High Cholesterol: Are Your Genes to Blame?

Cholesterol, Featured Article, Healthy Heart
on September 30, 2014
inherited high cholesterol

We all know that to lower our risk for heart disease, we need to keep our cholesterol levels low. The higher our LDL—the so-called “bad” cholesterol—and the lower our levels of HDL—dubbed the “good” cholesterol—the greater our risk for heart disease. But an estimated one in 200 to 500 people have cholesterol levels that remain stubbornly high, no matter how hard they try to lower them, putting them at risk for early onset heart disease and heart attacks.

The culprit: A condition called familial hypercholesterolemia, or FH. Typically, LDL travels to the liver where it leaves the body. But people with FH have a mutation in the gene that helps the liver get rid of LDL, explains Clyde W. Yancy, M.D., chief of the division of cardiology at Northwestern Memorial Hospital at Northwestern University School of Medicine in Chicago. “The end result is a lot of this bad cholesterol circulating through the bloodstream,” says Dr. Yancy. In fact, levels of LDL can be dangerously high.

The result: FH is characterized by LDL levels of 220 or higher in adults, and total cholesterol levels topping 300. But someone whose LDL reaches 190 may send up a red flag. “It’s unusual for someone to have an LDL greater than that,” says Dr. Yancy.

Tip-offs that a child may have FH: An LDL higher than 170 and total cholesterol levels greater than 250. “Children rarely, if ever, have high cholesterol,” says Dr. Yancy. “So a child with a high cholesterol value is certainly someone who potentially has FH.” In some children who inherit the FH gene from one parent, LDL cholesterol levels can soar as high as 500; in kids who get the gene from both parents, levels can skyrocket to 1000.

How It’s Diagnosed: In some people, the first sign that they have FH is a heart attack, says Dr. Yancy. But routine cholesterol testing will tell your doctor if you have high LDL and total cholesterol levels. If your doctor suspects FH, tests can be done to look for the genetic mutation. However, further testing won’t change the treatment, says Dr. Yancy. If your LDL is high and you have a family history of early onset heart disease or one or more relatives who had a heart attack in their 30s and 40s, your doctor will diagnose FH. Diagnosing FH in children is a challenge since routine cholesterol screening isn’t done on them. So any one who has a family history of FH or early heart disease should have their kids’ cholesterol levels checked.

Other red flags for FH: Chest pain at an early age or clear marble-like collections of fat on the surface of the skin around joints such as the hands, knees, and elbows. Another sign is a cholesterol deposit in the eye, characterized by a white or blue perimeter around the cornea of the eye. However, not everyone with FH develops these deposits.

How It’s Treated: Making major lifestyle changes is important for anyone with high LDL and total cholesterol. You need to follow a low-fat diet; limit dietary cholesterol; exercise regularly; maintain a healthy weight; lower your blood pressure; get your diabetes under control if you’ve been diagnosed with it; and if you smoke, quit.

But if you have FH, waiting to see if these lifestyle changes will lower your cholesterol levels and heart disease risk is not an option. You need to start a cholesterol-lowering statin immediately and take it for the rest of your life. In people with FH, “we know the risk for heart disease is incredibly high,” says Dr. Yancy. “Statin therapy is the only intervention proven to change the outcome that might happen if we don’t treat the high cholesterol.”

And this may be even more crucial in children with FH. According to Dutch researchers, starting children with FH on statins may have life-saving benefits. The researchers evaluated 214 children ages 8 to 18 who were treated with statins and found that at age 30 young adults who had begun statins during childhood had a 100 percent survival rate for coronary heart disease. By contrast their parents had a 93 percent survival rate. However, children with serious forms of FH may be candidates for a liver transplant.

But lifestyle changes and statin therapy are only part of the equation. “Often we check a patient’s cholesterol every eight to 12 weeks to see if we have it under control,” says Dr. Yancy. “Even when it’s controlled, we test cholesterol at least once a year. This really is big league preventive maintenance.”