Phenotype of normal spirometry in an aging population

COPD Risk Phenotypes in Older Smokers: Evaluation in GLI- and GOLD-Defined Respiratory Impairment

PURPOSE

In aging populations, the Global Initiative for Obstructive Lung Disease (GOLD) spirometry threshold may misclassify normal spirometry as airflow limitation. The Global Lung Initiative (GLI) method provides age-adjusted criteria. We investigated how the use of GOLD or GLI thresholds in an algorithm affects the classification of elderly smokers into COPD risk phenotypes.

METHODS

Using a modified COPDGene algorithm, including exposure, symptoms, and abnormal spirometry, 200 smokers aged 60 years and older were classified into 4 mutually exclusive phenotypes: Phenotype A (no symptoms, normal spirometry; reference), Phenotype B (symptoms, normal spirometry; possible COPD), Phenotype C (no symptoms, abnormal spirometry; possible COPD), and Phenotype D (symptoms, abnormal spirometry; probable COPD). Abnormal spirometry was defined according to the GOLD or GLI criteria. A comparison was made between the GOLD- and GLI-defined phenotypes.

RESULTS

Using GLI criteria/cut-offs, 18.5% (n = 37) had phenotype A (no COPD), 42% (n = 84) had phenotype B (possible COPD), 7.5% (n = 15) had phenotype C (possible COPD), and 32% (n = 64) had phenotype D (probable COPD). Using GOLD criteria cut-offs, 14.5% (n-29) had phenotype A (no COPD); 31% (n = 62) had phenotype B, 11.5% (n = 23) had phenotype C (probable COPD), and 43% (n = 86) had phenotype D (probable COPD). Eight smokers with GOLD phenotype C were reclassified as GLI phenotype A, while 22 with GOLD phenotype D were reclassified as GLI phenotype B. Smokers identified as ‟probable COPD" by GOLD alone (potential false positives) had better spirometry results than those identified as ‟probable COPD" by both GOLD and GLI.

CONCLUSION

The use of the GOLD threshold in an algorithm resulted in older smokers being classified into more severe COPD risk phenotypes compared to the GLI threshold. This suggests that GOLD may misclassify smokers with less affected phenotypes as having respiratory impairment, potentially leading to unnecessary and harmful treatments.

Reduced sensitivity to thyroid hormones is associated with lung function in euthyroid individuals

Background

The thyroid gland exhibits a subtle interconnection with the lungs. We further investigated the correlation between thyroid hormone sensitivity and lung function in euthyroid individuals.

Methods

Data on spirometry and mortality for participants aged 19-79 years were extracted from the NHANES database. Obstructive lung function was defined as a forced expiratory volume in 1 s to forced vital capacity ratio (FEV1/FVC) < 0.70, while restrictive lung function was considered when FEV1/FVC ≥0.70 and baseline FVC <80 % predicted. Central and peripheral sensitivities to thyroid hormones were mainly evaluated by Thyroid Feedback Quantile-based Index (TFQI) and Free Triiodothyronine/Free thyroxine (FT3/FT4) ratio. Logistic regression and subgroup analysis were used to examine potential associations between thyroid hormone sensitivity and lung function. The association between TFQI and all-cause mortality risk was also investigated.

Results

A total of 6539 participants were analyzed, 900 with obstructive lung function and 407 with restrictive lung function. The prevalence of impaired lung function, both obstructive and restrictive, increased with higher TFQI levels. Logistic regression analysis showed that increased TFQI and decreased FT3/FT4 levels were independent risk factors for obstructive and restrictive lung function (P < 0.05). After adjusting for the impact of lung function, TFQI (HR = 1.25, 95 % CI 1.00-1.56, P = 0.048) was an independent risk factor for all-cause mortality.

Conclusion

Reduced sensitivity to thyroid hormones has been linked to impaired lung function. TFQI and FT3/FT4 are potential epidemiological tools to quantify the role of central and peripheral thyroid resistance in lung function.

Regional differences in the contribution of smoking, dietary and cooking behaviours to airflow obstruction in China: A population-based case-control study

BACKGROUND AND OBJECTIVE

The major contributing risk factors to airflow obstruction (AO) in China remain largely unknown. We examined the environmental and lifestyle risk factors of unrecognized AO in the baseline of a population-based cohort drawn from 115 urban and rural communities across 12 provinces in China.

METHODS

Amongst 46,285 adults recruited from 2005 to 2009, 3686 were identified with AO on spirometry (defined by the ratio of forced expiratory volume in the first second to forced vital capacity <0.7) and without known chronic lung disease. These cases were age- and sex-matched to 11,129 controls with normal spirometry and no chronic lung disease from the same community. Conditional multivariable adjusted OR and population attributable fraction (PAF) were calculated for each identified risk factor and their combined effect.

RESULTS

Compared to controls, smoking initiation age <20 years (OR 1.22 [95% CI 1.01-1.48]), smoking duration ≥40 years (OR 1.82 [1.50-2.22]), low vegetables (OR 1.86 [1.67-2.07]) and fruits (OR 1.14 [1.02-1.29]) intake, cooking with biomass fuels (OR 2.54 [2.32-2.78]) and poor kitchen ventilation (OR 1.37 [1.19-1.58]) were significantly associated with elevated risks of unrecognized AO. The combined effect of these lifestyle factors significantly elevated the odds by 25 fold (18.6-34.3). The addition of prior tuberculosis and low socioeconomic status further increased the odds to 40.1 (28.2-57.0) and the PAF to 66.7% (51.1-78.1).

CONCLUSION

Smoking, unhealthy diet, biomass cooking fuels and low socioeconomic status are strongly associated with AO. Addressing these risk factors could substantially reduce the burden of AO in China.

Diagnostic and therapeutic approaches for elderly asthma patients: the importance of multidisciplinary and multidimensional management

INTRODUCTION

Asthma is commonly considered a disease of younger ages; however, it is not infrequent to pose a diagnosis of the disease in older individuals. Although current recommendations do not distinguish between young and old asthmatics in terms of diagnostic and therapeutic approaches, asthma in the elderly may present with peculiar features that contribute to complicate its management.

AREAS COVERED

The current review focuses on the challenges that arise when approaching an older individual with suspected asthma. Age-associated changes of the lung may complicate the diagnostic approach. Measurement of the forced expiratory volume in the first 6 s (FEV6) in an easier and faster alternative to FVC estimation, and residual volume should always be assessed. Older individuals are often affected by concomitant diseases, both age- and drug-related, that need to be considered when approaching elderly asthmatics, since they can affect the efficacy of the treatment as well as the control of the disease.

EXPERT OPINION

The potential drug to drug interaction should be routinely investigated, and documented in medical records. The effect of aging on the response to pharmacological therapy in older asthmatics should be explored. Therefore, the need of a multidisciplinary and multidimensional approach to the elderly asthmatics is strongly encouraged.

