The American Academy of Pediatrics (AAP) released a clinical report in July 2008 that replaces the 1998 AAP policy statement on cholesterol in childhood. The report recommends screening children and adolescents with a fasting lipid profile, and focuses on improving childhood and adolescent lipid and lipoprotein concentrations to lower the lifetime risk of cardiovascular disease. For prevention of cardiovascular disease, the report recommends following heart-healthy dietary guidelines and increasing physical activity.

Clinical Evaluation

The concentration of serum lipids and lipoproteins has been shown to increase during early childhood. By approximately two years of age, these concentrations reach levels similar to those seen in young adults. Therefore, concentrations for patients younger than two years may not accurately predict values for subsequent years of childhood and adulthood. Differences in cholesterol concentrations are also related to sex and ethnicity.

Children with progressive atherosclerosis are most at risk of cardiovascular disease in adulthood, and should be screened accordingly. However, there are no adequate, non-invasive, clinically applicable tools available for assessing the progression of atherosclerosis in children without a family history of high cholesterol. Instead, physicians have often used cholesterol concentrations as a surrogate marker for this risk. This is an accepted approach for adults and includes the use of the Framingham risk score. However, there is no similar risk score to determine which children are at the highest risk of cardiovascular disease. For children, there are currently no data that support a certain level of cholesterol that predicts risk of adult cardiovascular disease.

One drawback of the targeted approach to screening based on family history of cardiovascular disease or high cholesterol is that, although it will provide additional information about the genetic predisposition and shared environmental factors that may increase risk, the family history may not be known, or, if it is known, may be partial or misleading. Increases in the prevalence of obesity and high blood pressure may lead to an increased percentage of children who qualify for measurement of cholesterol concentration.

The cut points in Table 1 can be used to identify patients 18 years and younger with abnormal lipid and lipoprotein concentrations. Cholesterol concentrations are particularly variable during puberty. The lowest sensitivity of these cut-point concentrations for predicting adult lipid status occurs between 14 and 16 years of age, when cholesterol values are generally lower. Table 2 shows percentile values by patient age and sex for concentrations of total cholesterol, triglycerides, low-density lipoprotein (LDL), and high-density lipoprotein (HDL).

Treatment

Two main approaches are recommended for lowering or minimizing cholesterol levels in children: a population-based approach that focuses on lifestyle changes for all children, regardless of risk category, and an individual approach that focuses on those at high risk of cardiovascular disease.

The population approach provides recommendations on diet and levels of physical activity, with an emphasis on preventing the development of abnormal lipid and lipoprotein concentrations. Although individual changes are modest, this approach can reduce the number of persons who become high risk for developing cardiovascular disease. Dietary guidelines recommend that children older than two years achieve a healthy weight through a balanced caloric intake. They are encouraged to consume more fruits, vegetables, fish, whole grains, and low-fat dairy products, and less fruit juice, sugary drinks and foods, and salt. The new guidelines also recommend that trans fatty acids make up less than 1 percent of total calories. Parts of the dietary guidelines are not recommended for children younger than two years, who require a higher intake of dietary fat to support rapid growth and development. However, no harm has been associated with minor dietary changes, even soon after weaning; this can include switching to reduced-fat milk after 12 months of age.

The individual approach focuses on children at high risk of cardiovascular disease (e.g., those who have high total cholesterol and LDL concentrations, those with a family history of cardiovascular disease or high cholesterol). These children require a higher level of intervention than the population approach alone. This intervention is initially geared toward dietary modifications, but these children may need pharmacologic intervention if diet alone does not adequately lower their LDL concentrations (Table 3). Medications available for treatment in children older than eight years include bile acid-binding resins, statins, cholesterol-absorption inhibitors, and fibrates. The U.S. Food and Drug Administration approved the use of pravastatin (Pravachol) in children eight years and older who have familial hypercholesterolemia. Pharmacologic intervention in children younger than eight years is not recommended unless they have an elevation of LDL concentration greater than 500 mg per dL (12.95 mmol per L), which typically occurs with the homozygous form of familial high cholesterol. More aggressive treatment of high levels of LDL is indicated in children who are cancer survivors or who have diabetes, renal disease, congenital heart disease, or collagen vascular diseases.

The recommended diet for this group is similar to the dietary recommendations for the population approach, but the individual approach also recommends that saturated fat be no more than 7 percent of total calories and dietary cholesterol be no more than 200 mg per day. Consultation with a dietitian may be necessary at the start of this approach to guide families in making the appropriate dietary changes. Some children in the high-risk category will already be on a diet relatively low in saturated fat and may have a genetic cause of dyslipidemia. In this case, it is unlikely that dietary modifications alone will result in appropriate LDL concentrations, but the dietary changes may allow for the use of lower dosages of pharmacologic agents when they are started.

Additional changes may include increasing soluble fiber intake (this often requires fiber supplements), which can be helpful in reducing LDL concentrations. To determine an appropriate dosage of supplemental fiber, calculate the child's age plus 5 g per day, up to a dosage of 20 g per day for a patient 15 years of age. Adding plant stanols and sterols to the diet may also be beneficial, and has been shown to safely reduce cholesterol concentration in adults. Along with dietary changes, increasing physical activity levels may also help improve LDL, HDL, and triglyceride concentrations.

editor's note: In 2007, the U.S. Preventive Services Task Force (USPSTF) concluded that the evidence was insufficient to recommend for or against screening for lipid disorders in children or young adults up to 20 years of age. The USPSTF noted that although 50 percent of children and adolescents with dyslipidemia will also have it as adults, no studies have shown that diet or exercise interventions in this group improve lipid profiles or cardiovascular health in adulthood. The USPSTF also found no studies reporting the adverse effects of long-term use of lipid-lowering medications beginning in childhood. Therefore, the USPSTF was unable to assess the balance of benefits and harms of screening and treating children and adolescents for lipid disorders.—kenneth lin, md

U. S. Preventive Services Task ForceScreening for lipid disorders in children: U.S. Preventive Services Task Force recommendation statement.Pediatrics2007;120(1):e215–e219.