Association between serum n-terminal pro-brain natriuretic peptide concentration and left ventricular dysfunction and extracellular water in continuous ambulatory peritoneal dialysis patients.

BACKGROUND: This study investigated the association between serum N-terminal pro-brain natriuretic peptide (NT-pro-BNP) levels and extracellular water (ECW%) and left ventricular (LV) dysfunction in continuous ambulatory peritoneal dialysis (CAPD) patients. METHODS: The study involved 30 stable CAPD patients: 14 males, 16 females; mean age 52 +/- 14 years; mean CAPD duration 34 +/- 12 months; 12 with diabetes mellitus (DM) and 18 non-DM. Serum NT-pro-BNP levels were determined using electrochemiluminescence immunoassay. Baseline echocardiography was performed using a Hewlett-Packard Sonos 1000 (Andover, Massachusetts, USA) device equipped with a 2.25-MHz probe, allowing M-mode, two-dimensional, and pulsed Doppler measurements. Left ventricular mass index (LVMI) was calculated according to the Penn formula. A multifrequency bioimpedance analyzer was used; ECW% was calculated as a percentage of total body water and was considered the index of volume load. RESULTS: (1) Serum NT-pro-BNP level, ECW%, LVMI, and LV ejection fraction in CAPD patients were 3924 (240 - 74460) pg/mL, 36.7% +/- 2.2%, 158 +/- 48 g/m2, and 60.5% +/-11.2%, respectively. (2) Patients were divided into three tertiles (10 patients each) according to their serum NT-proBNP concentration [1st tertile 1168 (240 - 2096), 2nd tertile 4856 (2295 - 20088), 3rd tertile 35012 (20539 -74460) pg/mL]. The tertiles did not differ significantly in terms of age, sex, presence of DM, body mass index, or PD duration. Patients in the 3rd tertile (highest serum NT-proBNP concentration) had the highest LVMI (126 +/- 45 vs 160 +/-41 vs 200 +/- 23 g/m2 for 1st, 2nd, 3rd tertiles, respectively) and the lowest LV ejection fraction (66% +/- 11% vs 62% +/-6% vs 55% +/- 9%). ECW% did not differ significantly between tertiles (35.5% +/- 2.0% vs 37.5% +/- 2.0% vs 36.5% +/-2.0%). (3) In CAPD patients, serum NT-pro-BNP levels correlated positively with LVMI (r = 0.628, p = 0.003) and negatively with LV ejection fraction (r = -0.479, p = 0.033). Serum NT-pro-BNP levels did not correlate with ECW% (r = 0.227, p = 0.25). (4) Stepwise regression analysis showed that LV ejection fraction (beta = -0.610, p = 0.015) and LVMI (beta = 0.415, p = 0.007) were independently associated with the serum NT-pro-BNP concentration. CONCLUSIONS: There was no link between ECW% and serum NT-pro-BNP concentration. Thus, serum NT-pro-BNP levels may not provide objective information with respect to pure hydration status in CAPD patients. In contrast, serum NT-pro-BNP levels were linked to LVMI and LV ejection fraction in CAPD patients. Therefore, while the serum NT-proBNP concentration might not be a useful clinical marker for extracellular fluid volume load, it appears useful for evaluating LV hypertrophy and LV dysfunction in CAPD patients.     

Circulating natriuretic peptide concentrations in patients with end-stage renal disease: role of brain natriuretic peptide as a biomarker for ventricular remodeling.

OBJECTIVES: To determine levels of natriuretic peptides (NPs) in patients with end-stage renal disease (ESRD) and to examine the relationship of these cardiovascular peptides to left ventricular hypertrophy (LVH) and to cardiac mortality. PATIENTS AND METHODS: One hundred twelve dialysis patients without clinical evidence of congestive heart failure underwent plasma measurement of NP concentrations and echocardiographic investigation for left ventricular mass index (LVMI). RESULTS: Plasma atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) concentrations correlated positively with LVMI and inversely with left ventricular ejection fraction, whereas C-type NP and Dendroaspis NP levels did not correlate with LVMI. In dialysis patients with LVH (LVMI >125 g/m2), plasma ANP and BNP concentrations were increased compared with those in dialysis patients without LVH (both P<001). In a subset of 15 dialysis patients without LVH or other concomitant diseases, plasma BNP concentrations were not significantly increased compared with those in 35 controls (mean +/- SD, 20.1+/-13.4 vs 13.5+/-9.6 pg/mL; P=.06), demonstrating that the BNP concentration was not increased by renal dysfunction alone. Furthermore, the BNP level was significantly higher in the 16 patients who died from cardiovascular causes compared with survivors (mean +/- SD, 129+/-13 vs 57+/-7 pg/mL; P<.003) and was significantly associated with greater risk of cardiovascular death in Cox regression analysis (P<.001), as was the ANP level (P=.002). CONCLUSIONS: Elevation of the plasma BNP concentration is more specifically related to LVH compared with the other NP levels in patients with ESRD independent of congestive heart failure. Thus, BNP serves as an important plasma biomarker for ventricular hypertrophy in dialysis patients with ESRD.     

Peritoneal accumulation of AGE and peritoneal membrane permeability.

