[Plasma B-type natriuretic peptide level predicts the renal outcome in patients with chronic kidney disease].
OBJECTIVE
Elevation of the plasma level of B-type natriuretic peptide (BNP) is commonly seen in patients with chronic kidney disease (CKD), but its significance remains unclarified. We conducted a prospective study to evaluate the role of plasma BNP level as a predictive marker of renal outcome.


METHODS
237 patients with CKD stage 3, 4 not on dialysis were prospectively enrolled as a hospital cohort from August 2004 to December 2008. Combined renal endpoint was doubling of baseline serum creatinine or end-stage renal disease requiring dialysis. Endpoint free renal survival was calculated by Kaplan Meier analysis and compared by the log-rank test. We used Cox proportional hazards analysis to determine the independent predictor for renal outcome among the clinical data at the time of referral to a nephrologist. ROC analysis was used to determine the best cut-off value of plasma BNP level to predict the renal outcome.


RESULTS
The mean follow-up period was 2.5 +/- 1.1 years. Median age was 65 years. Of the subjects, 65.8% were men and 37.9% had diabetes mellitus. Median serum creatinine level was 2.7 mg/dL. Plasma BNP level was significantly higher among 147 patients who reached the combined renal endpoint compared with 90 patients who did not (116.0 pg/mL vs 54.5 pg/mL, p<0.001). After adjustment with other established predictive factors of renal outcome, plasma BNP level was selected to be the strongest predictive marker for renal endpoint (Hazard ratio 1.173, 95%CI 1.000-1.376). The optimal cut-off value of plasma BNP level suggested by ROC analysis was 69.5 pg/mL. Patients with a plasma BNP level above the cut-off point revealed a significantly poor renal outcome compared with those with a plasma BNP level below the cut-off point.


CONCLUSIONS
The present study suggests that the plasma BNP level might be a predictive marker for renal outcome and a guide for management of cardio-renal interaction.
Department of Nephrology, Izumisano Municipal Hospital, Rinku General Medical Center, Japan.
Keiko
K
Yasuda
Tomonori
T
Kimura
Yoshitsugu
Y
Obi
Koichi
K
Sasaki
Masaki
M
Hatanaka
Yoshitaka
Y
Isaka
Hiromi
H
Rakugi
Terumasa
T
Hayashi
D000368:Aged; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000175:diagnosis* / Q000503:physiopathology
D015415:Biomarkers; D020097:Natriuretic Peptide, Brain