Influences of Helicobacter pylori on serum pepsinogen concentrations in dialysis patients.
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BACKGROUND: Patients with impaired renal function have been known to have elevated concentrations of serum pepsinogens, which are raised by Helicobacter pylori infection of the stomach. The present study was performed to examine the effect of H. pylori infection on serum pepsinogen concentrations in dialysis patients. METHODS: Forty nine patients on dialysis and 48 subjects with no known kidney disease were examined for upper gastroduodenal endoscopy, H. pylori infection and serum concentrations of pepsinogen I and II. The status of H. pylori infection was evaluated from results of a urease test, histology and culture of biopsy specimens of the gastric mucosa. Serum pepsinogen levels were measured by radioimmunoassay. RESULTS: Serum concentrations of pepsinogen I and II were elevated in the dialysis patients in comparison with those in the controls (277.4+/-24.2 vs 52.6+/-4.0 pg/ml, P<0.01 for pepsinogen I, and 30.2+/-2.9 vs 14.9+/-1.3 pg/ml, P<0.01 for pepsinogen II). In both the dialysis patients and controls, those with H. pylori infection had significantly higher concentrations of serum pepsinogen I and II and a lower ratio of pepsinogen I to pepsinogen II than those without infection. Among the controls, 15 of 25 subjects with atrophic gastritis had a pepsinogen I/pepsinogen II ratio < or = 3.0, while only two out of 17 patients on dialysis fell into this range. CONCLUSIONS: We conclude that H. pylori status should be taken into account when serum pepsinogen concentrations are evaluated in dialysis patients. (+info)
Leptin in CAPD patients: serum concentrations and peritoneal loss.
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BACKGROUND: To determine whether serum leptin concentrations in patients undergoing continuous ambulatory peritoneal dialysis (CAPD) are influenced by peritoneal loss of leptin and to compare serum leptin levels of normal subjects with those of patients receiving renal replacement therapy such as haemodialysis (HD), CAPD, or kidney transplantation. SUBJECTS AND METHODS: Eighty-four individuals were investigated: six females and 14 males on standard CAPD; 13 females and 13 males on chronic HD; 10 female and eight male kidney transplant recipients, and 10 female and 10 male subjects as controls. Morning serum, 8-h and 24-h samples of peritoneal fluid concentrated to 6-20-fold by Centricon 3 (cutoff 3000 daltons), and 24-h urinary concentrations of leptin were measured with commercial RIA (Linco Research, Inc., USA). Venous blood and peritoneal fluid samples of albumin, beta2-microglobulin, glucose, urea, and creatinine were determined by standard laboratory techniques. Serum insulin levels were measured by radioimmunoassay. RESULTS: Patients (men and women) on CAPD and after kidney transplantation exhibited significantly higher serum concentrations of leptin and leptin/BMI ratios than control subjects. These increased values did not reach statistical significance in HD patients. Serum leptin concentrations were correlated very significantly with BMI in all cases (r=0.380, P<0.001). Moreover, in CAPD patients (r=0.630, P<0.007) and in HD patients (r=0.668, P<0.005), but not in kidney transplant recipients or control subjects, significant correlations were observed between serum leptin and insulin concentrations. Residual renal function (RRF) in the range 0-12.8 ml/min and serum beta2-microglobulin levels in the range 7.9-47.1 mg/l did not influence serum leptin levels in CAPD and HD patients. As expected, leptin was detected in the peritoneal fluid of CAPD patients. Twenty-four-hour peritoneal loss (30.95+/-21.05 ng/min) and 24-h peritoneal clearance (0.01+/-0.01 ml/kg/min) of leptin account for only 3.9% of estimated whole-body leptin production rate and 0.7% of leptin clearance from plasma respectively. Twenty-four-hour urinary losses of leptin in CAPD patients were negligible, accounting for 5.6+/-1.8% (range 0.3-15.2%) of total (peritoneal and urinary) loss of this hormone. CONCLUSIONS: These findings suggest that serum leptin levels are not affected by continuous peritoneal loss of leptin during CAPD and that insulin resistance and hyperinsulinaemia contribute to elevated serum leptin concentrations in CAPD and HD patients. The aetiology of increased serum leptin levels in kidney transplant recipients is probably different from that in dialysis patients. (+info)
Peritoneal clearance of leptin in CAPD patients: impact of local insulin administration.