BACKGROUND: In continuous ambulatory peritoneal dialysis (CAPD), the peritoneal membrane is continuously exposed to high-glucose-containing dialysis solutions. Abnormally high glucose concentration in the peritoneal cavity may enhance advanced glycosylation end-product (AGE) formation and accumulation in the peritoneum. Increased AGE accumulation in the peritoneum, decreased ultrafiltration volume, and increased peritoneal permeability in long-term dialysis patients have been reported. AIM: The purpose of the study was to evaluate the relation between peritoneal membrane permeability and peritoneal accumulation of AGE. METHODS: Peritoneal membrane permeability was evaluated by peritoneal equilibration test (PET) using dialysis solutions containing 4.25% glucose. Serum, dialysate, and peritoneal tissue levels of AGE were measured by ELISA method using polyclonal anti-AGE antibody. Peritoneal biopsy was performed during peritoneal catheter insertion [new group (group N), n = 18] and removal [long-term group (group LT), n = 10]. Peritoneal catheters were removed due to exit-site infection not extended into the internal cuff (n = 6) and ultrafiltration failure (n = 4) after 51.6+/-31.5 months (13 - 101 months) of dialysis. PET data obtained within 3 months after the initiation of CAPD or before catheter removal were included in this study. Ten patients in group N and 4 patients in group LT were diabetic. Patients in group LT were significantly younger (46.5+/-11.1 years vs 57.5+/-1.3 years) and experienced more episodes of peritonitis (3.5+/-2.1 vs 0.2+/-0.7) than group N. RESULTS: Peritoneal tissue AGE level in group LT was significantly higher than in group N, in both nondiabetic (0.187+/-0.108 U/mg vs 0.093+/-0.08 U/mg of hydroxyproline, p < 0.03) and diabetic patients (0.384+/-0.035 U/mg vs 0.152+/-0.082 U/mg of hydroxyproline, p < 0.03), while serum and dialysate levels did not differ between the groups in both nondiabetic and diabetic patients. Drain volume (2600+/-237 mL vs 2766+/-222 mL, p = 0.07) and D4/D0 glucose (0.229+/-0.066 vs 0.298+/-0.081, p < 0.009) were lower, and D4/P4 creatinine (0.807+/-0.100 vs 0.653+/-0.144, p< 0.0001) and D1/P1 sodium (0.886+/-0.040 vs 0.822+/-0.032, p < 0.0003) were significantly higher in group LT than in group N. On linear regression analysis, AGE level in the peritoneum was directly correlated with duration of CAPD (r = 0.476, p = 0.012), number of peritonitis episodes (r = 0.433, p = 0.0215), D4/P4 creatinine (r = 0.546, p < 0.027), and D1/P1 sodium (r = 0.422, p = 0.0254), and inversely correlated with drain volume (r = 0.432, p = 0.022) and D4/D0 glucose (r = 0.552, p < 0.0023). AGE level in the peritoneal tissue and dialysate were significantly higher in diabetics than in nondiabetics in group LT, while these differences were not found in group N. Serum AGE level did not differ between nondiabetics and diabetics in either group N or group LT. Drain volume and D4/D0 glucose were lower and D4/P4 creatinine and D1/P1 sodium higher in diabetics than in nondiabetics in both groups. CONCLUSION: Peritoneal accumulation of AGE increased with time on CAPD and number of peritonitis episodes, and was directly related with peritoneal permeability. Peritoneal AGE accumulation and peritoneal permeability in diabetic patients were higher than in nondiabetic patients from the beginning of CAPD.     

Effect of right ventricular apex pacing on the Tei index and brain natriuretic peptide in patients with a dual-chamber pacemaker

BACKGROUND: Asynchronous electrical activation induced by right ventricular apex (RVA) pacing can cause various abnormalities in left ventricular (LV) function, particularly in the context of severe LV dysfunction or structural heart disease. However, the effect of RVA pacing in patients with normal LV and right ventricular (RV) function has not been fully elucidated. The aim of this study was to characterize the effects of RVA pacing on LV and RV function by assessing isovolumic contraction time and isovolumic relaxation time divided by ejection time (Tei index) and by assessing changes in plasma brain natriuretic peptide (BNP). METHODS: Doppler echocardiographic study and BNP measurements were performed at follow-up (mean intervals from pacemaker implantation, 44+/-75 months) in 76 patients with dual chamber pacemakers (sick sinus syndrome, n=30; atrioventricular block, n=46) without structural heart disease. Patients were classified based on frequency of RVA pacing, as determined by 24-hour ambulatory electrocardiogram (ECG) that was recorded just before echocardiographic study: pacing group, n=46 patients with RVA pacing>or=50% of the time, percentage of ventricular paced 100+/-2%; sensing group, n=30, patients with RVA pacing<50% of the time, percentage of ventricular paced 3+/-6%. RESULTS: There was no significant difference in mean heart rate derived from 24-hour ambulatory ECG recordings when comparing the two groups (66+/-11 bpm vs 69+/-8 bpm). LV Tei index was significantly higher in pacing group than in sensing group (0.67+/-0.17 vs 0.45+/-0.09, P<0.0001), and the RV Tei index was significantly higher in pacing group than in sensing group (0.34+/-0.19 vs 0.25+/-0.09, P=0.011). Furthermore, BNP levels were significantly higher in pacing group than in sensing group (40+/-47 pg/mL vs 18+/-11 pg/mL, P=0.017). With the exception of LV diastolic dimension (49+/-5 mm vs 45+/-5 mm, P=0.012), there were no significant differences in other echocardiographic parameters, including left atrium (LA) diameter (35+/-8 mm vs 34+/-5 mm), LA volume (51+/-27 cm3 vs 40+/-21 cm3), LV systolic dimension (30+/-6 mm vs 29+/-7 mm), or ejection fraction (66+/-9% vs 63+/-11%), when comparing the two groups. CONCLUSIONS: These findings suggest that the increase of LV and RV Tei index, LVDd, and BNP are highly correlated with the frequency of the RVA pacing in patients with dual chamber pacemakers.     

