Serum leptin, resistin, and lipid levels in patients with end stage renal failure with regard to dialysis modality

Little information is available on the relationship between serum resistin levels and other adipokines with serum lipid levels and insulin resistance in uremic patients under different dialysis modalities. METHODS: This study investigated the effects of dialysis modality on serum leptin, adiponectin, resistin, interleukin 6 (IL-6), and tumor necrosis factor (TNF) alpha levels in age, sex, and total adipose tissue mass (TATM); matched 30 hemodialysis (HD) patients, 30 continuous peritoneal dialysis (CAPD) patients, and 30 healthy controls; and evaluated the relationship between these adipokines and dyslipidemia and insulin resistance. RESULTS: Serum resistin, adiponectin, IL-6, TNF-alpha, and high sensitive C reactive protein (hsCRP) levels were significantly increased in dialysis patients compared to controls (p < 0.05). In CAPD patients, serum leptin, resistin, triglycerides, and total cholesterol levels were higher than those in HD patients (p < 0.05). Leptin levels were positively correlated with TATM, serum triglycerides, total cholesterol, and low density lipoprotein (LDLc) levels in both dialysis groups. Resistin levels were found to positively correlate with TATM and triglycerides in CAPD patients. No relationship was found between the homeostasis model assessment-insulin resistance index (HOMA-IR) and adipokines studied. CONCLUSION: Serum leptin, resistin, triglycerides, and total cholesterol levels were higher in CAPD patients. Leptin levels were positively correlated with TATM, serum triglycerides, total cholesterol, and LDLc levels in dialysis patients. Resistin levels were positively correlated with TATM and triglycerides in CAPD patients. Glucose load during CAPD may be an important factor in increased in leptin, resistin, triglycerides, and total cholesterol levels in CAPD patients. These results highlight the importance of leptin and resistin as determinants of dyslipidemia, especially in CAPD patients.     

Serum erythropoietin levels and hematocrit in end-stage renal disease: influence of the mode of dialysis

Serum erythropoietin (Ep) levels were measured by radioimmunoassay in 70 patients with end-stage renal disease (ESRD) to evaluate the influence of the mode of dialysis on the relationship between serum Ep levels and the severity of anemia. Thirty-five patients were on hemodialysis (HD), seven were on intermittent peritoneal dialysis (IPD), and 28 were on continuous ambulatory peritoneal dialysis (CAPD). Compared to HD, CAPD patients had higher serum Ep (CAPD), 46.1 +/- 13.4 v HD, 16.9 +/- 2.2 mU/mL) and hematocrit (CAPD, 33.9 +/- 2.5 v HD, 24.8 +/- 1.4%; P less than 0.05). The Ep and Hct values for IPD patients were intermediate between the other two groups. Serum Ep levels were higher in CAPD patients in the first 4 weeks of initiation of CAPD (144 +/- 35 mU/mL, n = 6) than later (39 +/- 6.4 mU/mL, n = 24). A significant fluctuation in serum Ep and Hct values was noted in patients on all three modes of dialysis, when multiple samples were obtained at different time intervals. There was a weak correlation between serum Ep and Hct in the three groups of dialysis patients; r = 0.36, P less than 0.005. The data suggest that CAPD provides a better biochemical milieu for Ep production and responsiveness than HD treatment of ESRD.     

Serum Leptin,Resistin, and Lipid Levels in Patients with End Stage Renal Failure with Regard to Dialysis Modality

Little information is available on the relationship between serum resistin levels and other adipokines with serum lipid levels and insulin resistance in uremic patients under different dialysis modalities. Methods. This study investigated the effects of dialysis modality on serum leptin, adiponectin, resistin, interleukin 6 (IL-6), and tumor necrosis factor (TNF) α levels in age, sex, and total adipose tissue mass (TATM); matched 30 hemodialysis (HD) patients, 30 continuous peritoneal dialysis (CAPD) patients, and 30 healthy controls; and evaluated the relationship between these adipokines and dyslipidemia and insulin resistance. Results. Serum resistin, adiponectin, IL-6, TNF-α, and high sensitive C reactive protein (hsCRP) levels were significantly increased in dialysis patients compared to controls (p < 0.05). In CAPD patients, serum leptin, resistin, triglycerides, and total cholesterol levels were higher than those in HD patients (p < 0.05). Leptin levels were positively correlated with TATM, serum triglycerides, total cholesterol, and low density lipoprotein (LDLc) levels in both dialysis groups. Resistin levels were found to positively correlate with TATM and triglycerides in CAPD patients. No relationship was found between the homeostasis model assessment-insulin resistance index (HOMA-IR) and adipokines studied. Conclusion. Serum leptin, resistin, triglycerides, and total cholesterol levels were higher in CAPD patients. Leptin levels were positively correlated with TATM, serum triglycerides, total cholesterol, and LDLc levels in dialysis patients. Resistin levels were positively correlated with TATM and triglycerides in CAPD patients. Glucose load during CAPD may be an important factor in increased in leptin, resistin, triglycerides, and total cholesterol levels in CAPD patients. These results highlight the importance of leptin and resistin as determinants of dyslipidemia, especially in CAPD patients.     

