The GOLD Summit on chronic obstructive pulmonary disease in low- and middle-income countries.

Chronic obstructive pulmonary disease (COPD) is one of the top three causes of death worldwide, but governments and non-governmental organisations have not given its prevention and treatment the priority it requires. This is particularly true in low- and middle-income countries, where most of the people suffering from this disease live. The United Nations (UN) has targeted a reduction of premature deaths from non-communicable diseases (NCDs) by a third by 2030; however, a coordinated UN/World Health Organization (WHO) strategy to address the burden of COPD (one of the most important NCDs) is still lacking. To explore the extent of the problem and inform the development of policies to improve the situation, the Board of Directors of the Global Initiative for Chronic Obstructive Lung Disease (GOLD) held a 1-day Summit. The key themes that emerged were the need to ensure accurate data on prevalence, raise awareness of the disease among the public, healthcare professionals and governments, including the fact that COPD aetiology goes beyond smoking (and other inhaled pollutants) and includes poor lung development in early life, and ensure that spirometry and both pharmacological and non-pharmacological therapies are available and affordable. Here, we present the actions that must be taken to address the impact of COPD. We believe that the WHO is particularly well-positioned to co-ordinate an attack on COPD, and GOLD will do all it can to help and rally support.

Patient Related Outcomes-BODE (PRO-BODE): A composite index incorporating health utilization resources predicts mortality and economic cost of COPD in real life.

Multidimensional scores were proposed for defining COPD outcomes, but without any incorporation of the economic COPD cost to clinical indices. AIM: using mortality as an outcome, the hypothesis that adding total health care cost to the BODE index would better predict mortality in COPD was investigated. METHODS: 275 COPD patients were surveyed. Anthropometrics, lung function, the BODE and the Charlson Comorbidity Index were determined. History of exacerbations, ER visits, hospitalizations and mortality were also determined over the next three years, being their rates graded and added to the BODE index according to a simple algorithm. The novel PRO-BODE index ranged 0-10 points; its relationship to annual total COPD cost and survival was assessed by linear regression analysis. RESULTS: total COD cost showed the highest relationship with survival (r = -0.58), even higher than that of age and of BODE index (r = -0.28 and r = -0.21, respectively). The integrated Pro-BODE score proved proportional to the cost of care and inversely proportional to the length of survival. CONCLUSIONS: Pro-BODE is a novel composite index which helps in predicting in real life the impact of COPD over three years, both in terms of patients' survival and of COPD economic burden.

Quality and reproducibility of spirometry in COPD patients in a randomized trial (UPLIFT®).

BACKGROUND: This study explores spirometry quality and reproducibility in the Understanding Potential Long-term Impacts on Function with Tiotropium (UPLIFT(®)) trial. METHODS: Four-year, randomized, double-blind, placebo-controlled, multicenter trial in 5993 patients with chronic obstructive pulmonary disease. Within-test variability of pre- and post-bronchodilator forced expiratory volume in 1 s (FEV(1)) was compared across study visits. Between-test variability of best pre- or post-FEV(1) values between two visits 6 months apart was compared at the start, middle and end of the trial. RESULTS: Three or more acceptable maneuvers were obtained in 93% of visits. Within-test variability of pre- and post-FEV(1) (mean standard deviation: 0.092 and 0.098 L) decreased during the trial. Between-test variability also decreased: pre-FEV(1) (visit 3-5 = 0.141 ± 0.138 L; visit 9-11 = 0.129 ± 0.121 L; visit 17-19 = 0.121 ± 0.122 L); post-FEV(1) (0.139 ± 0.140, 0.126 ± 0.123, 0.121 ± 0.122 L, respectively), and was dependent on age, sex, smoking status and disease stage, but not on bronchodilator response or study treatment. CONCLUSION: Spirometry quality in UPLIFT(®) was good and improved during the trial. Between-test variability across patient subgroups suggests that relevant cut-offs for individual disease monitoring are difficult to establish. TRIAL REGISTRATION NUMBER: NCT00144339.

The 6-min walk distance in healthy subjects: reference standards from seven countries.

