Primary and secondary disorders of lipid metabolism in pediatrics.

In the circulation, cholesterol and triglycerides are enveloped in apolipoproteins and phospholipids, and transported as complex particles called lipoproteins. Abnormal levels of lipoproteins occur in children either because of a genetic defect in lipid metabolism pathways (primary lipid disorders, e.g. familial hypercholesterolemia [FH]) or secondary to other diseases or conditions (e.g. insulin resistance) and can be clinically significant; for example, elevated low-density lipoprotein cholesterol levels are a major risk factor for future cardiovascular disease. Patients with primary lipid disorders in childhood such as FH can exhibit early atherosclerotic lesions in childhood. Other risk factors for cardiovascular disease, such as obesity and type 2 diabetes mellitus, are increasingly common in the pediatric population, and are often associated with dyslipidemia. Thus, pediatricians should be aware of how to screen, diagnose and treat dyslipidemia. The majority of lipid disorders in children can be managed with diet and lifestyle modification. Pharmacologic therapy (e.g. statins) may be added if target lipoprotein levels are not achieved. Clinicians may be guided in patient management by recent scientific statements from the American Heart Association; however, existing National Cholesterol Education Program treatment guidelines should be urgently updated to incorporate new evidence regarding atherosclerosis pathophysiology, obesity and the metabolic syndrome, emerging cardiovascular risk factors, and pharmacologic therapy in pediatric patients.