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.     

Accumulation of circulating advanced oxidation protein products is an independent risk factor for ischaemic heart disease in maintenance haemodialysis patients

Aim: Whether the burden of advanced oxidation protein products (AOPP) accumulation, a marker of oxidative stress, is affected by dialysis modality remains unclear. We compared the serum levels of AOPP in patients on haemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) and tested the hypothesis that an accumulation of AOPP was an independent risk factor for cardiovascular disease. Methods: This was a cross-section study. A total of 2095 patients (1539 HD, 556 CAPD) were recruited from the nine largest dialysis centres in China. Persons in medical centres for disease screening were selected as controls. Patients maintained on HD were dialyzed twice or thrice weekly. CAPD patients used lactate-buffered, glucose-containing solutions. The patients' data were abstracted from the medical record. The serum levels of AOPP were determined by spectrophotometric detection. Results: The levels of AOPP were significantly elevated in both HD and CAPD patients compared to healthy controls. Accumulation of AOPP was more significant in HD compared to CAPD population. Meanwhile, AOPP accumulation was associated with the presence of ischaemic heart disease (IHD) only in HD, but not CAPD patients. A higher proportion of IHD was found in the HD population among those with higher levels of AOPP in each category of age and irrespective of the presence or absence of high triglyceride. Multivariate regression analysis indicated that accumulation of AOPP was an independent risk factor for IHD in HD population. Conclusion: Accumulation of AOPP was more significant in HD compared to CAPD patients. The level of AOPP was independently associated with IHD only in HD patients.     

The uremic dyslipidemia: a cross-sectional and longitudinal study.

Patients on maintenance hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) exhibit numerous disturbances of serum lipids and apoproteins that may contribute to their high cardiovascular mortality. Cross-sectional studies have found that lipid levels are inversely related to time on dialysis. However, it is not known whether this association is the result of the attrition of hyperlipidemic patients or a decrease in lipid levels over time in all patients. Additionally, few studies have investigated the effect of dialysis modality on the lipoprotein disturbances of uremia adjusting for the confounding influences of demographics, or nutritional and endocrine status. To address these issues, we undertook a cross-sectional and longitudinal study of lipids, apoproteins, and atherogenic risk ratios in patients maintained on HD and CAPD. Patients were enrolled in annual cohorts from 1987 to 1990 and monitored until 1991. A total of 196 HD and 77 CAPD patients were studied. Total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), apoprotein (apo) A-I, and apo B were measured on enrollment and remeasured annually in survivors through 1990. Using multivariate methods, we examined the relationship of the lipids, apoproteins, their respective ratios, and their changes over time, to a broad range of clinical factors and to mortality. Compared with HD patients, CAPD patients had significantly higher TC, apo A-I, and apo B, and a significantly lower apo A-I/apo B ratio. Serum albumin correlated directly with TC and apo B and inversely with apo A-I/apo B. For patients with normal serum albumin (> or = 3.5 g/dL [35 g/L]), CAPD patients had a significantly higher TC/HDL-C than HD patients; otherwise the ratios were similar for CAPD and HD. Independent influences on lipoprotein levels in HD and CAPD patients were also demonstrated for race, gender, and diabetes, but not for parathyroid hormone (PTH) levels. For both dialysis modalities, patients who died had significantly lower TC and apo B, and significantly higher apo A-I/apo B throughout their entire courses compared with survivors. In the subset of patients followed longitudinally for 2 or more years, apo B tended to decrease with time, but TC, HDL-C, and apo A-I were stable. The longitudinal changes in lipoproteins did not correlate with outcome or other factors. In conclusion, CAPD patients have more atherogenic lipoprotein profiles than HD patients. Improved visceral protein nutritional status, as defined by serum albumin level, is associated with hyperlipidemia and, especially vor CAPD, worsened atherogenic risk ratios.(ABSTRACT TRUNCATED AT 400 WORDS)     