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INTRODUCTION: The ob gene product leptin is secreted by fat cells and the serum leptin levels reflects the body fat content. Markedly elevated serum leptin levels have been reported in patients with chronic renal failure. The aim of the present study was to assess if the dialysate leptin levels in peritoneal dialysate are similar to what can be expected from passive diffusion or if intraperitoneal synthesis of leptin may occur. METHODS: We studied 39 patients (20 males), mean age 54+/-12 years, who had been treated with peritoneal dialysis for 17+/-12 months. Ten of the patients were diabetics of which seven used intraperitoneal insulin. A 24-h collection of dialysate was performed and dialysate and fasting blood samples were analysed for leptin, albumin and beta2-microglobulin, and the peritoneal clearances (PCl) were calculated for these solutes. RESULTS: Serum leptin (mean 47+/-76, range 3-350 ng/ml) was related to body mass index (r=0.35, P<0.05). In multiple regression analysis, serum leptin also correlated to serum TNF-alpha. Although dialysate leptin levels correlated to serum leptin, they were higher than expected from the molecular weight of 16 kD. PCl of leptin was 1.3 ml/min (range 0.2-5.9 ml/min), which was 1.6 times higher than expected from the molecular weight of leptin and PCl for albumin and beta2-microglobulin, not taking the protein binding of leptin into account. A strong correlation was found between PCI for albumin and beta2-microglobulin (r = 0.68, P < 0.0001) but neither PCl albumin, nor PCl beta2-microglobulin correlated to PCI leptin. The PCl of leptin was markedly higher in diabetics using intraperitoneal insulin (n = 7) compared to the other 32 patients (2.6+/-2.0 vs 1.1+/-0.7 ml/min, P<0.05). CONCLUSION: Serum leptin is locally produced in the peritoneal cavity, and intraperitoneal insulin enhances local production of leptin. (+info)
Dialysis adequacy and homocyst(e)ine concentrations in peritoneal dialysis patients.
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INTRODUCTION: Determinants of hyperhomocysteinaemia in peritoneal dialysis patients have been recently reported but there is still conflicting data on the influence of dialysis adequacy on homocysteine (Hcy). METHODS: We studied 46 consecutive new continuous ambulatory peritoneal dialysis (CAPD) patients to determine the variation of Hcy before and 1 and 6 months after dialysis. The variation in Hcy was analysed with respect to dialysis adequacy, factors known to influence its metabolism, and Hcy peritoneal clearance. RESULTS: Hcy was 31.9+/-9 micromol/l before dialysis. It was significantly higher before dialysis than 1 month after the onset of PD (31.9+/-9 micromol/l vs 23.2+/-6.9 micromol/l, P < 0.0005). Weekly PD Hcy clearance was 14.3+/-5.4 1. There was no relationship between pre-dialysis Hcy and 1 month post-dialysis Hcy (r=0.176, P=0.15). There was a strong relationship between PD Hcy clearance and both PD creatinine clearance (r=0.502, P<0.005) and Kt/V (r=0.42, P<0.005). There was no relationship between Hcy and PD creatinine clearance (r= -0.221, P=0.11). In contrast, the decrease in tHcy at 1 month was related to PD Hcy clearance (r=0.487, P<0.01), to PD creatinine clearance (r= 0.349, P<0.02) and to Kt/V (r=0.32, P<0.02). Multivariate analysis confirmed the relationship between the decrease in Hcy and dialysis adequacy. Eleven patients (24%) experienced arteriosclerotic complications. Fasting Hcy concentrations in this population were significantly higher before and 1 month-post-dialysis than in patients without cardiovascular complications. CONCLUSIONS: We observed a significant and prolonged reduction in Hcy concentrations by peritoneal dialysis in end-stage renal disease patients. The decrease in Hcy concentration was positively related to dialysis adequacy. This study suggests the possibility that dialysis adequacy may influence arteriosclerotic outcomes through an Hcy-lowering effect. (+info)
Leptin elimination in hyperleptinaemic peritoneal dialysis patients.
