Cholesterol in Children
- As has been repeatedly demonstrated in a variety of prospective epidemiologic studies over the past several decades, CAD (coronary heart disease) is a multi-factorial disease whose roots begin at an early age. Elevated blood lipids are a fundamental feature of CAD, especially in persons with early onset of the disease. The vast majority of prospective epidemiologic investigations over the past four to five decades have shown that increasing levels of various serum lipids, most notably total and LDL-cholesterol levels in children are associated with an increased risk for CAD in middle-aged and beyond.
- Familial hypercholesterolemia is a common inherited disorder causing markedly elevated LDL-C (low-density lipoprotein cholesterol) levels from birth and resulting in premature atherosclerosis and heart attack in the second and third decade of life.1
- Nonoptimal levels of LDL and HDL cholesterol during young adulthood (age 18-30 years) are independently associated with coronary atherosclerosis two decades later (average age 45) as evidenced by a high coronary artery calcium score in the carefully conducted CARDIA study (Figure 072).2 The findings are consistent with the results of earlier epidemiologic studies in pediatric populations.
- The prevalence rates of coronary calcium were strongly associated with serum lipids prior to age 35 years; approximately 44% of persons with elevated LDL cholesterol levels (greater than 160 mg/dl) during young adulthood had coronary calcium detected as compared with only 8% of those with more optimal levels (less than 70 mg/dl). Similar trends were observed with regards to HDL cholesterol levels (in an inverse manner) and with serum triglyceride levels. The risk of silent heart disease increased progressively with increasing LDL-C. The multivariable adjusted risks of having coronary calcium present were 3 and 6 respectively, for persons with LDL cholesterol between 130-159 mg/dl and greater than 160 mg/dl compared to those with a desirable LDL cholesterol level of 70 mg or lower.2
- Given the presence of coronary calcification in the middle-aged years may be related to the development of heart attack later in life, it remains prudent for individuals with less than optimal serum lipids to modify their subsequent risk of CAD.
- It is also well known that abnormal lipid levels in young adults are associated with other important coronary risk factors, including diabetes and obesity, and further emphasize the need for preventive measures against CAD at a young age. These tried and proven methods include attention to dietary fat and total caloric intake, maintenance of optimal weight and waist girth, and engagement in regular exercise throughout all stages of life.
- It is never too early to engage in heart healthy lifestyle and eating practices to both prevent, and/or delay to the latter years of life, the development of CAD.
- Several studies, including findings from the seminal Bogalusa Heart Study of children and adolescents, have shown that serum lipid levels “track” over time, though many individuals change their track, most typically downwards, with more prolonged observation. At a minimum, children should have multiple determinations of their serum lipids performed to more accurately characterize their actual lipid/lipoprotein profile.3
- In Bogalusa Heart Study children with low LDL-C levels (less than 70 mg/dl) showed an average increase of 13 mg/dl whereas there were average declines of 21 mg/dl and 34 mg/dl in persons with LDL-C levels of 160-189 mg/dl and greater than190 mg/dl, respectively when the measurement was repeated 20 years later, possibly due to more rigorous lifestyle changes in those with high LDL-C.3
When to Screen Children for Cholesterol?
- One in three children with dangerously high cholesterol is missed by current screening recommendations.4
- Children with high LDL or bad cholesterol levels are at risk of diabetes and heart attack in early adulthood and need medical attention. Children with a genetic tendency for very high cholesterol ─ about one in 500 ─ need treatment. To find them, it’s recommended that pediatricians offer cholesterol screening to kids whose parents or grandparents have very high cholesterol and/or heart disease. But not all of these kids actually get tested.4
- Besides, about 10% of children without such family history may have high cholesterol requiring dietary modification and 2% may have high enough LDL-C requiring medication (LDL-C >160 mg/dl) according to a study involving more than 20,000 fifth grade school children.4 These children may be identified by screening for abdominal obesity or high blood pressure. Cholesterol can be tested at age 2 years and those found to have high levels should be managed with aggressive modification of lifestyle with special focus on reduced intake of saturated fat and trans fat (until eight years of age when pharmacological therapy should be initiated if the LDL-C goals are not met).
- Tried and proven methods of primary prevention, namely maintenance of optimal body weight through physical activity and proper caloric balance, not smoking, and eating fresh fruits and vegetables, should be applied to all children, irrespective of their serum lipid levels, as part of an effective primary prevention approach.3
Statin use in Children
- Statins have been shown to be effective in reducing LDL-C, restoring endothelial dysfunction and flow-mediated dilation, as well as slowing carotid intima-media thickening (silent heart disease) in children. Several statins are approved for use in children.
- Compared with placebo, rosuvastatin 10mg and 20 mg/d reduced LDL-C by 45%, and 50% respectively. With a maximum allowed dose of 20 mg/d, 40% achieved the treatment goal of <110 mg/dl (baseline LDL-C was 232 mg/dl). Rosuvastatin was well tolerated, with no apparent adverse impact on growth or development.5(see Statins)
1. Goldberg AC, Hopkins PN, Toth PP, et al. Familial hypercholesterolemia: screening, diagnosis and management of pediatric and adult patients: clinical guidance from the National Lipid Association Expert Panel on Familial Hypercholesterolemia. J Clin Lipidol. Jun 2011;5(3 Suppl):S1-8.
2. Pletcher MJ, Bibbins-Domingo K, Liu K, et al. Nonoptimal lipids commonly present in young adults and coronary calcium later in life: the CARDIA (Coronary Artery Risk Development in Young Adults) study. Ann Intern Med. Aug 3 2010;153(3):137-146.
3. Freedman DS, Wang YC, Dietz WH, Xu JH, Srinivasan SR, Berenson GS. Changes and variability in high levels of low-density lipoprotein cholesterol among children. Pediatrics. Aug 2010;126(2):266-273.
4. RitchieSK, Murphy EC, Ice C, et al. Universal versus targeted blood cholesterol screening among youth: The CARDIAC project. Pediatrics. Aug 2010;126(2):260-265.
5. Avis HJ, Hutten BA, Gagne C, et al. Efficacy and safety of rosuvastatin therapy for children with familial hypercholesterolemia. J Am Coll Cardiol. Mar 16 2010;55(11):1121-1126.