The 6-min walk distance (6MWD) predicted values have been derived from small cohorts mostly from single countries. The aim of the present study was to investigate differences between countries and identify new reference values to improve 6MWD interpretation. We studied 444 subjects (238 males) from seven countries (10 centres) ranging 40-80 yrs of age. We measured 6MWD, height, weight, spirometry, heart rate (HR), maximum HR (HR(max)) during the 6-min walk test/the predicted maximum HR (HR(max) % pred), Borg dyspnoea score and oxygen saturation. The mean ± sd 6MWD was 571 ± 90 m (range 380-782 m). Males walked 30 m more than females (p < 0.001). A multiple regression model for the 6MWD included age, sex, height, weight and HR(max) % pred (adjusted r² = 0.38; p < 0.001), but there was variability across centres (adjusted r² = 0.09-0.73) and its routine use is not recommended. Age had a great impact in 6MWD independent of the centres, declining significantly in the older population (p < 0.001). Age-specific reference standards of 6MWD were constructed for male and female adults. In healthy subjects, there were geographic variations in 6MWD and caution must be taken when using existing predictive equations. The present study provides new 6MWD standard curves that could be useful in the care of adult patients with chronic diseases.

Systemic manifestations and comorbidities of COPD.

Increasing evidence indicates that chronic obstructive pulmonary disease (COPD) is a complex disease involving more than airflow obstruction. Airflow obstruction has profound effects on cardiac function and gas exchange with systemic consequences. In addition, as COPD results from inflammation and/or alterations in repair mechanisms, the "spill-over" of inflammatory mediators into the circulation may result in important systemic manifestations of the disease, such as skeletal muscle wasting and cachexia. Systemic inflammation may also initiate or worsen comorbid diseases, such as ischaemic heart disease, heart failure, osteoporosis, normocytic anaemia, lung cancer, depression and diabetes. Comorbid diseases potentiate the morbidity of COPD, leading to increased hospitalisations, mortality and healthcare costs. Comorbidities complicate the management of COPD and need to be evaluated carefully. Current therapies for comorbid diseases, such as statins and peroxisome proliferator-activated receptor-agonists, may provide unexpected benefits for COPD patients. Treatment of COPD inflammation may concomitantly treat systemic inflammation and associated comorbidities. However, new broad-spectrum anti-inflammatory treatments, such as phosphodiesterase 4 inhibitors, have significant side-effects so it may be necessary to develop inhaled drugs in the future. Another approach is the reversal of corticosteroid resistance, for example with effective antioxidants. More research is needed on COPD comorbidities and their treatment.

Sex differences in mortality in patients with COPD.

Little is known about survival and clinical prognostic factors in females with chronic obstructive pulmonary disease (COPD). The aim of the present study was to determine the survival difference between males and females with COPD and to compare the value of the different prognostic factors for the disease. In total, 265 females and 272 males with COPD matched at baseline by BODE (body mass index, airflow obstruction, dyspnoea, exercise capacity) and American Thoracic Society/European Respiratory Society/Global Initiative of Chronic Obstructive Lung Disease criteria were prospectively followed. Demographics, lung function, St George's Respiratory Questionnaire, BODE index, the components of the BODE index and comorbidity were determined. Survival was documented and sex differences were determined using Kaplan-Meier analysis. The strength of the association of the studied variables with mortality was determined using multivariate and receiver operating curves analysis. All-cause (40 versus 18%) and respiratory mortality (24 versus 10%) were higher in males than females. Multivariate analysis identified the BODE index in females and the BODE index and Charlson comorbidity score in males as the best predictors of mortality. The area under the curve of the BODE index was a better predictor of mortality than the forced expiratory volume in one second for both sexes. At similar chronic obstructive pulmonary disease severity by BODE index and forced expiratory volume in one second, females have significantly better survival than males. For both sexes the BODE index is a better predictor of survival than the forced expiratory volume in one second.

Circulating fibronectin to C-reactive protein ratio and mortality: a biomarker in COPD?

The balance between inflammatory and repair processes is important in maintaining lung homeostasis in chronic obstructive pulmonary disease (COPD). The aim of the present study was to determine whether or not an integrated index of a biomarker involved in inflammation, C-reactive protein (CRP), and another involved in wound repair, fibronectin, may be a good measure to predict clinical outcomes in COPD. Circulating blood levels of CRP and fibronectin were measured in 4,787 individuals with mild-to-moderate COPD who were prospectively followed for >7 yrs after blood collection as part of the Lung Health Study. To assess the balance between repair and inflammation, a simple ratio was calculated by dividing fibronectin levels by CRP levels and a Cox proportional hazards model was used to determine the relationship between this ratio and all-cause and disease-specific causes of mortality. The relationship between the fibronectin to CRP ratio and all-cause mortality was L-shaped. There was an exponential decay in the adjusted hazard function (i.e. the risk of mortality) as the ratio decreased until a value of 148 was reached, beyond which point the hazard function did not change significantly. Similar results were observed for the risk of coronary and cardiovascular mortality. Circulating fibronectin to CRP ratio is significantly associated with all-cause mortality of COPD patients. However, in contrast to other biomarkers, the relationship appears to be L-shaped (and not linear), suggesting a threshold at approximately 150. While promising, future studies are needed to validate this simple index as a biomarker in COPD.