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BACKGROUND: Elevated plasma concentrations of leptin, a hormone thought to regulate body composition by influencing food intake/metabolic rate, are prevalent in renal failure patients. The mechanism for these increases is not known, but evidence suggests that simple accumulation due to decreased elimination is insufficient explanation. METHODS: We studied the incidence of hyperleptinaemia in 28 end-stage renal disease patients treated with continuous ambulatory peritoneal dialysis (CAPD), compared with body-mass-index-and sex-matched controls. Results were separated by gender because women have higher leptin concentrations than men. Excretion of leptin and other substances in dialysis fluid was also studied. RESULTS: Hyperleptinaemia was prevalent in women CAPD subjects, but not in men. Plasma leptin concentrations correlated strongly with the daily excretion of leptin in dialysis fluid. Clearance of leptin in dialysis fluid was greater in men than women CAPD subjects. Single regression analysis found that fasting insulin, glucose content of dialysis fluid, plasma albumin, C-reactive protein, erythropoietin dose, urinary creatinine clearance and plasma beta2-microglobulin were not determinants of plasma leptin concentrations. Stepwise forward multiple regression, examining the dependence of plasma leptin on body mass index, renal creatinine clearance, plasma albumin, daily dialysis fluid glucose load, daily leptin in dialysis fluid, erythropoietin dose and plasma C-reactive protein found only erythropoietin dose as a consistent negative predictor of plasma leptin concentrations. CONCLUSIONS: The results suggest that hyperleptinaemia of CAPD was due to predisposing loss of renal elimination capacity combined with increased production due to obesity (more prevalent in women subjects of this study) and potentially female gender. (+info)
Management of inguinal herniae in patients on continuous ambulatory peritoneal dialysis: an audit of current UK practice.
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Patients receiving continuous ambulatory peritoneal dialysis are at increased risk for the development of inguinal herniae, with a reported prevalence of 14%. Elective hernia repair is indicated for these patients as strangulation is associated with a high mortality in this population. There are currently no national guidelines relating to the optimal peri-operative management of these patients, in particular the appropriate pre- and post-operative dialysis regimen. The aim of the current study was to evaluate current practice in the UK by means of a postal questionnaire sent to all centres undertaking renal transplantation. Replies were received from 34/37 centres. The principal study finding was the wide variation in surgical practice between different centres with regard to pre- and post-operative dialysis regimes. Only 44% of centres had an established protocol. Based upon the study findings we have devised a protocol that we hope to see implemented into UK practice. Following its introduction, a re-assessment will be performed and the audit cycle completed. (+info)
Apolipoprotein B-containing lipoproteins in renal failure: the relation to mode of dialysis.
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BACKGROUND: The aim of this study was to establish whether there is a differential effect of mode of dialysis, hemodialysis (HD), or continuous ambulatory peritoneal dialysis (CAPD) on the dyslipidemia of renal failure. METHODS: The lipoprotein profile was determined in 61 non-diabetic patients on chronic HD (N = 30) and CAPD treatment (N = 31), and in a control group of 27 healthy subjects. The analysis included the measurement of individual apolipoprotein (apo) A- and apo B-containing lipoproteins (LPs) separated by sequential immunoaffinity chromatography. Apo A-containing lipoproteins include lipoprotein A-I with apo A-I and lipoprotein A-I:A-II with apo A-I and apo A-II as the main protein constituents, whereas apo B-containing lipoproteins comprise simple cholesterol-rich lipoprotein B (LP-B), with apo B as the only protein moiety and complex triglyceride (TG)-rich lipoprotein B complex (LP-Bc) particles with apo B, apo A-II, apo C, and/or apo E as the protein constituents. RESULTS: