St Peter John V, Hartley Guilford G, Murakami MaryAnn M, Apple Fred S
College of Pharmacy and School of Medicine, University of Minnesota, Minneapolis, 55455-0343, USA.
Clin Chem. 2006 Apr;52(4):680-5. doi: 10.1373/clinchem.2005.062562. Epub 2006 Feb 23.
Further investigations are warranted to better characterize variables that may confound the clinical interpretation of plasma natriuretic peptide measurements, which are increasingly recognized to have diagnostic and predictive importance.
Blood samples (EDTA plasma) from patients (n = 206) attending clinics for the medical treatment and follow-up of obesity were analyzed for B-type natriuretic peptide (BNP; Bayer assay) and the N-terminal segment of its prohormone (NT-proBNP; Roche assay). Natriuretic peptide concentration ranges were evaluated in those without diagnosis of congestive heart failure (CHF) or chronic kidney disease (CKD).
BNP and NT-proBNP were directly correlated (r = 0.87; P = 0.01), with NT-proBNP concentrations higher relative to BNP. Of obese patients without CHF or CKD, 21.6% (40 of 185) had NT-proBNP concentrations greater than the published assay upper reference limit. Concentrations of both natriuretic peptides were higher in patients currently exposed to beta blockers, patients with the diagnosis of hypertension or type 2 diabetes, and patients with a history of gastric bypass surgery. An inverse relationship between body mass index (BMI) and both BNP and NT-proBNP was evident. According to the National Institutes of Health, National Heart, Lung, and Blood Institute classification, more than 95% of the participants sampled in this study were either obesity class 2 (35 kg/m(2) < BMI < 39.9 kg/m(2)) or class 3 (BMI >or=40 kg/m(2))
A substantial proportion of obese patients without CHF or CKD have concentrations greater than the upper reference limit for NT-proBNP but not for simultaneously measured BNP. A history of gastric bypass surgery appeared to be a significant predictor of increased natriuretic peptide concentrations when assessed in a population of patients with class 2 or 3 obesity.
血浆利钠肽测量在临床诊断和预测中愈发重要，有必要进一步研究以更好地明确可能混淆其临床解读的变量。
对206例到肥胖症诊治及随访门诊就诊患者的血样（乙二胺四乙酸血浆）进行B型利钠肽（BNP；拜耳检测法）及其前体激素的N末端片段（NT-proBNP；罗氏检测法）分析。在未诊断为充血性心力衰竭（CHF）或慢性肾病（CKD）的患者中评估利钠肽浓度范围。
BNP与NT-proBNP呈直接相关（r = 0.87；P = 0.01），NT-proBNP浓度相对于BNP更高。在无CHF或CKD的肥胖患者中，21.6%（185例中的40例）的NT-proBNP浓度高于已公布检测方法的参考上限。当前使用β受体阻滞剂的患者、诊断为高血压或2型糖尿病的患者以及有胃旁路手术史的患者，其两种利钠肽的浓度均较高。体重指数（BMI）与BNP和NT-proBNP之间存在明显的负相关。根据美国国立卫生研究院、国立心肺血液研究所的分类，本研究中超过95%的抽样参与者为2级肥胖（35kg/m² < BMI < 39.9kg/m²）或3级肥胖（BMI≥40kg/m²）。
相当一部分无CHF或CKD的肥胖患者，其NT-proBNP浓度高于参考上限，但同时检测的BNP浓度未高于上限。在2级或3级肥胖患者群体中评估时，胃旁路手术史似乎是利钠肽浓度升高的重要预测因素。
