Relationship between neonatal adrenomedullin and bilirubin levels

Introduction: Oxidative stress and inflammation are the basic molecular mechanisms in bilirubin neurotoxicity. We aimed to investigate the relationship between serum bilirubin and an antioxidant, anti-inflammatory and neuroprotective peptid, adrenomedullin (AM) levels. Methods: The correlation between serum bilirubin and AM levels was investigated in a total of 87 newborns. Newborns were further divided into two groups according to the serum bilirubin levels. Group I (with significant hyperbilirubinemia) and Group II (without significant hyperbilirubinemia) were compared with respect to demographic, anthropometric and biochemical parameters including serum AM levels. Results: In the correlation analysis, a significant positive correlation was detected between serum indirect bilirubin and AM levels in 87 newborns (p < 0.001, r = 0.945). In demographic, anthropometric and biochemical comparison of the two study groups, serum indirect bilirubin levels were 21.53 +/- 3.59 and 9.37 +/- 4.87 mg/dl in Groups I and II, respectively (p < 0.001), and serum AM levels were 1.45 +/- 0.06 and 1.28 +/- 0.07 ng/ml in Groups I and II, respectively (p < 0.001) Conclusion: AM probably plays a significant role in adverse effects and neuronal injury steps of significant hyperbilirubinemia. In parallel with the results of this study the role, effects and physiopathological basis of AM in neonatal hyperbilirubinemia should be established especially with further animal studies. Results of this study may be used in establishing reference values for AM as there are very limited number of studies in newborns.