Effects of hyperinflation on the oxygen pulse as a marker of cardiac performance in COPD.

A decreased inspiratory capacity (IC)/total lung capacity (TLC) ratio is associated with dynamic hyperinflation and decreased exercise capacity. The present authors hypothesised that static (low IC/TLC) and dynamic hyperinflation impair cardiac function as assessed by oxygen pulse at rest and during cardiopulmonary exercise testing (CPET). Lung function, body mass index, hand grip strength and CPET parameters were measured (oxygen uptake (mL x kg(-1) x min(-1)) and oxygen pulse (mL x beat(-1))) in 87 chronic obstructive pulmonary disease (COPD) patients (American Thoracic Society/European Respiratory Society/Global Initiative for Chronic Obstructive Lung Disease stage 3-4) and 46 controls. The patients were divided into those with IC/TLC > 25% or < or = 25%. The IC/TLC ratio at rest and at peak exercise was associated significantly with oxygen pulse. Patients with IC/TLC < or = 25% (n = 45) had significantly lower exercise capacity, peak oxygen pulse, peak minus baseline oxygen pulse, peak IC, peak IC/TLC ratio and % change from baseline to peak IC/TLC ratio compared with patients with IC/TLC > 25% and controls. During CPET, the oxygen pulse was lower at iso-work in patients with IC/TLC < or = 25% than in those with IC/TLC > 25%. Resting hyperinflation (inspiratory capacity/total lung capacity) is associated with lower oxygen pulse, peak exercise inspiratory capacity/total lung capacity and exercise capacity in patients with severe chronic obstructive pulmonary disease. The present results support an interaction between hyperinflation and decreased cardiac function that may contribute to exercise limitation in these patients.

The modified BODE index: validation with mortality in COPD.

Peak oxygen uptake (V'(O(2))) remains the gold standard measurement of exercise capacity and has been associated with survival. A modified BODE (body mass index, airflow obstruction, dyspnoea, exercise capacity) index replacing the 6-min walk distance (6MWD) with V'(O(2)) as % predicted (mBODE%) has been developed and found to have excellent correlation with the conventional BODE index. The objectives of the present study were to compare the ability of the conventional BODE and the mBODE% to predict mortality in 444 patients with chronic obstructive pulmonary disease (COPD) followed for a mean+/-SD period of 71+/-34 months. Anthropometrics, spirometry, lung volumes, comorbidity, cardiopulmonary cyclo-ergometry test and 6MWD were determined at entry. The mean BODE indices for the cohort were: BODE 4.1+/-2 and mBODE% 5.5+/-2. Both indices were significantly correlated with mortality. Logistic regression analysis with COPD survival as the dependent variable identified the BODE index, Charlson's and exercise capacity (in W) as variables associated with this outcome. In conclusion, the conventional BODE index, which uses the 6-min walk distance, predicts mortality in chronic obstructive pulmonary disease as well as the modified index using peak oxygen uptake. The results support the use of the simpler index, which includes the 6-min walk distance in the comprehensive evaluation of patients with chronic obstructive pulmonary disease.

Outcomes for COPD pharmacological trials: from lung function to biomarkers.

The American Thoracic Society/European Respiratory Society jointly created a Task Force on "Outcomes for COPD pharmacological trials: from lung function to biomarkers" to inform the chronic obstructive pulmonary disease research community about the possible use and limitations of current outcomes and markers when evaluating the impact of a pharmacological therapy. Based on their review of the published literature, the following document has been prepared with individual sections that address specific outcomes and markers, and a final section that summarises their recommendations.

Validation and comparison of reference equations for the 6-min walk distance test.

