Postprandial secretion of ghrelin in hemodialysis patients with and without diabetic nephropathy

INTRODUCTION Ghrelin is a hormone produced mainly by the stomach, which enhances gastric emptying. The disturbances of ghrelin secretion and/or biodegradation may play an important role in the pathogenesis of gastroparesis in hemodialysis patients, especially those with diabetic nephropathy. OBJECTIVES The aim of the study was to assess postprandial changes in plasma ghrelin in hemodialysis patients with diabetic or non-diabetic nephropathy. PATIENTS AND METHODS Thirty-two hemodialysis patients (116 with diabetic nephropathy [HD-DM], 16 with non-diabetic nephropathies [HD]) and 15 healthy subjects (C) were enrolled into the study. Plasma ghrelin concentrations were assessed in the fasting state and at 30, 60 and 120 min after ingestion of a test meal. Gastric emptying was assessed based on changes in serum paracetamol concentrations ingested with the meal. RESULTS In both HD groups fasting plasma ghrelin levels were significantly higher than in C. After ingestion of a test meal plasma ghrelin levels declined mostly at 60 min. In contrast to C, decreased ghrelinemia persisted over 120 min after ingestion of a test meal in both hemodialysis groups. There was no correlation between postprandial reduction in plasma ghrelin at 60 and 120 min and serum paracetamol concentration in HD and HD-DM, while in C decrease in postprandial plasma ghrelin at 60 min correlated with serum paracetamol concentrations. CONCLUSIONS In hemodialysis patients plasma ghrelin levels are significantly elevated compared to healthy subjects. Prolonged postprandial suppression of ghrelin secretion may contribute to the pathogenesis of gastric emptying disorders in hemodialysis patients. Abnormal postprandial ghrelinemia was observed especially in patients with diabetic nephropathy.