neuropeptide-y and Renal-Insufficiency

Effects of online hemodiafiltration (HDF) using acetate-free bicarbonate dialysis (AFD) fluid on microinflammation, resulting in improved nutritional status in hemodialysis patients, were examined and compared with conventional acetate-containing bicarbonate dialysis (ACD) fluid. A total of 24 hemodialysis patients were registered for a cross-over design study for a 6-month period. These patients were subjected to ACD for the first 3 months followed by AFD fluid for the latter 3 months. Blood variables of C-reactive protein (CRP), interleukin-6 (IL-6), leptin, neuropeptide Y (NPY), protein catabolic rate (PCR) and %creatinine (Cr) index were determined after the first and last 3-month period. The filters and the conditions of HDF and drug regimens including erythropoiesis-stimulating agents were unchanged throughout the cross-over study. Predialysis blood pH and bicarbonate were significantly higher in the AFD phase than in the ACD phase. Blood CRP and IL-6 levels were significantly decreased in the AFD group compared to the ACD group. Concerning nutritional evaluation, leptin and NPY were significantly lower and higher, respectively, in the AFD phase than in the ACD phase. PCR tended to be higher in the AFD phase than in the ACD phase. A significantly higher %Cr index level was observed in the AFD phase than in the ACD phase. These results suggest that online HDF using AFD fluid contributes to alleviating bioincompatible events associated with microinflammation, leading to improvement in the nutritional status in hemodialysis patients.

Topics: Acetates; Adult; Aged; C-Reactive Protein; Cross-Over Studies; Female; Hemodiafiltration; Humans; Inflammation; Interleukin-6; Leptin; Male; Middle Aged; Neuropeptide Y; Nutritional Status; Renal Dialysis; Renal Insufficiency; Treatment Outcome

To assess whether endocrine dysfunction may cause derangement in energy homeostasis in patients undergoing hemodialysis (HD), we profiled hormones, during a 3-day period, from the adipose tissue and the gut and the nervous system around the circadian clock in 10 otherwise healthy HD patients and 8 normal controls. The protocol included a 40-h fast. We also measured energy-protein intake and output and assessed appetite and body composition. We found many hormonal abnormalities in HD patients: 1) leptin levels were elevated, due, in part, to increased production, and nocturnal surge in response to daytime feeding, exaggerated. 2) Peptide YY (PYY), an anorexigenic gut hormone, was markedly elevated and displayed an augmented response to feeding. 3) Acylated ghrelin, an orexigenic gut hormone, was lower and did not exhibit the premeal spike as observed in the controls. 4) neuropeptide Y (NPY), a potent orexigenic peptide, was markedly elevated and did not display any circadian variation. 5) Norepinephrine, marginally elevated, did not exhibit the normal nocturnal dip. By contrast, α-melanocyte-stimulating hormone and glucagon-like peptide-1 were not different between the two groups. Despite these hormonal abnormalities, HD patients maintained a good appetite and had normal body lean and fat mass, and there was no evidence of increased energy expenditure or protein catabolism. We explain the hormonal abnormalities as well as the absence of anorexia on suppression of parasympathetic activity (vagus nerve dysfunction), a phenomenon well documented in dialysis patients. Unexpectedly, we noted that the combination of high leptin, PYY, and NPY with suppressed ghrelin may increase arterial blood pressure, impair vasodilatation, and induce cardiac hypertrophy, and thus could predispose to adverse cardiovascular events that are the major causes of morbidity and mortality in the HD population. This is the first report attempting to link hormonal abnormalities associated with energy homeostasis to adverse cardiovascular outcome in the HD patients.

Topics: Adult; Anorexia; Appetite; Body Composition; Cardiovascular Diseases; Circadian Rhythm; Endocrine System Diseases; Energy Metabolism; Fasting; Female; Ghrelin; Homeostasis; Humans; Leptin; Male; Middle Aged; Neuropeptide Y; Norepinephrine; Peptide YY; Protein-Energy Malnutrition; Renal Dialysis; Renal Insufficiency; Risk Factors