Lipoprotein (a) levels in children with heterozygous familial hypercholesterolemia

BACKGROUND: Recent studies show that lipoprotein (a), or Lp(a), plays a specific role in the development of atherosclerosis. Lp(a) promotes atherogenesis by increasing production of pro-inflammatory cytokines and depositing on the arterial wall. There are limited studies of Lp(a) in children with familial hypercholesterolemia (FH), and the results are not specified by age. AIM: To determine serum Lp(a) in children with heterozygous FH for different age groups. MATERIALS AND METHODS: A comparative, prospective, longitudinal, cohort study was conducted in 2017–2022. The study group included 243 children aged 5 to 17 years (Ме 11 [7.0–15.0]), of which 122 children had heterozygous FH. The control group included 121 healthy children. The control and study groups were divided into 3 age subgroups (5–7, 8–12, 13–17 years). Total cholesterol, triglycerides, high density lipoprotein cholesterol, low density lipoprotein cholesterol, and Lp(a) were determined in all children. RESULTS: All first-degree relatives in the FH group had concomitant cardiovascular diseases (84.1% on the paternal side, 9.1% on the maternal side). Coronary artery disease was diagnosed in 84% (102) of parents, 89% (109) had atherosclerosis of brachiocephalic arteries, and 6.6% (8) had cerebrovascular accident (atherothrombotic stroke). The analysis revealed a significantly increased Lp(a) levels in FH patients (14.8 [6.3–24.3] mg/dL) compared to the control group (10.8 [5.5–14.8] mg/dL, p=0.0002). An individual serum Lp(a) analysis in the study and control groups showed that no healthy children had Lp(a) levels above 30 mg/dL. Among FH patients, 14.7% (18) had increased Lp(a) levels 30 mg/dL, and Lp(a) 50 mg/dL was noted in 4 of them. Children with FH and Lp(a) levels 30 mg/dL were found to be 3.5 times more likely (95% confidence interval: 1.14–10.33, p=0.0239) to have family members with the onset of acute coronary syndrome prior to 40 years of age. CONCLUSION: High heritability estimates for Lp(a) highlights the need to measure it in patients with FH and offers an opportunity for reverse cascade screening to identify adult family members with FH at even greater risk of early cardiovascular accidents.