Serum free carnitine, carnitine esters and lipids in patients on peritoneal dialysis and hemodialysis

Serum free and esterified carnitine levels as well as lipids were investigated in patients undergoing regular hemodialysis (HD) treatment before and during 12 weeks of treatment with L-carnitine (1 g i.v.) at the end of each HD. The results were compared with those obtained in patients on continuous ambulatory peritoneal dialysis (CAPD; n = 15) or intermittent peritoneal dialysis (IPD; n = 3) and healthy controls (CO; n = 20). In HD patients (n = 23) total carnitine (TC) was 49.9 +/- 3.9 (CO: 46.0 +/- 2.5; NS), free carnitine (FC) was 31.6 +/- 2.8 (CO: 37.4 +/- 1.3; p less than 0.05), short-chain acylcarnitine (SCC) was 17.0 +/- 1.8 (CO: 7.2 +/- 0.9; p less than 0.0001) and long-chain acylcarnitine (LCC) was 1.2 +/- 0.2 mumol/l (CO: 0.6 +/- 0.1; p less than 0.05). FC was in the normal range in CAPD (35.6 +/- 3.2) and IPD (44.5 +/- 8.0 mumol/l) patients, whereas SCC (30.1 +/- 3.5) and LCC (2.9 +/- 0.2) levels were maximal elevated in IPD patients (11.8 +/- 0.8 and 1.5 +/- 0.2 on CAPD). Therefore, TC was higher in IPD than in CAPD patients (77.5 +/- 5.0 vs. 49.0 +/- 3.5 mumol/l). 12 weeks after L-carnitine supplementation in HD patients, TC was 313.9 +/- 22.6, FC was 207.7 +/- 12.4, SCC was 99.6 +/- 12.1 and LCC was 7.1 +/- 0.6 mumol/l. TC and FC were significantly lower in females compared with males. Total cholesterol and ketone bodies were normal, HDL cholesterol was significantly decreased before and after L-carnitine supplementation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Malnutrition-inflammation-atherosclerosis (MIA) syndrome components in hemodialysis and peritoneal dialysis patients

BACKGROUND: Malnutrition, inflammation, and atherosclerosis (MIA syndrome) are common in end-stage renal disease (ESRD) patients. Each component of MIA syndrome is the predictor of outcomes in ESRD patients. In this cross-sectional study, we aimed to compare both dialysis modalities for MIA syndrome components. MATERIAL AND METHODS: Thirty hemodialysis (HD) (mean age 44 +/- 11 years, 14 male and 16 female, mean time on dialysis: 31.0 +/- 19.0 months) and 30 continuous ambulatory peritoneal dialysis (CAPD) patients (41 +/- 9 years, 12 male and 18 female, mean time on dialysis: 25.5 +/- 21.5 months) were included. In order to determine malnutrition in ESRD patients, serum albumin level and anthropometric measurements were used. For inflammation, serum C-reactive protein level, erythrocyte sedimentation rate, and fibrinogen levels were measured. Mean-carotid artery intima media thickness (m-CIMT), presence of carotid plaque and serum homocysteine level were used to determine atherosclerosis. RESULTS: Five CAPD patients (16%) and one HD patient (3%) was hypoalbuminemic. HD and CAPD groups were similar for inflammation. Mean-CIMT and serum homocysteine level were higher in HD patients than CAPD patients. There was a positive correlation between homocysteine and m-CIMT. CONCLUSION: Before choosing renal replacement therapy, malnutrition, inflammation, and atherosclerosis parameters must be investigated in ESRD patients. Hemodialysis seems to be more advantageous for malnutrition components than CAPD. Both dialysis modalities seem to be similar for inflammation, and CAPD modality has superiority for atherosclerosis. Before choosing the type of renal replacement therapy, assessment of MIA syndrome components could be useful for individualization of the decision on which dialytic modality is appropriate in ESRD patients.     

Leptin in CAPD patients: serum concentrations and peritoneal loss.

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.     

