Direct LDL-C estimation in preschoolers: Practicable first step for FH screening.

Background: Individuals with FH develop cardiovascular disease due to lifelong cumulative exposure to elevated LDL-C. Effective screening for FH is not yet established.

Objective: To evaluate the practicability of a FH screening by measuring directly the LDL-C in preschoolers.

Methods: LDL-C measurement through capillary blood sampling during the compulsory routine check-ups by the pediatrician in children aged 2 to 6 years including information on family history as dyslipidemia and/or premature cardiovascular disease in first and second grade of pedigrees.

Results: 15,009 children (52.2% males, median age 3.9 years [IQR 3.0-5.1]) participated in the study. Positive family history for hyperlipidemia was stated in 40.9% cases, in 12.0% also in at least one 1st degree relative. In the total cohort, median LDL-C was 93 mg/dL [IQR 79-109 mg/dL]. Boys had significantly higher LDL-C levels than girls (p < 0.0001), whereas there was no difference regarding their age (p = 0.757). Children from families with a positive history for hypercholesterolemia/dyslipidemia had significantly higher LDL-C levels (p < 0.001) and were more frequently among those with LDL-C values above 135 mg/dL (3.5 mmol/L, 96 percentile; 53.2% vs. 40.3%, p < 0.001) and those with LDL-C levels above 160 mg/dL (4.1 mmol/L, 99 percentile; 45.3% vs. 40.7%, p < 0.001) than children without positive family history.

Conclusions: Direct measurement of LDL-C levels in children at ages 2-6 years during the compulsory routine check-ups as well as at any voluntary visits to the pediatrician's office is practicable and delivers reliable information, which can be used for a FH screening strategy in the general population.