Relationship of dialysis modality and other factors to cognitive function in chronic dialysis patients

To determine if dialysis modality may be an independent factor in the level of cognitive function in chronic dialysis patients, cognitive function was studied in 17 pairs of continuous ambulatory peritoneal dialysis (CAPD) and center hemodialysis (CHD) subjects matched for sex, age, diabetic status, and interval since dialysis onset. Data on current metabolic, medical, psychological, and vocational function status were obtained. Neuropsychological (NP) measures included the Number Cancellation Protocol (NCP), Trailmaking test forms A and B (TMT A, TMT B), Symbol Digit Modalities (SDM), and the Rey Auditory Verbal Learning Test (RAVLT). The CAPD subject group had consistently more efficient cognitive function than the CHD subject group. Regardless of modality, the groups of subjects under age 51 and those who were vocationally active had significantly better NP performance. No cognitive function differences were found in groups categorized by sex or duration of dialysis. Creatinine levels were more highly correlated with NP scores than were BUN levels, with higher creatinine levels associated with better cognitive function. Serum calcium, CO2, total protein, albumin, and SGOT levels also were correlated with NP scores. CAPD may be more effective than HD in reversing uremic encephalopathy by mechanisms mostly unrelated to serum creatinine and BUN levels. Longitudinal studies will be needed to determine if dialysis modality is an independent factor in the degree of reversal of uremic encephalopathy.     

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.     

Serum beta 2-microglobulin concentration and its removal in patients treated with continuous ambulatory peritoneal dialysis

This study was performed to clarify serum beta-2 microglobulin (beta 2-M) level and its change in 50 CAPD and 56 HD patients. There was significant correlation between duration of dialysis and serum beta 2-M level in CAPD and HD patients treated under 12 months, but no correlation in those treated over 12 months. Serum beta 2-M level was 33.5 +/- 9.1 mg/l in 45 CAPD patients treated over 12 months, and 46.2 +/- 21.1 mg/l in 35 HD patients. In 26 CAPD patients treated over 12 months, clearance and removal of beta 2-M were 1.0 +/- 0.3 ml/min and 43.0 +/- 17.8 mg/day. There was significant correlation between dwell time and beta 2-M removal (p less than 0.01), and these results suggested beta 2-M was removed by diffusion. Because CAPD treatment can lower serum beta 2-M level compared to HD, there is possibility that CAPD is useful at prevention of dialysis associated amyloidosis.     

Insulin-like growth factor system components in relation to erythropoietin therapy and bone metabolism in dialyzed patients and kidney transplant recipients

Insulin-like growth factor (IGF) system components appear to be the most important regulators of bone cell function. On the other hand, IGF-1 is shown to be an important regulator for erythropoiesis. The aim of the study was to examine the relationships between IGF system, requirements of erythropoietin, endogenous erythropoietin levels, bone metabolism assessed by biochemical markers, markers of nutrition such as cholesterol and albumin in recombinant human erythropoietin (rHuEPO)-treated patients maintained on chronic hemodialyses or peritoneal dialyses as well as in kidney transplant recipients. The studies were performed on 79 chronically hemodialyzed patients; 28 of them did not receive rHuEPO, 51 subjects received rHuEPO, 34 patients on continuous ambulatory peritoneal dialysis (CAPD), 16 of them did not receive rHuEPO, 18 were given rHuEPO and 46 kidney allograft recipients. Endogenous erythropoietin concentration, bone-specific alkaline phosphatase and serum CrossLaps were assayed by ELISA. Intact PTH, osteocalcin, 1,25-(OH)(2) D(3), 25-OH D(3), IGF-1, procollagen type I carboxy-terminal extension peptide (PICP) and procollagen type I cross-linked carboxy-terminal telopeptide (ICTP) were studied by RIA, whereas IGFBP-1 and IGFBP-3 concentrations were assayed by IRMA. We found a significantly higher IGF-1 and IGFBP-3 in rHuEPO-treated HD patients when compared to CAPD subjects given rHuEPO as well as to hemodialysis (HD) patients not treated with rHuEPO. IGF-1 was significantly higher in kidney transplant recipients when compared to dialyzed patients without rHuEPO therapy. IGFBP-1 was similar in all groups of patients (including kidney transplant recipients) studied. In CAPD patients not given rHuEPO concentrations of ICTP and PICP were significantly lower when compared to rHuEPO-treated CAPD subjects and HD patients not receiving rHuEPO therapy. Serum CrossLaps in CAPD patients treated with rHuEPO were significantly higher when compared to CAPD subjects without rHuEPO treatment and to kidney transplant recipients. In rHuEPO-treated CAPD subjects IGF-1 and IGFBP-1 correlated positively with serum CrossLaps (r = 0.61, p < 0.05 and r = 0.64, p < 0.05, respectively), whereas in hemodialyzed patients without rHuEPO a significant negative correlation between IGFBP-3 and serum CrossLaps was found (r = --0.69, p < 0.001) as well as between IGFBP-3 and aluminium (r = 0.51, p < 0.05), IGF-1 and ICTP (r = --0.43, p < 0.05). In conclusion, our data indicate a probable functional relationship between IGF system components, erythropoietin treatment in dialyzed patients and bone metabolism in renal replacement therapy in a form of hemodialyses, peritoneal dialyses and kidney transplantation. Dialyzed patients exhibit more pronounced renal osteodystrophy than kidney allograft recipients. IGF system components are influenced by erythropoietin therapy, but are not related to serum erythropoietin levels and rHuEPO requirements.     

