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>

Salmeterol/fluticasone treatment reduces circulating C-reactive protein level in patients with stable chronic obstructive pulmonary disease / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Evidence suggests that systemic inflammation may play an important role in the progression and morbidity of chronic obstructive pulmonary disease. It remains controversial whether inhaled corticosteroid in combination with a long-acting beta(2)-adrenoceptor agonist can attenuate systemic inflammation. We evaluated the effect of salmeterol/fluticasone propionate on circulating C-reactive protein level in stable chronic obstructive pulmonary disease patients.</p><p><b>METHODS</b>An open-label clinical trial was conducted to recruit 122 outpatients with stable moderate-to-severe chronic obstructive pulmonary disease from department of respiratory medicine in two teaching hospitals between June 2007 and March 2008. Patients were randomized into two groups (1:1) to receive either the combination of 50 microg salmeterol and 500 microg fluticasone twice daily (n = 61), or the combination of 206 microg albuterol and 36 microg ipratropium q.i.d (n = 61) over 6 months. Circulating C-reactive protein concentrations were measured before randomization and during the follow-up. The efficacy of treatment was also assessed by spirometry, as well as health status and dyspnea score at baseline and after 6-month treatment.</p><p><b>RESULTS</b>Baseline characteristics of two groups were similar. Compared with ipratropium/albuterol, the combination of salmeterol/fluticasone significantly reduced circulating level of C-reactive protein (-1.73 vs. 0.08 mg/L, respectively, P < 0.05) after 6-month treatment. Forced expiratory volume in one second (FEV(1)) and health status also improved significantly in salmeterol/fluticasone group compared with ipratropium/albuterol. Salmeterol/fluticasone treatment subjects who had a decrease of circulating C-reactive protein level had a significant improvement in FEV(1) and St George's Respiratory Questionnaire total scores compared with those who did not (185 vs. 83 ml and -5.71 vs. -1.79 units, respectively, both P < 0.01).</p><p><b>CONCLUSION</b>Salmeterol/fluticasone treatment reduced circulating C-reactive protein concentration in clinically stable moderate-to-severe chronic obstructive pulmonary disease patients after 6-month treatment.</p>

Helicobacter pylori seroprevalence in patients with obstructive sleep apnea syndrome among a Chinese population

To investigate the seroprevalence of Helicobacter pylori [H. pylori] in patients with obstructive sleep apnea syndrome [OSAS], and to determine any association between H. pylori infection and severity of OSAS. Two hundred and forty-three subjects were recruited in this cross-sectional study at the Department of Respiratory Medicine in the West China Hospital, Sichuan, P. R. China, from October 2006 to April 2008. Polysomnography [PSG] was used to determine the apnea-hypopnea index [AHI], and enzyme-linked immunosorbent assay was used to test H. pylori IgG. According to the AHI, subjects were divided into 4 groups: the control group [AHI <5/hours], patients with mild OSAS group [AHI: 5-14/hours], moderate OSAS group [AHI: 15-29/hours], and severe OSAS group [AHI: >/= 30/hours]. The prevalence of H. pylori infection in patients with OSAS was 75.5%, and in the controls it was 53.4% [p=0.000]. The prevalence of H. pylori infection in patients with mild OSAS was 57.1%, with moderate OSAS was 76.5%, and with severe OSAS was 90.9%. There were significant differences between patients with moderate and severe OSAS and the controls, as well as among the mild, moderate, and severe OSAS groups. Helicobacter pylori infection may be associated with OSAS. In addition, increased severity of OSAS might be associated with higher seroprevalence of H. pylori