Continuous ambulatory peritoneal dialysis is responsible for an increase in plasma norepinephrine.

OBJECTIVE: To investigate the reason for increasing norepinephrine (NE) levels reported in continuous ambulatory peritoneal dialysis (CAPD) patients. METHODS: Norepinephrine was measured in the plasma and peritoneal dialysate of CAPD patients (n = 22) and in the plasma and the urine of healthy subjects (n = 20). It was also measured in the plasma of patients with chronic renal failure (CRF) (n = 15) and patients on hemodialysis (HD) (n = 15). RESULTS: It was found that NE was increased in CAPD patients compared with healthy individuals (687+/-221 pg/mL vs 199+/-25 pg/mL, p < 0.01).The daily removal of NE from the peritoneum of CAPD patients was lower compared with the amount of NE excreted in the urine of healthy subjects. Plasma NE increased after infusion of peritoneal dialysate. In 15 new patients on CAPD, it was found that NE plasma levels increased from 329+/-67 pg/mL before initiation of dialysis, to 584+/-173 pg/mL after 12 months of treatment (p < 0.01). Finally, plasma NE in CAPD patients (687+/-221 pg/mL) was significantly higher compared with the already increased levels in patients on HD or with CRF (406+/-143 pg/mL and 378+/-142 pg/mL, respectively). CONCLUSIONS: It is concluded that CAPD in patients with end-stage renal disease is responsible for a progressive increase of plasma norepinephrine.     

QT dispersion and signal-averaged electrocardiogram in hemodialysis and CAPD patients.

OBJECTIVE: The aim of this study was to compare QT dispersion (QTd) and signal-averaged electrocardiogram (SA-ECG) parameters that may predict risk of malignant arrhythmias in patients on hemodialysis (HD), on continuous ambulatory peritoneal dialysis (CAPD), and in controls. SETTING: Controlled cross-sectional study in a tertiary-care setting. PATIENTS: 28 HD (M/F 18/10; mean age 32 +/- 9 years), 29 CAPD (M/F 17/12; mean age 34 +/- 10 years), and 29 healthy controls (M/F 17/12; mean age 32 +/- 8 years) were included. INTERVENTIONS: On ECG, minimum (QTmin) and maximum (QTmax) QT duration and their difference (QTd) were measured. In SA-ECG, duration of filtered QRS, HFLA signals less than 40 microV, and RMS voltage (40 ms) were also measured. RESULTS: Higher serum Ca2+ and lower K+ levels were found in CAPD compared to HD. All QT parameters were increased in HD and CAPD compared to controls. QT dispersion was significantly prolonged in HD compared to CAPD. In HD, QTd was correlated with left ventricular (LV) mass index (r = 0.53, p = 0.004), but not in CAPD (r = -0.09, p = 0.63). QT dispersion was significantly prolonged in patients with LV hypertrophy compared to patients without hypertrophy on HD (68 +/- 18 ms vs 49 +/- 18 ms, p = 0.008). In the analysis of SA-ECG, 3 of the 28 (11%) HD and 2 of the 29 (7%) CAPD patients had abnormal late potentials. Patients on HD and CAPD had significantly higher filtered-QRS duration compared to controls (105 +/- 15 ms and 104 +/- 12 ms vs 95 +/- 5 ms, respectively, p = 0.04). Patients with LV hypertrophy had higher filtered-QRS duration compared to patients without hypertrophy (109 +/- 12 ms vs 95 +/- 8 ms, p < 0.001). CONCLUSION: Dialysis patients had prolonged QTd and increased filtered-QRS duration in SA-ECG compared to controls. Patients on HD had longer QTd than patients on CAPD. QTd has been correlated to LV mass index in HD, but not in CAPD. This difference might be due to the effect of different dialysis modalities on electrolytes, especially the higher serum Ca2+ levels.     

Sodium removal in patients undergoing CAPD and automated peritoneal dialysis.

