Elevated calcitonin gene-related peptide in polycythemic newborn infants

In this study, calcitonin gene-related peptide levels were measured in cord and at 16-36 h of extrauterine life in 43 polycythemic newborns; 20 healthy term infants were also studied as controls. Calcitonin gene-related peptide values were significantly higher in polycythemic neonates in comparison with controls both at delivery and at 16-36 h after birth. Five polycythemic (11.6%) infants who develop hypocalcemia had greater elevated calcitonin gene-related peptide concentrations. Our data suggest that calcitonin gene-related peptide may be implicated in the circulatory adaptation to extrauterine life. In polycythemic neonates, calcitonin gene-related peptide is probably increased to compensate for blood hyperviscosity; in some cases, high calcitonin gene-related peptide concentrations may induce hypocalcemia.