Natriuretic peptides in chronic kidney disease.
OBJECTIVE
B-type natriuretic peptide (BNP) and amino-terminal pro-B-type natriuretic peptide (NT-proBNP) are biomarkers of cardiovascular disease that is common in patients with chronic kidney disease (CKD). Conflicting data on the influence of glomerular filtration rate (GFR) on BNP and NT-proBNP levels in CKD may stem from failure to account fully for the effects of coexistent cardiac disease, dysfunction, and volume overload.


METHODS
Prospective head-to-head comparison of plasma BNP and NT-proBNP in ambulatory euvolemic CKD patients with normal LV ejection fraction and no manifest cardiac or vascular disease. GFR was estimated by the Modification of Diet in Renal Disease formula, BNP and NT-proBNP measured using Abbott AxSYM and Roche Elecsys assays, respectively, and cardiac morphology and function assessed by transthoracic echocardiography.


RESULTS
In 142 patients (42% female) of mean age 60 +/- 11 yr, mean left ventricular ejection fraction was 71% +/- 6%, GFR 38 +/- 14 ml/min per 1.73 m(2), and median BNP and NT-proBNP level 59 and 311 pg/ml, respectively. Multivariate predictors of NT-proBNP level were GFR, beta-blocker usage, LV mass index, and hemoglobin level. Plasma BNP was independently predicted by LV mass index and beta-blocker usage but not GFR. In the 74 patients without diastolic dysfunction, there was a significant rise in NT-proBNP but not BNP as GFR declined.


CONCLUSIONS
Unlike NT-proBNP, plasma BNP level is relatively independent of GFR. BNP may therefore be the more appropriate biomarker to screen for cardiac dysfunction in CKD.
Tagore
Rajat
R
Division of Nephrology, Department of Medicine, National University Hospital, Singapore. Rajat_Tagore@nuhs.edu.sg
Ling
Lieng H
LH
Yang
Hong
H
Daw
Hla-Yee
HY
Chan
Yiong-Huak
YH
Sethi
Sunil K
SK
D000368:Aged; D015415:Biomarkers / Q000097:blood; D002318:Cardiovascular Diseases / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology; D002908:Chronic Disease; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007674:Kidney Diseases / Q000150:complications / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013318:Stroke Volume; D016277:Ventricular Function, Left
D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain