COPD heterogeneity: Gender differences in the multidimensional BODE index

Background:

The BODE index was recently validated as a multidimensional tool for the evaluation of patients with COPD. The influence of gender on the BODE index has not been studied.

Hypothesis:

The contribution of each component of the disease to the BODE index may differ according to gender.

Methods:

We evaluated age, forced expiratory volume in one second (FEV₁), Modified Medical Research Council (MMRC) score, 6-min walk distance (6MWD), and body mass index (BMI) in 52 men and 52 women with COPD and the same BODE index. We compared the studied parameters between men and women and then performed a multiple regression analysis by gender.

Results:

We found statistically significant differences between men and women in all parameters: FEV₁ % (55 ± 17 vs 63 ± 18, p < 0.001), MMRC [1 (0–2) vs 1 (1–2) p = 0.03], BMI [28 (26–30) vs 25 (22–30), p = 0.05], and 6MWD [546 (451–592) vs 462 (419–520), p = 0.001]. Multiple regression analysis revealed that each component of the BODE index had different weight (β standardized coefficient) in men and women respectively: FEV₁% (0.74 vs 0.62), MMRC (0.31 vs 0.48), BMI (−0.09 vs −0.17), and 6MWD (0.13 vs 0.10).

Conclusions:

The contribution of each component to the BODE index differs by gender in subjects with similar BODE scores. Long term longitudinal studies will help determine the significance of our findings.     

Effect of add-on therapy of tiotropium in COPD treated with theophylline

Background

Although combination therapy with bronchodilators is recommended for chronic obstructive pulmonary disease (COPD), there is insufficient evidence for the efficacy of some combinations of long-acting bronchodilators.

Objective

We investigated the effects of a combination therapy with tiotropium and theophylline in COPD patients.

Methods

In a 12-week, open-labeled, parallel-group randomized study, pulmonary functions and dyspnea scores were compared between the combination and theophylline alone therapy at baseline, and 4 and 8 weeks after randomization in COPD.

Results

Sixty-one COPD patients completed the trial (31 combination therapy, 30 theophylline alone; mean age 70 years; 58 males; mean dyspnea score 2.0 and forced expiratory volume in one second (FEV₁) 1.5 L [62.5% predicted]). FEV₁ in the combination group, but not in the theophylline alone, was significantly increased at 4 (1.56 ± 0.13 L, p < 0.001) and 8 weeks (1.60 ± 0.13 L, p < 0.001) from the baseline (1.40 ± 0.12 L). In the combination group, but not the theophylline alone group, the dyspnea score was significantly improved after 4 (p < 0.01) and 8 weeks (p < 0.05) compared with baseline. In 17 patients who did not receive theophylline at screening, treatment with 4 or 8 weeks of theophylline alone did not improve dyspnea score or FEV₁.

Conclusion

Addition of tiotropium therapy to theophylline treatment can improve dyspnea and pulmonary function in COPD. Although this study did not assess whether there was any benefit of adding theophylline to patients treated with tiotropium, tiotropium can be a useful addition in COPD already treated with theophylline.     

Comparison of oxygenation in peripheral muscle during submaximal aerobic exercise, in persons with COPD and healthy, matched-control persons

Objective

The purpose of this study was to compare peripheral muscle oxygenation in persons with chronic obstructive pulmonary disease (COPD) to healthy control persons, during submaximal exercise.

Methods

Eight persons with COPD (forced expiratory volume in one second [FEV₁] = 1.00 ± 0.27 L) and eight healthy control persons (FEV₁ = 1.88 ± 0.55L) performed a submaximal graded exercise test (GXT), and completed 4 min of constant load exercise (CON) at 50% of peak GXT. Measurements included oxygen uptake, heart rate, arterial oxygen saturation and peripheral muscle oxygenation (%StO₂) at rest, during exercise, and recovery.

Results

Significantly greater workloads were attained for controls compared with COPD for peak GXT and CON. No significant differences in %StO₂ were observed between groups at: rest (GXT: 29.5 ± 22.8 vs 30.4 ± 17.3%; CON: 33.3 ± 15.4 vs 35.1 ± 17.2%); peak GXT (29.4 ± 19.4 vs 26.5 ± 15.9%); 4 min of CON (25.9 ± 13.5 vs 34.5 ± 21.8%); and recovery (GXT: 46.6 ± 29.1 vs 44.3 ± 21.7%; CON: 40.9 ± 21.5 vs 44.5 ± 23.2%).

