[Lipoprotein(a) concentrations and apolipoprotein(a) phenotype frequencies in cord blood of newborn infants and sera of children in Japan].

Lipoprotein(a) [Lp(a)] is considered to be an additional, independent, and largely genetically risk factor for the development of premature coronary heart disease. We measured Lp(a) levels and apo(a) phenotype in cord blood samples from 140(72 males, 68 females) Japanese newborn infants, and those in serum samples from seventy-nine normolipidemic out-patient children from the pediatrics. In the present study, we determined the relations between cord blood Lp(a) levels and apo(a) phenotypes. Maternal age, gestational age, weight and height were analyzed as covariates. The distribution of Lp(a) levels in cord blood was highly skewed towards the lower levels, as previously described. The mean Lp(a) concentration was 4.6 mg/dl(SD of 2.22 mg/dl) and median of 4.0 mg/dl, approximately three-fold lower than that observed in Japanese adult subjects. We did not find differences in the mean and median cord blood Lp(a) levels between male and female. Phenotyping of apo(a) was performed for 140 sera. The mean Lp(a) level in the B type was almost three times higher than that for the S4 type. A strong inverse relationship was found between the apparent molecular weight of apo(a) isoforms and serum Lp(a) concentration. The concentrations of Lp(a) reached to adult levels within first five years of life.