Association of chronic obstructive pulmonary disease with coronary artery disease / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The relationship between chronic obstructive pulmonary disease (COPD) and coronary artery disease (CAD) remains largely unknown. This study aimed to explore the association of COPD with CAD, especially with multi-vessel disease (VD).</p><p><b>METHODS</b>The data of 354 patients who underwent multi-detector computed tomography (MDCT) for suspected CAD were analyzed. Luminal narrowing was defined as at least one lesion 50% or greater stenosis. The analysis of serum biochemistry profile and spirometry were performed on all eligible patients, and the diagnosis of COPD was defined as the criteria of Global Initiative for Chronic Obstructive Lung Disease.</p><p><b>RESULTS</b>Patients with CAD had a significantly higher complication of COPD than those without CAD (11.8% vs. 3.7%, P < 0.001). Comparing with patients without COPD, those with COPD were more likely to have multi-VD, proportion of smoking and high C-reactive protein (CRP) (P < 0.001). Multivariate Logistic regression analysis revealed that the multi-VD was significantly correlated with COPD (P=0.012) and CRP (P=0.015).</p><p><b>CONCLUSIONS</b>There was a high complication of COPD in patients with CAD, and COPD may be a critical risk factor for CAD, especially for multi-VD. CAD and COPD were closely associated and the interplay of systemic inflammation might in part explain the relationship between them.</p>

Relationship between 6-minute walk test and pulmonary function test in stable chronic obstructive pulmonary disease with different severities / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The relationship between the 6-minute walk test (6MWT) and pulmonary function test in stable chronic obstructive pulmonary disease (COPD) remains unclear. We evaluate the correlation of 6MWT and spirometric parameters in stable COPD with different severities. 6MWT data assessed included three variables: the 6-minute walk distance (6MWD), 6-minute walk work (6MWORK), and pulse oxygen desaturation rate (SPO(2)%).</p><p><b>METHODS</b>6MWT and pulmonary function test were assessed for 150 stable COPD patients with different severities. Means and standard deviations were calculated for the variables of interest. Analysis of variance was performed to compare means. Correlation coefficients were calculated for 6MWT data with the spirometric parameters and dyspnea Borg scale. Multiple stepwise regression analysis was used to screen pulmonary function-related predictors of 6MWT data.</p><p><b>RESULTS</b>The three variables of 6MWT all varied as the severities of the disease. The 6MWD and 6MWORK both correlated with some spirometric parameters (positive or negative correlation; the absolute value of r ranging from 0.34 to 0.67; P < 0.05) in severe and very severe patients, and the SPO2% correlated with the dyspnea Borg scale in four severities (r = -0.33, -0.34, -0.39, -0.53 respectively; P < 0.05). The 6MWD was correlated with the 6MWORK in four severities (r = 0.56, 0.57, 0.72, 0.81 respectively, P < 0.05), and neither of them correlated with the SPO(2)%. The percent of predicted forced expiratory volume in 1 second (FEV(1)% predicted) and residual volume to total lung capacity ratio (RV/TLC) were predictors of the 6MWD, and the maximum voluntary ventilation (MVV) was the predictor of the 6MWORK.</p><p><b>CONCLUSIONS</b>6MWT correlated with the spirometric parameters in severe and very severe COPD patients. 6MWT may be used to monitor changes of pulmonary function in these patients.</p>

Long-term non-invasive positive pressure ventilation in severe stable chronic obstructive pulmonary disease: a meta-analysis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The evidence for non-invasive positive pressure ventilation (NIPPV) used in patients with severe stable chronic obstructive pulmonary disease (COPD) is insufficient. The aim of the meta-analysis was to assess the treatment effects of long-term NIPPV on gas change, lung function, health-related quality of life (HRQL), survival and mortality in severe stable COPD patients.</p><p><b>METHODS</b>Randomized controlled trials (RCTs) and crossover studies comparing the treatment effects of NIPPV with conventional therapy were identified from electronic databases and reference lists from January 1995 to August 2010. Two reviewers independently assessed study quality. Data were combined using Review Manager 5.0. Both pooled effects and 95% confidence intervals were calculated.</p><p><b>RESULTS</b>Five RCTs and one randomized crossover study with a total of 383 severe stable COPD patients were included. NIPPV improved gas change significantly when using a higher inspiratory positive airway pressures. The weighted mean difference (WMD) for the partial pressure of carbon dioxide in artery (PaCO2) was -3.52 (-5.26, -1.77) mmHg and for the partial pressure of oxygen in artery (PaO2) 2.84 (0.23, 5.44) mmHg. There were significant improvements in dyspnea and sleep quality, but gained no benefits on lung function. The standardized mean difference (SMD) for the forced expiratory volume in 1 second (FEV(1)) was 0.00 (0.29, 0.29). And the benefits for exercise tolerance, mood, survival and mortality remained unclear.</p><p><b>CONCLUSIONS</b>Patients with severe stable COPD can gain some substantial treatment benefits when using NIPPV, especially improvements in gas change, dyspnea and sleep quality. Studies of high methodological quality with large population, especially those based on a higher inspiratory positive airway pressures are required to provide more evidences.</p>