Effects of chronic peritoneal dialysis on thyroid function tests

Peritoneal dialysis is associated with large losses of protein. In order to quantify thyroid hormone excretion in the dialysate and to examine the possibility that peritoneal dialysis may result in clinical hypothyroidism, nine endstage renal disease (ESRD) patients undergoing either continuous ambulatory peritoneal dialysis (CAPD) or chronic intermittent peritoneal dialysis (IPD) were studied. Total protein excretion in the peritoneal fluid was 21.5 +/- 2.1 g/24 h and did not vary with the mode of peritoneal dialysis. Thyroid binding globulin (TBG) excretion was 6.4 +/- 1.3 mg/24 h, higher than the values reported in the literature for urinary TBG excretion in patients with the nephrotic syndrome. Despite the higher TBG losses, serum TBG remained in the normal range. Mean peritoneal total T4 and T3 were 8.1 +/- 1.6 micrograms/24 h and 89.5 +/- 14.6 ng/24 h, and there was a significant correlation between peritoneal T4 and TBG (r = 0.69; P less than 0.01) and between peritoneal total proteins and T4 (r = 0.80; P less than 0.001). Despite the finding that large amounts of protein are lost in peritoneal fluid, T4 and T3 losses were relatively modest and remained below their daily production rates, and none of the patients were overtly hypothyroid. Serum thyroid stimulating hormone (TSH) was mildly elevated in three of nine patients and was consistent with early thyroid failure. The patients' serum iodine levels were higher than normal but did not predict the patients' thyroid status. We conclude that major protein losses could predispose patients undergoing CAPD to thyroid failure and that long-term follow-up of thyroid function is warranted in these patients.     

Hemodialysis and continuous ambulatory peritoneal dialysis effects on erythropoiesis in renal failure

Parameters of erythropoiesis were studied in patients with endstage renal disease established on continuous ambulatory peritoneal dialysis (CAPD) and regular hemodialysis treatment (RDT). Serum erythropoietin was measured by radioimmunoassay, and erythroid progenitor cell (CFU-E) formation was assayed in fetal mouse liver cultures. Serum erythropoietin concentrations in both CAPD (35.3 +/- 4.0 mU/ml) and RDT (31.9 +/- 1.9 mU/ml) patients were significantly higher (P less than 0.01) than normal values (23.1 +/- 1.0 mU/ml). The serum erythropoietin concentration did not correlate with either hematocrit or inhibition of CFU-E formation in either group of dialysis patients. In both CAPD and RDT patients the hematocrit correlated significantly (P less than 0.001) with the degree of serum inhibition of CFU-E formation. CFU-E formation decreased from 74.5 +/- 2.5 to 62.5 +/- 3.5% of control with increasing concentrations of uremic serum in cell cultures from 5 to 20%. In RDT patients a single hemodialysis produced a decrease in the mean serum erythropoietin concentration from 31.8 +/- 2.1 to 27.4 +/- 1.8 mU/ml (P less than 0.01) but no significant change in CFU-E formation. In conclusion, although serum immunoreactive erythropoietin levels are elevated above the normal range in dialysis patients, the response remains inadequate for the severity of the anemia, and it is the degree of serum inhibition of erythropoiesis in both CAPD and RDT patients which correlates with and possibly determines the degree of anemia.     

Relationships between brain natriuretic peptide, troponin I and QT dispersion in asymptomatic dialysis patients

OBJECTIVES: The relationships between increased wall stress, myocyte death, and ventricular repolarization instability in patients with heart failure were reported. DESIGN AND METHODS: The relationships between brain natriuretic peptide (BNP), a predictor of increased wall stress of hearth; troponin I (cTnI), a predictor of myocyte death; and QT dispersion (QTd), a reflection of ventricular repolarization instability were evaluated in age- and sex-matched asymptomatic 29 hemodialysis (HD) patients and 26 peritoneal dialysis (PD) patients, and the finding were compared. RESULTS: Serum BNP and cTnI levels in HD patients (722.9 +/- 907.9 pg/mL, 0.05 +/- 0.07 microg/L, respectively), just before HD, were significantly higher than those of PD patients (255.4 +/- 463.7 pg/mL, 0.02 +/- 0.02 microg/L, respectively; p < 0.05). There was no significant difference between groups with regard to corrected QTd and maximum and minimum QT intervals (p > 0.05). Serum cTnI levels were significantly and positively correlated with serum BNP levels in both dialysis groups (r = 0.447, p = 0.048). No relationship was found between plasma BNP and ECG parameters studied in both groups (p > 0.05). CONCLUSION: Increased serum cTnI levels were associated with elevated BNP levels in both dialysis groups. The increases in BNP and troponin I are more likely to reflect hypervolemia. Although CAPD patients were receiving dialysis daily and HD patients were more hypervolemic, CAPD patients have similar QTdc and accordingly a similar tendency toward arrhythmias. This suggests that factors other than electromechanical interaction may be important in determining the QT interval length in patients on dialysis.     

