Magrì Damiano, Brioschi Maura, Banfi Cristina, Schmid Jean Paul, Palermo Pietro, Contini Mauro, Apostolo Anna, Bussotti Maurizio, Tremoli Elena, Sciomer Susanna, Cattadori Gaia, Fiorentini Cesare, Agostoni Piergiuseppe
Centro Cardiologico Monzino-IRCCS, Istituto di Cardiologia, Università di Milano, Milan, Italy.
Circ Heart Fail. 2009 May;2(3):175-80. doi: 10.1161/CIRCHEARTFAILURE.108.819607. Epub 2009 Mar 30.
Surfactant protein type B (SPB) is needed for alveolar gas exchange. SPB is increased in the plasma of patients with heart failure (HF), with a concentration that is higher when HF severity is highest. The aim of this study was to evaluate the relationship between plasma SPB and both alveolar-capillary diffusion at rest and ventilation versus carbon dioxide production during exercise.
Eighty patients with chronic HF and 20 healthy controls were evaluated consecutively, but the required quality for procedures was only reached by 71 patients with HF and 19 healthy controls. Each subject underwent pulmonary function measurements, including lung diffusion for carbon monoxide and membrane diffusion capacity, and maximal cardiopulmonary exercise test. Plasma SPB was measured by immunoblotting. In patients with HF, SPB values were higher (4.5 [11.1] versus 1.6 [2.9], P=0.0006, median and 25th to 75th interquartile), whereas lung diffusion for carbon monoxide (19.7+/-4.5 versus 24.6+/-6.8 mL/mm Hg per min, P<0.0001, mean+/-SD) and membrane diffusion capacity (28.9+/-7.4 versus 38.7+/-14.8, P<0.0001) were lower. Peak oxygen consumption and ventilation/carbon dioxide production slope were 16.2+/-4.3 versus 26.8+/-6.2 mL/kg per min (P<0.0001) and 29.7+/-5.9 and 24.5+/-3.2 (P<0.0001) in HF and controls, respectively. In the HF population, univariate analysis showed a significant relationship between plasma SPB and lung diffusion for carbon monoxide, membrane diffusion capacity, peak oxygen consumption, and ventilation/carbon dioxide production slope (P<0.0001 for all). On multivariable logistic regression analysis, membrane diffusion capacity (beta, -0.54; SE, 0.018; P<0.0001), peak oxygen consumption (beta, -0.53; SE, 0.036; P=0.004), and ventilation/carbon dioxide production slope (beta, 0.25; SE, 0.026; P=0.034) were independently associated with SPB.
Circulating plasma SPB levels are related to alveolar gas diffusion, overall exercise performance, and efficiency of ventilation showing a link between alveolar-capillary barrier damage, gas exchange abnormalities, and exercise performance in HF.
肺泡表面活性物质B（SPB）对于肺泡气体交换至关重要。心力衰竭（HF）患者血浆中的SPB水平升高，且在HF严重程度最高时浓度更高。本研究的目的是评估血浆SPB与静息时肺泡-毛细血管扩散以及运动期间通气与二氧化碳产生之间的关系。
连续评估了80例慢性HF患者和20例健康对照者，但仅71例HF患者和19例健康对照者达到了所需的检查质量标准。每位受试者均接受了肺功能测量，包括一氧化碳肺扩散和膜扩散能力，以及最大心肺运动试验。通过免疫印迹法测量血浆SPB。在HF患者中，SPB值更高（中位数和第25至75四分位数间距分别为4.5[11.1]对1.6[2.9]，P = 0.0006），而一氧化碳肺扩散（19.7±4.5对24.6±6.8 mL/mm Hg每分钟，P<0.0001，平均值±标准差）和膜扩散能力（28.9±7.4对38.7±14.8，P<0.0001）更低。HF患者和对照组的峰值耗氧量和通气/二氧化碳产生斜率分别为16.2±4.3对26.8±6.2 mL/kg每分钟（P<0.0001）以及29.7±5.9和24.5±3.2（P<0.0001）。在HF人群中，单因素分析显示血浆SPB与一氧化碳肺扩散、膜扩散能力、峰值耗氧量以及通气/二氧化碳产生斜率之间存在显著关系（所有P<0.0001）。多变量逻辑回归分析显示，膜扩散能力（β，-0.54；标准误，0.018；P<0.0001）、峰值耗氧量（β，-0.53；标准误，0.036；P = 0.004）以及通气/二氧化碳产生斜率（β，0.25；标准误，0.026；P = 0.034）与SPB独立相关。
循环血浆SPB水平与肺泡气体扩散、整体运动表现以及通气效率相关，表明HF患者的肺泡-毛细血管屏障损伤、气体交换异常与运动表现之间存在联系。
