Lipoprotein(a) in Children and Adolescents with Genetically Confirmed Familial Hypercholesterolemia Followed Up at a Specialized Lipid Clinic

Background and aim: Many children with an FH mutation also exhibit elevated lipoprotein(a) levels, which is an independent risk factor for atherosclerotic cardiovascular disease. Studies have reported higher levels of lipoprotein(a) in adult and middle-aged women than men. There is limited knowledge on the concentration and change of lipoprotein(a) levels in children with genetic FH, and therefore we investigated sex-differences in lipoprotein(a) level and change in lipoprotein(a) in girls and boys with genetically confirmed FH. Methods: Medical records were reviewed retrospectively in 438 subjects with heterozygous FH that started follow-up below the age of 19 years at the Lipid Clinic, Oslo University Hospital in Norway, and of these we included 386 subjects with at least one Lp(a) measurement. Results: Mean (SD) age at baseline was 13.8 (7.3) years and the age was similar between sexes. Girls had a higher lipoprotein(a) level than boys at baseline: median (25–75 percentile) 223 (108–487) vs. 154 (78–360) mg/L, respectively (p < 0.01). From baseline to follow-up measurement (mean [SD] 8.9 [6.1] years apart), the mean (95 % CI) absolute and percentage change in Lp(a) level in girls was 151.4 (54.9–247.8) mg/L and 44.8 (16.4–73.1) %, respectively, and in boys it was 66.8 (22.9–110.8) mg/L and 50.5 (8.8–92.3) %, respectively (both p > 0.05). Conclusions: We found an increase in Lp(a) levels in children with genetic FH with age, and higher levels in girls than boys, which could impact risk assessment and future ASCVD. Further research is needed to elucidate whether subjects with FH could benefit from lipoprotein(a)-lowering therapies that are under current investigations.