The effect of renal replacement therapies on serum gastrointestinal system hormones

BACKGROUND: The kidney is a major site for the inactivation, degradation, and clearance of a variety of peptide hormones. It has been shown that the uremia increases or decreases gastrointestinal system (GIS) hormones. Moreover, studies investigating the serum GIS hormones levels in chronic renal failure (CRF) were conducted mainly in a particular period of the renal replacement therapy, and the changes caused by continuous ambulatory peritoneal dialysis (CAPD) and hemodialysis (HD) could not be fully demonstrated. In this study, we investigated the effect of CAPD and HD on serum GIS hormones (amylase, lipase, trypsinogen, and gastrin) levels in CRF patients who were diagnosed for the first time. METHODS: Serum amylase, lipase, trypsinogen, and gastrin levels were measured in 36 patients who were just diagnosed with CRF, 22 patients with CAPD and 14 patients with HD. GIS hormones of these patients were measured before treatment and three months from the beginning of CAPD and HD treatment. As the control group, 20 normal healthy cases with well-matched age and gender were used. RESULTS: The mean serum amylase, lipase, secretin, and gastrin levels were found meaningfully decreased according to the beginning values at third months of the CAPD and HD treatment. However, they were higher than control group. CONCLUSION: In patients receiving CAPD or HD as renal replacement therapy, GIS hormone levels were found to be lower, albeit higher than the healthy control group.     

The Effect of Renal Replacement Therapies on Serum Gastrointestinal System Hormones

Background. The kidney is a major site for the inactivation, degradation, and clearance of a variety of peptide hormones. It has been shown that the uremia increases or decreases gastrointestinal system (GIS) hormones. Moreover, studies investigating the serum GIS hormones levels in chronic renal failure (CRF) were conducted mainly in a particular period of the renal replacement therapy, and the changes caused by continuous ambulatory peritoneal dialysis (CAPD) and hemodialysis (HD) could not be fully demonstrated. In this study, we investigated the effect of CAPD and HD on serum GIS hormones (amylase, lipase, trypsinogen, and gastrin) levels in CRF patients who were diagnosed for the first time. Methods. Serum amylase, lipase, trypsinogen, and gastrin levels were measured in 36 patients who were just diagnosed with CRF, 22 patients with CAPD and 14 patients with HD. GIS hormones of these patients were measured before treatment and three months from the beginning of CAPD and HD treatment. As the control group, 20 normal healthy cases with well-matched age and gender were used. Results. The mean serum amylase, lipase, secretin, and gastrin levels were found meaningfully decreased according to the beginning values at third months of the CAPD and HD treatment. However, they were higher than control group. Conclusion. In patients receiving CAPD or HD as renal replacement therapy, GIS hormone levels were found to be lower, albeit higher than the healthy control group.     

CAPD versus haemodialysis: A comparison in the same patients

Most studies comparing CAPD and haemodialysis (HD) were done in different populations, matched for sex and age. The present report compared 13 non-diabetic end-stage renal failure patients who were treated for at least six months with each type of therapy. Analysis of the data revealed a higher haemoglobin during CAPD but no differences in the blood transfusion requirements. Serum creatinine, BUN and potassium were lower during CAPD and serum calcium was higher during HD. Serum cholesterol levels were higher during CAPD and returned to pre-CAPD levels during the fourth month after being transferred to HD. Hospitalization rates were similar with the two treatments. Our study confirmed previous sex- and age-matched studies comparing CAPD and HD therapy.     

