Endocrine Abstracts

Introduction: LDL cholesterol (LDL-C) is usualy estimated using the Friedewald equation. This equation assumes a fixed factor of 5 for the ratio of triglycerides to very LPL cholesterol (TG:VLDL-C); however, the actual TG:VLDL-C ratio varies significantly across the range of triglyceride and cholesterol levels. A new method was proposed by Martin, S and co-workers using NHANES data. We aimed to evaluate the concordance Friedewald formula with the new method for LDL-C estimation from the standard lipid profile using an adjustable factor for the TG:VLDL-C ratio.

Design and settings: We used the results of consecutive clinical lipid profiles obtained from 2000 through 2015 from 40 339 patients of our outpatient clinic, at our hospital lab. The measurements were done mainly in type 2 diabetic – 66.1%. Females were 52% of cases cholesterol concentrations were directly measured after vertical spin density. LDL-C was measured if tryglicerides over 400 mg/dl and calculated by Friedewald formula if lower. Data were analysed in SPSS package v20.

Results: Diabetic patients had lower LCL-C levels than non diabetics (92 vs 101 mg/dl – P<0.001). Results of LCL-C are highly correlated in the all lipid profiles (93% P<0.001) but mean values are 108.3 vs 96.4 mg/dl using Friedewald formula vs the new method. Wilcokson rank test find significant differences between the 2 methods (P<0.001).

Conclusions and relevance: This novel method to estimate LDL-C using an adjustable factor for the TG:VLDL-C ratio produces significant lower values of LDL-C than the Friedewald equation. These findings require external validation, as well as assessment of their clinical importance. The implementation of the new method into clinical practice is particular relevant when triglycerides are higher than 400 mg/dl.