You’ve probably heard that “bad” cholesterol isn’t good for your heart.
High levels of low-density lipoprotein—known as the “bad” cholesterol—are usually due to a high-fat diet, not exercising enough or being overweight. But some people are born with dangerously high levels of this type of cholesterol. They have what is called familial hypercholesterolemia (FH). About 1 out of 250 people have this inherited disorder.
FH happens when there is a harmful change (called a mutation) to one of several genes in the body. Most often, the “defect” is in the LDL-receptor gene that usually helps to find and remove cholesterol in the body. But in people with FH, this gene is either missing or doesn’t work well. Meanwhile, the liver continues to make cholesterol, so LDL levels quickly rise in the blood.
Having such high levels of LDL cholesterol in the blood from such a young age puts people with FH at especially high risk of heart disease—even dying early. Sadly, 90% of people with FH don’t know they have it. As a result, they remain very likely to have a heart attack or die in the prime of their lives, often with no warning.
“The lifetime risk of a cardiovascular event—the chance having a heart attack or stroke—is five to 20 times greater for someone with FH than for the general population,” said James A. Underberg, MD, a cholesterol specialist and clinical assistant professor of medicine at New York University Medical School.
The good news is that when FH is found and treated early, cholesterol can be lowered. With the right treatment, an individual’s cardiovascular risk can go back down to what would be expected in the general population.
Knowing that you or a loved one has FH early on is key to being able to take steps to treat it and can help prevent potentially life-threatening problems.
FH runs in families. FH occurs when a there is a change in a gene that you are born with that makes the body unable to remove LDL, or "bad" cholesterol, from the blood. If you have FH, each child has a 50% chance of being born with it, too. If both parents have FH, then any children will have FH. However, this is rare.
Many people with FH are young and appear otherwise healthy, yet their arteries may tell a different story. That’s because high levels of “bad” cholesterol have been circulating in their bodies—often unchecked—since they were born. Over time, this can damage the blood vessels and block the heart’s arteries.
“It is very different from high cholesterol in the general population because these people have had many more years of dangerously high cholesterol. Finding and treating FH early is critical,” said Laurence Sperling, MD, FACC, director of preventive cardiology at the Emory University School of Medicine in Atlanta.
Because it is underdiagnosed, FH is often first suspected after someone has had a heart attack or stroke at a very early age. Untreated men with FH have a 50% chance of having a cardiac event by 50 years of age, and untreated women have a 30% chance by age 60.
The risk for problems is even higher in people who have other risk factors such as smoking or diabetes.