Familial hypercholesterolemia twice as common as previously believed

According to the Dutch Lipid Clinic criteria, one in 250 Americans are affected by familial hypercholesterolemia, researchers reported in Circulation.

 “It’s more common than we thought and it’s important to look for it at a young age because someone with FH [familial hypercholesterolemia] may have no symptoms until there is serious heart disease,” Sarah de Ferranti, MD, MPH, assistant professor of pediatric cardiology at Harvard Medical School and director of preventive cardiology at Boston Children’s Hospital, said in a press release. “A common story might be someone who develops chest pain or has [an MI] in their 30s or 40s — even though they look healthy, eat well, and are thin and fit.”

Previous research conducted outside of the United States in less diverse populations suggested that the prevalence of FH was one in 500 adults. For their study, de Ferranti and colleagues assessed data from 36,949 adults (aged 20 years or older) from the 1999-2012 National Health and Nutrition Examination Survey using Dutch Lipid Clinic criteria, which included LDL, as well as personal and family history of early atherosclerotic CVD, and then extrapolated to 210 million U.S. adults.

The researchers estimated that 834,500 U.S. adults may have FH. No differences were observed between men and women; however, there were some racial differences: One in 249 whites may be affected compared with one in 211 blacks, one in 414 Mexican Americans and one in 343 people of other races. FH also is more common in those who are older (one in 1,577 people in their 20s vs. one in 118 people in their 60s) and those who are obese (one in 172 obese people vs. one in 325 nonobese people).

“The fact that [FH] varies by age and obesity shows that there are other factors at play in raising LDL cholesterol levels in addition to genetics,” de Ferranti said.

In a secondary analysis, the researchers estimated prevalence for adolescents aged 12 to 19 years using only LDL data from 13,343 adolescents and found that one in 237 American adolescents may have FH, a rate similar to the adults.

The researchers said a lack of genetic information was a limitation of the study.

“The next step forward could be to take blood samples from a data set such as NHANES and look for prevalence of [FH] genetic mutations and the [MI] rate,” de Ferranti said. – by Tracey Romero

Disclosure: de Ferranti reports receiving funding from the Patient-Centered Outcomes Research Institute and receiving royalties from UpToDate for review topics on cholesterol screening and treatment in childhood. Please see full study for list of all other researchers’ relevant financial disclosures.

Source: www.healio.com