Asthma Across the Ages: Adults

Asthma is a common disease affecting approximately 300 million people worldwide, across all age ranges. Despite advances in asthma outcomes of the last few decades, there remains room for improvement in asthma management and for patient outcomes, particularly in older patients. The heterogeneity of asthma is now well recognized, and is known to complicate response to treatment and patient behavior and impact health outcomes. Asthma and its heterogeneity change according to age. Asthma affects people differently across the life span. In adults, prevalence is highest among those in middle age; however, mortality is greater in the older age group. In this clinical commentary, we describe how age impacts asthma prevalence and incidence, outcomes, disease expression, and approach to management in adulthood and in older patients.

500 Meters Is a Result of 6-Minute Walk Test Which Differentiates Patients with High and Low Risk of Postoperative Complications after Lobectomy-A Validation Study

The 6-min walk test (6MWT) is a simple method of identifying patients with a high risk of postoperative complications. In this study, we internally validated the previously obtained threshold value of 500 m in the 6MWT as differentiating populations with a high and a low risk of postoperative complications after a lobectomy. Between November 2011 and November 2016, 624 patients who underwent a lobectomy and performed the 6MWT preoperatively entered this study. We compared the complication rates of two groups of patients—those who walked more than and those who walked less than 500 m. The patients who did not reach the distance of 500 m in the 6MWT were older (70 vs. 63 years p < 0.001), had worse pulmonary function tests (FEV1% 84 vs. 88 p = 0.041) and had a higher Charlson Comorbidity Index (p < 0.001). The patients who had a worse result in the 6MWT had a higher complication rate (52% vs. 42% p = 0.019; OR: 1.501 95% CI: 1.066–2.114) and a longer median postoperative hospital stay (7 vs. 6 days p = 0.010). In a multivariate analysis, the result of the 6MWT and pack-years proved to independently influence the risk of postoperative complications. This internal validation study confirms that 500 m is a result of the 6MWT which differentiates patients with a higher risk of postoperative complications and a prolonged hospital stay after a lobectomy.

Airway obstruction can be better predicted using Global Lung Function Initiative spirometry reference equations in Marfan syndrome

Marfan syndrome is a genetic disorder of the connective tissue, including involvement of the lungs.Pulmonary function test was performed in 32 asymptomatic adult Marfan patients using European Community for Coal and Steel (ECCS) and Global Lung Function Initiative (GLI) reference values.Using GLI equations for reference, significantly lower lung function values were noted for forced vital capacity (FVC) (87.0 ± 16.6% vs. 97.1 ± 16.9%; P < 0.01) and forced expiratory volume in the first second (FEV1) (79.6 ± 18.9% vs. 88.0 ± 19.1%; P < 0.01) predicted compared to ECCS. Obstructive ventilatory pattern was present in 25% of the cases when calculating with GLI lower limit of normal (LLN), and it was significantly more common in men as compared to women (n = 6, 50% vs. n = 2, 10%; P = 0.03).GLI is more suitable to detect early ventilatory changes including airway obstruction in young patients with special anatomic features, and should be used as a standard way of evaluation in asymptomatic Marfan population.

Value of metalloproteinases in predicting COPD in heavy urban smokers

Background

Emphysema in asymptomatic heavy smokers can be detected during CT-scan screening for lung cancer. Metalloproteinases (MMPs) have been found to play a role in the pathogenesis of chronic obstructive pulmonary disease and to possibly serve as biomarkers for emphysema.

Methods

The NYU Lung Cancer Biomarker Center enrolled study subjects over 50 years of age with lung cancer risk factors from January 1, 2010, to December 31, 2015. These subjects received chest multi-detector computed tomography, spirometry, and provided serum for immunoassays for metalloproteinases (MMP) -1, -2, -7, -9, -10 and tissue inhibitor of metalloproteinases (TIMP) -1 and -2.

Results

Three hundred sixteen study subjects were enrolled. Of the 222 patients who met the inclusion criteria, 46% had emphysema. Smokers with emphysema had increased pack-years of smoking compared to smokers without emphysema (51 ± 24 pack-years (mean ± sd) versus 37 ± 20; p < 0.0001). Smokers with emphysema also had lower FEV₁/FVC percent compared to smokers without emphysema (68 ± 11 (mean ± sd) versus 75 ± 8; p < 0.0001). Increased age and pack-years of smoking were associated with increased odds of emphysema. None of the metalloproteinases or tissue inhibitors of metalloproteinases were useful to predict the presence of emphysema in smokers.

Conclusion

Emphysema was detected by CT in almost half of heavy urban smokers. Serum MMP levels provided minimal additional information to improve the detection of mild emphysema among smokers given their clinical characteristics (age, pack-years, and FEV₁/FVC ratio).

Diffusing capacity in normal-for-age spirometry and spirometric impairments, using reference equations from the global lung function initiative

BACKGROUND

Reference equations from the Global Lung Function Initiative (GLI) are now available for both spirometry and diffusion. However, respiratory phenotypes defined by GLI-based measures of diffusion have not yet been evaluated in GLI-based normal-for-age spirometry or spirometric impairments.

METHODS

We evaluated cross-sectional data from 2100 Caucasians, aged 40-85 years. GLI-based spirometric categories included normal-for-age and the impairments of restrictive-pattern and three-level severity of airflow-obstruction (mild, moderate, severe). GLI-based diffusion included diffusing capacity of the lung for carbon monoxide (D_LCO) and measured components of alveolar volume (V_A) and transfer coefficient (K_CO): D_LCO = [V_A]x[K_CO]. Using multivariable regression models, adjusted odds ratios (adjORs) for D_LCO, V_A, and K_CO < lower limit of normal (LLN) were calculated for spirometric impairments, relative to normal-for-age spirometry.

RESULTS

Relative to normal-for-age spirometry, the restrictive-pattern increased the adjORs (95% confidence intervals) for D_LCO and V_A < LLN-4.61 (3.62, 5.85) and 15.53 (11.8, 20.4), respectively, but not for K_CO < LLN-1.02 (0.79, 1.33). Also relative to normal-for-age spirometry, airflow-obstruction from mild to severe increased the adjORs for D_LCO < LLN-from 1.22 (0.80, 1.86) to 6.63 (4.91, 8.95), for V_A < LLN-from 1.37 (0.85, 2.18) to 7.01 (5.20, 9.43), and for K_CO < LLN-from 2.04 (1.33, 3.14) to 3.03 (2.29, 3.99). Notably, in normal-for-age spirometry, 34.5%, 19.7%, and 25.3% of participants had D_LCO, V_A, or K_CO < LLN, respectively.

CONCLUSION

Abnormal diffusion is most prevalent in spirometric impairments but also occurs in normal-for-age spirometry. These results further inform the respiratory phenotypes of GLI-based spirometric categories and, in turn, the spirometric evaluation of respiratory disease.

Outcome measures to be considered on asthma in elderly

PURPOSE OF REVIEW

Asthma is a chronic heterogeneous respiratory disease which is characterized by airflow limitation and variable respiratory symptoms. Asthma in patients more than 65 years of age has an important negative impact on quality of life. The pathophysiology and treatment of asthma in older patients are not as well identified as in younger groups of ages. In this review we intend to outline characteristics found in elderly adults which distinguish them from other age groups of patients with asthma.

RECENT FINDINGS

With increasing age, there are alterations in the innate and adaptive immune responses, known as 'immunosenescence.' These age-associated modifications include an altered response after a pathogenic exposure or tissue injury, moderately mediated through an irreversible loss of cellular replication and defective tissue repair.

