Comparison of non-fasting LDL-C levels calculated by Friedewald formula with those directly measured in Chinese patients with coronary heart disease after a daily breakfast

Background: LDL-C level can be measured by direct methods (LDL-CM) or calculated by Friedewald formula (LDL-C-C). The aim of this study was to investigate the difference between LDL-C-M and LDL-C-C after a daily breakfast in Chinese patients with coronary heart disease (CHD). Methods: Three hundred and three inpatients, including 203 CHD patients (CHD group) and 100 non-CHD controls (CON group), were enrolled in this study. Scrum levels of blood lipid parameters, including LDL-C-C and LDL-C-M, at 0, 2 and 4 h (h) were monitored after a daily breakfast in all subjects. Results: LDL-C-M was significantly higher than LDL-C-C in fasting state in each group and at 4 h postprandially in CHD group (P <.05). Postprandial LDL-C-M and LDL-C-C significantly decreased in each group (P <.05). Postprandial decline in LDL-CM was significantly greater than that of LDL-C-C (P <.05). For CHD patients taking statins for >= 1 month before admission, non-fasting percent attainment of LDL-C-M or LDL-C-C was significantly higher than its fasting value, especially at 4 h (P <.05). The percent deviation of LDL-C-M from 1.8 mmol/L at 4h was significantly different from its fasting value. However, there was no significant difference in percent deviation of LDL-C-C from 1.8 mmol/L between fasting and non-fasting states. Conclusions: It indicated that the clinical monitoring of non-fasting LDL-C level in CHD patients could be relatively complex, and the judgement may depend not only on the method to acquire LDL-C level, but also on the evaluation method.