Variability of plasma lipids and lipoproteins: the Jerusalem Lipid Research Clinic Study

We examined the variability of lipid and lipoprotein concentrations in plasma from a population sample from the Jerusalem Lipid Research Clinic study. Coefficients of variation of about 8% for plasma cholesterol, 11% to 15% for low- and high-density-lipoprotein cholesterol, and about 30% for triglyceride were reported, both for 17-year-olds and adults examined twice, with a median period of two months between measurements. Stability was similar in a subsample of adults who had an additional measurement a median of 28 months later. Within-assay analytical variation (CV) was 1.9-2.0% for cholesterol, 1.5-2.3% for triglyceride, and 4.5% for high-density-lipoprotein cholesterol. Between-assay variation was 3-5% for cholesterol and triglyceride and 10% for high-density-lipoprotein cholesterol. The lower stability of the lipoprotein fractions of cholesterol than of total cholesterol emphasizes the need for repeated measurements of these fractions for more accurate characterization of subjects, especially those with extreme values, both for clinical use and for predicting outcome in follow-up studies.