Role of erythropoietin in the reversal of anemia of renal failure with continuous ambulatory peritoneal dialysis

We report serum erythropoietin levels in a patient who showed significant improvement in hematocrit when switched from hemodialysis to continuous ambulatory peritoneal dialysis (CAPD) treatment. This 22-year-old woman had severe anemia and low serum immunoreactive erythropoietin levels (8.0 +/- 1.2 mU/ml; n = 5) while on hemodialysis for 7 years. Serum erythropoietin levels were 80 and 177 mU/ml, 2 and 3 weeks, respectively, after starting CAPD. This was followed by an increase in reticulocyte count from 3.9 to 22% and hematocrit from 19 to 48%. The serum erythropoietin concentration obtained on CAPD treatment (62.7 +/- 15.2 mU/ml; n = 9) was significantly higher than that obtained on hemodialysis. Our findings indicate that CAPD facilitates increased erythropoietin production compared to hemodialysis and that the anemia of uremia may reverse if sufficient erythropoietin is available.     

Fibronectin in patients with chronic renal failure undergoing dialysis

Fibronectin (FN) levels were determined in 64 cases with chronic renal failure (CRF), some of whom were undergoing dialysis. FN levels were 14.9 +/- 7.6 mg/dl in CRF (n = 20), 13.4 +/- 4.3 mg/dl in patients on continuous ambulatory peritoneal dialysis (CAPD) (n = 20) and 16.7 +/- 7.2 mg/dl in patients on hemodialysis (HD) (n = 24). All the levels were significantly lower than in normal subjects (23.1 +/- 4.6 mg/dl). Serum FN was compared with some nutritional indices. Positive correlations were found between serum FN and nitrogen balance (BN), serum prealbumin (PreA) and transferrin (Tf) in all the patients. With serum albumin (Alb), however, this correlation was only found in patients undergoing dialysis. Negative correlations were found between serum FN and the ratio of serum urea to serum creatinine (Surea/Scr) in CAPD and HD patients. In 10 CAPD patients, the low serum FN levels went up after increased protein intake. This indicates that it was the result of malnutrition due to decreased protein intake. Serum FN level reflects a negative BN earlier and better than serum PreA, Tf and Alb. It is a sensitive, reliable and simple index for judging the nutritional protein status and the effect of nutritional treatment in patients with CRF undergoing dialysis.     

The influence of l-carnitine supplementation on hematocrit and hemoglobin levels in patients with end stage renal failure on CAPD

The influence of L-carnitine supplementation on hematocrit (Hct) and hemoglobin (Hb) levels, in patients suffering from end stage renal disease (ESRD) on maintenance hemodialysis, are well known from several studies. The data concerning the serum levels of carnitine, in patients with ESRD on continuous ambulatory peritoneal dialysis (CAPD) are contradictory, but most of them support that they are rather normal. In this study the effect of L-carnitine supplementation on Hct, and Hb levels were investigated in patients suffering from ESRD on CAPD. In the study 12 patients were included (5F, 7M), aged from 39 to 92 years old (median 65.5 years), who were on CAPD for more than 6 months (from 6 to 15 months, mean +/- SD = 8.6 +/- 3.6), with normal serum ferrum and ferritin levels at the beginning of the study. Two grams of L-carnitine/ day per os (Superamin, Vianex Hellas), were administered in all the patients and the serum ferrum levels were tried to be kept stable, by exogenous ferrum administration, during the study period. If the Hct levels were more than 36% per month the erythropoietin (rHuEpo) dose of the patient was decreased monthly at the half dose/week. The changes of Hct, Hb, ferrum and ferritin levels, as well as the Indice de Rigidite (IR) of the erythrocytes were recorded, before and after the first, second and third month of the study period. Finally, the rHuEpo dose/ patient was registered monthly before and during the study. During the observations, Hct (35.4 +/- 3.3 vs. 38.1 +/- 3.4, ANOVA, p < 0.03) and Hb levels (11.0 +/- 1.1 vs. 11.9 +/- 1, ANOVA, p < 0.01), were significantly increased. On the other hand, rHuEpo dose necessity/patient/week was decreased significantly (3,833 +/- 3326 vs. 1,292 +/- 1,712, ANOVA, p < 0.01), in order to succeed the target Hct level. Furthermore, red blood cells IR also appeared to have a significant decrease (16.6 +/- 7.4 vs. 13.0 +/- 3.9, paired t-test, p < 0.03). Finally, the ferrum and ferritin levels were stable during the study period. It was concluded, that in patients on, CAPD the per os L-carnitine supplementation decreased, the red blood cells IR which contributes to the: (a) Increase of Hct and Hb levels and (b) decrease of the patients rHuEpo dose/week.     

