Lowering CVD risk among pediatric patients
Arterial plaque (yellow and blue) may cause clot formation.
At a glance
- Candidates for screening include young patients with CVD risk factors and those with a family history of dyslipidemia or premature CVD.
- Dietary intervention is recommended as the primary means of cardiovascular risk reduction in children and
adolescents—whether or not they have dyslipidemia.
- Increased physical activity may improve dyslipedemia.
- Guidelines for medication are stringent. Statins are by and large the drugs of choice.
Although cardiovascular disease (CVD) is pre-eminently an adult disorder, the atherosclerotic process begins in childhood. To integrate new data on risk reduction, especially those relating to the use of pharmacotherapy, the American Academy of Pediatrics has issued a clinical report, Lipid Screening and Cardiovascular Health in Childhood, its first update on the subject since 1998.
“The current epidemic of childhood obesity” and its cardiovascular consequences later in life lend urgency to the report, the authors say.
Cholesterol in childhood (defined as up to age 19 years) is increasingly a primary-care problem, according to Stephen R. Daniels, MD, PhD, chairman of the department of pediatrics at The Children's Hospital in Denver and first author of the report. “Traditionally, young patients identified [as having] lipid abnormalities were transferred to a subspecialist for care. In the future, [primary-care providers], as well as pediatricians, will take care of more and more of [these patients].”
Whom to screen
Like its 1998 predecessor the new document advocates a targeted approach to childhood screening. (The authors note that controversy surrounds the issue: Some experts conclude a lack of evidence for or against any screening, and others advocate universal screening.)
Candidates for screening include young patients with CVD risk factors, such as obesity, hypertension, or diabetes mellitus, and those with a family history of dyslipidemia or premature CVD (at age 55 years or younger for men and age 65 years or younger for women).
Screening is also recommended when family history is not known, which in practice demands clinical judgment, Dr. Daniels says. Parents' ignorance of their own cholesterol status and the prevalence of “fragmented families” frequently make a full family history impossible to obtain, he notes. “When you know the history on one side but not the other, is that insufficient?”
If the guidelines are applied liberally, as many as 75% of children would be screened, Dr. Daniels estimates.
Children who are deemed at risk should be screened via fasting lipid profile for the first time between the ages of 2 and 10 years and retested three to five years later.
Diet—a two-pronged approach
The report recommends dietary intervention as the primary means of cardiovascular risk reduction in children and adolescents—whether or not they have dyslipidemia.
The population approach, which is applicable to all children older than 2 years, implements dietary guidelines proposed by the U.S. Department of Agriculture (USDA) and endorsed by the American Heart Association. In broad terms, these call for “a balanced caloric intake [ranging from 1,000 to 2,200 per day, depending on age and sex] with sufficient physical activity to achieve an appropriate weight.” Fats should make up between 25% and 35% of calories.
The report further recommends that children and adolescents consume more fruits, vegetables, low-fat dairy products, and whole grains and limit their intake of fruit juices, beverages sweetened with sugar, and salt.
Following the lead of the USDA guidelines, the report suggests fat-free milk for children 2 years of age and older.
The individual approach should be adopted for children and adolescents who have dyslipidemia (total cholesterol and LDL are “elevated” when >200 mg/dL and >130mg/dL, respectively) or other CVD risk factors.
This is a more aggressive intervention, with goals that include reducing saturated-fat intake to <7% of total calories and dietary cholesterol to <200 mg/day.
Nutritional counseling, possibly including the services of a dietitian, is advisable to help families make necessary dietary adjustments safely. “There have been anecdotal reports of parents implementing a very-low-fat diet without supervision, leading to nutritional insufficiency and failure to thrive,” the authors say.
A dietitian may be helpful in counseling children and parents about following the diet outside the home, including at school, friends' homes, and fast-food restaurants.
The authors note that increasing soluble fiber intake may augment the effectiveness of the low-fat diet. If supplemental fiber is used, the dosage should equal the child's age plus 5 g/day, to a maximum of 20 g/day.
Plant sterols and stanols, used as additives to spreads, orange juice, cereal bars, and other foods, may be helpful as well. Research with children is sparse, but one randomized controlled trial found LDL reduced by 8% when 20 g of plant sterol was added to the daily diet via a margarine product.
Although dietary modification is the primary focus of the guidelines, the authors also recommend increased physical activity to improve dyslipidemia. Exercise has its greatest impact on HDL and triglycerides but appears to lower LDL as well.
Overweight and metabolic syndrome
Obesity is (as previously noted) increasingly common, and although definitions for children have not been established, metabolic syndrome appears to have become more prevalent as well. Weight loss and lifestyle modification seem the most effective approach to characteristic HDL and triglyceride abnormalities in this group, Dr. Daniels says.
Guidelines for medication are stringent. Pharmacotherapy should be reserved for children older than 8 years whose LDL remains markedly elevated despite dietary modification. There are exceptional circumstances, including the dramatic LDL elevations (>500 mg/dL) seen in familial hypercholesterolemia or the presence of renal disease, congenital heart disease, or collagen vascular disease.
The recommended thresholds for medication are higher than the values that define elevated LDL: >190 mg/dL with no other risk factors; >160 mg/dL in the context of obesity, hypertension, smoking, or a family history of premature CVD; ≥130 mg/dL for children with diabetes mellitus.
(By these criteria, very few young patients would require medication—0.8% of adolescents aged 12-17, according to analysis of data from the National Health and Nutrition Examination Survey [Circulation. 2009;119:1108-1115].)
Questions remain about appropriate target values, Dr. Daniels says. “Should we try to get LDL below 190, or push to below 130? We don't have the evidence base to show whether being more aggressive is more effective.”
Statins are by and large the drugs of choice. Among these, pravastatin has been approved for children age 8 years and older; atorvastatin, fluvastatin, and simvastatin are approved for those older than 10 years (although younger age, “should not preclude their use,” according to Dr. Daniels).
When prescribing statins, monitor liver aminotransferase and creatine kinase levels regularly, and counsel children to report muscle aches or cramping, the authors advise.
The use of other agents is limited by tolerability. Bile acid-binding resins are effective but associated with GI distress and poor compliance. And because of its adverse effects, niacin “should not be recommended for routine use in the treatment of pediatric dyslipidemia,” the authors say.
Fibrate use in children has limited data but may be indicated when triglycerides are very high, says Dr. Daniels.
Ezetimibe, a cholesterol-absorption inhibitor, has few adverse effects and comes in small tablets. But it has been little studied in children, and more data are needed to evaluate this medication's long-term effectiveness.
Lipid Screening and Cardiovascular Health in Childhood was published in Pediatrics (2008;122:198-208).