Department of Business Administration, Hallym University College of Business, Chuncheon, Korea.
Department of Diagnostic Laboratory Medicine, Korea Association of Health Promotion Gangwon Branch, Chuncheon, Korea.
Korean J Intern Med. 2020 Jan;35(1):150-159. doi: 10.3904/kjim.2017.233. Epub 2018 Mar 21.
BACKGROUND/AIMS: The aim of this study is to compare Friedewald-estimated and directly measured low density lipoprotein cholesterol (LDL-C) values and assess the concordance in guideline risk classification between the two methods.
The data were derived from the 2009 to 2011 Korea National Health and Nutrition Examination Survey. We included subjects with triglyceride (TG) levels < 400 mg/dL. Analysis was done for 6,454 subjects who had all lipid panels- total cholesterol, directly measured LDL-C, high density lipoprotein cholesterol (HDL-C), and TG.
The subjects ranged in age from 10 to 87 years old. The mean age was 41.5 ± 17.3 years. For subjects with TG < 400 mg/dL, overall concordance in guideline risk classification was 79.1%. The Friedewald formula tended to underestimate LDL-C more at higher TG or lower HDL-C levels. Especially, the percent of subjects who were misclassified into a lower risk category was 31% when TG were 200 to 299 mg/dL; and 45.6% when TG were 300 to 399 mg/dL. A greater underestimation of LDL-C occurred at higher TG and lower Friedewald-estimated LDL-C levels. Of subjects with a Friedewald-estimated LDL-C < 70 mg/dL, 55.4% had a directly measured LDL-C ≥ 70 mg/dL when TG were 200 to 399 mg/dL.
The Friedewald equation tends to underestimate LDL-C in highrisk subjects such as hypertriglyceridemia and hypo-HDL-cholesterolemia. For these individuals accurate assessment of LDL-C is crucial, and therefore additional evaluation is warranted.
背景/目的：本研究旨在比较 Friedewald 估算的和直接测量的低密度脂蛋白胆固醇（LDL-C）值，并评估两种方法在指南风险分类中的一致性。
数据来自 2009 年至 2011 年韩国国家健康和营养调查。我们纳入了甘油三酯（TG）水平<400mg/dL 的受试者。对所有血脂谱（总胆固醇、直接测量的 LDL-C、高密度脂蛋白胆固醇（HDL-C）和 TG）的 6454 名受试者进行了分析。
受试者年龄在 10 岁至 87 岁之间，平均年龄为 41.5±17.3 岁。对于 TG<400mg/dL 的受试者，指南风险分类的总体一致性为 79.1%。在更高的 TG 或更低的 HDL-C 水平下，Friedewald 公式往往更倾向于低估 LDL-C。特别是，当 TG 为 200-299mg/dL 时，有 31%的受试者被错误地归类为低风险类别；当 TG 为 300-399mg/dL 时，有 45.6%的受试者被错误地归类为低风险类别。在更高的 TG 和更低的 Friedewald 估计 LDL-C 水平下，LDL-C 的低估程度更大。在 Friedewald 估计的 LDL-C<70mg/dL 的受试者中，当 TG 为 200-399mg/dL 时，有 55.4%的受试者直接测量的 LDL-C≥70mg/dL。
在高甘油三酯血症和低 HDL 胆固醇血症等高危人群中，Friedewald 方程往往低估 LDL-C。对于这些个体，准确评估 LDL-C 至关重要，因此需要进行额外的评估。