SUMMARY

Asthma is a consequence of complex gene-environment interactions, with diversity in clinical presentation and the type and intensity of airway inflammation and remodeling. Age-associated changes in lung physiology and morphology may occur and contribute to asthma. Aging is correlated with a notable decrease in elastic recoil, greater chest wall rigidity, and poor respiratory muscle strength. Underreporting of symptoms by elderly patients is common because of multiple underlying causes. VIDEO ABSTRACT: http://links.lww.com/COAI/A17.

Association of Breathing Reserve at Peak Exercise With Body Composition and Physical Function in Older Adults With Obesity

BACKGROUND

Adiposity-related ventilatory constraints in older adults can potentially contribute to greater risk of exercise intolerance and mobility disability. This study investigated whether ventilatory limitation, measured by breathing reserve (BR) at peak exercise, is associated with body composition and physical function in older adults with obesity.

METHODS

This study was a cross-sectional analysis of data from a community-based cohort (N = 177) of older men and women (65-79 years) with obesity (body mass index = 30-45 kg/m2). All participants underwent cardiopulmonary exercise testing on a treadmill, dual-energy X-ray absorptiometry for body composition, and physical function assessments. We examined relationships between BR and body composition and physical function using multiple linear regression and compared a subset with (BR ≤ 30%; BR-low; n = 56) and without (BR ≥ 45%; BR-high, n = 48) ventilatory limitation using unpaired Student's t test and analysis of covariance.

RESULTS

BR was inversely related to total body mass, lean mass, fat mass, % body fat, and waist circumference (p < 0.05 for all). BR was positively related to 400 m walk time (p = .006) and inversely related to usual gait speed (p = .05) and VO2peak (p < .0001), indicative of worse physical function. BR-low had greater adiposity, but also greater lean mass, higher VO2peak, and faster 400 m walk time, compared to BR-high (p < .05, for all).

CONCLUSIONS

Older adults with obesity who also have ventilatory limitation have overall higher measures of adiposity, but do not have lower peak exercise capacity or physical function. Thus, ventilatory limitation does not appear to be a contributing factor to obesity-related decrements in exercise tolerance or mobility.

Re-evaluation of the Uplift Clinical Trial Using Age-Appropriate Spirometric Criteria

BACKGROUND

The clinical trial of tiotropium in COPD, UPLIFT, enrolled adults with a mean age of 65 years and moderate-to-severe airflow obstruction, based on criteria from the Global Initiative for Chronic Obstructive Lung Disease (GOLD). For the UPLIFT cohort, however, GOLD-based criteria are not age-appropriate.

RESEARCH QUESTION

Will the use of more age-appropriate criteria for airflow obstruction from the Global Lung Function Initiative (GLI) modify the spirometric classification of the UPLIFT cohort and, in turn, the mortality effect of tiotropium in COPD?

STUDY DESIGN AND METHODS

Baseline spirometric classifications were first cross-tabulated by GLI- and GOLD-based criteria. Next, in GLI- and GOLD-based airflow obstruction, modified intention-to-treat analyses evaluated differences in time to death over 4 years, comparing tiotropium vs placebo. Because treatment response may differ by COPD severity, the mortality effect also was evaluated within stratum defined by GLI- and GOLD-based moderate and severe airflow obstruction.

RESULTS

Of 5,898 participants with GOLD-based airflow-obstruction, staged as moderate in 2,739 (46.4%) and severe in 3,156 (53.5%), GLI-based criteria established airflow obstruction in 5,750 (97.5%), staged as moderate in 795 (13.5%) and severe in 4,947 (83.9%). Relative to placebo, tiotropium yielded statistically nonsignificant adjusted hazard ratios (adjHRs) (95% CI) for death of 0.91 (0.80-1.04) and 0.91 (0.79-1.03) in GLI- and GOLD-based airflow obstruction, respectively. However, statistically significant effect modification was observed, but only in GLI-based moderate and severe airflow-obstruction, with tiotropium yielding adjHRs for death of 0.53 (0.34-0.81) and 0.99 (0.86-1.13), respectively. The P value for interaction was .007.

INTERPRETATION

Mortality reduction by tiotropium was only statistically significant in GLI-based moderate airflow-obstruction, a group that was underrepresented in UPLIFT because of severity misclassification by the original GOLD-based enrollment criteria.

Impacts of Different Spirometry Reference Equations and Diagnostic Criteria on the Frequency of Airway Obstruction in Adult People of North China

Background and Objective

The reference equations and diagnostic criteria play a critical role in the interpretation of pulmonary function tests (PFTs). The aim was to investigate the impacts of different reference equations and diagnostic criteria on the frequency of airway obstruction in adult people of a large teaching hospital of North China.

Methods

The spirometry data of all adult people who underwent PFTs in Qilu hospital from April 2012 to November 2015 were collected. Two spirometry reference equations, namely, Zhongshan-2011 and Global Lung Function Initiative 2012 (GLI-2012) were compared. The frequency of airway obstruction using different spirometry prediction equations and diagnostic criteria including forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) <92% of predicted value and FEV1/FVC <lower limits of normal (LLN) were investigated.

Results

A total of 57,888 subjects were recruited with a mean age of 55.5 ± 13.72. There were significant differences in LLN and predicted value between the GLI-2012 and Zhongshan-2011. The average age of those who had an LLN of FEV1/FVC below 0.7 was 66.59 ± 6.05 years using GLI-2012, which was significantly lower than that in Zhongshan-2011 (77.46±2.63, P<0.001). Using FEV1/FVC<LLN as diagnostic criteria, Zhongshan-2011 identifies more obstructive subjects than GLI-2012 in each age group. In 45–59 or 60–80 age group, more participants were defined as obstructive using FEV1/FVC<92%pred than FEV1/FVC<LLN (both P<0.001).

Conclusion

Zhongshan-2011 identifies more airway obstruction than GLI-2012 in adult people of North China. Compared to FEV1/FVC<LLN, FEV1/FVC<92%pred may lead to overdiagnosis of airway obstruction in elderly people.

FEV1 as a Standalone Spirometric Predictor and the Attributable Fraction for Death in Older Persons

BACKGROUND

Commonly used thresholds for staging FEV₁ have not been evaluated as standalone spirometric predictors of death in older persons. Specifically, the proportion of deaths attributed to a reduced FEV₁, when staged by commonly used thresholds in L, percent of predicted (% pred), and Z scores, has not been previously reported.

METHODS

In 4,232 white persons ≥ 65 y old, sampled from the Cardiovascular Health Study, FEV₁ was stratified as stage 1 (FEV₁ ≥ 2.00 L, ≥80% pred, and Z score ≥-1.64), stage 2 (FEV₁ 1.50-1.99 L, 50-79%pred, and Z score -2.55 to -1.63), and stage 3 (FEV₁ < 1.50 L, < 50% pred, and Z score < -2.55). Notably, a Z score threshold of -1.64 defines normal-for-age lung function as the lower limit of normal (ie, 5th percentile of distribution), and accounts for differences in age, sex, height, and ethnicity. Next, adjusted odds ratios and average attributable fractions for 10-y all-cause mortality were calculated, comparing FEV₁ stages 2 and 3 against stage 1, expressed in L, % pred, and Z scores. The average attributable fraction estimates the proportion of deaths attributed to a predictor by combining the prevalence of the predictor with the relative risk of death conferred by that predictor.