CAPD patients had significantly higher concentrations of total cholesterol (6.8 vs. 5.1 mmol/liter), low-density lipoprotein (LDL) cholesterol (4.6 vs. 3.2 mmol/liter), TG (2.3 vs. 1.5 mmol/liter), apo B (155.3 vs. 105.7 mg/dl), LP-B (136.0 vs. 91.9 mg/dl), and LP-Bc (19.3 vs. 13.8 mg/dl) than HD patients. Both HD and CAPD patients had significantly higher TG, VLDL cholesterol, apo C-III, and apo E and significantly lower high-density lipoprotein cholesterol, apo A-II, and lipoprotein A-I:A-II levels than control subjects. The distribution of apo C-III in high-density lipoprotein and VLDL-LDL was altered in CAPD patients in comparison with control subjects. This suggests that the removal of TG-rich lipoproteins is less efficient in patients on CAPD. Normotriglyceridemic (NTG; TG < or = 1.7 mmol/liter, 150 mg/dl) CAPD patients had significantly higher levels of TC, LDL cholesterol, apo B, and LP-B than NTG-HD patients. There was little difference in the LP-Bc levels between NTG-CAPD, NTG-HD, and controls. Similarly, hypertriglyceridemic (HTG) CAPD patients had significantly higher TC, LDL cholesterol, apo B, and LP-B levels than HTG-HD patients. The LP-Bc levels were significantly increased in HTG-HD and HTG-CAPD patients compared with controls, but the slightly higher levels in the CAPD patients did not differ significantly from the HD group. CONCLUSION: CAPD and HD patients have a lipoprotein profile characteristic of renal failure. Patients on long-term CAPD have higher levels of cholesterol-rich apo B-containing lipoproteins unrelated to TG levels. Many patients on CAPD also have a substantial elevation of the plasma concentrations of TG-rich LPs. The clinical significance of increased levels of potentially atherogenic LP-B during CAPD remains to be investigated. (+info)
Does a high peritoneal transport rate reflect a state of chronic inflammation?
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OBJECTIVE: It has recently been reported that a high peritoneal transport rate was associated with increased mortality in continuous ambulatory peritoneal dialysis (CAPD) patients. One possible explanation is that a high peritoneal transport rate might be caused by a state of chronic inflammation, which also per se might result in increased mortality. Therefore, in this study we investigated whether high peritoneal transport rate patients are in a state of chronic inflammation. METHODS: The study included 39 clinically stable peritoneal dialysis patients (free of peritonitis) who had been on PD for more than 3 months (16.8+/-11.8 months). Seven patients were treated with continuous cycling peritoneal dialysis (CCPD) and the others were on CAPD. A 4-hour standard peritoneal equilibration test (PET) using 2.27% glucose solution was performed in each patient. Dialysate samples at 4 hours and blood samples at 2 hours were measured for interleukin-1beta (IL-1beta), tumor necrosis factor(alpha)(TNFalpha), C-reactive protein (CRP), and hyaluronan as markers of inflammation. RESULTS: There was no significant correlation between dialysate/plasma (DIP) creatinine (0.82+/-0.15, range 0.51 - 1.15) and blood concentrations of IL-1beta (11.2 ng/L, range <5 - 65.9 ng/L),TNFalpha (12.1 ng/L, range <5 - 85.4 ng/L), CRP (<10 mg/L, range <10 - 76 mg/L), nor with the blood hyaluronan concentration (165 microg/L, range 55 - 955 microg/L). The dialysate concentrations of IL-1beta and TNFalpha were below the detectable level in most of the samples. Although dialysate hyaluronan concentration (334 microg/L, range 89 - 1100 microg/L) was correlated with D/P creatinine (r= 0.36, p< 0.05), there was no correlation between the total amount of hyaluronan in the effluent and D/P creatinine. However, a significant correlation was found between serum hyaluronan concentration and glomerular filtration rate (GFR) (r = -0.49, p< 0.005); GFR also tended to be correlated with serum TNFalpha (r = -0.31, p = 0.058) but not with serum IL-1beta and serum CRP. CONCLUSION: Our results suggest that a high peritoneal transport rate is not necessarily related to a state of chronic inflammation in CAPD patients. The high mortality rate observed in high transporters may relate to other issues, such as fluid balance or abnormal nutrition and metabolism, rather than to chronic inflammation. (+info)