Monday, November 14, 2011
Panel Recommends Universal Cholesterol Screening for Kids
Medscape Medical News from American Heart Association (AHA) 2011 Scientific Sessions From Heartwire Michael O'Riordan November 13, 2011 (Orlando, Florida) — An expert panel is recommending that all children, regardless of family history, undergo universal screening for elevated cholesterol levels. The panel recommends that children undergo lipid screening for non fasting non–HDL-cholesterol levels or a fasting lipid panel between the ages of 9 and 11 years followed by another full lipid screening test between 18 and 21 years of age. The guidelines, from the Expert Panel on Integrated Guidelines for Cardiovascular Health and Risk Reduction in Children and Adolescents, appointed by the National Health, Lung, and Blood Institute (NHLBI) and endorsed by the American Academy of Pediatrics (AAP), also recommend measuring fasting glucose levels to test for diabetes in children 10 years of age (or at the onset of puberty) who are overweight with other risk factors, including a family history, for type 2 diabetes mellitus. "The goal of the expert panel was to develop comprehensive evidence-based guidelines that address the known risk factors for cardiovascular disease to assist all primary pediatric care providers in both the promotion of cardiovascular health and the identification and management of specific risk factors from infancy into young adult life," write panel chair Dr Stephen Daniels (University of Colorado School of Medicine, Denver) and colleagues in Pediatrics. The level of evidence supporting the "strongly recommended" cholesterol screening recommendation is graded B, meaning that it is based on consistent evidence from observational studies, genetic natural history studies, or diagnostic studies with minor limitations. However, as some critics have pointed out, there are no randomized, controlled, clinical trials showing that the treatment of elevated cholesterol levels in children has a long-term clinical impact on cardiovascular outcomes, as well as no data showing that the use of lipid-lowering drugs is safe in children this young or when used for decades. In addition to the publication, Daniels and members of the writing committee plan to present their report at the American Heart Association 2011 Scientific Sessions this week. Not Going to Have a Heart Attack Tomorrow Dr Steven Nissen (Cleveland Clinic, OH), who was not part of the writing committee, called the guidelines "irrational," saying pediatricians have pushed widespread cholesterol screening forward in the absence of evidence supporting pharmacologic interventions if children are found to have elevated LDL-cholesterol levels. Nissen told heartwire that while the guidelines stress dietary and lifestyle intervention in kids with elevated cholesterol levels, the temptation to use the drugs in this population will be too high. "Plus, what is the 20-year risk of cardiovascular disease in a patient who is 11 years old?" asked Nissen. "It's zero." What is the 20-year risk of cardiovascular disease in a patient who is 11 years old? It's zero. In their recommendations, the expert panel acknowledged that a focus on cardiovascular risk reduction in children and adolescents is tough, because the likelihood of a clinical end point of manifest cardiovascular disease is remote. Speaking with heartwire , Dr Daphne Hsu (The Children's Hospital at Montefiore, NY) took a different interpretation of the guidelines but acknowledged that pediatricians are forced to infer how risk factors might translate into clinical outcomes 30 to 40 years down the road. Still, she said there are data showing a risk of subclinical atherosclerosis in young patients with elevated cholesterol levels. Moreover, the new recommendations cull together the best data currently available, and based on her assessment of the risks of screening and the potential benefits, the new AAP/NHLBI guidelines make sense. As for the risks, Hsu does not believe that universal screening will lead to an increased use of cholesterol-lowering medications, such as statins. "If we find a patient has elevated cholesterol levels, we know their risk is not very high, and it is not going to be high enough to warrant treatment, but the screening could be enough to spur changes in behavior," said Hsu. "If they have elevated levels, we can then begin to look for why this is the case, and we can look for ways to change their eating habits, change what they eat, and change how often they exercise." Hsu said that it was "highly unlikely" that screening would lead to more children being treated with cholesterol-lowering medications, probably less than 1%. She said the greatest benefit would be to children with major lipid disorders who might have been missed with other screening tools. She said the 2008 AAP document on lipid screening and cardiovascular health provides guidance on treatment with pharmacologic agents. Written also by Daniels and Dr Frank Greer (University of Wisconsin Medical School, Madison), along with the Committee on Nutrition, the document says that treatment should be started if LDL-cholesterol levels are higher than 190 mg/dL . The cutoff point for therapy is 160 mg/dL for children with other risk factors, with targets as low as 130 mg/dL or even 110 mg/dL when there is a strong family history of cardiovascular disease, especially with other risk factors, such as obesity, diabetes, metabolic syndrome, and other higher-risk situations. An Age When They'll Listen to You In her practice, Hsu said she sees firsthand the epidemic of childhood obesity, with many young children having pre-metabolic syndrome. With screening of children aged 9 to 11 years old, she believes they are at a vulnerable age that might be more responsive to recommendations from their family doctor, whereas older children, particularly teenagers, don't like being told what to eat or how much to exercise. She said cholesterol screening can signal potential long-term complications and can serve as an increased wake-up call for families. "We're not telling the kids or families that they're going to have a heart or stroke tomorrow but instead saying that we want them to live until they're 85 years old," said Hsu. "We want to see them live longer than their grandmother or grandfather." Nissen, on the other hand, isn't buying the argument, stating there is no evidence-based data showing that young patients or their families change their behavior when presented with evidence of a bad test result, such as increased cholesterol levels. Proponents of other screening modalities have made similar arguments in the past, suggesting that evidence of calcification or stenosis is a motivating factor to move toward heart-healthy behaviors, but the data do not bear this out. Earlier this year in the Journal of the American Society of Echocardiography, researchers reported that abnormal findings on an office-based carotid ultrasound test changed physician behavior, with doctors changing their use of aspirin and cholesterol-lowering medications, including setting more aggressive lipid and blood-pressure targets. Patients, on the other hand, failed to make changes to their diet or increase physical activity levels and, in some instances, even failed to quit smoking, despite an increased awareness of their cardiovascular-disease risk. "Shouldn't we be counseling children on the benefits of healthy eating and lots of physical exercise even without knowing their LDL-cholesterol levels?" said Nissen. "I don't see how screening changes this at all. We simply have no evidence that patients will change their behavior based on more screening." The expert panel also provides guidance on the assessment of family history of cardiovascular disease, tobacco exposure, nutrition and diet, growth and overweight/obesity assessments, blood pressure, and physical activity.
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