in the PP state, respectively. Mean high-density lipoprotein (HD L) cholesterol values were 27% lower in cases in both the fasting and PP st ates. After eating, triglycerides, RLP cholesterol, and RLP triglycerides i ncreased 64%, 71%, and 290% in controls, respectively, whereas in cases the se levels increased by 71%, 94%, and 340%, respectively (all p<0.0001). Per cent increases in the PP state were not significantly different in cases ve rsus controls. Following the fat-rich meal, LDL and HDL cholesterol decreas ed by 5% and 4% in controls, and by 7% and 6% in patients, with no signific ant difference in percent changes between groups. Fasting values correlated very highly with PP values for all parameters (all p<0.0001). Our data ind icate that although patients with CHD have higher fasting and PP levels of triglycerides, RLP cholesterol, and RLP triglycerides than controls, the re sponse (percent increase) to a fat-rich meal is comparable in both groups. Thus, a feeding challenge is not essential for assessment of these lipoprot eins. Moreover, it is not necessary to obtain a fasting sample to assess di rect LDL and HDL cholesterol. (C) 2001 by Excerpta Medica, Inc.