Eating behavior in continuous ambulatory peritoneal dialysis and hemodialysis patients.

Three groups consisting of 12 subjects each (continuous ambulatory peritoneal dialysis [CAPD] patients, hemodialysis patients, and healthy controls) matched for age, sex, and body weight were invited to a test meal for the study of hunger, fullness, and food preferences. They were served an excess portion of hash served on a plate placed on a hidden scale ("VIKTOR"), which was connected to a computer registering the eating process on-line. The patients filled in visual analogue scales (VAS) concerning appetite and food preferences before and after the test meal. Mean total intake of food (+/- SD) was significantly higher for healthy controls (357 +/- 175 g) compared with hemodialysis patients (295 +/- 105 g), which in turn was higher than in CAPD patients (206 +/- 70 g). Eating velocity was lower in both dialysis groups compared with controls. CAPD patients experienced less hunger and desire to eat compared with hemodialysis patients and controls. The reason for the low eating drive in CAPD patients despite their great need for protein and calories is unknown, but might be explained by gastric retention, insufficient dialysis, metabolic effects of the high sugar load from the dialysate, or combinations of these factors.     

Plasma levels of human atrial natriuretic factor in patients treated by hemodialysis and continuous ambulatory peritoneal dialysis

We measured plasma levels of immunoreactive human atrial natriuretic factor (ANF) in chronic renal failure patients treated by hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD). Predialysis plasma ANF was significantly higher in HD patients (271.8 +/- 173.4 pg/ml) as compared to CAPD patients (81.8 +/- 80.5 pg/ml) and healthy subjects (31.5 +/- 19.8 pg/ml). Plasma volume was higher in HD patients than in CAPD patients. Plasma ANF and plasma volume showed a significant positive correlation. In HD patients, high plasma ANF value decreased significantly to a value comparable with that of CAPD patients after each dialysis. The removal rates of ANF by HD and CAPD were comparable. Ultrafiltration corresponding to 2% of body weight without dialysis also reduced plasma ANF. Thus, the difference in plasma ANF values between HD and CAPD patients seems to be mostly due to the difference in plasma volume, indicating that plasma ANF is sensitive to volume status even in chronic dialysis patients.     

Lipoprotein abnormalities in hemodialysis and continuous ambulatory peritoneal dialysis patients

Lipid abnormalities are important variables in the development of vascular atherosclerotic lesions in ESRD patients while Lp(a) represents an independent risk factor. In order to evaluate lipid changes in HD and CAPD patients, serum cholesterol (TC), HDLc, LDLc, TG, apolipoproteins (AI,AII,B,E), Lp(a), and albumin levels were estimated in 109 ESRD dialyzed patients, 46 in HD and 63 in CAPD (mean duration 50 +/- 40 and 25 +/- 19 months, respectively), and 45 volunteers with high serum levels of C and TG, without renal insufficiency. Both HD and PD group revealed statistically significantly higher levels than controls for TC, TG, LDL-C, Apo-B,-E, while HDL-C levels were significantly lower. Except for the lower serum albumin levels in both dialyzed groups after six months lower ApoAI levels and higher ApoB levels were observed in HD and PD patients respectively. Lp(a) levels remained unchanged in HD group, while a statistically significant increase appeared in PD patients that was negative correlated with the decreased serum albumin levels. These results indicate that renal replacement modalities result in a different effect in lipoprotein metabolism that may play an important role in atherosclerotic vascular disease of dialyzed ESRD patients.     

Plasma concentrations of 18-hydroxycorticosterone and aldosterone in continuous ambulatory peritoneal dialysis and hemodialysis patients

This study explores the hypothesis that the continuous ultrafiltration that accompanies continuous ambulatory peritoneal dialysis (CAPD) produces greater activation of the renin-angiotensin aldosterone axis than does the intermittent ultrafiltration that accompanies thrice weekly hemodialysis (HD). Plasma renin activity (PRA), active renin (AR), total renin (TR), inactive renin (IR), 18-hydroxycorticosterone (18-OH-B), aldosterone (PAC), and cortisol were measured in plasma from CAPD (n = 6) and HD (n = 10) patients. Blood from CAPD patients was sampled at 8 AM after overnight recumbency and at 12 noon after four hours ambulation. Blood from HD patients was sampled immediately pre-HD (8 AM) and post-HD (12 noon) at both 8 AM and 12 noon. PRA (P less than 0.01), AR (P less than 0.01), and AR/TR (100%; P less than 0.01) were higher in CAPD than in HD. IR and TR were not different in the two groups. Plasma 18-OH-B was normal in HD but markedly elevated in CAPD. 18-OH-B was higher in CAPD than in HD at 8 AM (P less than 0.05) and at 12 noon (P less than 0.05). Plasma cortisol was not different in the two groups. We conclude that the greater degree of renin activation in CAPD versus HD contributes to the higher levels of 18-OH-B and PAC observed in CAPD patients.     