Concentrations of thyroxine-binding globulin in sera and peritoneal dialysates in patients on chronic peritoneal ambulatory dialysis

Losses in thyroxine-binding globulin (TBG) in peritoneal dialysate and thyroid function were evaluated in patients undergoing continuous ambulatory peritoneal dialysis (CAPD), in comparison to patients on hemodialysis (HD) without TBG loss in the dialysate. The TBG concentration in the peritoneal dialysate was 0.26 +/- 0.09 microgram/ml (mean +/- SD, n = 24), with a daily loss of 2.47 +/- 0.94 mg. The serum TBG level in CAPD patients was 21.0 +/- 4.71 micrograms/ml (n = 24), which was not significantly different from that in HD patients (20.0 +/- 5.72 micrograms/ml, n = 24) or in healthy Japanese subjects. The serum TBG level correlated positively with the TBG loss and TBG level in the peritoneal dialysate (p less than 0.001). The serum T4 level in CAPD patients (4.93 +/- 1.38 microgram/dl, n = 24) was significantly greater than in HD patients (4.08 +/- 1.30 microgram/dl, n = 24, p less than 0.05).     

Comparison of the humoral markers of bone turnover and bone mineral density in patients on haemodialysis and continuous ambulatory peritoneal dialysis

Renal osteodystrophy is an important complication in patients with end-stage renal disease on maintenance dialysis. The aim of this study was to compare the biochemical markers of bone formation (serum collagen type I C-terminal propeptide) and resorption (serum deoxypyridinoline - DPD - and pyridinoline - PYR) with the bone mineral density (BMD) at lumbar spine, femoral neck, and forearm in patients with end-stage renal disease on haemodialysis (HD) versus continuous ambulatory peritoneal dialysis (CAPD). Fifty-nine adult patients, 45 on CAPD (18 females, 27 males) and 14 on HD (2 females, 12 males), were studied. The mean age was 44 +/- SEM 1.6 and 54.4 +/- 4.8 years, respectively. No significant differences in serum calcium, phosphorus, creatinine, and parathyroid hormone were found between patients on HD and CAPD in predialysis samples. Serum urea was significantly lower (p = 0.02) in the CAPD group. Serum PYR (nmol/l) and DPD (nmol/l) were significantly higher in patients on HD as compared with those on CAPD: 105 +/- 23.3 versus 43.7 +/- 3.47 (p = 0.007) and 31.0 +/- 2.4 versus 24.4 +/- 1.4 (p = 0.027), respectively. The results were still significantly higher in the HD patients following correction for serum creatinine and body mass index. There was a close correlation between dialysate DPD and creatinine in both dialysis modalities (HD r = 0.9, CAPD r = 0.76). The clearance of DPD did not differ significantly between the CAPD membrane and the HD membrane (p = 0.22). Serum collagen type I C-terminal propeptide was not significantly different between the HD and CAPD patients. The results were unaffected following correction for age and gender. The BMD was measured in 38 (65%) of the patients (HD n = 8, CAPD n = 30) by dual-energy X-ray absorptiometry and expressed as 'Z' scores. This was reduced at all sites in the patients with end-stage renal disease. The BMD was significantly lower at the ultradistal forearm (mostly trabecular bone) in HD patients as compared with CAPD patients (n = 0.02). A similar trend was observed at the lumbar spine, although the results failed to reach significance. In the whole population (n = 38), linear regression analysis revealed a significant negative correlation between BMD at the ultradistal forearm and serum PYR (r = -0.35, p = 0.04) and DPD (r = -0.33, p = 0.049). Combined measurements of BMD and biochemical markers of bone resorption may have potential in the identification of patients at high risk of bone loss who may require further evaluation of bone remodeling by bone histomorphometry.     

