Original Article Peritoneal transport characteristics and dwelling time significantly impact ghrelin clearance in peritoneal dialysis patients Chia-Chu Chang 1,5 , Ching-Hui Hung 2 , Hung-Lin Chen 4 , Kai-Lin Hwang 6 and Ching-Yuang Lin 3,5 1 Nephrology Division and 2 Cardiac Division, Department of Internal Medicine, 3 Department of Pediatrics, 4 Department of Medical Nutrition Therapy & Food Service, Changhua Christian Hospital, Changhua, 5 College of Health Sciences, Institute of Medical Research, Chang Jung Christian, Tainan and 6 Department of Public Health, Chung Shan Medical University, Taichung, Taiwan Abstract Background. Plasma ghrelin exerts widespread bioactivities. Although it is effectively removed from the blood by a single course of haemodialysis, peritoneal clearance of ghrelin is uncertain. Our study aimed to determine (i) whether there is a correlation between plasma ghrelin levels and characteristics of peritoneal ghrelin clearance, and (ii) whether plasma ghrelin levels significantly impact markers of mortality or morbidity in continuous ambulatory peritoneal dialysis (CAPD) patients. Methods. We enrolled 50 qualified CAPD patients. Blood was drawn during the fasting state and 2 h post- prandially. Also during these periods, peritoneal effluents were collected for radioimmunoassay of total plasma ghrelin level and measurement of other parameters. Twenty-four hour ascites were collected for determination of ghrelin daily mass transfer. Results. Peritoneal ghrelin clearance was positively correlated with the dialysate-peritoneal creatinine (D/P Cr ) ratio. Fasting plasma ghrelin levels were inversely correlated with the peritoneal/plasma (D/P ghrelin ) ratio (P ¼ 0.045). Plasma ghrelin levels were negatively correlated with body mass index, waist-hip ratio, fasting insulin and triglyceride level, and positively correlated with lean body mass. Plasma ghrelin levels were positively correlated with left ventricular mass (LVM), left ventricular mass index and blood pressure. Conclusions. Peritoneal transporter characteristics may modulate plasma ghrelin levels in CAPD subjects. By contributing to the level of plasma ghrelin, dwelling time may have an impact on LVM and associated morbidity in CAPD patients. Keywords: continuous peritoneal ambulatory dialysis; left ventricular mass; plasma ghrelin; visual analogue scales Introduction Protein-energy malnutrition is a highly prevalent morbidity in the continuous peritoneal ambulatory dialysis (CAPD) population [1]. Recent studies have shown that the appetite status (measured via visual analogue scale rating) of dialysis patients is a key indicator of their general health and quality of life, and is also a main contributor to nutritional status and clinical outcome [2]. Foley et al. [3] showed that 74% of patients in maintenance dialysis had left ventricular hypertrophy, which was an independent predictor of cardiac events in the Framingham cohort [4]. Cardiac disease is still the leading cause of death among patients receiving long-term dialysis, accounting for 44% of overall mortality [3]. Ghrelin, an endogenous ligand for growth hormone secretagogue receptor, is a 28-amino acid (3300 Da) peptide that is predominantly produced by the stomach, but exerts hormonal actions throughout the body [5]. Besides having orexigenic properties coupled with control of energy homoeostasis, the acylated and desacyl forms of ghrelin exert many significant biological actions [6]. Wynne et al. [7] showed that subcutaneous administration of ghrelin may enhance acute food intake, and result in a significant fall in mean arterial blood pressure in malnourished patients who receive maintenance peritoneal dialysis (PD) [7]. In our previous study in non-diabetic haemodialysis (HD) patients [8], we showed that plasma ghrelin levels are positively correlated with lean body mass (LBM) and left ventricular mass (LVM), and that plasma ghrelin was efficiently cleared during HD. Iglesias et al. [9] demonstrated that PD is accompanied by a striking decrement in baseline ghrelin Correspondence and offprint requests to: Ching-Yuang Lin, MD, PhD, Department of Pediatrics, Children’s Hospital, Changhua Christian Hospital, No. 135 Nan-Shiao Street, Changhua, 500, Taiwan. Email: 100966@cch.org.tw Nephrol Dial Transplant (2007) 22: 224–228 doi:10.1093/ndt/gfl540 Advance Access publication 27 September 2006 ß The Author [2006]. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org Downloaded from https://academic.oup.com/ndt/article/22/1/224/1811572 by guest on 11 January 2022