Exercise impairment as measured by the 6-min walk distance (6MWD) test afflicts many patients with chronic obstructive pulmonary disease (COPD) and is known to predict mortality. Reference equations for the 6MWD in adults have been published but not yet validated. The present authors prospectively followed 1,379 COPD patients for 55+/-30 months and tested the predictive value of the baseline 6MWD in metres, the 6MWD work (kg.m(-1)) and as a percentage of predicted values the 6MWD in meters according to two reference equations. All-cause mortality was the validating outcome. The best threshold values were identified for each of the tests using receiver operating characteristic (ROC) curves. The threshold values obtained were: 350 m for the 6MWD, 25,000 kg.m(-1) for the 6MWD work, and 67 and 54% predicted for the two reference equations. All modalities of the testing were similar at predicting COPD mortality and correlated well with the 6MWD test. In conclusion, all modalities of testing predict mortality in chronic obstructive pulmonary disease equally well. In the 6-min walk distance test, a value <350 m is associated with increased mortality and should be regarded as abnormal.

Exacerbations of chronic obstructive pulmonary disease.

Exacerbations of chronic obstructive pulmonary disease are of major importance in terms of their prolonged detrimental effects on patients, the acceleration in disease progression and high healthcare costs. There is still debate about how exacerbations should be defined and graded, and their mechanisms are poorly understood. The major causal agents are either bacteria or viral infections, or a combination of the two. Noninfective causes include air pollution and pulmonary embolus but, in some patients, no cause is identified. Exacerbations represent an increase in the inflammation that is present in the stable state, with increased numbers of inflammatory cells (particularly neutrophils), cytokines, chemokines and proteases in the airways, and increased concentrations of certain cytokines and C-reactive protein in the blood. There are presently no reliable biomarkers with which to predict exacerbations. Exacerbations have a long-lasting adverse influence on health status. High doses of bronchodilators are the mainstay of treatment and systemic corticosteroids have some benefit. The routine use of antibiotics remains controversial but they are of benefit with exacerbations of a bacterial origin. Noninvasive ventilation is beneficial in preventing the need for intubation and its important complications but it is not certain whether its use in stable patients prevents exacerbations. Although important advances have been made, more effective treatments are needed in the future for prevention and treatment of exacerbations.

The 6-min walking distance: long-term follow up in patients with COPD.

The 6-min walking distance (6MWD) test is used in clinical practice and research into patients with chronic obstructive pulmonary disease (COPD). However, little is known about natural long-term change in this parameter. The 6MWD was measured at baseline and then annually for 5 yrs in 294 patients with COPD and its annual rate of decline was determined. Forced expiratory volume in one second (FEV1) was also measured and the relationship between changes in both markers was explored. At baseline, the median 6MWD was 380 m (range 160-600 m). It declined by 19% (16 m.yr(-1)) over the 5 yrs compared with baseline in patients with American Thoracic Society/European Respiratory Society stage III COPD (FEV1 30-50% predicted) and by 26% (15 m.yr(-1)) in patients with stage IV COPD (FEV1 <30% pred). Over the 5-yr follow-up, the proportion of patients with a minimal clinically significant decline of 54 m increased with the severity of the disease. It was 24% in stage II, 45% in stage III, and 63% in stage IV disease. In contrast, the rate of decline of FEV1 was greater in patients with milder airflow obstruction and lesser in patients with lower absolute FEV1 values. In conclusion, the 6-min walking distance test provides increasingly useful information as the severity of chronic obstructive pulmonary disease increases.

C-reactive protein levels and clinically important predictive outcomes in stable COPD patients.

The aim of this study was to determine the relationship between C-reactive protein (CRP) levels and factors known to predict outcome in stable chronic obstructive pulmonary disease (COPD) patients. The following were studied in 130 stable COPD patients: spirometry, lung volume, arterial oxygen tension (P(a,O2)), dyspnoea, 6-min walk distance (6MWD), body mass index, fat-free mass index, BODE (body mass index, obstruction, dyspnoea and exercise capacity), health-related quality of life, smoking status, the presence of cardiovascular risk factors or disease, corticosteroid use and number of exacerbations in the previous year. CRP levels were measured in these patients and in 65 controls. Using univariate and multivariate analyses, any possible association with the predictors of outcomes was evaluated. CRP levels were higher in COPD patients than in controls (4.1 versus 1.8 mg.L(-1), respectively). Correlation was found with the following variables: forced expiratory volume in one second (FEV1; -0.23), FEV1 % (-0.20), forced vital capacity (FVC; -0.24), FVC % (-0.24), Global Initiative for Chronic Obstructive Lung Disease stage (0.17), BODE (0.17), inspiratory capacity/total lung capacity (-0.20), P(a,O2) (-0.40) and 6MWD (-0.30). Using multivariate analysis, P(a,O2) and 6MWD manifested the strongest negative association with CRP levels. C-reactive protein levels in stable chronic obstructive pulmonary disease patients are best correlated with arterial oxygen tension and 6-min walk distance. This should be considered when C-reactive protein levels are measured in stable chronic obstructive pulmonary disease patients.

