Obestatin and ghrelin interplay in hemodialysis patients

Objective: Compounds involved in the regulation of appetite and body composition appear to be of interest in chronic kidney disease. The purpose of this study was to analyze plasma obestatin and acyl and des-acyl ghrelin in patients on hemodialysis (HD). Methods: Fifty patients on HD (56.0% women, mean age 62.2 +/- 15.2 y) were studied. Blood samples were collected during fasting, before a regular HD session. Serum acyl and des-acyl ghrelin levels, leptin, and obestatin were measured using enzyme immunometric assay methods. Anthropometric parameters, appetite score, and food intake were recorded. Results: Patients showed elevated serum leptin (34.1 +/- 30 ng/mL), normal acyl ghrelin (137 +/- 116.5 pg/mL), high des-acyl ghrelin (670 +/- 479 pg/mL), and low obestatin (2.0 +/- 1.4 ng/mL) levels compared with healthy volunteers. According to body mass index (BMI), patients with a BMI >23 kg/m(2) had significantly lower plasma obestatin. In contrast, leptin levels were increased and acyl ghrelin tended to be higher in these patients. There was a strong positive correlation between obestatin and des-acyl ghrelin (r = 0.56, P = 0.0001) and inverse correlations between obestatin and BMI (r = -0.40, P = 0.007), waist circumference (r = -0.38, P = 0.024), and C-reactive protein (r = -0.29, P = 0.048). By multivariate analysis, obestatin was independently and positively correlated with des-acyl ghrelin (P = 0.01), but not with C-reactive protein, BMI, or waist circumference. Conclusion: In summary, patients on HD exhibited increased plasma levels of des-acyl ghrelin, normal acyl ghrelin levels, and low obestatin levels. In lean patients, the obestatin and des-acyl ghrelin levels were increased, suggesting that these hormones may influence appetite and body composition in patients on HD. (C) 2010 Elsevier Inc. All rights reserved.