Changes of Serum Leptin Concentration Shortly after Start of Peritoneal Dialysis

Oh, Dong Jin; Kim, Dae Joong; Kim, Bum; Kang, Woo Heon; Lee, Bang Hun; Huh, Woo Sung; Oh, Ha Young

Abstract

Elevated serum leptin concentration can contribute to anorexia and poor nutrition in patients with chronic renal failure, since leptin is elevated in chronic renal failure patients with or without dialysis, especially in chronic ambulatory peritoneal dialysis(CAPD) patients. The aim of this study to find whether leptin can be removed by peritoneal dialysis(PD) and to analyze factors that can affect serum leptin concentration after start of CAPD by observing the changes of serum leptin shortly after start of CAPD and their correlations with body mass index(BMI), serum insulin concentration and residual renal function(Creatinine clearance+Urea clearance/2). Twenty patients who started CAPD during the observation periods were studied. Serum leptin concentration was measured before start of CAPD, 3-5 days and 1, 3 months after start of CAPD by RIA method. Simultaneously, body weight, serum insulin concentration and residual renal function were measured. Removal of leptin was assessed by measuring dialysate leptin concentration divided by average serum leptin concentration before and after peritoneal equilibration test(PET) to compensate for the circardian rhythm of leptin. Leptin was eliminated by PD with dialysate to serum ratio of leptin to be 0.16+/-0.07 which was comparable to removal of beta2-microglobulin(0.14+/-0.06). The mean serum leptin concentration did not decrease after 3-5 days of CAPD(8.4+/-13.1-->11.9+/-18.0) despite its removal by PD and increased markedly 189%, 260% of basal serum leptin concentration on 1 month and 3 months after start of PD, respectively. Correlation coefficients(Spearmann's) between changes of serum leptin concentration and changes of BMI, serum insulin concentration, residual renal function were 0.267(P>0.05, n=20), 0441(P>0.05, n= 16), 0.706(P>0.05, n=8) respectively. Leptin was removed by peritoneal dialysis. Serum leptin concentration did not decrease in 5 days after start of PD despite its removal by PD, and increased markedly 3 months after start of PD. We could not find significant correlation between changes of serum leptin concentration and changes of BMI. Factors other than fat mass gain can stimulate leptin increase shortly after start of PD.