Clinicians Face Confusion on Lipid Screenings for Children

Clinicians receive conflicting advice on whether to order blood tests to screen for lipids in children. A new study could add to the confusion. Researchers found that a combination of physical proxy measures such as hypertension and body mass index (BMI) predicted the risk for future cardiovascular events as well as the physical model plus lipid labs, questioning the value of those blood tests.

Some medical organizations advise screening only for high-risk children because more research is needed to define the harms and benefits of universal screening. Diet and behavioral changes are sufficient for most children, and universal screening could lead to false positives and unnecessary further testing, they said.

Groups that favor lipid tests for all children say these measurements detect familial hypercholesterolemia (FH) that would not otherwise be diagnosed, leading to treatment with drugs like statins and a greater chance of preventing cardiovascular disease (CVD) in adulthood.

Researchers from the new study said their findings do not address screenings for FH, which affects 1 in 250 US children and puts them at a risk for atherosclerotic CVD.

Recommending Blood Tests in Age Groups

One of the seminal guidelines on screening lipids in children came from the National Heart, Lung, and Blood Institute (NHLBI), which in 2011 recommended children undergo dyslipidemia screening between the ages of 9 and 11 years and again between 17 and 21 years. Children should receive a screening starting at age 2 years if they have a family history of CVD or dyslipidemia or have diabetes, an elevated BMI, or hypertension. The American Academy of Pediatrics shortly followed suit, issuing similar recommendations.

Screening for the two subsets of ages was an expansion from the original 1992 guidelines from the National Cholesterol Education Program, which recommended screening only for children with either a family history of early CVD or elevated total cholesterol levels.

A 2011 panel for the NHLBI said the older approach identified significantly fewer children with abnormal levels of low-density lipoprotein cholesterol (LDL-C) than the addition of two age groups for screening, adding that many children do not have a complete family history. The American College of Cardiology and American Heart Association later supported NHLBI’s stance in their joint guidelines on the management of cholesterol.

Mark Corkins, MD, chair of the AAP’s Committee on Nutrition, told Medscape Medical News that if children are screened only because they have obesity or a family history of FH, some with elevated lipid levels will be missed. For instance, studies indicate caregiver recall of FH often is inaccurate, and the genetic disorder that causes the condition is not related to obesity.

“The screening is to find familial hypercholesterolemia, to try to find the ones that need therapy,” that would not be caught by the risk-based screening earlier on in childhood, Corkins said.

Only Screen Kids With Risk Factors

But other groups do not agree. The United States Preventive Services Task Force (USPSTF) found insufficient evidence to recommend for or against screening for lipid disorders in asymptomatic children and teens.

The group also said it found inadequate evidence that lipid-lowering interventions in the general pediatric population lead to reductions in cardiovascular events or all-cause mortality once they reached adulthood. USPSTF also raised questions about the safety of lipid-lowering drugs in children.

“The current evidence is insufficient to assess the balance of benefits and harms of screening for lipid disorders in children and adolescents 20 years or younger,” the panel wrote.

The American Academy of Family Physicians supports USPSTF’s recommendations.

Low Rate of Screening

While the uncertainty over screening in children continues, the practice has been adopted by a minority of clinicians.

A study published in JAMA Network Open in July found 9% of 700,000 9- to 11-year-olds had a documented result from a lipid screening. Among more than 1.3 million 17- to 21-year-olds, 13% had received a screening.

As BMI went up, so did screening rates. A little over 9% children and teens with a healthy weight were screened compared with 14.7% of those with moderate obesity and 21.9% of those with severe obesity.

Among those screened, 32.3% of 9- to 11-year-olds and 30.2% of 17- to 21-year-olds had abnormal lipid levels, defined as having one elevated measure out of five, including total cholesterol of 200 mg/dL or higher or LDL-C levels of 130 mg/dL or higher.

Justin Zachariah, MD, MPH, an associate professor of pediatrics-cardiology at Baylor College of Medicine in Houston, spoke about physicians screening children based only on factors like obesity during a presentation at the recent annual meeting of the American Academy of Pediatrics. He cited research showing roughly one in four children with abnormal lipids had a normal weight.

If a clinician is reserving a lipid screening for a child who is overweight or has obesity, “you’re missing nearly half the problem,” Zachariah said during his presentation.

One reason for the low rate of universal screening may be inattention to FH by clinicians, according to Samuel S. Gidding, MD, a professor in the Department of Genomic Health at Geisinger College of Health Sciences in Bridgewater Corners, Vermont.

For instance, a clinician has only a set amount of time during a well-child visit and other issues may take precedence, “so it doesn’t make sense to broach preventive screening for something that could happen 30 or 40 years from now, vs this [other] very immediate problem,” he said.

Clinicians “are triggered to act on the LDL level, but don’t think about FH as a possible diagnosis,” Gidding told Medscape Medical News.

Another barrier is that in some settings, caregivers must take children and teens to another facility on a different day to fulfill an order for a lipid test.

“It’s reluctance of doctors to order it, knowing patients won’t go through with it,” Gidding said.

Samuel Gidding is a consultant for Esperion Therapeutics, Inc. Other sources in this story reported no relevant financial conflicts of interest.

Brenda Sandburg is a freelance journalist who has written about policies of the US Food and Drug Administration, the biopharmaceutical industry, and legal issues for the Pink Sheet and American Lawyer Media.