Cardiovascular disease affects an estimated one in three adults, more than half of which are due to coronary artery disease. A heart attack results from blockage in one of the coronary arteries, the vessels which supply oxygenated blood to the heart muscle. The chief component of this obstruction is cholesterol. A similar process of blockage in blood vessels supplying the brain can lead to a stroke.
The National Institute of Health issued guidelines, endorsed by the American Academy of Pediatrics (AAP), for all children to undergo routine screening of cholesterol between ages 9-11 and again between ages 17-21. This represents a significant departure from the prior recommendation, which called for targeted screening of children based upon a family history of heart attacks at a young age (under the age of 55 for men, under the age of 65 for women) or other risk factors (e.g. diabetes, kidney disease).
The new guidelines for universal cholesterol screening have been met with some skepticism in the pediatrics community. Although an elevated cholesterol level increases the risk for later heart attacks, in most cases the high levels are largely a function of lifestyle. Consequently, counseling emphasizes the usual principles with which we’re all familiar - regular exercise (the AAP advises 60 minutes of activity daily), eating a favorable diet (low in saturated fats, high in fruits and vegetables) and tobacco avoidance.
If the therapy (e.g. adhering to a healthy lifestyle) is the same for children with an elevated cholesterol and those who are normal, why the recommendation for universal screening? It is primarily to identify a relatively uncommon genetic disorder, heterozygous familial hypercholesterolemia, which has an incidence of approximately 1 in 500 in the general population.
As a group, subjects with this disorder have an extremely high level of LDL cholesterol that is unresponsive to lifestyle changes. Without drug intervention, the long-term prognosis for these patients is extremely poor. Untreated, affected individuals are at risk for heart attacks in their 30s, and 50 percent of males will have a heart attack by age 50.
Numerous studies over the last 40 years have demonstrated a causal role of high LDL cholesterol in heart attacks among adults. The use of statin drugs for decreasing cholesterol is largely credited for the declining incidence of fatal heart attacks during that time. Consequently, for those with the genetic form of hypercholesterolemia, statin therapy initiated after the onset of puberty appears to be the best option for reducing the risk for a heart attack at a young age.
However, statin drugs may also have significant side effects, which on rare occasions may be fatal. So for the vast majority of children and young adults with elevated cholesterol, preventive strategies should focus on regular exercise, a diet low in saturated fat and smoking avoidance.
Dr. Burt Bromberg is a Mercy Kids cardiologist with Mercy Children's Hospital St. Louis.