RESULTS

FEV₁ stage 2 and 3 in L, % pred, and Z scores yielded similar adjusted odds ratios of death: 1.40-1.51 for stage 2 and 2.35-2.66 for stage 3. Conversely, FEV₁ stages 2 and 3 in L, % pred, and Z scores differed in prevalence: 12.8-28.6% for stage 2 and 6.4-17.5% for stage 3, and also differed in the adjusted average attributable fraction for death: 3.2-6.4% for stage 2 and 4.5-9.1% for stage 3.

CONCLUSIONS

In older persons, the proportion of deaths attributed to a reduced FEV₁ is best stratified by Z score staging thresholds because these yield a similar relative risk of death but a more age- and sex-appropriate prevalence of FEV₁ stage.

Re-evaluation of combination therapy in chronic obstructive pulmonary disease (COPD)

BACKGROUND

Clinical trials of COPD pharmacotherapy typically involve aging populations with moderate-to-severe COPD, but the latter is often diagnosed by spirometric criteria that are not age-appropriate across the continuum of lung function. We have therefore re-evaluated the clinical effect of combination therapy (salmeterol plus fluticasone) in moderate-to-severe COPD, using more age-appropriate spirometric criteria from the Global Lung Function Initiative (GLI) and trial data from Towards a Revolution in COPD Health (TORCH).

METHODS

Of the 6112 TORCH participants, 5688 (93.1%) had GLI-based moderate-to-severe COPD (mean age 64.8 years). The primary outcome was all-cause mortality and the primary comparison was combination therapy vs. placebo. Secondary outcomes included COPD and cardiovascular (CV) mortality and pneumonia. A modified intention-to-treat analysis evaluated differences in time-to-event over a three-year period, using Cox proportional hazards models with statistical significance at p < 0.010 (acknowledging repeated significance testing).

RESULTS

Relative to placebo, combination therapy yielded a statistically non-significant reduction in all-cause mortality-adjusted hazard ratio [adjHR] 0.78 (95% confidence interval [CI]: 0.64, 0.95), p = 0.012. Relative to placebo, combination therapy also yielded statistically non-significant reductions in COPD and CV mortality-adjHR 0.75 (95% CI: 0.55, 1.02), p = 0.068 and adjHR 0.76 (95% CI: 0.53, 1.09), p = 0.135, respectively. In contrast, combination therapy yielded a statistically significant increased risk of pneumonia, relative to placebo-adjHR 1.80 (95% CI: 1.46, 2.21), p < 0.001.

CONCLUSION

In GLI-based moderate-to-severe COPD, combination therapy yields a statistically significant increased risk of pneumonia but the reductions in mortality are not statistically significant, although could potentially be clinically meaningful.

Advances in spirometry testing for lung function analysis

Introduction: Spirometry, the most common lung function test, is used to evaluate individuals with respiratory complaints or known respiratory disease. However, its underutilization and the misinterpretation of its parameters are causes for concern. Areas covered: This review describes new spirometry-derived metrics, new reference equations, recent recommendations for presentation of results, recent spirometry-based prevalence studies, and technological advances in spirometry equipment. Expert opinion: The underutilization of spirometry can be overcome by increasing access to portable, hand-held, and user-friendly spirometers, together with strategies that increase awareness of the importance of spirometry. New metrics derived from spirometry, together with traditional spirometric criteria, can identify individuals with structural lung disease and respiratory morbidity. Some problems with the reference equations were solved by the Global Lung Function Initiative (GLI), which covers a wider age range and more ethnic groups and provides limits of normality using the z-score. Despite these advantages, the GLI equations lack data from large populations (especially those from Africa, South Asia, and Latin America) and greater representation of older people. Another disadvantage attributed to the GLI is the lack of predicted values for peak expiratory flow and other airflows, limiting the interpretation of the maximal expiratory flow-volume curve.

The Effect of Defining Chronic Obstructive Pulmonary Disease by the Lower Limit of Normal of FEV1/FVC Ratio in Tiotropium Safety and Performance in Respimat Participants

RATIONALE

There is continuing debate about whether to define airflow obstruction by a post-bronchodilator ratio of forced expiratory volume in 1 second (FEV₁) and forced vital capacity (FVC) below 0.70, or by ratio values falling below the age-dependent lower limit of normal (LLN) derived from general population data.

OBJECTIVES

To determine whether using the LLN criterion affects the classification and outcomes of patients previously defined as having chronic obstructive pulmonary disease by the fixed FEV₁/FVC ratio.

METHODS

We applied the LLN definition to pooled data from the Tiotropium Safety and Performance in Respimat study that used the fixed FEV₁/FVC ratio for the clinical diagnosis of chronic obstructive pulmonary disease.

RESULTS

A total of 17,072 patients were analyzed; of these, 1,807 (10.6%) patients had a ratio greater than or equal to LLN. Patients with a ratio greater than or equal to LLN had similar risks of death from any cause and fatal major adverse cardiovascular (CV) event as those below LLN. Patients with a ratio below LLN had a significantly lower risk of major adverse CV events (hazard ratio = 0.69; 95% confidence interval [CI] = 0.55-0.86; P = 0.001), and had significantly greater risks of moderate to severe exacerbation (rate ratio = 1.48; 95% CI = 1.36-1.61; P < 0.0001) and severe exacerbation (rate ratio = 2.01; 95% CI = 1.68-2.40; P < 0.0001) when compared with patients greater than or equal to LLN. Study outcomes by treatment arm (5 μg tiotropium Respimat vs. 18 μg HandiHaler) were comparable.

CONCLUSIONS

Using the LLN to define airflow obstruction would have excluded patients in the Tiotropium Safety and Performance in Respimat study with a higher risk of nonfatal major adverse CV events and a lower risk of exacerbation; study outcomes by treatment arm (2.5 μg/5 μg tiotropium Respimat vs. 18 μg HandiHaler) remained similar. Clinical trial registered with www.clinicaltrials.gov (NCT01126437).

Joint Indian Chest Society-National College of Chest Physicians (India) guidelines for spirometry

Although a simple and useful pulmonary function test, spirometry remains underutilized in India. The Indian Chest Society and National College of Chest Physicians (India) jointly supported an expert group to provide recommendations for spirometry in India. Based on a scientific grading of available published evidence, as well as other international recommendations, we propose a consensus statement for planning, performing and interpreting spirometry in a systematic manner across all levels of healthcare in India. We stress the use of standard equipment, and the need for quality control, to optimize testing. Important technical requirements for patient selection, and proper conduct of the vital capacity maneuver, are outlined. A brief algorithm to interpret and report spirometric data using minimal and most important variables is presented. The use of statistically valid lower limits of normality during interpretation is emphasized, and a listing of Indian reference equations is provided for this purpose. Other important issues such as peak expiratory flow, bronchodilator reversibility testing, and technician training are also discussed. We hope that this document will improve use of spirometry in a standardized fashion across diverse settings in India.