Intraperitoneal secretion of interleukin-6 during continuous ambulatory peritoneal dialysis

Interleukin-6 (IL-6) was determined in serum and peritoneal dialysis effluent (PDE) of patients on chronic ambulatory peritoneal dialysis (CAPD) by a biological assay measuring the proliferation of the IL-6-dependent 7TD1 cell line. Six patients free of peritonitis displayed low but significant levels of IL-6 (mean +/- 42 pg/ml) in PDE, while IL-6 was undetectable in serum. In 6 patients with staphylococcal peritonitis, a tremendous increase in PDE levels of IL-6 was noted (range: 5,832-37,491 pg/ml), while serum IL-6 remained either undetectable or on a low level except in one case. After 5 days of antibiotic treatment, IL-6 levels in PDE returned to basal values. We conclude that CAPD results in an intraperitoneal secretion of IL-6 which is markedly but transiently increased during peritonitis episodes.     

Plasma oxalate in patients with chronic renal failure receiving continuous ambulatory peritoneal dialysis or hemodialysis

Plasma oxalate was measured in 20 patients receiving continuous ambulatory peritoneal dialysis (CAPD) and 20 patients receiving hemodialysis (HD). All patients had levels well above the reference range of less than 2.0 to 5.0 mumol/L (less than 0.18 to 0.44 mg/L), the medians being 34 mumol/L (2.99 mg/L) and 42 mumol/L (3.70 mg/L) for the two groups, respectively. Plasma oxalate did not differ significantly in the two groups. Plasma oxalate was not influenced by the number of months patients had received dialysis treatment, but a significant correlation was found between oxalate and creatinine in the 40 patients studied (P less than 0.02, r = 0.38). Predialysis oxalate levels were reduced by approximately 60% following HD, but returned to 80% of the predialysis levels within 24 hours and 95% within 48 hours. Oxalate levels did not differ significantly in samples taken before, during, and after exchanges of CAPD fluid. That the patients treated with CAPD did not have higher oxalate levels than the HD group suggests that the continuous nature of the former treatment compensates for the lower oxalate clearance by the peritoneum. The reported higher risk of oxalosis associated with intermittent peritoneal dialysis has led to a similar risk being postulated for CAPD; however, the present study indicates that if such a risk exists, it cannot be explained by higher levels of oxalate or ionized calcium in these patients.     

Mechanism of increased serum soluble interleukin-2 receptor levels in patients on continuous ambulatory peritoneal dialysis.

OBJECTIVE: The aim of this study was to investigate the mechanism underlying the increase of serum soluble interleukin-2 receptor (IL-2R) levels in patients on continuous ambulatory peritoneal dialysis. MATERIAL AND METHODS: In 13 dialysis patients and 17 healthy controls, serum soluble IL-2R levels were determined by enzyme-linked immunosorbent assay, and CD25-positive (cell surface IL-2R-positive) cells were detected by flow cytometry. Soluble IL-2R levels were also measured in the supernatant of cultured peripheral blood mononuclear cells. RESULTS: The serum soluble IL-2R level was significantly higher in the patients than in the healthy controls (p < 0.0001). In contrast, both the percentage and the absolute count of CD25-positive cells showed no significant differences, and neither did the soluble IL-2R level in culture supernatant. Serum soluble IL-2R levels showed a positive correlation with the serum beta2-microglobulin level (p < 0.01), the age of the patients (p < 0.05), and duration of dialysis (p < 0.05), as well as a negative correlation with the urine volume (p < 0.05). CONCLUSIONS: The increase of serum soluble IL-2R in patients on peritoneal dialysis may be caused by accumulation due to its low transperitoneal clearance and low urinary excretion.     