Conclusion

These results suggest that peripheral skeletal muscle oxygenation is not compromised in COPD during submaximal exercise, and limitations in exercise capacity are most likely a result of muscle disuse and poor lung function.     

A meta-analysis on the efficacy of oral theophylline in patients with stable COPD

Background

Theophylline is a nonspecific inhibitor of phosphodiesterases that, despite exerting bronchodilator and anti-inflammatory effects, is a third-line therapy rarely used to treat chronic airflow limitation. We wished to evaluate the efficacy of oral theophylline as measured by improvements in trough (pre-dose) or peak (post-dose) FEV₁ and FVC in patients with clinically stable COPD.

Design

Meta-analysis of randomized, placebo-controlled trials reported as of June 2005 in which theophylline was orally administered to stable COPD patients and the functional evaluations included pre- and post-theophylline values for FEV₁ and FVC.

Results

A total of 18 trials were included in the meta-analysis. The weighted mean differences (WMD) with 95% confidence intervals (95% CI) for improvement over placebo in trough FEV₁ and FVC were 0.108L (0.053–0.163) and 0.186L (0.036–0.336), respectively, while peak FEV₁ and FVC improved by 0.096L (0.044–0.147) and 0.242L (0.11–0.374), respectively.

Conclusions

Treatment with oral theophylline improves both trough and peak FEV₁ and FVC in clinically stable COPD patients. These results support previously reported benefits of theophylline in COPD.     

Pulmonary rehabilitation program including respiratory conditioning for chronic obstructive pulmonary disease (COPD): Improved hyperinflation and expiratory flow during tidal breathing

Background

Pulmonary rehabilitation has generally relieved symptoms, strengthened exercise endurance and improved health-related quality of life (QOL) in patients with COPD, but recovery of pulmonary function remains questionable. This analysis of our innovative rehabilitation program is directed at documenting changes in patients’ expiratory airflow limitation, pulmonary symptoms and QOL. This program is designed to provide “respiratory conditioning”, a physical therapist-assisted intensive flexibility training that focuses on stretching and rib cage mobilization.

Methods

Thirty-one patients with COPD who attended rehabilitation sessions at Juntendo University Hospital from 1999 to 2006 were analyzed. Pulmonary function, expiratory flow limitation during tidal breathing, six minute walk distance (6MWD), respiratory muscle strength, and St. George Respiratory Questionnaire (SGRQ) were measured before and after pulmonary rehabilitation.

Results

In participants ages 68±7 years, the FEV₁% predicted was 39.3±15.7%. 6MWD, SGRQ and respiratory muscle strength were significantly improved after pulmonary rehabilitation. Although neither FEV₁% predicted nor FEV₁/FVC was affected to a significant extent, indicating little effect on airflow limitation, expiratory flow limitation in supine as well as seated during tidal breathing improved significantly. Moreover, rehabilitation significantly diminished TLC% predicted, FRC% predicted, RV% predicted and RV/TLC values, thus indicating a reduction of hyperinflation of the lungs at rest.

Conclusions

The present results suggest that our rehabilitation program with respiratory conditioning significantly lowered the hyperinflation of lungs at rest as well as the expiratory flow limitation during tidal breathing. In patients with COPD, overall pulmonary function improved, exercise endurance increased and health-related QOL was enhanced.Key Words: Expiratory flow limitation, hyperinflation, negative expiratory pressure, pulmonary rehabilitation, respiratory conditioning     

Creatine supplementation and physical training in patients with COPD: A double blind, placebo-controlled study

Study objectives

Patients with chronic obstructive pulmonary disease (COPD) have low exercise capacity and low content of high energetic phosphates in their skeletal muscles. The aim of the present study was to investigate whether creatine supplementation together with exercise training may increase physical performance compared with exercise training in patients with COPD.

Design

In a randomized, double-blind, placebo-controlled study, 23 patients with COPD (forced expiratory volume in one second [FEV₁] < 70% of predicted) were randomized to oral creatine (n = 13) or placebo (n = 10) supplementation during an 8-week rehabilitation programme including exercise training. Physical performance was assessed by Endurance Shuttle Walking Test (ESWT), dyspnea and leg fatigue with Borg CR-10, quality of life with St George’s Respiratory Questionnaire (SGRQ). In addition, lung function test, artery blood gases, grip strength test, muscle strength and fatigue in knee extensors were measured.

