From chronic kidney disease to transplantation: The roles of obestatin

Background: Kidney transplantation is the therapy of choice in most cases of end stage renal disease. The purpose of the present study was to evaluate serum obestatin levels in kidney transplant recipients (Tx), compare levels in patients with renal failure (CKD) with those in healthy subjects (HS), and to assess the role of this hormone in energetic metabolism. Patients and methods: A total of 95 subjects were studied: 40 were Tx; 35 had CKD and 20 were HS. Inclusion criteria were age>18 years and good allograft function. Patients with an inflammatory disease or a diagnosis of cancer were excluded from the study. Results: Obestatin levels in Tx patients were significantly lower than in HS (3.5 [3-4.8] versus 11 [8.56-28.60] ng/mL; p<0.0001) and patients with CKD (3.5 [3-4.8] versus 4.7 [3, 5-6, 1] ng/mL; p = 0.008). At univariate analysis, a direct correlation was found between obestatin and calcemia (p: 0.0001; r: 0.51), phosphoremia (p: 0.0005; r: 0,46), calcium-phosphate product (p<0.0001; r: 0.53), and parathormone (p: 0.01; r: 0.32), whereas significant inverse correlations were evidenced for BMI (p<0.0001; r: -0.52). At multivariate analysis, significance was maintained for the correlation between obestatin and phosphoremia (beta=0.47; p = 0.008), for the calcium-phosphate product (beta=0.55; p = 0.0005) and for BMI (beta=-0.53; p = 0.01). Conclusion: Obestatin, present in lower levels in Tx patients than in CKD patients and HS, plays a role in energy metabolism, affecting BMI and the metabolism of calcium-phosphorus. (C) 2011 Elsevier B.V. All rights reserved.