Clinical performance measures: the changing status of peritoneal dialysis.

BACKGROUND: The Peritoneal Dialysis-Clinical Performance Measures Project (PD-CPM) characterizes peritoneal dialysis within the U.S. Current survey results are reported and compared to those of previous years. METHODS: Prevalence data from random national samples of adult peritoneal dialysis (PD) patients participating in the United States End-Stage Renal Disease (ESRD) program have been collected annually since 1995. RESULTS: In 1995, 79% of the respondents used continuous ambulatory peritoneal dialysis (CAPD) rather than automated peritoneal dialysis (APD). The mean hematocrit (Hct) of PD patients was 32% and only 66% of individuals had a measurement of dialysis adequacy reported. The mean weekly Kt/Vurea (wKt/V) and weekly creatinine clearance (wCCr) reported for CAPD patients in 1995 were 1.9 and 67 L/1.73 m2/week, respectively. In 2000 the median age of PD patients was 55 years and 63% were white. The leading cause of ESRD was diabetes mellitus (34%) and 54% of adult PD patients performed some form of APD rather than CAPD. Age, sex, size, hematocrit, peritoneal permeability, dialysis adequacy, residual renal function and nutritional indices did not differ between APD and CAPD patients. The mean hemoglobin (Hb) for the 2000 PD-CPM population was 11.6 +/- 1.4 g/dL (mean +/- 1 SD) and 11% of patients had an average Hb below 10 g/dL. The average serum albumin was 3.5 +/- 0.5 g/dL by the bromcresol green method and 56% of subjects had an average serum albumin equal to or above 3.5 g/dL (or 3.2 g/dL by bromcresol purple). In 2000 85% of patients had a dialysis adequacy measurement reported and the mean calculated wKt/V and wCCr were 2.3 +/- 0.6 and 72.7 +/- 24.9 liters/1.73 m2/week for CAPD patients and 2.3 +/- 0.6 and 71.6 +/- 25.1 L/1.73 m2/week for APD patients. PD subjects had a mean body weight of 76 +/- 19 kg and body mass index (BMI) of 27.5 +/- 6.4 kg/m2. The protein equivalent of nitrogen appearance (nPNA) of these patients was 0.95 +/- 0.31 g/kg/day, their normalized creatinine appearance rate (nCAR) equaled 17 +/- 6.5 mg/kg/day, resulting in a percent lean body mass (%LBM) of 64 +/- 17% of actual body weight. Serum albumin correlated in a positive fashion with BMI, nPNA, nCAR and %LBM, but not with wCCr. CONCLUSIONS: The majority of indicator variables monitored by the PD-CPM have improved since 1995. PD patients have higher hemoglobins and a greater proportion of patients meet the criteria for adequate dialysis. Serum albumin values, however, remain marginal and unchanged over the five-year project. Furthermore, serum albumin values fail to correlate with the intensity of renal replacement therapy and are not strongly correlated with alternative estimates of nutritional status.     

Thyroid function and morphology in kidney transplant recipients, hemodialyzed, and peritoneally dialyzed patients

