Ghrelin and other appetite-regulating hormones in paediatric patients with chronic renal failure during dialysis and following kidney transplantation

Background. Patients with renal insufficiency often suffer from cachexia and growth retardation due to low appetite and increased resting metabolic rate. The neuroendocrine hormone ghrelin, a growth hormone secretagogue, enhances food intake, but its role in the development of a cachectic state in renal insufficiency is unclear. Objective. The aim of our study was to investigate the plasma concentration of total ghrelin and other hormones involved in appetite regulation in children with preterminal chronic renal failure (CRF, n = 24), children undergoing dialysis (n = 19), children after renal transplantation (RTx, n = 59) and healthy controls (n = 10). Results. Total ghrelin was significantly elevated in CRF patients (1370 +/- 182 pg/ml; mean +/- SEM) when compared to control subjects (682 +/- 106 pg/ml; P = 0.016) or patients following RTx (859 +/- 51 pg/ml; P = 0.002). Furthermore, a negative correlation between glomerular filtration rate and total ghrelin was observed in CRF and transplant recipients (r = 0.36, P = 0.0006). BMI SDS (standard deviation score) is lower in CRF patients compared to the other groups (P < 0.0001). Leptin, adiponectin, blood glucose, insulin, IGF-I, IGFBP-3 and growth hormone concentrations did not differ among groups. Conclusions. We observed elevated ghrelin levels in uraemic patients despite poor appetite, but the underlying reasons remain unclear. Normal ghrelin levels can be re-achieved following RTx.