Department of Pathology & Microbiology, Aga Khan University, Stadium Road, P.O. Box 3500, Karachi 74800, Pakistan.
BMC Nephrol. 2013 May 31;14:117. doi: 10.1186/1471-2369-14-117.
The effect of impaired kidney function on B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) is vague. This study was performed to examine the effect of kidney dysfunction on the afore-mentioned markers and determine appropriate cutoffs for systolic heart failure (SHF).
In this cross sectional study adults with estimated glomerular filtration rate (eGFR) <60 ml/min for ≥3 months were identified in consulting clinics from June 2009 to March 2010. SHF was defined as documented by a cardiologist with ejection fraction of < 40% and assessed by New York Heart Association classification (NYHA). Plasma was assayed for creatinine (Cr), BNP and NT-proBNP.
A total of 190 subjects were enrolled in the study, 95 with and 95 without SHF. The mean age of patients was 58 (±15) years, 67.4% being males. Mean BNP levels showed a 2.5 fold and 1.5 fold increase from chronic kidney disease (CKD) stage 3 to stage 5 in patients with and without SHF respectively. NT-proBNP levels in non-heart failure group were 3 fold higher in CKD stage 5 compared to stage 3. Mean NT-proBNP levels were 4 fold higher in CKD stage 5 compared to stage 3 in patients with SHF. Optimal BNP and NT-proBNP cutoffs of SHF diagnosis for the entire CKD group were 300 pg/ml and 4502 pg/ml respectively.
BNP and NT-proBNP were elevated in kidney dysfunction even in the absence of SHF; however the magnitude of increase in NT-proBNP was greater than that of BNP. BNP and NT-proBNP can be useful in diagnosing SHF, nonetheless, by using higher cutoffs stratified according to kidney dysfunction. NT-proBNP appears to predict heart failure better than BNP.
肾功能受损对 B 型利钠肽（BNP）和 N 端脑利钠肽前体（NT-proBNP）的影响尚不明确。本研究旨在探讨肾功能障碍对上述标志物的影响，并确定用于诊断收缩性心力衰竭（SHF）的合适截断值。
本横断面研究于 2009 年 6 月至 2010 年 3 月在就诊诊所中确定肾小球滤过率（eGFR）<60 ml/min 且持续时间≥3 个月的成年人。SHF 由射血分数<40%的心脏病专家确诊，并通过纽约心脏协会（NYHA）分级进行评估。检测血浆肌酐（Cr）、BNP 和 NT-proBNP。
共纳入 190 例患者，其中 95 例有 SHF，95 例无 SHF。患者平均年龄为 58（±15）岁，67.4%为男性。有 SHF 的患者中，慢性肾脏病（CKD）3 期至 5 期 BNP 水平分别增加了 2.5 倍和 1.5 倍；无 SHF 的患者中，非心衰组的 NT-proBNP 水平在 CKD 5 期比 3 期高 3 倍。有 SHF 的患者中，CKD 5 期 NT-proBNP 水平比 3 期高 4 倍。整个 CKD 组诊断 SHF 的最佳 BNP 和 NT-proBNP 截断值分别为 300pg/ml 和 4502pg/ml。
即使在无 SHF 的情况下，肾功能障碍也会导致 BNP 和 NT-proBNP 升高；然而，NT-proBNP 的升高幅度大于 BNP。BNP 和 NT-proBNP 可用于诊断 SHF，但需要根据肾功能障碍使用更高的截断值进行分层。NT-proBNP 似乎比 BNP 更能预测心力衰竭。
