Familial hyperlipoproteinemia(a) is an inherited condition that leads to higher levels of a molecule known as lipoprotein(a) or Lp(a) (called “lipoprotein little A”). Lipoproteins are important for moving fats and cholesterol around the body. Changes in the normal levels of certain lipoproteins, such as low density lipoprotein (LDL) and high density lipoprotein (HDL), can be risk factors for heart disease. The role of Lp(a) as a risk factor is less certain, particularly when LDL and HDL levels are normal and there is no family history of early cardiovascular disease.
Does Lp(a) increase the risk for cardiovascular disease?
Lp(a) is thought to increase risk for cardiovascular disease by increasing the formation of blood clots and causing damage to blood vessels. Lp(a) gets into the cells found in the wall of the blood vessels. Over time this can lead to build up of the plaque that causes “hardening of the arteries”.
What is considered a normal level of Lp(a)?
In adults, levels of Lp(a) below 30 mg/dl is considered the normal range, however, normal Lp(a) levels may vary by race. Average Lp(a) levels seem to be higher in African Americans, without increasing the risk for cardiovascular disease.
How common is high Lp(a)?
Approximately 25% of the US population have levels above 30mg/dl. Lp(a) levels stay fairly consistent throughout life though it can increase slightly with age. Levels can also be higher in people with kidney disease and diabetes. Higher levels are also found in the African American population. Despite having been discovered nearly 50 years ago, a biological function for Lp(a) has not been identified.
Who should be tested?
If there are close blood relatives (parent, sibling, child, aunt/uncle, grandparent) with premature cardiovascular (heart and blood vessel) disease such as heart attack and stroke (under 55 years in men and under 65 years in women) your health care provider should consider testing your Lp(a) level.
What does the research say?
There have been mixed results about how useful it is to know a person’s Lp(a) level. Some studies show that high Lp(a) levels increase the risk for cardiovascular disease regardless of other cholesterol values. However other research found an increased risk mainly when other lipids are abnormal, such as elevated LDL or low HDL. One study found the risk from high Lp(a) levels was reduced just by lowering LDL levels. For now, the risk for heart disease due to high Lp(a) levels remains unclear. More research may help us understand this better over time.
Is there a treatment for high Lp(a)?
Lipoprotein (a) levels do not change in response to changes in lifestyle. Improving one’s diet or increasing physical activity will not lower Lp(a) directly, but could help reduce your overall risk for heart disease.
Medications used to improve cholesterol levels, such as statins like Lipitor, do not lower Lp(a). Niacin in high doses (3 – 4 grams/day) will lower Lp(a) in some people, although it is not successful in everyone. It may be advisable for females with high Lp(a) and on estrogen therapy take a low dose (81mg) aspirin. This should be decided with the help of a physician.
Created by: Suzanne Kordesh, MPH, RD, Pediatric Lipid Clinic Coordinator
Reviewed by: Dr. Leslie Manace Brenman, MD MPhil, Sub-Chief, Kaiser Oakland Genetics
Last Updated: January 2016