OBJECTIVES: To compare sodium removal in continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis (APD) patients, and to identify the main factors that modify Na removal in clinical practice in these patients. DESIGN: Study in three steps. Cross-sectional observational (Study A), and longitudinal interventional (Studies B and C). PATIENTS AND METHODS: First (Study A) we carried out a cross-sectional survey of Na removal in 63 patients on CAPD and 78 patients on APD. Second (Study B), we studied Na removal in 32 patients before and after changing from CAPD to APD therapy. Finally (Study C), we analyzed the impact on Na removal of introducing icodextrin for the long dwell in 16 patients undergoing CAPD or APD. RESULTS: In Study A, total Na removal averaged 210 mmol/day for CAPD patients and 91 mmol/day for APD patients (p < 0.001); Na removal was < 100 mmol/day in 7.1% of CAPD patients and 56.4% of APD patients. Multivariate analysis identified ultrafiltration [B = 125 mmol/day, 95% confidence interval (CI) 110,140], CAPD therapy (B = 60 mmol/day, 95%CI 37, 83), and residual diuresis (B = 51 mmol/L, 95%CI 34, 69) as independent predictors of Na removal (adjusted r2 = 0.76). For APD patients, longer nocturnal dwell times and performing a supplementary diurnal exchange were also independently associated with higher Na removal rates. In Study B, Na removal decreased from 192 to 92 mmol/day (median) after the change to APD (p = 0.02). In Study C, peritoneal Na removal increased from 98 to 148 mmol/day (median) (p = 0.04) after introducing icodextrin. CONCLUSIONS: Standard APD schedules are frequently associated with poor Na removal rates. For any degree of ultrafiltration, Na removal is better in CAPD than in APD. Icodextrin, supplementary diurnal exchanges, and longer nocturnal dwell times improve Na removal in APD. Sodium removal can be estimated from ultrafiltration in patients on CAPD, but must be specifically monitored in patients on APD.     

SEN virus infection in patients on peritoneal dialysis.

BACKGROUND: Many reports have demonstrated SEN virus (SEN-V) infection rates in hemodialysis patients, but the SEN-V infection rate in peritoneal dialysis (PD) patients has never been reported. In this study, we determined the prevalence rate of SEN-V viremia in a PD population. METHODS: Serum samples from 47 PD patients and a control group of 43 subjects from the general population at their health examination were assayed for SEN-V-D and -H viremia using polymerase chain reaction. RESULTS: The proportions of female gender (p = 0.001), previous transfusion (p < 0.0001), and higher mean serum AST level (p = 0.012) were significantly higher in PD patients. The prevalence rates of SEN-V-D and/or -H viremia were not significantly different between PD patients and controls (27.7% vs 32.6%). SEN-V-D(+) patients had lower mean duration of PD than SEN-V(-) patients. Mean ALT level was significantly lower in SEN-V-H(+) than in SEN-V(-) patients (12.8 +/- 5.8 vs 19.6 +/- 12.1 (IU/L), p = 0.025). None of the SEN-V-infected PD patients had overt clinical or biochemical signs of liver disease. There were no statistically significant differences in prevalence of SEN-V-D and/or -H viremia between automated PD (APD) patients and continuous ambulatory PD (CAPD) patients. CONCLUSIONS: These results indicate that the SEN-V infection rate is not different between healthy individuals and PD patients. Infection with SEN-V is not associated with evident liver disease in PD patients and SEN-V infection rate is not different between APD patients and CAPD patients.     

Permanent and atrial-synchronized ventricular stimulation for clinically stable patients with normal or impaired left ventricular systolic function

BACKGROUND: Ventricular desynchronization imposed by permanent dual-chamber ventricular pacing (VDD) may compromise ventricular function. METHODS: We investigated the impact of background VDD pacing on the right and left ventricular (LV) function on 129 clinically stable outpatients (mean age 69 +/- 10) implanted chronically with a dual-chamber pacemaker or an automatic defibrillator by using echocardiographic techniques including tissue doppler imaging (TDI) and color M-mode (CMM) examinations, and B-type natriuretic peptide (BNP) measurements. Patients were divided into two groups of normal (n = 65) or impaired (n = 64) LV systolic function (ejection fraction 63 +/- 6% and 38 +/- 10%, respectively) according to clinical and echocardiographic criteria. Each patient group included two subgroups on the basis of the underlying permanent and atrial-synchronized heart rhythm: either intrinsic ventricular activation (IVA) or VDD pacing. RESULTS: The BNP levels (mean, 95% CI) of patients with impaired LV systolic function were approximately threefold higher than those of patients with normal LV systolic function [189 (145-245) pg/mL vs 65 (50-85) pg/mL, P < 0.0001], but did not differ between subgroups of patients with IVA vs VDD pacing. By two-way analysis of variance and analysis of covariance, and after adjustment for age and gender, significant VDD pacing effects were found in terms of lower E/A ratio (P < 0.05) and increased LV end-systolic volume (P < 0.05). VDD pacing did not significantly affect the BNP levels and the LV filling pressures, as determined by the E/Ea and E/Vp ratios. CONCLUSIONS: Long-term VDD pacing may not be harmful in clinically stable patients with normal or moderately reduced LV systolic function.     

The association of peritoneal transport properties with 24-hour blood pressure levels in CAPD patients.

