The relationship between biochemical adrenarche and decreasing alpha-2-macroglobulin levels in children

Alpha-2-macroglobulin (alpha 2-MG) is one of the major serum protease inhibitors in adults and appears to be even more important in children. Previous studies have suggested that alpha 2-MG levels are dependent upon age and sex. In order to evaluate the influence of biochemical adrenarche on alpha 2-MG, we compared alpha 2-MG concentrations in normal children and children with premature adrenarche (PA) with levels of dehydroepiandrosterone sulfate (D-S), the marker for biochemical adrenarche. We found that alpha 2-MG was inversely correlated with age and with log10 [D-S] in the normal children. In the children with PA, the alpha 2-MG levels were significantly lower than predicted based on age alone and were similar to the predicted values based on log10 [D-S] levels. We suggest that adrenarche is the process that causes the age-related changes in alpha 2-MG.