Results

COPD patients receiving creatine supplementation increased their average walking time by 61% (ESWT) (p < 0.05) after the training period compared with 48% (p = 0.07) in the placebo group. Rated dyspnea directly after the ESWT decreased significantly from 7 to 5 (p < 0.05) in the creatine group. However, the difference between the groups was not statistically significant neither in walking time nor in rated dyspnea. Creatine supplementation did not increase the health related quality of life, lung function, artery blood gases, grip strength and knee extensor strength/fatigue.

Conclusions

Oral creatine supplementation in combination with exercise training showed no significant improvement in physical performance, measured as ESWT, in patients with COPD compared with exercise training alone.     

Portuguese-language version of the COPD Assessment Test: validation for use in Brazil

OBJECTIVE:

To validate a Portuguese-language version of the COPD assessment test (CAT) for use in Brazil and to assess the reproducibility of this version.

METHODS:

This was multicenter study involving patients with stable COPD at two teaching hospitals in the city of Fortaleza, Brazil. Two independent observers (twice in one day) administered the Portuguese-language version of the CAT to 50 patients with COPD. One of those observers again administered the scale to the same patients one week later. At baseline, the patients were submitted to pulmonary function testing and the six-minute walk test (6MWT), as well as completing the previously validated Portuguese-language versions of the Saint George''s Respiratory Questionnaire (SGRQ), modified Medical Research Council (MMRC) dyspnea scale, and hospital anxiety and depression scale (HADS).

RESULTS:

Inter-rater and intra-rater reliability was excellent (intraclass correlation coefficient [ICC] = 0.96; 95% CI: 0.93-0.97; p < 0.001; and ICC = 0.98; 95% CI: 0.96-0.98; p < 0.001, respectively). Bland Altman plots showed good test-retest reliability. The CAT total score correlated significantly with spirometry results, 6MWT distance, SGRQ scores, MMRC dyspnea scale scores, and HADS-depression scores.

CONCLUSIONS:

The Portuguese-language version of the CAT is a valid, reproducible, and reliable instrument for evaluating patients with COPD in Brazil.     

Systemic inflammation after inspiratory loading in chronic obstructive pulmonary disease

Objective

Patients with chronic obstructive pulmonary disease (COPD) present systemic inflammation. Strenuous resistive breathing induces systemic inflammation in healthy subjects. We hypothesized that the increased respiratory load that characterizes COPD can contribute to systemic inflammation in these patients.

Patients and methods

To test this hypothesis, we compared leukocyte numbers and levels of circulating cytokines (tumor necrosis factor alpha [TNFα], interleukin-1β [IL-1β], IL-6, IL-8, and IL-10), before and 1 hour after maximal incremental inspiratory loading in 13 patients with stable COPD (forced expiratory volume in one second [FEV₁] 29 ± 2.5% ref) and in 8 healthy sedentary subjects (FEV₁ 98 ± 5% ref).

Results

We found that: (1) at baseline, patients with COPD showed higher leukocyte counts and IL-8 levels than controls (p < 0.01); and, (2) one hour after maximal inspiratory loading these values were unchanged, except for IL-10, which increased in controls (p < 0.05) but not in patients with COPD.

Conclusions

This study confirms the presence of systemic inflammation in COPD, shows that maximal inspiratory loading does not increase the levels of pro-inflammatory cytokines (IL-1β, IL-8) in COPD patients or controls, but suggests that the former may be unable to mount an appropriate systemic anti-inflammatory response to exercise.     

Postoperative outcome after coronary artery bypass grafting in chronic obstructive pulmonary disease

BACKGROUND:

It is uncertain if the presence and severity of airflow obstruction in chronic obstructive pulmonary disease (COPD) is predictive of surgical morbidity and mortality after coronary artery bypass grafting (CABG).

METHODS:

Retrospective study of patients who underwent CABG between 1998 and 2003 in a university-affiliated hospital for whom a preoperative spirometry was available. COPD was diagnosed in smokers or ex-smokers 50 years of age or older in the presence of irreversible airflow obstruction. Patients were divided into three groups depending on the spirometry: controls (forced expiratory volume in 1 s [FEV₁] 80% or more, FEV₁/forced vital capacity [FVC] greater than 0.7), mild to moderate COPD (FEV₁ 50% or more and FEV₁/FVC 0.7 or less) and severe COPD (FEV₁ less than 50% and FEV₁/FVC 0.7 or less).

