Objective: To evaluate the consistency of blood lipid test result under different storage conditions.
Methods: Blood samples from 140 subjects were collected, centrifuged and were divided into five aliquots. One aliquot was used to determine serum total cholesterol(TC), triglyceride(TG), high density lipoprotein cholesterol(HDL-C) and low density lipoprotein cholesterol(LDL-C) immediately, and the other four parts were stored at 4 ℃ for 4 h, 24 h, and frozen at-20 ℃ and-80 ℃ for 30 d, respectively, for the further measurement.
Results: Immediate 0 h detection was compared with 4 ℃ for 4 h and 24 h, -20 ℃and-80 ℃ for 30 d: The difference Bland-Altman method was used to analyze TC and LDL-C data, and the mean TC difference values was 0.00, 0.00, 0.07 and 0.03 mmol/L, respectively. LDL-C difference value was-0.02, -0.04, -0.02 and-0.07 mmol/L, respectively, and 95% of the points were within the clinically acceptable conformance threshold. Ratio Bland-Altman method was used to analyze TG and HDL-C data. The mean TG ratios was 1.01, 1.00, 1.05, 1.05, and the mean HDL-C was 1.01, 1.03, 1.05 and 1.03, respectively. Ninety-five percent of the points were within the clinically acceptable consistency boundary. According to the 2021 Interlaboratory Quality Evaluation Standard of Clinical Laboratory Center of National Health Commission, the Bland-Altman analysis showed good consistency between the test result of different blood samples under different storage conditions and the immediate test result.
Conclusion: In large population epidemiological studies, the results of TC, LDL-C, HDL-C and TG in sera being refrigerated at 4 ℃ for 4 h and 24 h, and frozen at-20 ℃ and-80 ℃ for 30 d, were consistent with the result of immediate detection.
Keywords: Bland-Altman; blood storage; consistency analysis.