LDL - C (Low-density lipoprotein cholesterol)
Measured Factor Disease
- Low-density lipoprotein cholesterol
Measured Factor Detail
LDL-C concentration estimation by Friedewald formula (FF) using Total Cholesterol (TC ), high-density lipoprotein cholesterol (HDL-C) and triglyceride (TG). Increased levels of LDL-C correlates with the risk of developing coronary heart diseases.
Multiple body systems
LDL cholesterol = Total cholesterol - HDL - (Triglycerides / 5)
Measured Factor Low Impact
- <100 mg/dL and 100-129 mg/dL interprets optimal and near to optimal LDL levels.
Measured Factor High Impact
- 130-159 mg/dL, 60-189 mg/dL and ≥190 mg/dL interprets borderline high, high and very high LDL levels.
- Critical High: 160-189 mg/dL
- Normal: <100 mg/dL
- Normal Adult Male: <100 mg/dL
- Normal Adult Female: <100 mg/dL
Result High Conditions
- Risk of coronary artery disease
Friedewald formula cannot be used for samples containing triglyceride levels > 400 mg/ dL. Additionally to samples containing chylomicrons, patients with dysbetalipoproteinemia (Fredrickson Type III). Lastly, some authors suggested this formula does not help patients with diabetes, nephropathies or hepatopathies.
Study Validation 1
This comparative study was aimed to estimate the LDL-C using two different formulas. 515 fasting patients of at least 18 years were included in the study and data was collected for their lipid profile samples. Total cholesterol, total glycerrides and LDL-C were measured enzymatically using reagents kits. Friedewald’s and Anandaraja’s formulas were used for calculation of LDL-C The mean LDL-C levels were 123.3 ± 53.2, 112.4 ± 50.2 and 109.2 ± 49.8 mg/dl for D-LDL-C, F-LDL-C and A-LDL-C, respectively. The results of this study showed that Friedewald’s formula is better in agreement with D-LDL-C than Anandaraja’s formula for estimation of LDL-C by calculation though both lead to its underestimation.
Study Validation 2
The main objective of this comparative study was to validate the Friedewald formula (FF) in patients with serum triglycerides (TGs) <400 mg/dl. Low-density lipoprotein (LDL)-cholesterol was measured by Friedewald formula and by direct method in lab. A comparison was done between results measured by both methods and it was found that FF correlated with directly measured LDL with correlation coefficient of 0.89. LDL was under estimated and over estimated in some instances by FF method .This study concludes that there is more need for validation studies for use of FF formula in calculating LDL-C
Study Validation 3
This study aimed to validate various existing formulas and derived a more accurate formula to determine LDL-C in a Serbian population. 1010 patients with TG < or = 4.52 mmol/L were involved in the study. For LDL-C measurement Friedewald's ,Anandaraja's formulas and direct lab methods were utilized. The results of all three methods were then compared. The mean LDL-C concentrations were 3.9 +/- 1.09 mmol/L, 3.63 +/- 1.06 mmol/L and 3.72 +/- 1.04 mmol/L measured by a direct homogenous assay, calculated by Friedewald's formula and calculated by Anandaraja's formula respectively. Then combining all these methods anewly modified method was applied on second set of patients which showed better results compared to both Friedewald's and Anandaraja's formulas
Study Additional 1
The purpose of this study was to compare the performance of assay methods in predicting cardiovascular disease (CVD) by measuring LDL cholesterol (LDL-C). LDL-C was measured in all patients using different assay methods. The results of 27,331 with triglycerides <or=4.52 mmol/L (<or=400 mg/dL), baseline fasting Friedewald LDL-C was compared with fasting and non-fasting direct homogenous assay method. The results of both the methods were nearly correlated with some misclassifications by direct LDL-C measurement method
Study Additional 2
This study was aimed to compare the performance of homogeneous method and Friedewald formula in measuring the LDL- cholesterol in a large heterogeneous population. The measurements of total cholesterol (TC) and triglycerides (TG) were performed using traditional enzymatic methods. Direct method and Friedewald formula was utilized in measuring LDL-C. Results showed there was significant correlation (P < 0.001) between both the methods. However there was some bias occurred in Friedewald formula. This study concluded that performance of Friedewald formula was not homogeneous for estimating LDL-C levels.
Study Additional 3
This study was conducted in 487 schizophrenic patients treated with clozapine in polytherapy with aim to validate the Anandaraja's formula by comparing its result with Friedewald and agar gel electrophoresis method. Total 487 serum samples was evaluated obtained from schizophrenic patients treated with clozapine in polytherapy. LDL-C, HDL was measured using all 3 methods. Results showed higher correlation of the electrophoresis results was found with those of Friedewald formula compared to Anandaraja method. This study concluded that Anandaraja's formula tends towards an overestimation or underestimation of LDL cholesterol levels and suggest Friedewald formula is more accurate tool in measuring LDL-C levels