RESULTS:

Among the 411 files studied, 322 (249 men, 68±8 years of age) were retained (controls, n=101; mild to moderate COPD, n=153; severe COPD, n=68). The mortality rate (3.0%, 2.6% and 0%, respectively) was comparable among the three groups. Patients with severe COPD had a slightly longer hospital stay than controls (mean difference 0.7±1.4 days, P<0.05). Pulmonary infections were more frequent in severe COPD (26.5%) compared with mild to moderate COPD (12.4%) and controls (12.9%), P<0.05. Atrial fibrillation tended to be more frequent in severe COPD than in the other two groups.

CONCLUSION:

Mortality rate associated with CABG surgery is not influenced by the presence and severity of airflow obstruction in patients with COPD. The incidence of pulmonary infections and length of hospital stay were increased in patients with severe COPD.     

Evaluation of von Willebrand factor in COPD patients

OBJECTIVE:

To compare the absolute serum von Willebrand factor (vWF) levels and relative serum vWF activity in patients with clinically stable COPD, smokers without airway obstruction, and healthy never-smokers.

METHODS:

The study included 57 subjects, in three groups: COPD (n = 36); smoker (n = 12); and control (n = 9). During the selection phase, all participants underwent chest X-rays, spirometry, and blood testing. Absolute serum vWF levels and relative serum vWF activity were obtained by turbidimetry and ELISA, respectively. The modified Medical Research Council scale (cut-off score = 2) was used in order to classify COPD patients as symptomatic or mildly symptomatic/asymptomatic.

RESULTS:

Absolute vWF levels were significantly lower in the control group than in the smoker and COPD groups: 989 ± 436 pg/mL vs. 2,220 ± 746 pg/mL (p < 0.001) and 1,865 ± 592 pg/mL (p < 0.01). Relative serum vWF activity was significantly higher in the COPD group than in the smoker group (136.7 ± 46.0% vs. 92.8 ± 34.0%; p < 0.05), as well as being significantly higher in the symptomatic COPD subgroup than in the mildly symptomatic/asymptomatic COPD subgroup (154 ± 48% vs. 119 ± 8%; p < 0.05). In all three groups, there was a negative correlation between FEV₁ (% of predicted) and relative serum vWF activity (r² = −0.13; p = 0.009).

CONCLUSIONS:

Our results suggest that increases in vWF levels and activity contribute to the persistence of systemic inflammation, as well as increasing cardiovascular risk, in COPD patients.     

A randomized controlled trial to assess the efficacy of tiotropium in Canadian patients with chronic obstructive pulmonary disease

BACKGROUND:

Patients with chronic obstructive pulmonary disease (COPD) who smoke have a greater annual rate of decline in forced expiratory volume in 1 s (FEV₁) than those patients who have stopped smoking.

OBJECTIVES:

To assess the effect of tiotropium on pre-dose (trough) FEV₁ in patients with COPD followed in Canada.

METHODS:

A total of 913 patients were randomly assigned to receive either tiotropium 18 μg once daily (n=608) or placebo (usual care minus inhaled anticholinergics) (n=305) for 48 weeks in the present randomized, double-blind, parallel-group study. The effect of tiotropium on measurements of lung function (FEV₁, FEV₆ and forced vital capacity), symptoms, health-related quality of life (St George’s Respiratory Questionnaire) and exacerbations were examined.

RESULTS:

Tiotropium improved trough FEV₁ in both current and ex-smokers compared with placebo. Baseline FEV₁ in smokers and ex-smokers was 1.03 L and 0.93 L, respectively (P<0.001). At week 48, the mean difference between the tiotropium and placebo groups was 0.14±0.04 L (P<0.001) in the smoker group and 0.08±0.02 L (P<0.0001) in the ex-smoker group. Tiotropium also significantly improved trough forced vital capacity and FEV₆ compared with placebo throughout the treatment period (P<0.05, for all). Furthermore, tiotropium significantly improved the St George’s Respiratory Questionnaire total score compared with placebo at week 48 (40.9 versus 43.7 units, P<0.005).

CONCLUSIONS:

Compared with the placebo group, tiotropium provides sustained improvements in lung function in patients with COPD, with improvements for smokers and ex-smokers.     

