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.

Assessment of fluid shifts of body compartments using both bioimpedance analysis and blood volume monitoring.

Fluid shifts are commonplace in chronic hemodialysis patients during the intra- and interdialytic periods. In this study, we evaluated fluid shifts of body compartments using both bioimpedance spectroscopy and blood volume monitoring from the start to the end of hemodialysis. 24 stable hemodialysis patients were included on the study. Relative change of blood volume was progressively reduced from the start to the end of hemodialysis (1 hr, -7.22+/-3.23%; 2 hr, -9.78+/-4.69%; 3 hr, -12.88+/-5.65%; 4 hr, -15.41+/-6.54%, respectively). Mean % reduction of intracellular fluid was not significantly different to that of extracellular fluid at the end of hemodialysis (delta ICF, -6.58+/-5.34% vs. delta ECF, -7.07+/-5.12%). Mean % fluid reduction of arms, legs and trunk was -11.98+/-6.76%, -6.43+/-4.37% and -7.47+/-4.56%, respectively at the end of hemodialysis. There were 3 characteristic patterns in blood-volume change. Similar amounts of fluid were removed from the extracellular and intracellular compartments during hemodialysis, with the arms showing the greatest loss in terms of body segments. The pattern of blood volume change measured by blood volume monitoring may be useful for more accurate determination of dry-weight and for correcting volume status in hemodialysis patients.

Heat shock protein expression in adenosine triphosphate depleted renal epithelial cells.

BACKGROUND: In this study, the putative interactions between apoptosis and heat shock proteins disturbed as a result of ATP depletion were investigated as a hypoxia model. METHODS: The direct cellular damages were assessed by the release of LDH from the cytoplasm of the human tubular epithelial cells (HK-2 cells) following ATP depletion. The Bcl-2/Bax mRNA expression ratio, used as an index to assess to what extent apoptosis contributed to tubular cell damage, and the expressions of HSP 90, 72 and 27 in relation to the Bcl-2/Bax ratio in the ischemic model, as parameters of their functional contributions to tubule cell damage, were also studied. Heat preconditioning (HS) was performed at 43 degrees C in a temperature-regulated water bath for 1 h. RESULTS: The release of LDH due to ATP depletion was not significantly increased in HK-2 cells compared to the control, but was slightly increased in heat preconditioned cells compared to non heat preconditioned cells, but the difference was not statistically significant (6.33 +/- 0.57 U/L vs. 8.67 +/- 2.52 U/L, p>0.05). The Bcl-2/ Bax mRNA expression ratio increased progressively from the control to the heat preconditioned and ATP depleted cells (control; 100%, ATP depletion; 154 +/- 6%, heat preconditioning; 212 +/- 6%, heat preconditioning and ATP depletion; 421 +/- 8%). No contribution of heat preconditioning and ATP depletion was observed on the expressions of HSP90 and HSP27. However, HSP72 expression was prominent by ATP depletion, especially after heat preconditioning. CONCLUSION: There may be a possibility that the preservation of cytolytic damage and an increase in the Bcl-2/Bax mRNA expression ratio is related to the increase of HSP72 in ATP depletion as a hypoxia model.