中文摘要：

目的：观察和分析直接法测定血清低密度脂蛋白胆固醇（LDL-C）的含量与Friedewald公式换算值之间的关系。方法：采集1330例送检者的血脂水平，其血清三酰甘油均低于400mg·dL^-1（4．52mmol·L^-1）。测定LDL-C采用选择性水解法和根据Friedewald公式换算。结果：两种方法检测LDL-C值随非高密度脂蛋白胆固醇（non-HDL-C）水平的线性变化而波动，其偏差超过直接法检测值10％以上的占所有血样的40．76％。结论t直接法和Friedewald公式法检测血清LDL-C含量存在明显的偏差，可能与两种方法的系统误差有关。

英文摘要：

Objective：To investigate and analyze the relationship between serum low-density lipoprotein cholesterol （LDL-C） values measured by the direct method and by the Friedewald formula. Methods： The levels of blood lipids were obtained from 1330 cases. All of the triglyceride levels were less than 400 mg/dl （4.52 mmol/L）. The levels of LDL-C were measured direct- ly by a selective hydrolytic and enzymatic assay and calculated indirectly by the Friedewald formula. Results：The LDL-C values measured by either of the methods were found fluctuating along with the linear change of Non-high-density lipoprotein cholesterol （Non-HDL-C） values. The values of their deviation in 40. 76% of total samples were 10% more than those by the direct method. Conclusion：An obvious deviation was found between serum LDL-C values measured by the direct method and the Friedewald formula, it may be associated with the systemic errors of both methods.