S Hirany1, D Li, I Jialal. 1. Division of Clinical Chemistry, Parkland Memorial Hospital, USA.
Abstract
PURPOSE: This study was conducted to determine if the direct low-density lipoprotein (LDL) cholesterol assay would provide a more valid measure of LDL cholesterol in diabetic patients compared with the Friedewald equation. PATIENTS AND METHODS: Fasting plasma from 148 diabetic patients, 40 with insulin-dependent diabetes (IDDM) and 108 with non-insulin dependent diabetes (NIDDM) with triglyceride levels < 400 mg/dL, were analyzed for LDL cholesterol using the Friedewald equation, the direct LDL assay, and beta-quantification. Forty-six diabetic patients with triglyceride levels > or = 400 mg/dL were also studied to determine the validity of the direct LDL cholesterol assay with hypertriglyceridemia. RESULTS: The friedewald equation and the direct LDL cholesterol assay correlated well with beta-quantification (r = 0.969 and r = 0.971, respectively) for LDL cholesterol determination in diabetic patients. Although the Friedewald equation in comparison with beta-quantification underestimated (8%) LDL cholesterol values in diabetic patients, the direct LDL cholesterol assay had a mean bias of < 1%. Also, the underestimation by the Friedewald equation exceeded 10% for the triglyceride subgroup of 200 to 400 mg/dL. Furthermore, the accuracy of the direct LDL cholesterol assay was superior to the Friedewald equation since LDL cholesterol levels determined by the two methods coincided within +/- 10% of beta-quantification in 85% and 68% of diabetic patients, respectively (P = 0.0005). Similar results for both the Friedewald equation and the direct LDL cholesterol assay in comparison with beta-quantification were seen when diabetic patients were subgrouped into IDDM and NIDDM. Also, the direct LDL cholesterol assay appeared to provide a reliable estimate in patients with triglycerides > or = 400 mg/dL. CONCLUSION: The results of our studies indicate that the direct LDL cholesterol assay is a more reliable and accurate method than the Friedewald formula for LDL cholesterol determination in diabetic patients and is more rapid and cost effective than the reference method.
PURPOSE: This study was conducted to determine if the direct low-density lipoprotein (LDL) cholesterol assay would provide a more valid measure of LDL cholesterol in diabeticpatients compared with the Friedewald equation. PATIENTS AND METHODS: Fasting plasma from 148 diabeticpatients, 40 with insulin-dependent diabetes (IDDM) and 108 with non-insulin dependent diabetes (NIDDM) with triglyceride levels < 400 mg/dL, were analyzed for LDL cholesterol using the Friedewald equation, the direct LDL assay, and beta-quantification. Forty-six diabeticpatients with triglyceride levels > or = 400 mg/dL were also studied to determine the validity of the direct LDL cholesterol assay with hypertriglyceridemia. RESULTS: The friedewald equation and the direct LDL cholesterol assay correlated well with beta-quantification (r = 0.969 and r = 0.971, respectively) for LDL cholesterol determination in diabeticpatients. Although the Friedewald equation in comparison with beta-quantification underestimated (8%) LDL cholesterol values in diabeticpatients, the direct LDL cholesterol assay had a mean bias of < 1%. Also, the underestimation by the Friedewald equation exceeded 10% for the triglyceride subgroup of 200 to 400 mg/dL. Furthermore, the accuracy of the direct LDL cholesterol assay was superior to the Friedewald equation since LDL cholesterol levels determined by the two methods coincided within +/- 10% of beta-quantification in 85% and 68% of diabeticpatients, respectively (P = 0.0005). Similar results for both the Friedewald equation and the direct LDL cholesterol assay in comparison with beta-quantification were seen when diabeticpatients were subgrouped into IDDM and NIDDM. Also, the direct LDL cholesterol assay appeared to provide a reliable estimate in patients with triglycerides > or = 400 mg/dL. CONCLUSION: The results of our studies indicate that the direct LDL cholesterol assay is a more reliable and accurate method than the Friedewald formula for LDL cholesterol determination in diabeticpatients and is more rapid and cost effective than the reference method.
Authors: Stuart B Prenner; Claire K Mulvey; Jane F Ferguson; Michael R Rickels; Anish B Bhatt; Muredach P Reilly Journal: Atherosclerosis Date: 2014-07-22 Impact factor: 5.162