Performance of new spirometry reference values in preoperative assessment of lung function

BACKGROUND

Pulmonary function is not routinely assessed in patients without respiratory disease and symptoms before surgery, even if they are smokers. We aimed to check whether the new spirometric reference values of the worldwide Global Lung Initiative (GLI) affected the preoperative assessment of lung function in allegedly lung-healthy patients compared with the still commonly used old predicted values.

METHODS

Two hundred nineteen allegedly lung-healthy non-smokers, past and current smokers were examined by spirometry before elective surgery. The obtained values of forced expiratory volume in 1 second (FEV₁ ), forced vital capacity (FVC) and FEV₁ /FVC were transformed into z-scores according to the GLI guidelines. A comparison between the new and old reference values was performed. FEV₁ was used for the grading of airway obstruction.

RESULTS

One hundred eighty-three subjects performed the ventilation manoeuvre according to the GLI recommendations and were analysed. Most non-smokers and past smokers met the new references ranges for spirometric values. Only z-scores of FEV₁ /FVC distinguished among all three patient groups, FEV₁ between smokers and the other two groups and FVC did not discriminate the groups, irrespective of the reference values used. Airway obstruction was identified in 24% of asymptomatic smokers by z-scores of FEV₁ /FVC but in only 14% by the old predicted values. In elderly smokers (>60 years), the corresponding values rose to 50% and 30%. Old predicted values of FEV₁ underestimated the degree of airway obstruction mainly in middle-aged smokers.

CONCLUSION

Allegedly lung-healthy current smokers showed a higher proportion of preoperatively reduced lung function when z-scores were used, especially in elderly subjects.

Physiologic Insights from the COPD Genetic Epidemiology Study

COPD Genetic Epidemiology Study (COPDGene^®) manuscripts have provided important insights into chronic obstructive pulmonary disease (COPD) pathophysiology and outcomes, including a better understanding of COPD phenotypes relating computed tomography (CT) anatomic data to spirometric and patient-reported outcomes. Spirometry significantly underdiagnoses smoking-induced lung disease, and there is a marked improvement in sensitivity and specificity with CT scanning. This review also highlights the COPDGene^® exploration of specific spirometry phenotypes (e.g.,PRISm), contributors to spirometric decline, composite physiologic measures, asthma-COPD overlap (ACO) syndrome, consequences of bronchodilator responsiveness, newer methods to assess small airway dysfunction, and spirometric correlates of comorbid diseases such as obesity and diabetes.

Heterogeneous burden of lung disease in smokers with borderline airflow obstruction

Background

The identification of smoking-related lung disease in current and former smokers with normal FEV₁ is complex, leading to debate regarding using a ratio of forced expiratory volume in 1 s to forced vital capacity (FEV₁/FVC) of less than 0.70 versus the predicted lower limit of normal (LLN) for diagnosis of airflow obstruction. We hypothesized that the discordant group of ever-smokers with FEV₁/FVC between the LLN and 0.70 is heterogeneous, and aimed to characterize the burden of smoking-related lung disease in this group.

Methods

We compared spirometry, chest CT characteristics, and symptoms between 161 ever-smokers in the discordant group and 940 ever-smokers and 190 never-smokers with normal FEV₁ and FEV₁/FVC > 0.70 in the SPIROMICS cohort. We also estimated sensitivity and specificity for diagnosing objective radiographic evidence of chronic obstructive pulmonary disease (COPD) using different FEV₁/FVC criteria thresholds.

Results

The discordant group had more CT defined emphysema and non-emphysematous gas trapping, lower post-bronchodilator FEV₁ and FEF_25–75, and higher respiratory medication use compared with the other two groups. Within the discordant group, 44% had radiographic CT evidence of either emphysema or non-emphysematous gas trapping; an FEV₁/FVC threshold of 0.70 has greater sensitivity but lower specificity compared with LLN for identifying individuals with CT abnormality.

Conclusions

Ever-smokers with normal FEV₁ and FEV₁/FVC <  0.70 but > LLN are a heterogeneous group that includes significant numbers of individuals with and without radiographic evidence of smoking-related lung disease. These findings emphasize the limitations of diagnosing COPD based on spirometric criteria alone.

Electronic supplementary material

The online version of this article (10.1186/s12931-018-0911-z) contains supplementary material, which is available to authorized users.

Aging-related trajectories of lung function in the general population-The Doetinchem Cohort Study

The objective of this study was to explore trajectories of lung function decline with age in the general population, and to study the effect of sociodemographic and life style related risk factors, in particular smoking and BMI. For this purpose, we used data from the Doetinchem Cohort Study (DCS) of men and women, selected randomly from the general population and aged 20–59 years at inclusion in 1987–1991, and followed until the present. Participants in the DCS are assessed every five years. Spirometry has been performed as part of this assessment from 1994 onwards. Participants were included in this study if spirometric measurement of FEV₁, which in this study was the main parameter of interest, was acceptable and reproducible on at least one measurement round, leading to the inclusion of 5727 individuals (3008 females). Statistical analysis revealed three typical trajectories. The majority of participants followed a trajectory that closely adhered to the Global Lung Initiative Reference values (94.9% of men and 96.4% of women). Two other trajectories showed a more pronounced decline. Smoking and the presence of respiratory complaints were the best predictors of a trajectory with stronger decline. A greater BMI over the follow-up period was associated with a more unfavorable FEV₁ course both in men (β = -0.027 (SD = 0.002); P < 0.001) and in women (β = -0.008 (SD = 0.001); P < 0.001). Smokers at baseline who quit the habit during follow-up, showed smaller decline in FEV₁ in comparison to persistent smokers, independent of BMI change (In men β = -0.074 (SD = 0.020); P < 0.001. In women β = -0.277 (SD = 0.068); P < 0.001). In conclusion, three typical trajectories of age-related FEV1 decline could be distinguished. Change in the lifestyle related risk factors, BMI and smoking, significantly impact aging-related decline of lung function. Identifying deviant trajectories may help in early recognition of those at risk of a diagnosis of lung disease later in life.

Asthma Over the Age of 65: All's Well That Ends Well

Asthma in older adults (often classified as those 65 years or older) is relatively common, underdiagnosed, and suboptimally treated. It is an important health problem, as the population of the United States continues to age. Unfortunately, asthma morbidity and mortality rates are highest in this age group. Alterations in the innate and adaptive immune responses occur with aging, and contribute to pathophysiologic differences and subsequent treatment challenges. The symptoms of asthma may differ from those in younger populations, and often include fatigue. There are unique factors that can complicate asthma management among older adults, including comorbidities, menopause, caregiver roles, and depression. Pharmacologic therapies are often not as effective as in younger populations, and may have greater side effects. Spirometry, peak flow measurements, and asthma education are typically underused, and may contribute to delays in diagnosis as well as worse outcomes. There are specific strategies that health care providers can take to improve the care of older adults with asthma.

