High levels of "good cholesterol," or high-density lipoprotein, are unlikely to protect people from heart disease if their bloodstream also contains high levels of a newly identified biomarker of inflammation in the arteries.
This is the conclusion of research recently presented at the American College of Cardiology 2016 Scientific Sessions in Chicago, IL.
Inflammation of the artery walls raises the risk of a heart attack or stroke because it increases the chance of plaque on the arterial walls rupturing. If this happens, it can lead to the formation of blood clots and a blockage in the blood flow.
Cholesterol is a waxy, fat-like substance. The human body needs some cholesterol, but if there is too much, it can collect within the arteries, leading to heart disease and stroke. Heart disease is the number one cause of death in the US.
Low-density lipoprotein (LDL) - also known as "bad" cholesterol - is found in high levels in 33.5% of American adults, according to the Centers for Disease Control and Prevention (CDC).
On the other hand, high levels of high density lipoprotein (HDL), or "good" cholesterol, are thought to provide anti-inflammatory protection in the arteries.
Many people do not realize that their cholesterol is too high, because there are no symptoms. Exercising, eating a healthy diet and not smoking can help reduce cholesterol levels.
Individuals can increase their HDL levels through dietary measures such as consuming foods rich in omega-3s and following a Mediterranean diet, with a high proportion of plant-based foods and healthy fats, such as olive oil. Limiting intake of salt and red meat also helps.
GlycA may reduce benefits of HDL
Researchers from the Intermountain Medical Center Heart Institute in Salt Lake City, UT, used a test called NMR spectroscopy to measure lipoprotein particles and glycoprotein acetylation, or GlycA, in 2,848 patients.
- Total cholesterol levels should be less than 200 mg/dL
- LDL levels should be less than 100 mg/dL
- HDL levels should be 60 mg/dL or higher.
Participants had an average age of 63 years; 66% were male, and 65% had coronary artery disease.
Findings revealed a higher risk of heart attack or stroke among those with high levels of the biomarker GlycA.
The results suggest that an interaction may occur between GlycA and small HDL particles, restricting the capacity of HDL to act as an anti-inflammatory and increasing the chance of a heart attack or stroke.
Dr. Brent Muhlestein, co-director of cardiovascular research at the Intermountain Medical Center Heart Institute, explains that historically, C-reactive protein has been used as an indicator of inflammation in the body and a predictor of heart-related problems.
Now, it seems that GlycA, a marker of inflammation identified through NMR, could also predict adverse events such as heart attack or stroke.
Dr. Muhlestein describes GlycA as "a new particle we didn't know much about."
Now that research has established epidemiologic associations, he calls for further research to find ways to assess and understand how it works and how it interacts in the bloodstream.
The next step for researchers is to find out whether C-reactive protein and GlycA impact inflammation and heart disease independently.
Dr. Muhlestein says:
"The results of our study reinforce the importance of the recommendations we offer to our patients working to reduce inflammation in their arteries by exercising regularly and eating heart-healthy foods."
Medical News Today recently reported on research suggesting that too few Americans are using drugs to reduce their levels of "bad" or LDL cholesterol.