Comparison of buffering capacity in patients on hemodialysis and continuous ambulatory peritoneal dialysis

A standard acid loading test was used to assess the buffering capacity in 9 hemodialysis (HD) and 25 continuous ambulatory peritoneal dialysis (CAPD) patients. There was a significant increase in H+ concentration and a decrease in plasma bicarbonate levels after the acid loading in all patients; however, PaCO2 did not change significantly. CAPD patients tolerated the acid load better, at least in the first 2 h, than HD patients. The brief duration of experiments did not allow us to observe differences, if any, in the recovery rates between HD and CAPD patients. CAPD patients tolerated the acid load equally, whether studied with or without fresh dialysate in the peritoneal cavity. Their tolerance to the acid load did not change with an increasing duration of the CAPD therapy. Baseline values and acid tolerance curves were similar in CAPD patients on regular Dianeal (lactate 35 mEq/l) and Dianeal PD2 (lactate 40 mEq/l). It is concluded that the buffering capacity is marginally higher in CAPD than in HD patients, although the baseline acid-base parameters were essentially identical.     

Comparison of home hemodialysis to continuous ambulatory peritoneal dialysis

We evaluated prospectively various outcome measurements of patients assigned initially to continuous ambulatory peritoneal dialysis (CAPD) and home hemodialysis (HHD) from February 1979 to August 1981 and the causes for failures of the techniques. Morbidity was assessed by time in hospital/time on dialysis. Fifty-six patients were trained for CAPD and 37 for HHD. Those assigned to CAPD experienced an increased frequency of hospitalization (7.5% CAPD, 2.8% HHD, respectively) primarily due to episodes of peritonitis. There was also a higher modality failure rate (43% vs. 16%). However, the groups were not comparable in all respects. For example, the CAPD population included 21 patients with major cardiovascular diseases versus only three in the HHD group. The demographic characteristics of both populations including race, sex, age, income, place of residence, marital status, and education were similar. At the time of this study there is no direct evidence showing that healthy patients otherwise able to perform HHD may be maintained with less morbidity for a prolonged period utilizing CAPD. Therefore, we suggest that HHD is the home method of choice for patients able to proceed with this technique. CAPD may be indicated for patients in whom the period of home dialysis is expected to be relatively short and who would be otherwise unable to carry out home dialysis, for example, patients awaiting transplantation and those unable to be maintained on hemodialysis because of impaired cardiac function. To fully evaluate CAPD as a long-term maintenance therapy, a prospective trial must be performed.     

Serum and peritoneal dialysate thyroid hormone levels in patients on continuous ambulatory peritoneal dialysis

Thyroid function tests were performed on 16 clinically euthyroid patients with end-stage renal failure undergoing regular haemodialysis or continuous ambulatory peritoneal dialysis and compared with 8 healthy subjects. The patient groups were carefully matched, especially regarding relative duration of dialysis (mean of 24 months). Total serum thyroxine, total triiodothyronine, free thyroxine, free triiodothyronine and reverse triiodothyronine were significantly lower in both patient groups than control. The thyrothrophin response to the standard thyrotrophin-releasing hormone test was delayed and blunted. Using a novel concentration technique we measured loss of T4 in peritoneal dialysate effluent and found it to be approximately 10% of daily thyroidal T4 release.     

Leptin in peritoneal dialysate from continuous ambulatory peritoneal dialysis patients.

The adipocyte-derived hormone leptin is the 16-kd product of the ob gene that regulates food intake and body weight. Plasma leptin level is elevated in patients with chronic renal failure, partly because of impaired clearance through the kidney. In this study, we examined whether leptin is cleared into peritoneal dialysate in patients with end-stage renal disease treated by continuous ambulatory peritoneal dialysis (CAPD). The subjects were 46 CAPD patients and 67 age- and gender-matched healthy subjects. Leptin concentration in peritoneal dialysate from CAPD patients was measurable by a sensitive enzyme-linked immunosorbent assay (ELISA), and the daily loss of leptin by the peritoneal route was estimated to correspond to the amount contained in approximately 2 L plasma. Dialysate leptin concentration correlated positively with plasma leptin level and with percent body fat measured by dual-energy X-ray absorptiometry. The dialysate-to-plasma (D/P) ratio of leptin concentration was twice higher than expected from its molecular weight. D/P ratios of beta2-microglobulin, albumin, and transferrin showed strong correlations with each other (r = 0.768 to 0.801), whereas the correlation between D/P ratios of leptin and beta2-microglobulin was less impressive (r = 0.378). This was also the case with the relationship between apparent peritoneal clearances of these macromolecules, suggesting that dialysate leptin had some origins other than passive transport of plasma leptin. To test the hypothesis that abdominal visceral fat may contribute to the unexpectedly raised peritoneal dialysate leptin concentration, multiple regression analysis was performed. Leptin concentration in peritoneal dialysate showed significant association with plasma leptin level and D/P ratio of beta2-microglobulin, and it also showed an independent association with abdominal visceral fat but not with subcutaneous fat assessed by ultrasonography. These results showed that peritoneal dialysate from CAPD patients contained a significant amount of leptin, which derived presumably from both plasma and local visceral fat tissue.     

