From the time they exit the womb, American children are tested. It begins with the neonatal heel prick, which draws blood to test for phenylketonuria, cystic fibrosis, and an array of other conditions. The testing continues as the child grows: hearing tests, blood lead levels, scoliosis. Now the list will include yet another item: Last month, a panel convened by the National Heart, Lung, and Blood Institute recommended screening all children for high cholesterol before the age of 11. The American Academy of Pediatrics endorsed the recommendation, ensuring that doctors will take note.
The rationale for the panel’s new guidelines is that kids with high cholesterol generally go on to become adults with high cholesterol, and it’s better to detect and address the problem early rather than waiting several decades to do something about it. But are these tests really necessary? Will the screenings make kids healthier, or just burden them (and the health care system) with another routine procedure?
One thing's certain—the new guidelines mark a clear departure from what came before. Recommendations issued in 1992 advised screenings only for children with a family history of heart disease or high cholesterol. Kids who tested abnormally would be prescribed diet and exercise, or a drug if those didn't help. But cholesterol testing has never before been advised for all children, and the new guideline represents a staggering reduction—by nearly three decades—in the age at which the average person would receive his or her first cholesterol test. (The U.S. Preventative Services Task Force does not recommend routine cholesterol screening until age 35 for men and 45 for women.)
Since the 1992 guidelines came out, there haven’t been any new studies showing that screening children saves lives or prevents future heart disease. So why the change of direction? “The sense is that knowing is better than not knowing,” panel chair Stephen Daniels, a pediatrician at Children’s Hospital Colorado, told me. But knowing your cholesterol number only makes sense if it provokes you to do something you wouldn’t otherwise do. And that’s where the testing recommendation falls apart.
As under the old guidelines, if a 9-year-old tests high for cholesterol, the first line of treatment involves lifestyle changes like exercise and a healthy diet. But the new guidelines also advise children—all children, regardless of how they test—to exercise for 60 minutes per day and eat a diet low in added sugar and rich in whole grains, fruits, vegetables, fish, and lean meat. Kids with high cholesterol would presumably have extra incentive (and pressure from their doctors and parents) to follow this advice. "I tell these kids, do you want to be healthy or do you want to be having heart surgery when you're in the prime of your life?" says Daniels. In theory, these approaches might bring a child’s cholesterol into the normal range, but if they don’t, prescription drugs would be the next step. Daniels estimates that about 10 percent of kids would turn up with high cholesterol scores in the screening, and one percent would be put on statins or other cholesterol-lowering medications.
Programs across the country aim to improve eating and exercise habits on a community level but most adults find it very difficult to adjust their lifestyles individually. And while doctors like Daniels can warn individual children about the risks of heart disease, there’s no reason to expect that kids would have an easier time changing their habits than their parents do. Studies of adults show that fear-mongering doesn’t always work to foster healthy behavior; in fact, a few patients might even react in the opposite way, by deciding that it's not worth fighting their fate. Besides, how many 9-year-olds worry about what's going to happen to them at age 50? And what about the 90 percent of kids whose blood tests come out OK—will their parents be tempted to go ahead and let them eat french fries? There’s a fine line between encouraging good habits and ostracizing bad ones, and it’s not clear that singling out the “at-risk” kids would be of much help to anyone.
While studies have shown that most kids with elevated cholesterol continue to have it into adulthood, there’s scant evidence that treating high cholesterol at a young age will make a difference in the long run. To find out whether treating children with high cholesterol cuts their chances of developing heart disease, researchers would need a randomized, controlled trial lasting 40 years or more, and during that time it’s likely that the way we treat high cholesterol and heart disease will change. Add in the cost and the large numbers you’d need to enroll, and it’s virtually certain that such a trial will never take place.
The fact that we'll never prove the efficacy of early treatment doesn't mean it's a bad idea, of course. But absent a big trial, the question becomes, do the known benefits of cholesterol testing outweigh the costs and risks? Right now, the answer is no. Cholesterol screening for kids has some potential benefits—it can identify children who would benefit most from intervention, for instance—but it costs money and could lead to an unnecessary increase in prescription drug use among children. One can easily imagine a scenario in which statins become the standard treatment for kids with high cholesterol—not just because drugs are easier to prescribe (and stick to) than diet and exercise, but also because doctors are inherently biased toward doing something rather than nothing. A prescription for lifestyle changes puts the onus on the patient, but people usually go to their physician hoping that it’s the doctor who will take action.
That’s a real cause for concern. A 10-year-old who’s prescribed a statin could potentially continue taking the drug for another 60 years, with no hope of seeing any benefit for at least half that time. Side effects that might seem small over the course of a few months or a year could be unmasked and amplified over the decades, and we don’t have good data yet on the long-term safety and risk profile of statins for children.
So what convinced the panel that the testing was worthwhile? It's notable that among its 14 members, only five disclosed no conflicts of interest. Peter Kwiterovich, a physician and lipid researcher at Johns Hopkins University School of Medicine who chaired the cholesterol sub-panel, reported having received $150,629 from Pfizer (the maker of the statin Lipitor) last year. He has also reported having ties to nine different pharmaceutical companies, including the makers of the statins Zocor and Crestor, and a company that develops and licenses cholesterol tests.
Kwiterovich did not respond to my request for an interview, but when I asked Daniels if he was troubled by the fact that two-thirds of the panel members had declared conflicts of interest, he insisted that these relationships had not tainted their recommendations. “You will not find any group of people more committed to improving the health of kids,” he said. (Daniels himself has served as a consultant for two companies which make cholesterol-lowering drugs.)
Cholesterol drugs clearly help people with existing heart disease, but their benefits for those without heart trouble remain less clear. In the rush to prevent heart problems, we shouldn't lose sight of the actual finish line. High cholesterol is a risk factor, not a disease. Not everyone who has a heart attack has high cholesterol, and many people with high cholesterol do not go on to get heart disease. Right now, we don't have much evidence that tracking cholesterol earlier in life will change the end results we really care about—heart attacks, strokes and other life-threatening conditions.
Four years ago, the U.S. Preventative Services Task Force evaluated the existing studies and concluded that there was insufficient evidence to recommend for or against routine cholesterol screening for children. There haven't been any sweeping new studies since then, so why did the task force stop short of promoting cholesterol screening for children, while the NHLBI panel endorsed it? According to a pediatrician and dissenting panel member Dimitri Christakis, the divergence comes down to a difference in the way the two groups viewed the evidence.
Most of the NHLBI panelists are practicing physicians who work with individual patients. They’re doctors who are paid and trained to do things. The task force includes researchers with backgrounds in statistics, epidemiology and public health. They’ve crunched population data and seen the harms that can come from seemingly innocuous programs (such as prostate cancer screening). “They really take the approach that in the absence of evidence, it’s best not to do something,” Christakis says. Even in the age of high-tech medicine, the Hippocratic oath offers sage advice—first do no harm.