Interrelationship between plasma leptin concentration and severity of metabolic acidosis in haemodialysed patients with chronical renal failure

Patients with chronic renal failure are frequently characterized by malnutr ition, hyperleptinaemia and metabolic acidosis. Both hyperleptinaemia and c hronic metabolic acidosis are presumed to contribute to the pathogenesis of malnutrition observed in this group of patients. It has been reported, tha t in vitro adipocytes exposed to acidotic medium decrease leptin secretion. The aim of present study was to analyze the possible impact of uraemic met abolic acidosis on leptinaemia in haemodialysis patients with chronic renal failure. - 94 haemodialysed patients (58 M, 36 F; mean age 45 +/- 1 years) were enrolled in this study. 56 patients were on haemodialysis treatment f or one year using an acetate dialysis fluid, while 38 patients were haemodi alysed at least for 3 months with a dialysate buffered with bicarbonate. Pl asma leptin concentration, blood gases and body composition were assessed i n all examined subjects. - Patients haemodialysed with an acetate and bicar bonate buffered dialysate did not differ with respect to body weight. body mass index (BMI), total fat mass (TFM) and plasma leptin concentration. Pat ients haemodialysed with an acetate buffered dialysate were characterized b y a significantly more severe metabolic acidosis than patients on bicarbona te haemodialysis. Patients were divided according to the actual hydrogen io n concentration: over 60 nmol/l, 45-60 nmol/l and below 45 nmol/l. These su bgroups did not differ significantly by body weight, BMI and TFM. Only a sl ightly (not significantly), lower median leptinaemia was found in patients with elevated hydrogen ion concentration. No significant correlation was no ticed between blood hydrogen or hydrocarbonate ion concentration respective ly and logarithmic values of plasma leptin concentration (tau = 0.025, tau = 0.72; tau = -0.021, p = 0.76 respectively). - From results obtained in th is study we may conclude that, blood hydrogen ion concentration does not in fluence substantially or only moderately to plasma leptin concentration in haemodialysed patients.