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International Journal of Recent Trends in Science and Technology, ISSN 2277-2812 E-ISSN: 2249-8109
Volume 14, Issue 3, April 2015 pp 534-536
Comparison of the values of low density lipoprotein by the direct and indirect methods (friedewald equation)
Varsha Mohan1, Priyadarshini K S2, H V Shetty3, Usha S M R4
1IInd year Postgraduate, 2,4Professor, 3Professor and HOD, Department of Biochemistry, Rajarajeswari Medical College and Hospital, Bengaluru, Karnataka, INDIA.
Background: LDL-c is routinely estimated in clinical practice to guide treatment for hypercholesterolemia by Friedewald formula. It is also measured by direct homogenous assays in critical cases when accuracy is needed. Objective: To determine if, and to what extent LDL level is underestimated when it is calculated by the Friedwald formula compared with the LDL measured by a direct method. Methodology: About 1140 lipid profile reports wherein LDL was measured directly in fasting state and TG< 400 mg/dl were taken for the study. The data was divided based on the TG levels into four groups, A - <99mg/dl, B-100-199 mg/dl, C-200-299 mg/dl and D- < 400 mg/dl. LDL was calculated using Friedewald’s formula and was compared with homogenous enzymatic method derived direct LDL in all the groups. Data was statistically analysed to arrive at results. Results: A positive correlation was noted between the two methods of measured LDL in all the groups. In subjects with TG <100 there was no variation between c-LDL and d-LDL. Difference of 10-15mg was found in subjects with TG <300.Difference between c-LDL and d-LDL s increased with increase in TG level, 20-25mg when TG btw 300-400. Conclusion: The c- LDL tends to underestimate d- LDL as TG increases especially with TG>300.