OBJECTIVES: We aimed to investigate the effects of peritoneal transport characteristics on blood pressure (BP) parameters, measured by 24-hour ambulatory blood pressure monitoring (ABPM), and on the development of left ventricular hypertrophy (LVH) in continuous ambulatory peritoneal dialysis (CAPD) patients. DESIGN: Cross-sectional and prospective design. SETTING: Tertiary-care center. PATIENTS: 25 CAPD patients (11 male, 14 female; mean age 47 +/- 14 years) were included. Mean time on CAPD was 22.9 +/- 18 months and all patients had been dialyzed for more than 6 months. The patients were divided into high, high-average, low-average, and low transport groups according to peritoneal equilibration test results. MAIN OUTCOME MEASURES: Daytime and nighttime systolic and diastolic BP and left ventricular mass index among the different peritoneal transport groups; changes in BP parameters before and after increase in ultrafiltration. RESULTS: On 24-hour ABPM records, 13 patients (52%) were found to be hypertensive. Both mean systolic and diastolic BP were significantly increased in high-transporter groups compared to low transporters in both daytime and nighttime BP parameters. Left ventricular mass index was higher in high transporters compared to low transporters, without reaching statistical significance: 160 +/- 23 vs 119 +/- 41 g/m2, p > 0.05. Following increase in ultrafiltration, mean systolic (145 +/- 13 vs 128 +/- 5 mmHg, p < 0.001) and diastolic (96 +/- 10 vs 81 +/- 3 mmHg, p < 0.001) BP decreased, and BP levels returned to normotensive levels in 6 (46%) of the 13 hypertensive patients, requiring discontinuation of antihypertensive drugs. CONCLUSION: Improvement in volume status resulted in a decrease in both daytime and nighttime BP. Differences in peritoneal transport properties were associated with the development of hypertension and LVH.     

Assessment of B-type natriuretic peptide in patients with pneumonia

The mammalian heart synthesises and secretes B-type natriuretic peptide (BNP), which has potent diuretic, natriuretic and vascular smooth muscle-relaxing effects as well as complex interactions with the hormonal and nervous systems. Recent studies described that BNP was acute phase reactant. In this study, we aimed to evaluate BNP levels in patients with pneumonia. Twenty-one patients with pneumonia and 21 healthy control subjects were enrolled in this study. Their serum levels of BNP were measured in addition to the standard evaluations. Leucocyte count [19.3 (13.2-25.7) 10(6)/ml vs. 9.55 (3.7-13.9) 10(6)/ml, p < 0.001], erythrocyte sedimentation rate [73 (57-81) mm/h vs. 35 (4-55) mm/h, p < 0.001], C-reactive protein (CRP) [127.72 (27-290) mg/l vs. 13.19 (3-41) mg/l, p < 0.001] and BNP [53.1 (17-91) pg/ml vs. 16.24 (1-38) pg/ml, p < 0.001] levels significantly decreased after treatment period. Initial BNP levels were significantly higher than control groups (53.10 +/- 15.07 pg/ml vs. 18.62 +/- 14.05 pg/ml, p < 0.001) and decreased after treatment to the levels comparable with control subjects. BNP levels correlated with CRP levels at admission (r = 0.716, p < 0.001). We have shown that BNP levels show a transient increase in patients with pneumonia and correlate well with CRP.     

Impact of dialysis adequacy on cardiac function in pediatric CAPD patients.

BACKGROUND: Left ventricular hypertrophy is a major cause of morbidity and mortality among patients with chronic renal failure. Uremia-related risk factors play a fundamental role in its occurrence, thus better prognosis and prolonged survival can be attained by successful dialytic therapies. OBJECTIVE: To investigate whether dialysis adequacy has a beneficial effect on cardiac structure and function in children receiving continuous ambulatory peritoneal dialysis (CAPD). DESIGN: Cross-sectional study in the Pediatric Peritoneal Dialysis Unit of a university hospital. PATIENTS: Eighteen children, aged 13.3 +/- 2.8 years, being treated with CAPD, and 20 healthy age- and sex-matched control subjects were enrolled in this study. MAIN OUTCOME MEASURES: Echocardiographic evaluation was performed in all subjects. Dialysis adequacy indices [weekly urea (Kt/V) and creatinine clearance (TCCr)] were calculated in the dialysis group. RESULTS: Interventricular septal thickness, left ventricular (LV) posterior wall thickness, LV mass index (LVMI), and LV end systolic and diastolic dimensions were all found to be significantly higher in the CAPD group compared to the control subjects (p < 0.01). Ejection fraction and fractional shortening of the LV were not significantly different between the two groups. Mean Kt/V was 2.02 +/- 0.71 and mean TCCr was 58 +/- 33 L/wk/1.73 m2. There were significant negative correlations between dialysis adequacy indices and LV end systolic and diastolic dimensions (p < 0.05 and p < 0.001). Ejection fraction and fractional shortening were positively correlated with Kt/V (p < 0.01). Systolic and diastolic blood pressures were positively correlated with LVMI (r= 0.501 and r = 0.523). Significant inverse correlations between mean arterial pressure and both Kt/V and TCCr (r = -0.555 and r = -0.520) were detected. CONCLUSION: These data clearly document that cardiac structure and function are remarkably influenced by the uremic state and dialysis therapy in pediatric CAPD patients. The close relationships between echocardiographic findings and dialysis adequacy indices suggest that adequate dialysis has a beneficial effect on cardiac function via effective removal of toxic substances.     

Inflammation and extracellular volume expansion are related to sodium and water removal in patients on peritoneal dialysis.