Serum ionic fluoride levels in haemodialysis and continuous ambulatory peritoneal dialysis patients

High serum fluoride (F-) in patients with chronic renal failure (CRF) and end-stage renal disease (ESRD) is associated with risk of renal osteodystrophy and other bone changes. This study was done to determine F- in normal healthy controls and patients with ESRD on haemodialysis (HD) or peritoneal dialysis (PD). Seventeen healthy controls (12 males, 5 females) and 39 ESRD patients on dialysis (17 males, 22 females) were recruited in the study in a community with 47.4 +/- 3.28 microM/l (range 44-51 microM/l) of F- content in drinking water. Control subjects showed a mean serum F- concentration of 1.08 +/- 0.350 microM/l. Males in control group showed slightly higher F- levels (1.15 +/- 0.334, range 0.55-1.9 microM/l) than females (0.92 +/- 0.370, range 0.6-1.5 microM/l). Mean serum F- concentration did not correlate significantly with age and sex among control subjects, whereas such correlation was observed in patients with ESRD on dialysis. Mean serum F- concentration was significantly higher in patients on dialysis (2.67 +/- 1.09, range 0.8-5.2 microM/l) than normal controls. When grouped according to sex, the mean serum F- concentration in males (3.05 +/- 1.04, range 1.8-5.2 microM/l) was significantly higher than females (2.38 +/- 1.08, range 0.8-5.2 microM/l). When patients were grouped according to age, it was observed that F- concentration was significantly higher in patients with age groups 21-70 (2.86 +/- 1.05) than those with age group 13-20 years (1.42 +/- 0.531). Thus F- concentration correlated with age and sex, being higher in males and above 20 years. Despite appreciable clearance of F- (39-90%) across the peritoneum, patients on CAPD showed higher serum F- concentration than those on HD (3.1 +/- 1.97 vs 2.5 +/- 1.137 microM/l). Of the total 39 patients on dialysis 39% had their serum F- concentration above 3.0 microM/l, posing the risk of renal osteodystrophy.      

Carpal tunnel syndrome in dialysis patients: comparison between continuous ambulatory peritoneal dialysis and hemodialysis populations

Carpal tunnel syndrome (CTS) has been reported with increased frequency in hemodialysis (HD) patients. A comparative study of patients on continuous ambulatory peritoneal dialysis (CAPD) has not been previously reported. To delineate the significance of dialytic modality and access-related risk factors, this study investigated the incidence and patient characteristics of CTS in CAPD v HD populations. One hundred and fifty one patients (HD n = 90, CAPD n = 61) were evaluated by questionnaire, physical examination, and nerve conduction studies. Age, gender, renal diagnosis, access, diabetic history, and duration of dialysis were determined. Eight of 57 CAPD and 15/83 HD patients had CTS. chi 2 testing revealed no significant difference in incidence (P = 0.7). It is concluded that CTS occurs with similar incidence in CAPD and HD populations. Dialytic modality and access are not likely to be factors in the development of CTS. Rather, CTS is a metabolic complication of end-stage renal failure.     

Iodine retention and thyroid dysfunction in patients on hemodialysis and continuous ambulatory peritoneal dialysis

Povidone-iodine is frequently used as an antiseptic in patients on chronic dialysis. In order to determine if the use of povidone-iodine affects thyroid function in these patients, we measured serum iodine and thyroid hormone levels in dialysis patients prior to and following discontinuation of topical povidone-iodine antiseptics. Serum inorganic iodine levels were elevated initially in nearly 90% of the patients (19 on hemodialysis, 12 on continuous ambulatory peritoneal dialysis [CAPD]). Following discontinuation of povidone-iodine, iodine levels over a 3-month period decreased modestly in patients on CAPD (n = 5) and were unchanged in patients on hemodialysis (n = 5). Total and free thyroxine levels were frequently low but did not correlate with protein-bound or inorganic iodine levels and did not change after discontinuation of povidone-iodine. Thyrotropin levels correlated significantly (r = .62, P less than .01) with inorganic iodine levels in patients on hemodialysis, but not for patients on CAPD. We conclude that abnormal thyroid function tests are common in dialysis patients but are not related to iodine retention or to the routine use of topical povidone-iodine-containing antiseptics.     