C-reactive protein in patients with COPD, control smokers and non-smokers.

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) have raised serum levels of C reactive protein (CRP). This may be related directly to COPD and its associated systemic inflammation or secondary to other factors such as concomitant ischaemic heart disease (IHD) or smoking status. The aim of this study was to evaluate IHD and smoking as potential causes of raised CRP levels in COPD and to test the association between inhaled corticosteroid (ICS) use and serum CRP levels. METHODS: Cross sectional analyses comparing cohorts of 88 patients with COPD, 33 smokers (S), and 38 non-smoker (NS) controls were performed. Clinical assessments included a complete medical history, pulmonary function, 6 minute walk test (6MWT), cardiopulmonary exercise test, and high sensitivity serum CRP measurements. RESULTS: Serum CRP levels were significantly higher in patients with COPD (5.03 (1.51) mg/l) than in controls (adjusted odds ratio 9.51; 95% confidence interval 2.97 to 30.45) but were similar in the two control groups (S: 2.02 (1.04) mg/l; NS: 2.24 (1.04) mg/l). There was no clinical or exercise evidence of unstable IHD in any of the subjects. CRP levels were lower in COPD patients treated with ICS than in those not treated (3.7 (3.0) mg/l v 6.3 (3.6) mg/l); this association was confirmed in an adjusted regression model (p<0.05). CONCLUSION: CRP levels are raised in COPD patients without clinically relevant IHD and independent of cigarette smoking, and reduced in patients with COPD using ICS. CRP may be a systemic marker of the inflammatory process that occurs in patients with COPD.

Pulmonary rehabilitation and the BODE index in COPD.

The BODE index, which integrates body mass index, airflow limitation (forced expiratory volume in one second), dyspnoea and 6-min walk distance, predicts mortality in chronic obstructive pulmonary disease (COPD). Pulmonary rehabilitation (PR) improves some components of BODE. It was hypothesised that changes in BODE may reflect the effects of PR. To test this, participation in PR was offered to 246 patients (BODE quartiles 2-4). The patients were divided as follows: no PR (130 who declined rehabilitation or who dropped out from PR), and PR (116 who completed PR). BODE was determined at entry, after PR, and at 1 and 2 yrs. Other outcomes were: length of stay (LOS) for respiratory-related hospitalisations and mortality. At entry, the two groups had similar age and comorbidity but different BODE. After PR, the BODE improved by 19% and returned to baseline after 2 yrs. The BODE worsened in the no PR group by 4% at 12 months and 18% at 2 yrs. Respiratory mortality at 2 yrs for PR was 7%, compared with 39% for no PR. LOS at 1 yr for COPD decreased 20% in PR, while it increased 25% in no PR. In conclusion, pulmonary rehabilitation participation improves BODE and is associated with better outcomes. The BODE index change after pulmonary rehabilitation provides valuable prognostic information.

Increased gastro-oesophageal reflux disease in patients with severe COPD.

The prevalence and clinical consequences of gastro-oesophageal reflux disease (GERD) in chronic obstructive pulmonary disease (COPD) are not well characterised. The present study prospectively studied 42 males with COPD (forced expiratory volume in one second % predicted: 35%, range 20-49) and 16 healthy volunteers of similar age without respiratory or gastro-oesophageal symptoms. The diagnosis of GERD was confirmed using oesophageal 24 h pH monitoring. In the current study group, reflux symptoms were measured using the Vigneri score, cough and dyspnoea with the modified Medical Research Council questionnaire, and pulmonary function with bronchodilator response and health status using St George's Respiratory Questionnaire. Pathological reflux was documented in 26 out of 42 patients (62%) and in three volunteers (19%). In patients with GERD, 15 patients (58%) did not report any reflux symptoms. There were no differences in symptoms, health status, bronchodilator treatment and pulmonary function test between patients with and without GERD. Oxygen desaturation coincided with episodes of increased oesophageal acidity in 40% of patients with GERD. Patients with severe chronic obstructive pulmonary disease have a high prevalence of asymptomatic gastro-oesophageal reflux. The association between this reflux and oxygen desaturation deserves further attention.