Spirometric impairments, cardiovascular outcomes, and noncardiovascular death in older persons

BACKGROUND

In prior work involving older persons, the reported associations of spirometric impairments with cardiovascular outcomes may have been confounded by age-related changes in lung function. Hence, using more age-appropriate spirometric criteria from the Global Lung Function Initiative (GLI), we have evaluated the associations of spirometric impairments, specifically restrictive-pattern and airflow-obstruction, with cardiovascular death (CV-death) and hospitalization (CV-hospitalization). In these analyses, we also evaluated the competing outcome of noncardiovascular death (nonCV-death) and calculated measures of relative and absolute risk.

METHODS

Our study sample was drawn from the Cardiovascular Health Study (CHS), including 4232 community-dwelling white persons aged ≥65 years. Multivariable regression models included the following baseline predictors: GLI-defined restrictive-pattern and airflow-obstruction, age, male gender, obesity, waist circumference, current smoker status, ≥10 pack-years of smoking, hypertension, dyslipidemia, diabetes, and cardiovascular and cerebrovascular disease. Outcomes included adjudicated CV-death, CV-hospitalization, and nonCV-death, ascertained over 10 years of follow-up. Measures of association included hazard ratios (HRs), rate ratios (RRs), and average attributable fraction (AAF), each with 95% confidence intervals.

RESULTS

Restrictive-pattern and airflow-obstruction were associated with CV-death (adjusted HRs: 1.57 [1.18, 2.09] and 1.29 [1.04, 1.60]) and with nonCV-death (adjusted HRs: 2.10 [1.63, 2.69] and 1.79 [1.51, 2.12]), respectively. Airflow-obstruction, but not restrictive-pattern, was also associated with CV-hospitalization (adjusted RRs: 1.18 [1.02, 1.36] and 1.20 [0.96, 1.50], respectively). The adjusted AAFs of restrictive-pattern and airflow-obstruction were 1.68% (0.46, 3.06) and 2.35% (0.22, 4.72) for CV-death, and 3.44% (1.97, 5.08) and 7.77% (5.15, 10.60) for nonCV-death, respectively.

CONCLUSION

Assessment of GLI-defined spirometric impairments contributes to broad geriatric risk stratifications for both cardiovascular and non-cardiovascular outcomes.

Spirometric Criteria for Chronic Obstructive Pulmonary Disease in Clinical Trials of Pharmacotherapy

Clinical trials of pharmacotherapy in chronic obstructive pulmonary disease (COPD) often include older persons with moderate-to-severe airflow-obstruction, as defined by the Global Initiative for chronic Obstructive Lung Disease (GOLD). In this context, spirometric airflow-obstruction establishes COPD. Because GOLD misidentifies COPD and its severity in older persons, we set out to apply more age-appropriate spirometric criteria from the Global Lung function Initiative (GLI) in a prior clinical trial of COPD pharmacotherapy, specifically the Towards a Revolution in COPD Health (TORCH) trial - N = 6,112, mean age 65 years. In the TORCH trial, which enrolled GOLD-defined moderate COPD (26.2%, n = 1,200) and GOLD-defined severe COPD (73.8%, n = 4,511), the GLI reclassification yielded a higher frequency of severe COPD (89.6%, n = 5,474), the inclusion of restrictive-pattern (6.9%, n = 420) and, in turn, a very low frequency of moderate COPD (3.5%, n = 212). These GLI reclassification results suggest that GOLD-based enrollment criteria for the TORCH trial may have assembled a cohort that was: 1) less likely to respond to COPD pharmacotherapy, given the greater representation of severe COPD, very minor representation of moderate COPD, and inclusion of a non-obstructive spirometric impairment (restrictive-pattern); and 2) more likely to have medication-related adverse events, given the inappropriate use of COPD pharmacotherapy in misidentified COPD (restrictive-pattern). We therefore propose that future clinical trials of COPD pharmacotherapy should consider GLI criteria for defining COPD, including a greater representation of GLI-defined moderate COPD.

Asthma in the elderly and late-onset adult asthma

Elderly asthmatics are at a higher risk for morbidity and mortality from their asthma than younger patients. There are important age-related physiologic and immunologic changes that complicate the presentation, diagnosis, and management of asthma in the aged population. Evidence suggests that elderly asthmatics are more likely to be underdiagnosed and undertreated. Additionally, elderly patients with asthma have highest rates of morbidity and mortality from their disease than younger patients. The underlying airway inflammation of asthma in this age group likely differs from younger patients and is felt to be non-type 2 mediated. While elderly patients are underrepresented in clinical trials, subgroup analysis of large clinical trials suggests they may be less likely to respond to traditional asthma therapies (ie, corticosteroids). As the armamentarium of pharmacologic asthma therapies expands, it will be critical to include elderly asthmatics in large clinical trials so that therapy may be better tailored to this at-risk and growing population.

An Official American Thoracic Society Workshop Report: Evaluation and Management of Asthma in the Elderly

Asthma in the elderly (>65 yr old) is common and associated with higher morbidity and mortality than asthma in younger patients. The poor outcomes in this group are due, in part, to underdiagnosis and undertreatment. There are a variety of factors related to aging itself that affect the presentation of asthma in the elderly and influence diagnosis and management. Structural changes in the aging lung superimposed on structural changes due to asthma itself can worsen the disease and physiologic function. Changes in the aging immune system influence the cellular composition and function in asthmatic airways. These processes and differences from younger individuals with asthma are not well understood. Phenotypes of asthma in the elderly have not been clearly delineated, but it is likely that age of onset and overlap with chronic obstructive pulmonary disease impact disease characteristics. Physiologic tests and biomarkers used to diagnose and follow asthma in the elderly are generally similar to testing in younger individuals; however, whether they should be modified in aging has not been established. Confounding influences, such as comorbidities (increasing the risk of polypharmacy), impaired cognition and motor skills, psychosocial effects of aging, and age-related adverse effects of medications, impact both diagnosis and treatment of asthma in the elderly. Future efforts to understand asthma in the elderly must include geriatric-specific methodology to diagnose, characterize, monitor, and treat their disease.

The Global Lung Function Initiative (GLI) Network: bringing the world's respiratory reference values together

The Global Lung Function Initiative (GLI) Network has become the largest resource for reference values for routine lung function testing ever assembled. This article addresses how the GLI Network came about, why it is important, and its current challenges and future directions. It is an extension of an article published in Breathe in 2013 [1], and summarises recent developments and the future of the GLI Network.