Potassium metabolism in continuous ambulatory peritoneal dialysis patients

Background: Hypokalemia is common and may have contributed to the poor clinical outcome in peritoneal dialysis (PD) patients. In this study, we made a detailed investigation on the potassium metabolism in continuous ambulatory peritoneal dialysis (CAPD) patients and tried to find out the possible factors associated with the high prevalence of hypokalemia in PD patients. Methods: A cross-sectional survey in 243 clinically stable CAPD patients was made in our PD center in 2010. Patients were divided into four groups according to whether they were anuric or not and different dialysis regimens. Patients’ demographic data and data on potassium metabolism including dietary potassium intakes, residual renal potassium, and peritoneal dialysis potassium removal were collected. Results: The average potassium intake in our 243 PD patients was 32.1?±?11.1?mmol/day. The total potassium removal was significantly higher in non-anuric patients as compared to anuric patients (33.2?±?9.1 vs. 23.0?±?4.7?mmol/day for 3 exchanges per day and 35.2?±?8.9 vs. 28.6?±?6.3?mmol/day for 4 exchanges per day, respectively, p?p?p?p?R² linear?=?0.645, p?Conclusions: Our study suggested that if potassium intake was limited in PD patients, we should be aware of the risk of hypokalemia with high doses of PD when patients have good RRF. Our study also suggested that potassium removal in PD patients may not necessarily reflect potassium intake even if serum potassium is normal, the effect of ICW should be considered when evaluating potassium homeostasis.     

Aspergillus peritonitis in continuous ambulatory peritoneal dialysis patients

Aspergillus peritonitis is a rare and serious cause of peritonitis in continuous ambulatory peritoneal dialysis (CAPD) patients. We report 3 cases of aspergillus peritonitis in CAPD which were successfully treated by catheter removal and amphotericin. Two of the 3 patients returned temporarily to CAPD, but were subsequently transferred to hemodialysis because of membrane failure. A novel finding in 2 of the 3 cases was a positive Limulus amebocyte lysate test, despite negative bacterial cultures. We discuss the possible relevance of this finding to the diagnosis of aspergillus infections and emphasize the importance of early catheter removal for successful treatment of this condition.     

Emergency laparotomy in patients on continuous ambulatory peritoneal dialysis.

Peritonitis is the most common complication of chronic ambulatory peritoneal dialysis (CAPD). It is often a diagnostic challenge to differentiate those patients with CAPD-associated infections from those who have unrelated gastrointestinal pathology as the cause of peritonitis and would benefit from surgical exploration. A retrospective chart review was performed on all patients at a single institution who were on CAPD between the years 1990 and 1998 and who underwent laparotomy for peritonitis. Six patients underwent laparotomy. Four were male and two were female; ages ranged from 34 to 80 years. Perforated appendicitis was the cause of peritonitis in three patients, perforated diverticulitis was present in two, and one was without any suppurative intra-abdominal process. In each case CT scan of the abdomen was nondiagnostic. There was a delay in diagnosis of 10 days (range 3-21 days) and an operative mortality of 16 per cent.     

Protein C, protein S, and antithrombin III levels in patients on continuous ambulatory peritoneal dialysis and hemodialysis

Patients undergoing dialysis are subject to risk of thrombotic complications. We studied the plasma levels of natural coagulation inhibitors including protein C (PC), protein S (PS), and antithrombin III (AT III) in 20 patients on hemodialysis and 20 patients on continuous ambulatory peritoneal dialysis (CAPD). Total PS antigen, free PS antigen, immunological and functional activities of PC and AT III were measured. Hemodialysis patients had a higher total PS level but a lower free PS level compared with healthy controls. Both the immunological and functional activities of AT III in hemodialysis patients were significantly lower than those of controls. With the exception of total PS level, CAPD patients had comparable or even higher plasma level of natural coagulation inhibitors compared with healthy controls. Furthermore, the plasma levels of PC, PS, and AT III were significantly lower in hemodialysis patients compared with CAPD patients despite greater daily losses of PC, PS, and AT III through urinary and peritoneal routes in patients on CAPD treatment. Most of the AT III in the peritoneal dialysate was still functionally active but most of the PC was inactive. Our observations suggest an effective turnover and production of these natural coagulation inhibitors in patients on CAPD therapy but a similar compensatory mechanism does not operate efficiently in patients receiving hemodialysis.