HDL Cholesterol: The Good Cholesterol Can Go Bad

When discussing lipids and cholesterol the public, in particular, has been educated to the fact that the cholesterol is divided into several different types based on where it settles in a test tube after being spun in a centrifuge. The good cholesterol or HDL (high density lipoprotein) is said to be healthy and protective while the LDL (low density lipoproteins) are felt to be detrimental to your health. For years now we have been striving to lower the LDL cholesterol by eating correctly, exercising and when necessary taking medications such as statins.  At the same time we are trying to raise our HDL, or protective cholesterol, by exercising.  The higher your HDL cholesterol is, and the lower your LDL cholesterol is, your risks of not having a cardiovascular event improve.

In reality we know that HDL cholesterol carries bad cholesterol away from the blood vessel walls and deposits it in the liver where it is broken down and removed.  HDL is like a convoy of trucks ferrying your cholesterol away from vital places. The LDL cholesterol does just the opposite, carrying unwanted lipids to the vessel walls and depositing them there. 

 Just when we were getting comfortable with this concept, researchers at many institutions were able to break the LDL or bad cholesterol down into even more discrete groups. Apparently the large fluffy type of LDL is now considered beneficial. At the same time they have broken the HDL or protective cholesterol down into smaller divisions with some types being “broken” and causing inflammation in the artery walls leading to heart attacks and strokes. 

 Dr. Stanley Hazen, MD of the Cleveland Clinic’s Lemer Research Institution is one of the cardiologists promoting the concept of existing “broken” HDL which is damaging to our vessels and bodies.  Hazen’s research shows that in people with heart disease, about 1 in 5 HDL particles in the artery wall are dysfunctional.  People who have more of this dysfunctional HDL are at higher risk of heart disease, independent of the well-known risk factors such as age, diabetes, smoking and blood pressure.  This dysfunctional HDL is very hard for a lab to detect. 

 Dr. Hazen was part of a team that developed the MPO or myeloperoxidase blood level as a marker of plaque buildup in artery walls as a result of dysfunctional HDL and other risk elements.   High myeloperoxidase levels are associated with inflammation and damage to the vessel walls resulting in increased risks of heart attack and stroke.  The MPO test is licensed and copyrighted to the Cleveland Clinic and only available through the Cleveland Heart Labs program.

 We offer the Cleveland Heart Lab panel of tests as part of the cardiovascular risk assessment we present to individuals who do not have cardiovascular or cerebrovascular disease.  It is the only panel of tests that offers the Myeloperoxidase Level.  If interested please ask about this panel at your next visit.