Background: Although plasma concentrations of brain natriuretic peptides (BNP) increase in hemodialysis (HD) patients as well as patients with cardiovascular diseases (CD), the clinical significance of BNP in HD patients has yet to be elucidated. In this study, we investigated the pathophysiological significance of BNP in HD patients. Methods: Plasma BNP concentrations were measured in 164 HD patients after HD and 14 healthy volunteers. In 12 patients without CD, BNP was also measured before HD. Multiple regression analysis was performed to determine the important factors causing increased plasma BNP concentrations. Cardiac mortality was monitored for 36 months after baseline analysis, and the prognostic role of BNP was examined by Cox proportional hazards regression analysis. Results: Plasma BNP concentrations of HD patients without CD decreased significantly during HD session (124.5 ± 90.7 vs. 91.4 ± 67.6 pg/ml, mean ± SD, p = 0.004), but were still significantly higher than those of the healthy subjects (9.7 ± 9.2 pg/ml, p = 0.0002). Plasma BNP concentrations of patients with CD were significantly higher than of those without CD (579.6 ± 564.3 vs. 204.0 ± 241.5 pg/ml, p < 0.0001). Plasma BNP concentrations were also significantly higher in diabetes mellitus (DM) patients than in non-DM patients (514.1 ± 585.4 vs. 296.0 ± 347.0 pg/ml, p = 0.0031). Multiple regression analysis showed that left ventricular mass index (LVMI), CD and DM were independent factors for the elevated BNP (R² = 0.303, p < 0.0001). During a 36-month follow-up period, cardiac death occurred in 13 patients. Kaplan-Meier survival estimates of patients from varying plasma BNP quartiles (<200, 200–450, 450–700 and >700 pg/ml) differed between the four groups (p < 0.0001). The group with the highest BNP level (>700 pg/ml) had the lowest survival. When compared with patients with BNP <200, the hazard ratios for cardiac death of patients with BNP of 200–450, 450–700 and >700 pg/ml were 2.3 [95% confidence interval (CI) 0.14–36.7], 18.7 (1.9–183.4) and 51.9 (6.5–416.3), respectively. The univariate Cox proportional hazards model showed that BNP, left ventricular ejection fraction, LVMI, age, DM, serum albumin and C-reactive protein (CRP) were significantly associated with the risk of cardiac mortality. By stepwise multivariate Cox proportional hazards analysis, only BNP, LVMI and CRP remained powerful independent predictors of cardiac death. The relative risk ratios were 1.002 (95% CI 1.001–1.002) for BNP, 2.192 (1.532–3.135) for CRP and 1.027 (1.013–1.042) for LVMI. Conclusion: High plasma BNP concentrations in HD patients were associated with volume overload, left ventricular hypertrophy, CD and DM. Plasma BNP concentration may be a useful parameter for assessing the risk of cardiac death in HD patients by providing prognostic information independently of other variables previously reported.

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Background: It is well known that plasma atrial natriuretic peptide (ANP) is an indicator of extracellular fluid volume expansion and that plasma ANP is considered to be a marker for setting the proper dry weight of HD patients. Although the plasma ANP is a prognostic predictor of cardiac death, the prognostic role of ANP in HD patients has yet to be elucidated. In this study, we investigated the prognostic role of ANP in HD patients. Methods: Plasma ANP concentrations were measured in 105 HD patients after HD. Multiple regression analysis was performed to determine the major factors causing increased plasma ANP concentrations. Cardiac mortality was monitored for 24 months after baseline analysis, and the prognostic role of ANP was examined by Cox proportional hazards regression analysis. Results: Multiple regression analysis showed that cardiovascular disease (CD) and age were independent factors for elevated ANP (R² = 0.298, p < 0.0001). During a 24-month follow-up period, cardiac death occurred in 11 patients. Kaplan- Meier survival estimates of patients from varying plasma ANP levels (<50 and >50 pg/ml) differed between the two groups (p < 0.0001). The group with the higher ANP level (>50 pg/ml) had the lower survival. When compared with patients with ANP <50, the hazard ratios for cardiac death of patients with ANP of >50 pg/ml were 32.0 (95% confidence interval (CI) 4.1 to 252.4). Univariate Cox proportional hazards model showed that ANP, left ventricular ejection fraction (LVEF), LVMI, age, serum albumin and C-reactive protein (CRP) were significantly associated with the risk of cardiac mortality. By stepwise multivariate Cox proportional hazards analysis, only ANP, LVMI and CRP remained powerful independent predictors of cardiac death. The relative risk ratios were 3.483 (95% CI 1.640–7.397) for ln ANP, 1.023 (1.008–1.038) for LVMI, and 1.379 (1.115–1.705) for CRP. Conclusion: High plasma ANP level of post-HD were strongly associated with CD and age. Post-HD ANP level may be a reliable parameter for assessing the risk for cardiac death in HD patients by providing prognostic information independent of other variables previously reported.

We measured urinary N-acetyl-β-D-glucosaminidase (NAG) excretion before and after extracorporeal shock wave lithotripsy (ESWL) with a view to study the underlying factors which aggravate renal impairment immediately after ESWL. The factors associated with the significant elevation of urinary NAG after ESWL included female sex, a previous history of ESWL, and urinary tract infection (UTI). By studying the backgrounds of these factors, we found that both the female group and the group with a previous history of ESWL contained significantly more patients with UTI. These findings indicate that UTI may be one of the risk factors which aggravate renal damage immediately after ESWL, and that careful management is necessary in the ESWL treatment of urinary tract stones with UTI.

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