Question

23. What are the reference methods for the following?
1. Triglycerides
2. Total cholesterol
3. HDL-C
4. LDL-C
5. Lipoproteins (HDL, VLDL, Lp(a), LDL, Chylomicrons

24. What are the NCEP and ATP classifications of LDL, Total, and HDL
Cholesterol?

25. What is the typical reference interval for triglycerides?

please can you add your reference of your answers thank you

Answer 1

Answers;

1)The two routine triglycerides methods were fluorometric methods were the fluorometric method of kessler and lederer and the enzymatic method. The reference method are GS-MS method that is hydrolysis of fatty acids on TGs and measurement of glycerol

2)A referece method of total cholesetrol based on gas chromatography coupled with mass spectrometry and isotope dilutuon(GC-IDMS). 3)Accurate high density lipoprotein choleserol(HDL-C) measurements are impotant for management of cardiovascular diseases.The US centres for disease control and prevention (CDC) and cholesterol reference method laboratory network (CRMLN) perform ultracentrifugation (UC), reference measurement procedure (RMP) to value assign HDL-C.

4)Accurate measurement of blood lipids is crucial in cardiovascular disease risk management .the centers for disease control and prevention (CDC) cholesetrol reference method laboratory network (CRMLN) has assured the accuracy of these measurements forover 20 years using Beta quantification(BQ) method as reference measurement procedure (RMP) for high and low density lipoprotein cholesterol (HDLC,LDL-C).

5)Reference methods for lipoproteins and apolipoproteins have been developed for use as part of an accuracy base for institutional,national or international reference systems.a widely accepted reference method exists only for total cholesterol.well described interim or institutional in-house reference methods have been established for the other lipids,lipoproteins and apolipoproteins.the major criteria for a reference method are1)scientific basis,2)sound principles,3)available calibration and control materials,4)traceability to a definitive method or a point of reference,5)applicability to reference materials that provide traceability to clinical methods and transferability to other reference laboratories.

6) ATP classification of LDL,Total,HDL cholesterol       LDL cholesterol less than 100 --- Optimal 100-129 --- Near optimal/above optimal 130-159 --- Borderline high 160-189 --- High greater than 190 ---very high

Total cholesterol less than 200 --- Desirable 200-239 --- Borderline high .greater than240---High

HDL cholesterol less than 40 ----- low greater than 60 ---High

7) The reference intervals for triglycerides are;   Adult/elderly

Normal findings in adult and elderly individuals are as follows; * males-40-160mg/dL or 0.45-1.81mmol/L(SI units) * females-35-135 mg/dL or 0.40-152mmol/L(SI units)  

Reference;international journal of clinical chemistry, Eur j clin chem clin biochem,national library of medicine,clinical chemistry (W.Greg Miller,Gary L myers and Alan T. Remaley),