Introduction:
The American Academy of Pediatrics (AAP) recommends universal lipid screening in all children beginning at nine years of age. Although not a component of the lipid profile, an elevated lipoprotein (a) (Lp(a)) (≥30 mg/dL) is an independent risk factor for atherosclerotic cardiovascular disease (ASCVD) in adults. Plasma Lp(a) levels are a product of the Lp (a) gene, which is fully expressed by 5 years of age, and remains relatively unchanged into adulthood. Limited number of studies have examined Lp(a) levels in children diagnosed with a primary hypercholesterolemia.
Hypothesis:
To determine the frequency of Lp(a) excess, defined as ≥30 mg/dL, among children diagnosed with a primary hypercholesterolemia (i.e., Familial Hypercholesterolemia (FH), Familial Combined Hyperlipidemia (FCH), Polygenic Hypercholesterolemia (PH).
Methods:
We reviewed the Ascension St. John Children’s Center Lipid Clinic database between 8/1/2012 and 12/31/2019. Only children diagnosed with a primary hypercholesterolemia and having a baseline Lp(a) assessment were included. FH was diagnosed using the Dutch Lipid Score. PH was diagnosed as an elevated LDL-C level not associated with a monogenic mutation or a secondary cause. FCH was diagnosed as an elevated LDL-C in combination with any triglyceride elevation in the absence of secondary causes.
Results:
One-hundred and twenty patients were evaluated (mean age: 12.1 ± 2.0 years). Seventy-eight percent (93) of the children were white and 52% (62) were male. The frequency of an Lp(a) excess was 44% (53) in this group. The frequencies of Lp(a) excess by diagnosis, and the median Lp(a) and mean LDL-C levels are displayed in Table 1.
Conclusions:
Lp(a) excess is relatively frequent among children diagnosed with a primary hypercholesterolemia. Since an Lp(a) excess is an ASCVD risk factor, it should be considered clinically relevant when determining the baseline LDL-C level at which a lipid-lowering agent is initiated in children.