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.     

"High-dose" calcitriol for control of renal osteodystrophy in children on CAPD

High doses of calcitriol were used prospectively for 11 to 29 months to raise serum calcium levels in an effort to control renal osteodystrophy in 16 children undergoing CAPD. Serum Ca, P, iPTH and alkaline phosphatase were measured monthly; hand radiographs were obtained every six months, and a semiquantitative score of bone abnormalities was evaluated by two independent observers. During the study, serum Ca increased from 9.9 +/- 0.9 to 11.0 +/- 0.6 mg/dl (P less than 0.001); serum iPTH decreased by 113 +/- 131 microliter Eq/ml (P less than 0.005); serum P was unchanged; and serum alkaline phosphatase fell by 33 +/- 46% (P less than 0.02), 530 +/- 397 to 204 +/- 551 IU/liter. The radiographic score fell from 4.8 +/- 4.6 to 0.9 +/- 1.2 (P less than 0.005). The average and maximal doses of calcitriol were 0.61 +/- 0.37 and 0.95 +/- 0.56 microgram/day or 28 +/- 18 and 46 +/- 28 ng/kg body wt/day, respectively. Transient and asymptomatic hypercalcemia occurred in nine patients and two patients had reversible conjunctivitis in association with the hypercalcemia. Thus, "high dose" calcitriol prevented or controlled progression of hyperparathyroid bone disease in most pediatric CAPD patients. The failure to suppress PTH or reverse secondary hyperparathyroidism until the serum Ca rose to 10.5 to 11.0 mg/dl could reflect an increase in the "set point" for PTH suppression by serum calcium in many uremic children.     

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.     

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.     

透析患者脂蛋白A升高的意义

高脂血症是引起心血管和脑血管疾病的危险因素，为了解透析患者体内的血脂变化，测定了５０例维持性血液透析（ＨＤ）和３８例连续非卧床腹膜透析（ＣＡＰＤ）患者及５０例正常人的脂蛋白Ａ［Ｌｐ（ａ）］及其他血脂。结果ＨＤ组及ＣＡＰＤ组的Ｌｐ（ａ）均显著高于对照组（Ｐ＜０．０１），两组患者的甘油三酯、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇、载脂蛋白ＡＩ／载脂蛋白Ｂ、载脂蛋白ＡＩ、载脂蛋白Ｂ均有异常。两组患者Ｌｐ（ａ）的升高与其他异常血脂之间无相关性。３５例非糖尿病ＣＡＰＤ者Ｌｐ（ａ）升高与空腹血糖、血浆白蛋白无相关性。结果提示透析患者动脉粥样硬化的危险性可能增加。     

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.     

腹膜透析患者成纤维细胞生长因子23与骨代谢的关系

目的 探讨腹膜透析患者成纤维细胞生长因子23（FGF-23）与钙磷代谢及骨密度的关系。 方法 研究对象为中南大学湘雅医院持续性不卧床腹膜透析（CAPD）患者59例,按照世界卫生组织骨密度评分标准将CAPD患者分为骨质正常、骨质降低、骨质疏松3组,另设健康对照组30例。酶联免疫吸附法检测FGF-23、1,25（OH）2VitD3;免疫化学发光法检测甲状旁腺激素（PTH）;自动生化分析仪测量血钙（Ca）、磷（P）;双能X射线吸收仪测量骨密度（BMD）。 结果 CAPD患者股骨颈部位的骨质疏松率为23.7%,腰椎部位的骨质疏松率为35.6%。3组间FGF-23水平差异无统计学意义,但CAPD组FGF-23水平显著高于健康对照组（P ＜ 0.01）。Pearson相关分析显示log[FGF-23]与血磷呈正相关（r = 0.604,P ＜ 0.01）;与肾小球滤过率（GFR）、1,25（OH）2VitD3呈负相关（r = -0.651,P ＜ 0.01;r = -0.401,P ＜ 0.05）;与 PTH、Ca、T值、透析龄无相关。 结论 CAPD患者血FGF-23显著增高,血磷、肾功能状态、1,25（OH）2VitD3均可调节血FGF-23水平,但FGF-23与骨密度降低无直接关系。