#5941 SERUM LEPTIN AND MALNUTRITION IN PERITONEAL DIALYSIS PATIENTS: A CONNECTION YET TO BE FOUND

Abstract

Abstract Background and Aims Leptin is a hormone responsible for the modulation of the satiety signals and that it is known for being increased in patients undergoing Peritoneal Dialysis (PD) treatment. Nevertheless, conclusions about its role in the malnutrition associated with this technique remains to be done. Our study aimed to characterize the nutritional state of a Portuguese program of PD and to establish the impact that leptin levels had on it. Method A cross-sectional study was performed involving 28 patients of a PD program. To characterize the patients’ nutritional status we collected the following data: anthropometric measurements (weight, body mass index (BMI), fat tissue index and lean tissue index using Fresenius ® Body Composition Monitor), analytical values (albumin, total proteins, total cholesterol, high-density lipoprotein cholesterol, low-density cholesterol, triglycerides, leptin serum levels), protein metabolism (normalized protein catabolic rate (nPCR), normalized dialysate protein loss (nEPL), normalized urine protein loss (nUPL), normalized total protein loss (nTPL) and normalized dietary protein requirement (nDPR)) and peritoneal dialysis adequacy (total, renal and peritoneal kT/v; total, renal and peritoneal creatinine clearance). The collected data were statistically analyzed and correlations were made using Mann-Whitney U test and Spearman test, depending on the variable type. Results 7 (25%) patients were females, and the mean age was 59.5 years old (± 14.31). The mean dialysis vintage was 27.04 months (± 20.14) and the majority (n=23, 82,1%) preformed automated peritoneal dialysis (APD). Regarding the nutritional status, the mean BMI, FTI and LTI was 26.64 kg/m2 (±4.39), 14.24 kg/m2 (±5.47) and 11.62 kg/m2 (±2.52) respectively. 57.1% (n=16) had serum albumin below 3.5 mg/dL, with a mean phosphorus of 5.01mg/dl (±0.72) and a mean leptin of 28.58ng/mL (±28.44). The serum leptin was 5.4 times higher than the adjusted value for BMI in the population without kidney disease. The adjusted serum leptin for BMI was different between sex (U=15, P = .001) and it was positively correlated with total (ρ=0.47, P = .012) and high-density lipoprotein (HDL) cholesterol (ρ=0.535, P = .003). It was not associated with the protein metabolism (nPCR, nEPL, nUPL, nTOL and nDPR), albumin or total proteins and PD adequacy. Conclusion Leptin values independent of BMI are significantly higher amongst patients on PD. Alike the healthy population, women on PD are also prone to have higher serum leptin values. Although studies are still controversial about the association between this hormone and cholesterol, in this population there is a positive correlation. As so, hyperleptinaemia cannot yet be associated with the malnutrition that is generally present amongst PD patients, but it must be considered as a contribute to the already known increased cardiovascular risk.