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.

Are ghrelin and leptin involved in food intake and body mass index in maintenance hemodialysis?

OBJECTIVES: Both leptin and ghrelin (in the forms of acyl ghrelin and des-acyl ghrelin) are involved in food intake, and appear to be dysregulated in chronic kidney disease. This study describes plasma leptin, acyl, and des-acyl ghrelin concentrations in relation to protein intake and body mass index (BMI) in hemodialysis (HD) patients. DESIGN: This was a cross-sectional study. SETTING: This study was conducted during the baseline phase of the French multicenter Influence of a High-Flux Dialyzer on Long-Term Leptin Levels Study. PATIENTS: We studied 125 HD patients (aged 72.5+/-11.7 years; 59% males). MAIN OUTCOME MEASURE: Blood samples were collected during fasting, and before a regular HD session. Plasma ghrelin and leptin were evaluated. The protein equivalents of total nitrogen appearance and BMI were calculated. RESULTS: Patients demonstrated elevated serum leptin (48.0+/-49.0 ng/mL) and des-acyl ghrelin (646.6+/-489.5 pg/mL) levels, and low acyl ghrelin levels (29.8+/-58.5 pg/mL), according to normal values. Acyl ghrelin was negatively correlated with C-reactive protein (r=-0.34, P < .001). The des-acyl to acyl ghrelin ratio was negatively correlated with protein intake, as estimated by normalized Protein Nitrogen Appearance (r=-0.22, P=.01). Serum leptin exhibited its well-described positive correlation with BMI and waist circumference, but the other hormones did not. CONCLUSIONS: This study reports high des-acyl ghrelin and leptin levels and low acyl ghrelin levels in HD patients, a finding potentially associated with inflammation and food intake.