Exacerbations of COPD and symptoms of gastroesophageal reflux: a systematic review and meta-analysis

OBJECTIVE:

To examine the relationship between gastroesophageal reflux (GER) and COPD exacerbations.

METHODS:

We conducted a systematic search of various electronic databases for articles published up through December of 2012. Studies considered eligible for inclusion were those dealing with COPD, COPD exacerbations, and GER; comparing at least two groups (COPD vs. controls or GER vs. controls); and describing relative risks (RRs) and prevalence ratios-or ORs and their respective 95% CIs (or presenting enough data to allow further calculations) for the association between GER and COPD-as well as exacerbation rates. Using a standardized form, we extracted data related to the study design; criteria for GER diagnosis; age, gender, and number of participants; randomization method; severity scores; methods of evaluating GER symptoms; criteria for defining exacerbations; exacerbation rates (hospitalizations, ER visits, unscheduled clinic visits, prednisone use, and antibiotic use); GER symptoms in COPD group vs. controls; mean number of COPD exacerbations (with symptoms vs. without symptoms); annual frequency of exacerbations; GER treatment; and severity of airflow obstruction.

RESULTS:

Overall, GER was clearly identified as a risk factor for COPD exacerbations (RR = 7.57; 95% CI: 3.84-14.94), with an increased mean number of exacerbations per year (mean difference: 0.79; 95% CI: 0.22-1.36). The prevalence of GER was significantly higher in patients with COPD than in those without (RR = 13.06; 95% CI: 3.64-46.87; p < 0.001).

CONCLUSIONS:

GER is a risk factor for COPD exacerbations. The role of GER in COPD management should be studied in greater detail.     

Socioeconomic gradients in tiotropium use among adults with COPD

Background

Inequalities in the use of new medications may contribute to health disparities. We analyzed socioeconomic gradients in the use of tiotropium for chronic obstructive pulmonary disease (COPD).

Methods

In a cohort of adults with COPD aged ≥55 years identified through population-based sampling, we elicited questionnaire responses on demographics, socioeconomic status (SES; lower SES defined as high school education or less or annual household income ResultsOf 427 subjects, 44 (10.3%) reported using tiotropium in 2006. Adjusting for COPD severity, lower SES was associated with reduced odds of tiotropium use (OR 0.3; 95% CI 0.1–0.7; p = 0.005). Among the subset with lung function data (n = 95), after including COPD Global Obstructive Lung Disease (GOLD) Stage ≥2 in the model, lower SES remained associated with reduced odds of tiotropium use (OR 0.03; 95% CI < 0.001–0.7; p = 0.03). Including forced expiratory volume in one second in the model as a continuous variable instead of GOLD Stage ≥2 yielded similar results for lower SES (OR 0.1; 95% CI < 0.001–0.5; p = 0.02).

Conclusion

There was a strong SES gradient in tiotropium use such that there was less use with lower SES. To the extent that this is an efficacious medication for COPD, this gradient represents a potential source of health disparities.     

Outpatient pulmonary rehabilitation in patients with chronic obstructive pulmonary disease

Objective

To evaluate an entirely outpatient-based program of pulmonary rehabilitation in patients with chronic obstructive pulmonary disease COPD, using St.George’s Respiratory questionnaire (SGRQ), the 6-minutes walking test (6-MWT) and BODE index as the primary outcome measures.

Methods

A prospective, parallel-group controlled study of an outpatient rehabilitation program in 80 patients with COPD (67 men and 13 women; mean age 64.8 ± 10.6 years; FEV₁, 42.8% ± 7.6% of the predicted value. The active group (n = 40) took part in a 14-week rehabilitation program [3 h/wk, 1.5 h of education and exercise and 1.5 h of cycling]. The control group (n = 40) was reviewed routinely as medical outpatients. The following evaluations were carried out at study entry and after14 weeks: (1) pulmonary function studies; (2) 6-minutes walking test 6MWT; (3) quality of life; and (4) BODE index.