BACKGROUND: Inflammation is an important risk for mortality in dialysis patients. Extracellular fluid volume (ECFv) expansion, a condition commonly seen in peritoneal dialysis (PD) patients, may be associated with inflammation. However, published support for this relationship is scarce. OBJECTIVES: To quantify the proportion of patients on PD with inflammation and to analyze the role of ECFv expansion and the factors related to these conditions. DESIGN: A prospective, multicenter cross-sectional study in six hospitals with a PD program. Patients and METHODS: Adult patients on PD were studied. Clinical data, body composition, and sodium and fluid intake were recorded. Biochemical analysis, C-reactive protein (CRP), and peritoneal and urinary fluid and sodium removal were also measured. RESULTS: CRP values positive (>or=3.0 mg/L) for inflammation were found in 147 (80.3%) and negative in 36 patients. Patients with positive CRP had higher ECFv/total body water (TBW) ratio (women 47.69 +/- 0.69 vs 47.36 +/- 0.65, men 43.15 +/- 1.14 vs 42.84 +/- 0.65; p < 0.05), higher serum glucose (125.09 +/- 81.90 vs 103.28 +/- 43.30 mg/dL, p < 0.03), and lower serum albumin (2.86 +/- 0.54 vs 3.17 +/- 0.38 g/dL, p < 0.001) levels. They also had lower ultrafiltration (1003 +/- 645 vs 1323 +/- 413 mL/day, p < 0.005) and total fluid removal (1260 +/- 648 vs 1648 +/- 496 mL/day, p < 0.001), and less peritoneal (15.59 +/- 162.14 vs 78.11 +/- 110.70 mEq/day, p < 0.01) and total sodium removal (42.06 +/- 142.49 vs 118.60 +/- 69.73 mEq/day, p < 0.001). In the multivariate analysis, only ECFv/TBW was significantly (p < 0.04) and independently associated with inflammation. ECFv/TBW was correlated with fluid removal (r = 0.16, p < 0.03) and renal sodium removal (r = 0.2, p < 0.01). CONCLUSION: The data suggest that ECFv expansion may have a significant role as an inflammatory stimulus. The results disclose a relationship between the two variables, ECFv expansion and inflammation, identified as independent risk factors for mortality in PD patients.     

Serum cardiac troponin T in patients hospitalized with heart failure is associated with left ventricular hypertrophy and systolic dysfunction

BACKGROUND: Cardiac troponin T (cTnT) is a highly sensitive and specific marker of acute myocardial infarction. Serum cTnT is also slightly elevated in patients with severe heart failure and is associated with left ventricular hypertrophy (LVH) in patients treated with haemodialysis. In this study serum cTnT concentrations and echocardiographic findings were investigated in heart failure patients without acute coronary syndrome. cTnT was also compared with other cardiac markers and plasma levels of brain natriuretic peptide (BNP). METHODS: Twenty-six patients hospitalized with heart failure were included in the study. Echocardiographic measurements and blood sampling were carried out 12-36 h after admission. Serum cTnT (3rd generation assay), cardiac troponin I (cTnI), creatine kinase MB (CKMB) and CK were measured. Plasma BNP was analysed using the Shionoria assay. LVH was defined as left ventricular mass index (LVMI) > 125 g/m for males and > 110 g/m for females. Left ventricular systolic function was estimated from the mitral annulus motion (AV-mean LV). RESULTS: Median cTnT was 0.012 (< 0.010-0.032) microg/L. Sixty-two percent of the patients (16 of 26) had elevated serum cTnT >or= 0.010 micro/L. cTnT was positively correlated with CKMB (rho = 0.40, p = 0.04) and BNP (rho = 0.43, p = 0.03), but not with cTnI and CK. A negative correlation was found between cTnT and AV-mean LV (rho = -0.58, p = 0.007), and there was a positive correlation between cTnT and LVMI (rho = 0.44, p = 0.03). No other analyte was correlated to LVMI. CONCLUSIONS: Serum cTnT but not cTnI was associated with left ventricular dysfunction and LVH in patients hospitalized with heart failure. This explains why cTnT tends to be slightly elevated in patients with heart failure without symptoms of acute myocardial ischaemia.     

Erythrocyte glutathione peroxidase activity,plasma malondialdehyde and erythrocyte glutathione levels in hemodialysis and CAPD patients

OBJECTIVES: Cardiovascular disease is the major cause of mortality in patients receiving hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) due to chronic renal failure. Increased lipid peroxidation and depletion of antioxidants may contribute to increased risk of atherosclerosis. We have therefore assessed the effect of hemodialysis and CAPD on oxidant and antioxidant status. DESIGN AND METHODS: Plasma malondialdehyde (MDA), Glutathione (GSH) levels and glutathione peroxidase (Gpx) activities were determined in 20 healthy persons (control), 20 patients on HD, 16 patients on CAPD. RESULTS: MDA was elevated in posthemodialysis and CAPD patients in comparison to prehemodialysis and control groups (posthemodialysis 1.39 +/- 0.38 nmol/mL, CAPD 1.26 +/- 0.27 nmol/mL, prehemodilaysis 0.83 +/- 0.22 nmol/mL, controls 0.72 +/- 0.21 nmol/mL p < 0.0001). With respect to antioxidants, glutathione levels were significantly lower in prehemodialysis, posthemodialysis and CAPD groups than those in control group (prehemodialysis 16.82 +/- 6.73 mg/dL RBC, posthemodialysis 31.43 +/- 11.88 mg/dL RBC, CAPD 40 +/- 12.72 mg/dL RBC, controls 62.26 +/- 24.01 mg/dL RBC, p < 0.0001). While erythrocyte GSH levels were significantly lower in the prehemodialysis patients than those in posthemodialysis and CAPD patients (p < 0.0001), it was significantly lower in posthemodialysis patients than those in CAPD patients (p < 0.05). There were no significant differences with respect to erythrocyte Gpx levels among the groups (p > 0.05). CONCLUSIONS: These findings indicate oxidative stress in patients with chronic renal failure which is further exacerbated by hemodialysis and CAPD, as evidenced by increased lipid peroxidation and low antioxidant levels.     

