The concept of non-HDL cholesterol

The concept of non-HDL cholesterol

Non-HDL cholesterol  is defined as the difference between total cholesterol level and HDL cholesterol level. Non-HDL cholesterol includes several lipoproteins.

There are several reasons for measurement of Non-HDL cholesterol. First of all, when the triglyceride levels are high, calculation of LDL cholesterol levels with the Friedewald formula becomes inaccurate. High triglyceride levels are associated with higher levels of small dense LDL. Non-HDL cholesterol includes several atherogenic components like LDL, lipoprotein (a), intermediate density lipoprotein and very low density lipoprotein.

Non-HDL cholesterol measurement is a more accurate tool for risk assessment in the presence of high levels of triglycerides. It has also been considered as a metric of good quality of care [1]. Even though LDL is the primary target for cholesterol lowering therapies, the risk of future coronary events may remain high in patients who have achieved guideline directed LDL goals. In the PROVE-IT TIMI 22 trial 22.7% of patients had a recurrent event at 2 years of follow up in spite of LDL levels of 67 mg/dL and optimal medical care [2].

References

1. Virani SS. Non-HDL cholesterol as a metric of good quality of care: opportunities and challenges. Tex Heart Inst J. 2011;38(2):160-2.
2. Christopher P Cannon, Eugene Braunwald, Carolyn H McCabe, Daniel J Rader, Jean L Rouleau, Rene Belder, Steven V Joyal, Karen A Hill, Marc A Pfeffer, Allan M Skene, Pravastatin or Atorvastatin Evaluation and Infection Therapy-Thrombolysis in Myocardial Infarction 22 Investigators. Intensive versus moderate lipid lowering with statins after acute coronary syndromes. N Engl J Med. 2004 Apr 8; 350(15):1495-504.