Learn about the GLI Network, the largest resource reference for routine lung function testinghttp://ow.ly/ZZor30epWgi

Chronic obstructive pulmonary disease with mild airflow limitation: current knowledge and proposal for future research - a consensus document from six scientific societies

Chronic obstructive pulmonary disease (COPD) is a leading cause of mortality and morbidity worldwide, with high and growing prevalence. Its underdiagnosis and hence under-treatment is a general feature across all countries. This is particularly true for the mild or early stages of the disease, when symptoms do not yet interfere with daily living activities and both patients and doctors are likely to underestimate the presence of the disease. A diagnosis of COPD requires spirometry in subjects with a history of exposure to known risk factors and symptoms. Postbronchodilator forced expiratory volume in 1 second (FEV₁)/forced vital capacity <0.7 or less than the lower limit of normal confirms the presence of airflow limitation, the severity of which can be measured by FEV₁% predicted: stage 1 defines COPD with mild airflow limitation, which means postbronchodilator FEV₁ ≥80% predicted. In recent years, an elegant series of studies has shown that "exclusive reliance on spirometry, in patients with mild airflow limitation, may result in underestimation of clinically important physiologic impairment". In fact, exercise tolerance, diffusing capacity, and gas exchange can be impaired in subjects at a mild stage of airflow limitation. Furthermore, growing evidence indicates that smokers without overt abnormal spirometry have respiratory symptoms and undergo therapy. This is an essential issue in COPD. In fact, on one hand, airflow limitation, even mild, can unduly limit the patient's physical activity, with deleterious consequences on quality of life and even survival; on the other hand, particularly in younger subjects, mild airflow limitation might coincide with the early stage of the disease. Therefore, we thought that it was worthwhile to analyze further and discuss this stage of "mild COPD". To this end, representatives of scientific societies from five European countries have met and developed this document to stimulate the attention of the scientific community on COPD with "mild" airflow limitation. The aim of this document is to highlight some key features of this important concept and help the practicing physician to understand better what is behind "mild" COPD. Future research should address two major issues: first, whether mild airflow limitation represents an early stage of COPD and what the mechanisms underlying the evolution to more severe stages of the disease are; and second, not far removed from the first, whether regular treatment should be considered for COPD patients with mild airflow limitation, either to prevent progression of the disease or to encourage and improve physical activity or both.

Chronic Obstructive Pulmonary Disease in Farmers: A Systematic Review

OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is a significant public health problem but it is unclear whether agricultural work causes an increased risk of disease. The aim of this review was to study COPD risk among farmers and analyze occupational exposures in agricultural workplaces.

METHODS

A systematic literature search was conducted to identify epidemiological studies investigating COPD prevalence in farmers.

RESULTS

In the 14 studies reviewed, COPD prevalence ranged from 3% to 68% due to different characteristics of study population, working activities, case definition/diagnosis. Livestock farmers were at higher risk and significant associations were observed for exposure to organic dusts, endotoxins, mites, ammonia, and hydrogen sulfide.

CONCLUSIONS

Farming work was associated with greater risk of developing COPD. However, considering the several variables that may influence the disease prevalence in farmers, we suggest the adoption of a standardized research strategy.

Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Lung Disease 2017 Report. GOLD Executive Summary

This Executive Summary of the Global Strategy for the Diagnosis, Management, and Prevention of COPD, Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2017 report focuses primarily on the revised and novel parts of the document. The most significant changes include: (1) the assessment of chronic obstructive pulmonary disease has been refined to separate the spirometric assessment from symptom evaluation. ABCD groups are now proposed to be derived exclusively from patient symptoms and their history of exacerbations; (2) for each of the groups A to D, escalation strategies for pharmacologic treatments are proposed; (3) the concept of deescalation of therapy is introduced in the treatment assessment scheme; (4) nonpharmacologic therapies are comprehensively presented; and (5) the importance of comorbid conditions in managing chronic obstructive pulmonary disease is reviewed.

Epidemiology of Lung Disease in Older Persons

Older persons frequently report respiratory risk factors and symptoms and have a high prevalence of symptomatic lung disease, most commonly obstructive airway disease, interstitial lung disease, and lung cancer. Notably, coexisting nonrespiratory risk factors are also prevalent and may misidentify or modify respiratory diagnoses and their clinical course.

Spirometry, Static Lung Volumes, and Diffusing Capacity

BACKGROUND

Spirometric Z-scores from the Global Lung Initiative (GLI) rigorously account for age-related changes in lung function and are thus age-appropriate when establishing spirometric impairments, including a restrictive pattern and air-flow obstruction. However, GLI-defined spirometric impairments have not yet been evaluated regarding associations with static lung volumes (total lung capacity [TLC], functional residual capacity [FRC], and residual volume [RV]) and gas exchange (diffusing capacity).

METHODS

We performed a retrospective review of pulmonary function tests in subjects ≥40 y old (mean age 64.6 y), including pre-bronchodilator measures for: spirometry (n = 2,586), static lung volumes by helium dilution with inspiratory capacity maneuver (n = 2,586), and hemoglobin-adjusted single-breath diffusing capacity (n = 2,508). Using multivariable linear regression, adjusted least-squares means (adj_LSMeans) were calculated for TLC, FRC, RV, and hemoglobin-adjusted single-breath diffusing capacity. The adj_LSMeans were expressed with and without height-cubed standardization and stratified by GLI-defined spirometry, including normal (n = 1,251), restrictive pattern (n = 663), and air-flow obstruction (mild, [n = 128]; moderate, [n = 150]; and severe, [n = 394]).

RESULTS

Relative to normal spirometry, restrictive-pattern had lower adj_LSMeans for TLC, FRC, RV, and hemoglobin-adjusted single-breath diffusing capacity (P ≤ .001). Conversely, relative to normal spirometry, mild, moderate, and severe air-flow obstruction had higher adj_LSMeans for FRC and RV (P < .001). However, only mild and moderate air-flow obstruction had higher adj_LSMeans for TLC (P < .001), while only moderate and severe air-flow obstruction had higher adj_LSMeans for RV/TLC (P < .001) and lower adj_LSMeans for hemoglobin-adjusted single-breath diffusing capacity (P < .001). Notably, TLC (calculated as FRC + inspiratory capacity) was not increased in severe air-flow obstruction (P ≥ .11) because inspiratory capacity decreased with increasing air-flow obstruction (P < .001), thus opposing the increased FRC (P < .001). Finally, P values were similar whether adj_LSMeans were height-cubed standardized.

CONCLUSIONS

A GLI-defined spirometric restrictive pattern is strongly associated with a restrictive ventilatory defect (decreased TLC, FRC, and RV), while GLI-defined spirometric air-flow obstruction is strongly associated with hyperinflation (increased FRC) and air trapping (increased RV and RV/TLC). Both spirometric impairments were strongly associated with impaired gas exchange (decreased hemoglobin-adjusted single-breath diffusing capacity).

The View of the Turkish Thoracic Society on the Report of the GOLD 2017 Global Strategy for the Diagnosis, Management, and Prevention of COPD

Since the Global Initiative for Obstructive Lung Disease (GOLD) published its first guidelines on chronic obstructive pulmonary disease (COPD) in 2001, much has changed till 2017. Previous versions of GOLD guidelines mentioned the forced expiratory volume in one second (FEV1)-based approach for staging and treatment modalities. Since 2011, a composite multi-dimensional approach has been introduced to cover various aspects of the disease. Unfortunately, this approach was not found to be correlated with mortality as well as the FEV1-based approach, despite the fact that it was better for estimating exacerbation rates. Although this assessment tool has been considered as a big step in personalized medicine, the system was rather complex to use in daily practice. In 2017, GOLD introduced a major revision in many aspects of the disease. This mainly includes a revised assessment tool and treatment algorithm. This new ABCD algorithm has excluded spirometry for guiding pharmacological therapy. Treatment recommendations are mainly based on symptoms and exacerbation rates. Escalation and de-escalation strategies have been proposed for the first time. The spirometric measurement has only been retained to confirm the diagnosis and lead to nonpharmacological therapies. In this report, the Turkish Thoracic Society COPD assembly aimed to summarize and give an insight to the Turkish interpretation of GOLD 2017.

