LDL Cholesterol: Friedewald, Always the Best Option to Evaluate LDL cholesteRol Concentration in norMal and Dyslipidemic sUbjects, in Fasting and Pot-prandiaL State?

Purpose The LDL-C is a very important marker of the lipid panel which allows the introduction of a treatment and then the follow-up to prevent the cardiovascular risk. Friedewald et al have established the most widely used equation at the present time. However, it has many well-known limitations, as being false in postprandial period.

New equations have been developed recently. Our work consisted in the assessment of the accuracy of Friedewald, Sampson and Martin-Hopkins equations and evaluated the consequences in terms of misclassification. Given that European recommendations allow the realization of lipid profiles in postprandial period, we studied the accuracy of these equations in non-fasting state .

Method The LDL cholesterol concentrations will be calculated using at least three different equations (Friedewald, Sampson, Martin-Hopkins). Results will be compared between equations and between calculated and measured concentrations determined using an ultracentrifugation method. The study is conducted out according to The Code of Ethics of the World Medical Association (Declaration of Helsinki) and obtained the agreement of the Scientific and Ethics Committee of the Hospices Civils de Lyon (LDL EQUATION CNIL 21_488) Hypothesis

To evaluate the most accurate equation in different conditions:

• Fasting and non-fasting state
• In subjects with normal or dyslipidemic lipid profile To evaluate the clinical impact on risk re-classification and lipid treatment goals if LDL-c is calculated using the best equation instead of the Friedewald's.