Low HDL Cholesterol Levels Linked To Abdominal Aortic Aneurysm
HDL cholesterol is often called the good cholesterol because having higher levels is protective against cardiovascular disease. In a recent Australian study published in the May 15th issue of the American Journal of Cardiology, researchers have found that HDL cholesterol levels are also the most important lipid-derived predictor of the risk for abdominal aortic aneurysm (AAA).
An abdominal aortic aneurysm occurs when the large blood vessel that supplies blood to the abdomen, pelvis, and legs (called the aorta) becomes abnormally large or balloons outward. The condition usually does not have any symptoms until the aneurysm ruptures. Less than 40% of patients survive a ruptured AAA.
Having high cholesterol levels are a known risk factor for the development of an AAA. The most recent study focused on which lipid components played the greatest role in order to develop a therapeutic target.
Jonathan Golledge, of the James Cook University School of Medicine in Townsville, and colleagues assessed the association between fasting serum lipids and AAA’s in 3327 men ages 65 to 84 participating in the “Health in Men” study. About 7.4% of men had an AAA at screening, one-third had a history of dyslipidemia, and 31% were receiving lipid-lowering medication, usually statin drugs.
Serum HDL levels were significantly lower in men with AAA’s than those without, even after adjusting for other risk factors. Other serum lipid measures, including LDL cholesterol and triglycerides, were unrelated to the risk for AAA.
HDL cholesterol is thought to have anti-inflammatory and antioxidant effects that may be relevant to a protective role against AAA. About one-fourth to one-third of total blood cholesterol is HDL.
Healthy HDL cholesterol levels are above 40 mg/dL for men and above 50 mg/dL for women. Smoking, being overweight, and having a sedentary lifestyle (less than 30 minutes of physical activity each day) are all risk factors for low HDL cholesterol levels.