Results

The following patients completed the study: 35 patients (87.5%) from the active group (mean age, 63.7 ± 11.9 years; mean forced expiratory volume in one second (FEV₁), 41.9 ± 2.6% of the predicted value); and 36 patients (88%) from the control group (mean age, 65.9 ± 10.3 years; mean FEV₁, 43.33 ± 3.6% of the predicted value). We found no changes in pulmonary function parameters in the active group and the control one at 14weeks. On the other hand, there were significant changes within the components of the SGRQ (12.3 for the score total) for the patients of the active group but not for the patients of the control one (only 1.5 for the score total), we observed also a significant increase in the distance of the 6-MWT in the patients of the active group but not for the patients of the control one, and finally a decrease of two points (from 6 to 4) was noted in the score of the active group’s BODE index without any change in the control group’s one.

Conclusion

An outpatient-based of 14-week rehabilitation program significantly improved the quality of life and exercise tolerance without any change in the pulmonary function in patients with moderate COPD, and there was also a large decrease in the risk of death in rehabilitated patients as measured using the BODE index.     

Tomographic and functional findings in severe COPD: comparison between the wood smoke-related and smoking-related disease

OBJECTIVE:

Wood smoke exposure is a risk factor for COPD. For a given degree of airway obstruction, the reduction in DLCO is smaller in individuals with wood smoke-related COPD than in those with smoking-related COPD, suggesting that there is less emphysema in the former. The objective of this study was to compare HRCT findings between women with wood smoke-related COPD and women with smoking-related COPD.

METHODS:

Twenty-two women with severe COPD (FEV₁/FVC ratio < 70% and FEV₁ < 50%) were divided into two groups: those with wood smoke-related COPD (n = 12) and those with smoking-related COPD (n = 10). The two groups were compared regarding emphysema scores and airway involvement (as determined by HRCT); and functional abnormalities-spirometry results, DLCO, alveolar volume (VA), the DLCO/VA ratio, lung volumes, and specific airway resistance (sRaw).

RESULTS:

There were no significant differences between the two groups in terms of FEV₁, sRaw, or lung hyperinflation. Decreases in DLCO and in the DLCO/VA ratio were greater in the smoking-related COPD group subjects, who also had higher emphysema scores, in comparison with the wood smoke-related COPD group subjects. In the wood smoke-related COPD group, HRCT scans showed no significant emphysema, the main findings being peribronchial thickening, bronchial dilation, and subsegmental atelectasis.

CONCLUSIONS:

Female patients with severe wood smoke-related COPD do not appear to develop emphysema, although they do show severe airway involvement. The reduction in DLCO and VA, with a normal DLCO/VA ratio, is probably due to severe bronchial obstruction and incomplete mixing of inspired gas during the determination of single-breath DLCO.     

Sarcopenia in COPD: relationship with COPD severity and prognosis

Objective:

To evaluate the prevalence of sarcopenia in COPD patients, as well as to determine whether sarcopenia correlates with the severity and prognosis of COPD.

Methods:

A cross-sectional study with COPD patients followed at the pulmonary outpatient clinic of our institution. The patients underwent dual-energy X-ray absorptiometry. The diagnosis of sarcopenia was made on the basis of the skeletal muscle index, defined as appendicular lean mass/height² only for low-weight subjects and adjusted for fat mass in normal/overweight subjects. Disease severity (COPD stage) was evaluated with the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria. The degree of obstruction and prognosis were determined by the Body mass index, airflow Obstruction, Dyspnea, and Exercise capacity (BODE) index.

Results:

We recruited 91 patients (50 females), with a mean age of 67.4 ± 8.7 years and a mean BMI of 25.8 ± 6.1 kg/m². Sarcopenia was observed in 36 (39.6%) of the patients, with no differences related to gender, age, or smoking status. Sarcopenia was not associated with the GOLD stage or with FEV₁ (used as an indicator of the degree of obstruction). The BMI, percentage of body fat, and total lean mass were lower in the patients with sarcopenia than in those without (p < 0.001). Sarcopenia was more prevalent among the patients in BODE quartile 3 or 4 than among those in BODE quartile 1 or 2 (p = 0.009). The multivariate analysis showed that the BODE quartile was significantly associated with sarcopenia, regardless of age, gender, smoking status, and GOLD stage.

Conclusions:

In COPD patients, sarcopenia appears to be associated with unfavorable changes in body composition and with a poor prognosis.     

Effect of a noninvasive ventilatory support during exercise of a program in pulmonary rehabilitation in patients with COPD

Background:

Breathlessness is the most common symptom limiting exercise in patients with chronic obstructive pulmonary disease (COPD). Exercise training can improve both exercise tolerance and health status in these patients, intensity of exercise being of key importance. Nevertheless, in these patients extreme breathlessness and/or peripheral muscle fatigue may prevent patients from reaching higher levels of intensity.

