Abstract

### Accepted 30^{th} May, 2014

### Increased LDL level is one of the major causes of heart disease including arteriosclerosis.* *Hence an accurate and timely measure of LDL can prevent the incidence of cardiac disorders. In the present study we compared the results between directly measured plasma LDL and calculated LDL. The LDL level was measured by colorimetric method and the calculation was done using friedwald’s equation in hyperlipidemic patients and healthy populations. We aimed to measure the accuracy of colorimetric method and fridwald’s equation in the estimation of plasma LDL in hyperlipidemic patients and healthy populations and assess if there is correlation between cholesterol level and LDL level thereby prevent false diagnosis due to false or inaccurate results . 2.5ml of blood was taken in lithium heparin container from 50 hyperlipidemic and normal populations, then centrifuged at 4000r.p.m for 3mins, the plasma was separated. Estimation of cholesterol, triglyceride and LDL was done using the routine reagents. Control sera (normal and pathologic) were used for every patch, after incubation the reaction color was read in a colorimeter (JENWAY 6051), beer^{,}s and lambert^{,}s law was used to measure the concentrations of the samples. Then for the same samples the Fridwald’s equation was used to calculate the LDL level. Mean value of 139.5 mg/dl, and a standard deviation of 37.44 was found for the hyperlipidemic patient’s LDL level by direct measurement and a mean of 136.5 mg/dl, and a standard deviation of 43.90 was found by using the Fridwald’s equation. The p value was found equal to 0.624, which is statistically insignificant. Also a mean of 73.6 mg/dl, and a standard deviation of 17.65 was found for the normal subjects LDL level by direct measure, and a mean of 71.2 mg/dl and a standard deviation of 22.50 was found by using the equation. The p value was found equal to 0.60 which is statistically insignificant. A moderate correlation of 0.48 was found between patient’s cholesterol and LDL levels. Also a moderate correlation of 0.49 was found between normal subject’s cholesterol and LDL level. We conclude that both Fridewald’s equation and direct colorimetric method can be used for routine LDL levels because it gives acceptable results. Moreover there is a correlation between cholesterol level and LDL level.

Key words:** Hyperlipidemia, LDL, cholesterol, colorimetric method, Fridewald’s equation**