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Debate continues as to whether young children should have their cholesterol checked.

This summer, the U.S. Preventive Services Task Force (USPSTF) reiterated its stance that there's screening for lipid disorders in young kids and adolescents.

Pediatric cardiologists interviewed by 乌鸦传媒 acknowledge a dearth of long-term randomized controlled trials showing the benefits of screening so early, but they believe there's good evidence that strongly suggests a benefit.

Other doctors, including family medicine physicians, aren't so convinced. They believe significant issues with high cholesterol among kids will be caught through family history and clinical observation -- and treatment wouldn't be different from current recommendations of eating healthy and exercising.

Both sides are passionate about wanting to do what's best for children, even if the answers about the best approach aren't yet clear.

Origins of Screening Young Kids

In late 2011, the National Heart, Lung, and Blood Institute recommended in all kids ages 9 to 11 -- a change from that called for a risk-based approach using family history, and a population-wide approach of improving diet and exercise in all kids.

While most of the guidance wasn't controversial, the universal lipid screening recommendation caused a stir at the time, said Amy Peterson, MD, a pediatric cardiologist at the University of Wisconsin School of Medicine. It was the first time screening for lipid disorders had ever been recommended in kids.

The American Academy of Pediatrics (AAP) had published lipid screening guidance in 2008 that called for a risk-based approach, along with improved diet and exercise for all kids, in line with the earlier recommendations. But it and an AAP spokesperson said new guidelines are currently in development.

In the meantime, the AAP spokesperson noted that "information for parents on cholesterol screening" is available at , which states that AAP "recommends all children between 9 and 11 years old are screened for high blood cholesterol levels."

The American Heart Association and the American College of Cardiology, along with several other societies, also called for universal screening among kids ages 10 to 19 in its on cholesterol management. The recommendation is included in section 4.4 on primary prevention.

The recent USPSTF guidance remains essentially unchanged from its prior version released in 2016. It found insufficient evidence to recommend lipid screening in kids in light of both familial hypercholesterolemia (FH) -- a genetic condition that leads to elevated low-density lipoprotein (LDL) levels -- and multifactorial dyslipidemia, which is typically tied to environmental factors.

Breaking from the other societies, the American Academy of Family Physicians (AAFP) that there's insufficient evidence to recommend for or against routine screening for lipid disorders in kids.

Those in Favor

Sarah de Ferranti, MD, MPH, a pediatric cardiologist at Boston Children's Hospital and the lead author of an accompanying the publication of the latest USPSTF recommendations in JAMA this past summer, said the main reason for universal lipid screening in children is to identify and treat FH earlier.

Overall, FH -- both the homozygous and heterozygous type -- occurs in 1 in 250 to 500 people, de Ferranti and colleagues wrote. People with both types of FH do have cardiovascular events earlier in life than the general population -- but for heterozygous FH, the more common form, that risk manifests in middle age or later, so the "benefits of early identification had been difficult to quantify," they wrote.

The USPSTF sets a high bar for evidence, de Ferranti told 乌鸦传媒 in an interview. Trying to do a randomized controlled trial to show a benefit for screening in this population would be difficult, she said.

"You assign kids to be screened or not, then check in with them in 30 years to see the impact of that," de Ferranti said. "If you're a parent being asked for your child to participate, where they do or do not get a simple blood test to look for high cholesterol, and then in 30 years we call you back and say, 'How did it go?' That's a pretty hard one to sign up for, and logistically difficult."

Even in the absence of the gold-standard randomized controlled trial, de Ferranti said there's a growing body of evidence supporting universal screening.

She pointed to a showing that lower exposure to LDL cholesterol via certain genetic mutations was associated with a greater reduction in coronary heart disease risk over the lifespan compared with current practice of starting a statin later in life.

Another showed that increases in carotid intima-media thickness were smaller in treated FH patients compared with untreated ones, de Ferranti noted. And from Dutch researchers showed that starting a statin during childhood among FH patients slowed progression of carotid intima-media thickening. That study also showed that the incidence of cardiovascular events and death from cardiovascular causes by age 39 was lower among treated FH patients than among their affected parents.

Since FH is genetic, some may argue for targeted screening based on family history, but that may not be enough to pick up all cases, Peterson said. She pointed to an showing that using family history to determine screening would have missed many kids with moderate dyslipidemia and failed to detect a "substantial number" of those with genetic dyslipidemias that would benefit from medication therapy.

Peterson and de Ferranti both said that children tolerate statins well, and that they're generally safe and effective in this population. Also, levels don't need to be pushed down quite as low as adult patients because they haven't had cardiac events yet, de Ferranti said.

"We're trying to find the rare but not-rare-enough group of kids who could benefit from medication to treat a genetic condition that they can't do anything about," de Ferranti said. "All the healthy eating in the world is not going to be sufficient to lower their cholesterol."

Those Opposed

Sarah Nosal, MD, is a family physician in the South Bronx in New York, and a board member of AAFP, which supports the USPSTF's recommendations on lipid screening in kids.

For Nosal, it comes down to the fact that homozygous FH -- the type where kids can have cardiovascular events in their 20s -- is very rare, around 1 in 160,000 to 250,000, she said.

"That's incredibly rare and family history would indicate that kind of information," she said. "If I had a 7-year-old whose dad died at 25 because of a heart attack, that would be a huge concern for me to look for a cardiovascular problem of some type."

As a family physician, she said she's at an advantage because she often does have the benefit of getting a thorough family history: "I often know grandma, grandpa, the cousins. I'm often taking care of the entire extended family."

In situations of adoption, or not knowing the full family history, she would do a more thorough assessment, she said. But that's "not an appropriate reason to check every child in our office."

"We don't want to medicalize and do things to kids when we really need to be fighting and working for their wellness," she said.

As for heterozygous FH, Nosal says the literature suggests that overall life expectancy may be decreased by 15 to 30 years if there was never any intervention at all. But even in these cases, she's usually picking up some type of family history and is closely monitoring these kids, encouraging dietary and lifestyle interventions, and only initiating statin therapy sparingly. That's not population-based screening, though, she said.

"The vast majority of people are never going to be found to have a reason to screen for cholesterol, particularly children," she said. "It's unlikely we're going to treat 99.99% of the kids we screen."

Indeed, de Ferranti said her team is working on research projects assessing the impact of treatment at various time periods. For instance, what is the benefit of starting statin treatment at age 10 rather than age 20, especially for a child with heterozygous FH?

In Practice

It's not clear how often children ages 9 to 11 are being screened for high cholesterol in pediatric practices across America.

According to one survey of physicians in Wisconsin , 72% of pediatricians offered cholesterol screening in that age range, compared with 15% of family medicine physicians.

However, the majority of both groups of doctors felt it would be "reasonable" to add a test for inherited cholesterol disorders to newborn screening, the survey found.

More offices may offer the screening as finger-prick testing has become an acceptable alternative to a venous blood draw for lipid testing. Blood draws can be more anxiety-inducing for kids in this age group, the doctors said.

Peterson called finger-prick testing an "effective tool to remove barriers to cholesterol screening." De Ferranti said it's "convenient to do in the office, and if the results are abnormal, they can be followed up. It's a great strategy for making sure that kids are getting it done."

But Nosal isn't sold: "Why would we draw blood to a finger stick when the actual intervention is going to be exactly the same?" she asked, noting the answer would be diet and exercise. "That is critical to their comprehensive health and will impact the most likely reason that they would have issues with cholesterol."

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