Disturbances in thyroid function are common among patients on renal replacement therapy. The aim of the present study was to compare thyroid stimulating hormone (TSH) and thyroid morphology among patients on hemodialysis (HD), peritoneal dialysis (CAPD), and after kidney transplantation. The study was performed on three groups of patients: 48 transplant recipients (Tx) (receiving cyclosporine, azathioprine, and prednisone); 32 HD, and 26 CAPD patients. The control group included 40 healthy volunteers. Thyroid examinations were performed with a 7.5-MHz probe and the thyroid volume was calculated. Among Tx patients the thyroid volume was 25.16 +/- 12.27mL; 21.60 +/- 10.33mL in HD; 19.70 +/- 8.46 mL in CAPD; and 16.34 +/- 5.46mL in the healthy volunteers. Serum TSH was within the normal range in each group. Goiter was diagnosed in the majority of Tx, most HD patients, and some CAPD patients. Single and multiple nodules were found in 21 Tx, 12 HD, and 2 CAPD patients. Moreover, parathyroid glands were visualized on sonography in 10 Tx, 12 HD, and 8 CAPD subjects. In Tx observed correlations were positive between thyroid volume and creatinine, negative between thyroid volume and TSH. The time after transplantation correlated negatively with TSH. No correlation between TSH, thyroid volume, and time on dialysis was observed. The prevalence in patients on renal replacement therapy was higher than that in the general population. These findings suggest that screening for abnormal thyroid morphology should be performed in kidney patients and that iodide supplementation should be considered in Tx patients.     

Osteocalcin levels in uremic patients: influence of calcitriol treatment through two different routes and type of dialysis.

Osteocalcin, the most abundant non-collagen protein of bone, is synthesized by the osteoblast. Serum osteocalcin concentration depends primarily on new cellular synthesis, and is a sensitive marker of bone turnover reflecting osteoblastic function. In uremic and hemodialysis (HD) patients, a direct relationship between serum osteocalcin and histological parameters of bone formation has been observed. The modality of dialysis may influence serum osteocalcin levels though the available data are controversial. The aim of this study is to assess the acute and chronic effects of calcitriol and the influence of modality of dialysis on serum osteocalcin levels. Twelve patients on continuous ambulatory peritoneal dialysis (CAPD) were treated with calcitriol. For control purposes, 24 patients, 12 on CAPD and 12 on HD, not treated with calcitriol serum osteocalcin levels were included. In CAPD patients previously treated with calcitriol, serum osteocalcin levels were higher than in nontreated patients. The higher levels occur independent of serum levels of parathyroid hormone (PTH), Ca and P. Hemodialysis patients had osteocalcin levels similar to those of CAPD patients under calcitriol treatment. However, the levels of HD patients were higher than CAPD nontreated patients. Serum ionized Ca was similar in CAPD and HD nontreated patients; however, total Ca was significantly higher in HD than in CAPD patients, both with and without calcitriol. After the intravenous administration of calcitriol, serum osteocalcin levels increased from 9.2 + 2.5 to 13.5 + 5.4 ng/ml (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Measurement of erythropoietin in anephric children

Serum erythropoietin (Ep) levels were measured using a highly sensitive radioimmunoassay in 69 children undergoing chronic dialysis; 31 were anephric, whereas 38 were non-nephrectomized (nephric). Twenty-nine normal children were studied as controls. Serum Ep levels in the anephric group were much higher than anticipated (mean 19.7±1.8 mU/ml), albeit significantly lower than those measured in normal children (mean 26.2±2.4 mU/ml,P<0.05), or in nephric children on dialysis (33.0±2.9 mU/ml,P<0.001). Anephric children on peritoneal dialysis (PD) had significantly (P<0.05) higher serum levels of Ep (22.7±2.4 mU/ml,n=19) than anephric children on hemodialysis (HD) (15.1±2.3 mU/ml,n=12). There was no significant difference between Ep levels in anephric patients dialyzed for less than or equal to 1 year (19.6±2.0 mU/ml,n=20) compared with anephric patients dialyzed for more than 1 year (20.0±3.9 mU/ml,n=11). Although serum Ep levels showed a tendency to increase with time after nephrectomy, the mean values for <3 months (14.7±1.9), 3 months–12 months (21.0±2.7), and >12 months (21.6±6.0) were not significantly different from each other. This demonstration of relatively normal levels of serum Ep in anephric children suggests that extrarenal sites of Ep production are able to exert a significant response to severe anemia in patients who are devoid of renal parenchyma.Table of SPNSG centers and investigators, and source of patients studied: Offprint requests to: R. J. Hogg, Department of Pediatrics, Baylor University Medical Center, 3500 Gaston Avenue, Dallas, TX, 75246, USA     

Impact of dialysis therapy on insulin resistance in end-stage renal disease: comparison of haemodialysis and continuous ambulatory peritoneal dialysis.