Paradoxical changes in brain natriuretic peptide levels and loading conditions after intravenous conscious sedation.

BACKGROUND: Elevated filling pressure and wall stress have been proposed as stimuli for elevated brain natriuretic peptide (BNP) levels. Narcotic and benzodiazepine sedation, such as is used for transesophageal echocardiography (TEE), is known to decrease filling pressures. We hypothesized that lower filling pressure and wall stress associated with intravenous conscious sedation (IVCS) would lead to lower BNP levels. METHODS: We studied BNP levels, blood pressure, and echocardiographic indices of filling pressure and wall stress before and after IVCS and TEE. RESULTS: When data before and after IVCS and TEE were compared, mean blood pressure decreased (149 +/- 24/83 +/- 14 mm Hg vs 126 +/- 29/69 +/- 14; P < .01), as did mitral Doppler E wave velocity (82 +/- 23 cm/s vs 76 +/- 22; P < .05), right ventricular/atrial gradient (31 +/- 10 mm Hg vs 29 +/- 13; P < .05), and wall stress. However, BNP levels increased (195 +/- 407 pg/mL vs 238 +/- 458; P < .01). CONCLUSIONS: In a series of patients undergoing clinically indicated TEE, BNP levels increase above baseline after IVCS. The increase in BNP occurs despite lower blood pressure, lower mitral Doppler E velocity, lower right ventricular/atrial gradient, and lower wall stress compared with baseline. The mechanism of the paradoxical increase in BNP is not entirely clear, but it may conceivably be a result of counterregulatory hormone release caused by acute decrease in blood pressure.     

Brain natriuretic peptide in patients with ST segment elevation myocardial infarction. Prognostic significance

AIM: To study changes in the level of brain natriuretic peptide (BNP) in patients with ST segment elevation myocardial infarction (MI) to assess prognostic value of this marker and validity of its use as a criterion of therapy effects. MATERIAL AND METHODS: The trial enrolled 217 patients (102 males and 15 females, mean age 63.96 +/- 0.73 years) admitted to hospital on MI day 1. Plasmic level of BNP (Nt-proBNP) was measured 1, 7, 21 days, 8 weeks and 6 months after MI. RESULTS: The severity of chronic cardiac failure (CCF) correlated with peptide content in the blood: it was by 46.6% higher in patients with chronic heart failure (CHF) functional class (FC) IV than in those with CHF FC I (p = 0.047), in FC III by 27.5% higher (p = 0.003) and in FCII--by 13.1% (p = 0.485). Initially high levels of BNP correlated with early development of CHF (R2 = 0.9058), with hospital lethality (in the deceased--1040.0 +/- 65.8 fmol/ml, in the survivors--461.4 +/- 26.2 fmol/ml, r = 0.35, p < 0.001) and overall lethality. A more pronounced decrease in the peptide level was seen in patients after 3 week intake of beta-adrenoblocker esmolol than in those who did not take it (by 125.2 vs 74.1 fmol/ml, respectively, p < 0.05). By BNP level, efficacy of perindopril vs captopris was studied (group 1 and group 2, respectively), in patients with ejection fraction under 40%. Initially, BNP levels were elevated and did not differ among the groups. On MI week 8 there was a decrease in the level of BNP by 25.4% (p = 0.004), 19.1% (p = 0.06) in groups 1 and 2, respectively. Six months after MI patients of group 1 had normal levels of BNP (up to 269.6 +/- 18.3 fmol/l). CONCLUSION: Measurements of BNP levels are useful for prediction of poor prognosis in MI patients and evaluating efficacy of the treatment.     

