Background Homogenous assays for LDL-cholesterol (LDL-C) and
HDL-cholesterol (HDL-C) are highly accurate, with little interference from
triglyceride. Using these methods, we measured postprandial LDL-C and HDL-C. Earlier
studies suggested a postprandial decrease in LDL-C. Methods To elucidate
whether LDL-C and HDL-C decrease significantly during the day, we determined daily
profiles of LDL-C and HDL-C using homogeneous assays in subjects with normal coronary
arteries (N; n = 10), and subjects with coronary artery disease
(CAD; n = 23). Results In both groups, LDL-C and HDL-C
were significantly lower from after breakfast until midnight than they were before
breakfast. The next morning, they returned to baseline levels. The mean reduction in
LDL-C was 0·09--0·13 mmol/L in N and 0·05--0·20 mmol/L in CAD, while that in HDL-C
was 0·02--0·06 mmol/L in N and 0·00--0·05 mmol/L in CAD. Conclusion
LDL-C and HDL-C decrease significantly over the course of the day.