BACKGROUND: Insulin resistance contributes to the pathogenesis of atherosclerotic cardiovascular disease and, thus, has an important impact on the mortality of uraemic patients. Haemodialysis (HD) is known to improve insulin resistance observed in uraemia. However, it is not known whether continuous ambulatory peritoneal dialysis (CAPD) alleviates insulin resistance in adult uraemic patients. The objective of this study was to compare the effect of two different dialysis modalities, HD and CAPD, on insulin resistance in adult uraemic patients and to identify the possible predictive factors for changes in insulin resistance. METHODS: Insulin resistance was examined in 19 non-diabetic patients with end-stage renal disease (ESRD) before and after dialysis therapy (HD, n=10; CAPD, n=9), as well as in 10 healthy controls using the hyperinsulinaemic euglycaemic glucose clamp technique. The glucose disposal rate (GDR mg/kg/min) was used as an index of insulin sensitivity during the clamp technique. We also determined which of various biochemical parameters might be associated with change in insulin resistance by carrying out multiple logistic regression analysis. RESULTS: GDR was significantly lower (6.44+/-1.76) in ESRD subjects than in normal subjects (9.90+/-2.01). HD and CAPD therapies significantly normalized GDR from 6.53+/-1.84 to 9.74+/-2.88 and from 6.35+/-1.65 to 8.18+/-1.76 respectively. Multiple logistic regression analysis showed that changes in BUN, haematocrit and plasma bicarbonate were significant predictive factors for the change in insulin resistance. CONCLUSION: CAPD therapy, in spite of its possible adverse effects in patients with atherosclerotic disease, has been shown to improve insulin resistance in adult uraemic patients, similarly to HD therapy.     

The red blood cell deformability in patients suffering from end stage renal failure on hemodialysis or continuous ambulatory peritoneal dialysis

Anemia is the main problem for patients suffering from end stage renal disease (ESRD). This study aimed to determine whether the index of rigidity (IR), that shows red blood cells (RBCs) deformability and the possible IR disturbances can provide an explanation about the cause of anemia, in patients undergoing maintenance hemodialysis (HD) or on peritoneal dialysis. The IR was determined in 39 hemodialyzed patients, who were already in dialysis for a period of time ranging from 16 to 120 months (mean+/-SD=41.8 +/-24.1) (Group A). Furthermore, the IR was measured in 32 patients on continuous ambulatory peritoneal dialysis (CAPD), who were in CAPD for a period of time ranging from 6 to 60 months (mean+/-SD = 10.7+/-9.9) (Group B). Finally, the IR was determined in 17 normal individuals (group C). The RBCs IR was measured twice in group A (before and after the end of a hemodialysis session) and once in groups B and C. The IR was determined by hemorrheometry (method of filtration), using special equipment. In group A the IR was increased in comparison to the control group (C) (17.9+/-6.2 vs. 10.2+/-1.8, p<0.0001). This increase was even higher in the measurement at the end of the hemodialysis session (paired t-test, p < 0.0001). The RBCs IR in CAPD patients was significantly lower than that of HD patients (12+/-3.8 vs. 17.9+/-6.2, p<0.0001) and was not statistically different from the control group (12+/-3.8 vs. 10.2+/-1.8, p=0.068). It is concluded from the study that: 1) in HD patients occur disturbances in the deformability of the RBCs, that are worsened by the hemodialysis session; 2) the index of rigidity of RBCs is significantly higher in the HD patients than in CAPD patients; 3) in patients on CAPD, the disturbance of deformability of the RBCs was less in comparison to the control group, which however does not reach the statistically significant levels.     

High fluoride exposure in hemodialysis patients

The observation of higher plasma flouride levels in our hemodialysis (HD) patients than our continuous ambulatory peritoneal dialysis (CAPD) patients (4.0 +/- 0.5 mumol/L [n = 17] v 2.5 +/- 0.3 mumol/L [n = 17], P less than 0.005) prompted an evaluation of fluoride metabolism during HD. We found that serum fluoride was completely ultrafiltrable across cuprophane membranes (99% +/- 4%) and that HD produced acute changes in plasma fluoride levels that correlated well with the fluoride gradient between plasma and dialysis fluid at the start of dialysis. Our HD fluids contained significantly higher fluoride concentrations than were present in commercially prepared peritoneal dialysis fluid. Our fluids are prepared from fluoridated tap water that is purified by reverse osmosis (RO). We conclude that the different concentrations of fluoride in our dialysis fluids account for the differences in the plasma flouride concentrations between our dialysis groups. Since many HD units rely on RO systems to purify fluoridated tap water, it is likely that many HD patients are being exposed inadvertently to increased concentrations of fluoride.     

