Lipoprotein(a) and family history of cardiovascular disease in children with familial dyslipidemias.

OBJECTIVE: To investigate in children and adolescents with familial dyslipidemias the association between lipoprotein(a) [Lp(a)] level and family history of cardiovascular disease (CVD), and whether this association is independent of the disturbed lipid profile. STUDY DESIGN: Lp(a) level, lipid profile, and a 2-generation genealogic tree to detect cardiovascular events were evaluated in 231 patients with familial dyslipidemias. Lp(a) levels were stratified according to presence, age of occurrence, and number and type of cardiovascular events in the patient's kindreds. RESULTS: Lp(a) and other plasma lipid fractions did not differ between patients with and those without a family history of cardiovascular events. However, the percentage of patients with elevated Lp(a) level (≥85th percentile) was higher in those with a positive family history for early cardiovascular events (P = .01). Lp(a) level was a significant independent predictor of the number of premature cardiovascular events (β = 0.17; P = .01) and of cerebrovascular events in kindreds (OR, 2.5; 95% CI, 1.05-6.03; P = .039), independent of plasma lipid fractions and other cardiovascular risk factors. CONCLUSIONS: In children and adolescents with familial dyslipidemias, the overall association between Lp(a) level and family history of early CVD may be due to a threshold effect in those with the highest Lp(a) levels. However, multiple cardiovascular events and cerebrovascular events are predicted by any increase in plasma Lp(a) level, independent of other cardiovascular risk factors.