A comparison of outcomes between diabetic and nondiabetic CAPD patients in India

BACKGROUND: Continuous ambulatory peritoneal dialysis (CAPD) has been an established modality of renal replacement therapy in India for a decade, but there is a paucity of published data on the outcome of CAPD patients in India. We analyzed our data to determine the overall predictors of survival and compared patient survival between diabetic and nondiabetic end-stage renal disease patients on CAPD. METHODS: Of 373 patients, 197 were diabetic (165 males, 32 females) and 176 nondiabetic (104 males, 72 females). Patients were followed for 22 +/- 14 patient-months. Patients were prospectively followed until the study end point or death. RESULTS: Overall median survival was 48 patient-months. Median survival of diabetics (34.5 patient-months) was significantly inferior to nondiabetic patients (59 patient-months) p = 0.001. Overall patient survival at 1, 2, 3, 4, and 5 years was 90%, 72%, 60%, 49%, and 39%, respectively. Patient survival of diabetics versus nondiabetics at 1, 2, 3, 4, and 5 years was 85% versus 96%, 62% vs 82%, 48% vs 72%, 39% vs 62%, and 34% vs 42%, respectively. The relative risk of mortality in nondiabetics (34/176) was less than that in diabetic patients (71/197): odds ratio (OR) 0.43, 95% confidence interval (CI) 0.26 - 0.68; p = 0.001. On Cox regression analysis, diabetes (OR 1.95, 95% CI 1.23 - 3.07; p = 0.004), comorbidities (OR 0.39, 95% CI 0.25 - 0.61; p = 0.001), peritonitis (OR 1.79, 95% CI 1.19 - 2.68; p = 0.005), malnutrition (OR 0.52, 95% CI 0.29 - 0.94; p = 0.03), and residual glomerular filtration rate at initiation of CAPD (OR 0.87, 95% CI 0.81 - 0.93; p = 0.001) were significant predictors of overall mortality. Age (OR 0.68, 95% CI 0.45 - 1.03; p = 0.07), gender (OR 0.66, 95% CI 0.42 - 1.03; p = 0.06), and albumin level at initiation of CAPD (OR 0.92, 95% CI 0.64 - 1.33; p = 0.68) were not predictors of mortality. Age (56 +/- 10 vs 46 +/- 15 years, p = 0.001), comorbidities (51/197 vs 16/176, p = 0.001), peritonitis rate (0.68 vs 0.50 episodes/patient-year, p = 0.056), and severe malnutrition (27/197 vs 10/176, p = 0.002) were higher in diabetic than in nondiabetic patients. CONCLUSION: In India the majority of CAPD patients are diabetic. Patient survival was inferior in diabetic compared to nondiabetic patients on CAPD, but survival was statistically similar after adjustment for comorbidities. Diabetes, comorbidities, residual glomerular filtration rate, peritonitis, and severe malnutrition are predictors of mortality in CAPD patients.     

Serum magnesium concentration is an independent predictor of parathyroid hormone levels in peritoneal dialysis patients.

BACKGROUND: Parathyroid hormone (PTH) is a cardinal factor in the pathogenesis of bone disease in the dialysis population. The spectrum of renal osteodystrophy has been reported to have changed during the past years, and adynamic bone disease has emerged as the most common bone disorder in these patients. Continuous ambulatory peritoneal dialysis (CAPD) is considered a risk factor for the development of this condition, and furthermore, the adynamic bone lesion is associated with a state of relative hypoparathyroidism (hypo-PTH). Calcium, vitamin D, and phosphorus play a key role in the control of parathyroid gland function in uremic patients. However, magnesium may also be able to modulate PTH secretion in a way similar to calcium. OBJECTIVE: The aims of this study were (1) to analyze the serum Mg concentration in a large group of CAPD patients, (2) to study the relationship between serum Mg and PTH levels, and (3) to investigate whether this relationship is independent of other factors, such as calcium, phosphorus, and calcitriol, that regulate parathyroid function. PATIENTS AND METHODS: We studied 51 stable patients, aged 23-77 years, under maintenance CAPD for more than 6 months (range 8-48 months). Calcium carbonate was used as a phosphate binder in all patients, and 9 subjects also received aluminum hydroxide. No patient had been previously treated with vitamin D. Biochemical parameters were prospectively evaluated over 6 months, and the mean values were computed. RESULTS: The mean serum Mg was 1.08 +/- 0.19 mmol/L, and hypermagnesemia, defined as a Mg level higher than 1.01 mmol/L, was found in 30 patients (59%). Thirty-one subjects (60%) had an intact PTH (iPTH) level lower than 120 pg/mL and were diagnosed as having relative hypo-PTH. Except for the values of iPTH and alkaline phosphatase, the only difference between the two groups was the serum Mg concentration, which was significantly higher in patients with hypo-PTH (1.16 +/- 0.15 mmol/L vs 0.91 +/- 0.14 mmol/L; p< 0.001). Furthermore, iPTH levels were lower in patients with hypermagnesemia than in subjects with normal serum Mg (69 +/- 49 pg/mL vs 190 +/- 89 pg/mL, p < 0.001). There was a significant correlation between serum Mg and PTH levels (r= -0.70, p< 0.01). After controlling for the effect of other variables by partial correlation analysis, a significant positive association between P and PTH (r= 0.25, p < 0.05), and a negative relationship between Mg and PTH (r= -0.57, p < 0.001) were evident. A forward stepwise multiple regression analysis showed that only P and Mg predicted PTH values (multiple r = 0.59, p < 0.001). CONCLUSIONS: Hypermagnesemia and hypoparathyroidism are frequent in CAPD patients. There is a significant inverse relationship between serum Mg concentration and iPTH levels. Furthermore, this association is independent of the most important factors regulating parathyroid gland function (calcium, phosphorus, and calcitriol). These results suggest that hypermagnesemia may have a suppressive effect on PTH synthesis and/or secretion. Therefore, elevated serum Mg levels may play a role in the pathogenesis of adynamic bone disease.