Ultrasonic gallbladder function in chronic kidney disease: does predialysis, hemodialysis, or CAPD affect it?

BACKGROUND: There are contradictory reports about the prevalence of cholelithiasis in chronic kidney disease (CKD). The pathogenesis of gallstones is associated with the lithogenic changes of bile composition, increased tendency to nucleation, and decreased gallbladder motility. The studies related to these factors can predict the development of cholelithiasis. The aim of this study was to evaluate the ultrasonic gallbladder function in CKD and to compare it in predialysis (PreD), hemodialysis (HD), and continuous ambulatory peritoneal dialysis (CAPD) patients. METHODS: Age, gender, and body mass index matched 49 CKD patients (14 PreD, 19 HD, 16 CAPD), and 17 control individuals were included in the study. Diabetic and cirrhotic patients were not included. Ultrasonic gallbladder volume was evaluated in pre- and postprandial period, and ejection fraction was calculated. We also measured several biochemical parameters (cholesterol, triglyceride, blood urea nitrogen (BUN), creatinine, calcium, Phosphorus, parathormone, albumin, total protein) in blood. RESULTS: Preprandial gallbladder volume in PreD, HD, CAPD, and control groups were 26.7 +/-13.6, 20.8+/-10.4, 23.2+/-14.7, and 26.4+/-14.8 mL, respectively (p > 0.05). Ejection fractions were 54.1 +/- 22.9%, 54.9 +/- 23.9%, 48.6 +/- 15.9%, and 51.8 +/- 19.2% in PreD, HD, CAPD, and control groups, respectively (p > 0.05). Serum triglyceride was higher in PreD patients than control group (207 +/- 144 vs. 110 +/-48 mg/dL) (p<0.05). Serum BUN, Cre, P, and PTH levels were higher in CKD groups than the control group, whereas serum total protein and albumin levels were higher in the control group (p<0.05). Serum Ca was lower in PreD and HD patients than in the controls (p<0.05). CONCLUSIONS: In conclusion, CKD and renal replacement therapy (HD and CAPD) do not affect gallbladder functions, but more studies are needed to evaluate prevalence of gallstones, gallbladder motility, and the composition of bile in CKD.     

Comparison of five modes of dialysis in neurosurgical patients with renal failure

In neurosurgical patients with renal failure, dialysis entails specific problems, chief of which is increased intracranial pressure and progressive brain edema as a result of rapid lowering of the serum osmolality. Another major problem is a tendency to hemorrhage, in response to either systemic heparinization or insufficient dialysis. The authors describe the results obtained with hemodialysis (HD), continuous arteriovenous hemofiltration (CAVH), continuous ambulatory peritoneal dialysis (CAPD), continuous peritoneal dialysis (CPD), and intermittent peritoneal dialysis (IPD). Nine patients were treated with HD, one with CAVH, five with CAPD or CPD, and two with IPD. Three of the six patients treated with continuous dialysis (CAVH, CAPD, and CPD) died, whereas intermittent dialysis (HD and IPD) carried an 82% mortality rate (nine of 11 patients). The causes of death were progressive brain edema in three cases, intracranial hemorrhage in three, gastrointestinal bleeding in three, overhydration due to insufficient dialysis in one, septicemia in one, and rupture of a cerebral aneurysm in one. Continuous dialysis appeared to be superior to intermittent dialysis in these neurosurgical patients in that it produced less brain edema and was less often associated with hemorrhage due to insufficient dialysis. In HD and CAVH, systemic heparinization was also thought to account for the high incidence of hemorrhage. However, CAVH with short half-life anticoagulants may be useful in patients who have abdominal complications and are therefore not suitable candidates for peritoneal dialysis.