Study objective:

This study was to determine whether inspiratory pressure support (IPS) applied during sub maximal exercise could enable individuals with severe but stable COPD to increase their exercise tolerance.

Participants:

Twelve subjects with severe stable COPD (mean (SD): age = 63(8.2) years; FEV₁ = 0.89(0.42) L (34)% predicted; FEV₁/FVC = 0.31(0.07) only nine subjects completed the study.

Intervention:

Each subject completed ten sessions of cycling at 25%–50% of their maximum power without NIVS and another ten sessions using NIVS.

Measurements and results:

Dyspnea was measured using Borg scale. Subjects reached high levels of dyspnea 4.7 (1.81) during the sessions without NIVS vs low levels of dyspnea during the sessions using NIVS 1.3 (0.6). Exercise time during the sessions without NIVS and with NIVS was 19.37 (3.4) and 33.75 (9.5) min, respectively. Maximal workload during the sessions without NIVS and with NIVS was 27 (3.7) and 50 (10.5) watt, respectively.

Conclusion:

We conclude that IPS delivered by nasal mask can improve exercise tolerance and dyspnea in stable severe COPD patients and hence this mode of ventilatory support may be useful in respiratory rehabilitation programs.     

Does the multidimensional grading system (BODE) correspond to differences in health status of patients with COPD?

Study objectives

To verify whether and to what extent the body mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index correlates with a disease-specific index of health status in patients with COPD.

Design

Cross-sectional study.

Setting

University-affiliated hospital.

Patients

One hundred patients with stable COPD recruited from the outpatient clinic of a single institution.

Measurements

The BODE index was calculated for each patient using variables obtained within 2 weeks of enrollment. At enrollment, all patients completed the St George’s Respiratory Questionnaire (SGRQ). The Kruskal-Wallis test was used to compare health status scores with clinical and functional categories of COPD. The Spearman correlation coefficient (r) was calculated to assess the association between health status scores and clinical or functional variables.

Results

Categorizing the BODE scores into 4 quartiles, we found that higher BODE quartiles were associated with higher (worse) SGRQ scores. The differences among the BODE quartiles in health status indexes were significant for total SGRQ as well as all 3 of the SGRQ sub-scales. In all sections of the SGRQ, scores were moderately to strongly associated with the BODE quartiles (r = 0.27–0.46). In contrast, the association between the SGRQ total, impacts, activity and Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages were weaker (r = 0.27–0.28). There was no significant association between SGRQ symptoms and GOLD stages.

Conclusions

The BODE scoring system corresponds to important differences in health status of patients with COPD. This grading system is better correlated to the health status indexes of the SGRQ than the GOLD staging criteria.     

Mechanisms of improvement of respiratory failure in patients with COPD treated with NIV

Background

Noninvasive ventilation (NIV) improves gas-exchange and symptoms in selected chronic obstructive pulmonary disease (COPD) patients with hypercapnic respiratory failure. We hypothesized NIV reverses respiratory failure by one or all of increased ventilatory response to carbon-dioxide, reduced respiratory muscle fatigue, or improved pulmonary mechanics.

Methods

Nineteen stable COPD patients (forced expiratory volume in one second 35% predicted) were studied at baseline (D0), 5–8 days (D5) and 3 months (3M) after starting NIV.

Results

Ventilator use was 6.2 (3.7) hours per night at D5 and 3.4 (1.6) at 3M (p = 0.12). Mean (SD) daytime arterial carbon-dioxide tension (PaCO₂) was reduced from 7.4 (1.2) kPa to 7.0 (1.1) kPa at D5 and 6.5 (1.1) kPa at 3M (p = 0.001). Total lung capacity decreased from 107 (28) % predicted to 103 (28) at D5 and 103 (27) % predicted at 3M (p = 0.035). At D5 there was an increase in the hypercapnic ventilatory response and some volitional measures of inspiratory and expiratory muscle strength, but not isolated diaphragmatic strength whether assessed by volitional or nonvolitional methods.

Conclusion

These findings suggest decreased gas trapping and increased ventilatory sensitivity to CO₂ are the principal mechanism underlying improvements in gas-exchange in patients with COPD following NIV. Changes in some volitional but not nonvolitional muscle strength measures may reflect improved patient effort.