A particular type of lipoprotein, or molecule composed of proteins and fats that transports cholesterol and other lipids throughout the bloodstream. Lipoprotein (a) is often abbreviated Lp(a). High levels of Lp(a), which are elevated in an estimated 20% to 30% of the U.S. population, can raise the risk of coronary artery disease. It is thought that high levels of Lp(a), which are more commonly seen in people with diabetes, may help to account for the significantly increased risk of heart and blood-vessel disease seen in people with diabetes.
The Lp(a) molecule is very similar to low-density lipoprotein (LDL, or “bad”) cholesterol. Lp(a) is thought to carry cholesterol to the walls of the arteries, promoting atherosclerosis, or hardening and narrowing of the arteries. Recent studies suggest that Lp(a) may also promote the formation of blood clots, which can trigger a heart attack by blocking already narrowed arteries.
High levels of Lp(a) are also associated with diabetic kidney disease: Studies have shown that high levels of Lp(a) can promote the progression of diabetic kidney disease in people who have Type 2 diabetes and proteinuria (abnormal levels of protein in the urine), and that kidney disease in turn can cause elevated Lp(a) levels in people with either Type 1 or Type 2 diabetes. Researchers believe that elevated Lp(a) levels may help to account for the greater susceptibility to heart and blood-vessel disease seen in people with diabetic kidney disease.
Although some studies have shown that improved blood glucose control lowers Lp(a) levels in people with diabetes, other studies have not established an association between glycemic control and levels of Lp(a). Because of their high risk of dyslipidemia (blood lipid abnormalities) and coronary artery disease, all people with diabetes should have their blood lipid levels monitored regularly (at least once a year for most people) and treated if they are abnormal.