Global Strategy for the Diagnosis, Management and Prevention of Chronic Obstructive Lung Disease 2017 Report: GOLD Executive Summary

This Executive Summary of the Global Strategy for the Diagnosis, Management and Prevention of COPD, Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2017 Report focuses primarily on the revised and novel parts of the document. The most significant changes include: (i) the assessment of chronic obstructive pulmonary disease has been refined to separate the spirometric assessment from symptom evaluation. ABCD groups are now proposed to be derived exclusively from patient symptoms and their history of exacerbations; (ii) for each of the groups A to D, escalation strategies for pharmacological treatments are proposed; (iii) the concept of de-escalation of therapy is introduced in the treatment assessment scheme; (iv)non-pharmacological therapies are comprehensively presented and (v) the importance of co-morbid conditions in managing COPD is reviewed.

Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Lung Disease 2017 Report: GOLD Executive Summary

This Executive Summary of the Global Strategy for the Diagnosis, Management, and Prevention of COPD (GOLD) 2017 Report focuses primarily on the revised and novel parts of the document. The most significant changes include: 1) the assessment of COPD has been refined to separate the spirometric assessment from symptom evaluation. ABCD groups are now proposed to be derived exclusively from patient symptoms and their history of exacerbations; 2) for each of the groups A to D, escalation strategies for pharmacological treatments are proposed; 3) the concept of de-escalation of therapy is introduced in the treatment assessment scheme; 4) nonpharmacologic therapies are comprehensively presented and; 5) the importance of comorbid conditions in managing COPD is reviewed.

Spirometry reference values in the Brazilian population

The aim of the present study was to provide new spirometry reference equations in a sample of the Brazilian population for the following parameters: forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV1/FVC ratio, peak of expiratory flow (PEF), forced expiratory flow at 50% (FEF50%), 75% average vital capacity (FEF25-75%), and average forced expiratory flow time (FEFT). This was a prospective study using results from chest radiographs, electrocardiograms, and questionnaires to investigate the participants' respiratory symptoms, sedentarism, and comorbidities (Charlson comorbidity index). From December 2010 to July 2014, individuals were randomly selected from various locations in the state of Rio de Janeiro. All individuals were examined by a single technician in the morning at the laboratory, and performed the spirometry with the same spirometer. Spirometry values were tabulated for the creation of three equation models: linear regression, logarithmic regression, and logarithms through a method that incorporates the lambda, median, and coefficient of variation (LMS method). Initially, 7003 individuals from both genders were contacted, and 454 were recruited. The data from the new equations were compared with one Brazilian and eight international equations, resulting in a high correlation (r>0.9). The values derived from the LMS method and linear regression were very similar (P>0.5), and both could be used to acquire the reference values for Brazilian spirometry. Data derived from the equations of this study were different from the current Brazilian equation, which could be justified by the different method used.

Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Lung Disease 2017 Report: GOLD Executive Summary

This Executive Summary of the Global Strategy for the Diagnosis, Management, and Prevention of COPD (GOLD) 2017 Report focuses primarily on the revised and novel parts of the document. The most significant changes include: 1) the assessment of chronic obstructive pulmonary disease has been refined to separate the spirometric assessment from symptom evaluation. ABCD groups are now proposed to be derived exclusively from patient symptoms and their history of exacerbations; 2) for each of the groups A to D, escalation strategies for pharmacological treatments are proposed; 3) the concept of de-escalation of therapy is introduced in the treatment assessment scheme; 4) nonpharmacologic therapies are comprehensively presented and; 5) the importance of comorbid conditions in managing COPD is reviewed.

Age and Small Airway Imaging Abnormalities in Subjects with and without Airflow Obstruction in SPIROMICS

RATIONALE

Aging is associated with reduced FEV1 to FVC ratio (FEV1/FVC), hyperinflation, and alveolar enlargement, but little is known about how age affects small airways.

OBJECTIVES

To determine if chest computed tomography (CT)-assessed functional small airway would increase with age, even among asymptomatic individuals.

METHODS

We used parametric response mapping analysis of paired inspiratory/expiratory CTs to identify functional small airway abnormality (PRMFSA) and emphysema (PRMEMPH) in the SPIROMICS (Subpopulations and Intermediate Outcome Measures in COPD Study) cohort. Using adjusted linear regression models, we analyzed associations between PRMFSA and age in subjects with or without airflow obstruction. We subdivided participants with normal spirometry based on respiratory-related impairment (6-minute-walk distance <350 m, modified Medical Research Council ≥2, chronic bronchitis, St. George's Respiratory Questionnaire >25, respiratory events requiring treatment [antibiotics and/or steroids or hospitalization] in the year before enrollment).

MEASUREMENTS AND MAIN RESULTS

Among 580 never- and ever-smokers without obstruction or respiratory impairment, PRMFSA increased 2.7% per decade, ranging from 3.6% (ages 40-50 yr) to 12.7% (ages 70-80 yr). PRMEMPH increased nonsignificantly (0.1% [ages 40-50 yr] to 0.4% [ages 70-80 yr]; P = 0.34). Associations were similar among nonobstructed individuals with respiratory-related impairment. Increasing PRMFSA in subjects without airflow obstruction was associated with increased FVC (P = 0.004) but unchanged FEV1 (P = 0.94), yielding lower FEV1/FVC ratios (P < 0.001). Although emphysema was also significantly associated with lower FEV1/FVC (P = 0.04), its contribution relative to PRMFSA in those without airflow obstruction was limited by its low burden.

CONCLUSIONS

In never- and ever-smokers without airflow obstruction, aging is associated with increased FVC and CT-defined functional small airway abnormality regardless of respiratory symptoms.

Asthma-COPD overlap syndrome in the US: a prospective population-based analysis of patient-reported outcomes and health care utilization

Background

Prior work suggests that asthma–COPD overlap syndrome (ACOS) has a greater health burden than asthma alone or COPD alone. In the current study, we have further evaluated the health burden of ACOS in a nationally representative sample of the US population, focusing on patient-reported outcomes and health care utilization and on comparisons with asthma alone and COPD alone. Patient-reported outcomes are especially meaningful, as these include functional activities that are highly valued by patients and are the basis for patient-centered care.

Methods

Using data from the Medical Expenditure Panel Survey (MEPS), we evaluated patient-reported outcomes and health care utilization among participants who were aged 40–85 years and had self-reported, physician-diagnosed asthma or COPD. MEPS administered five rounds of interviews, at baseline and approximately every 6 months over 2.5 years. Patient-reported outcomes included activities of daily living (ADLs), mobility, social/recreational activities, disability days in bed, and health status (Short Form 12, Version 2). Health care utilization included outpatient and emergency department (ED) visits, and hospitalization.

Results

Of 3,486 participants with asthma or COPD, 1,585 (45.4%) had asthma alone, 1,294 (37.1%) had COPD alone, and 607 (17.4%) had ACOS. Relative to asthma alone, ACOS was significantly associated with higher odds of prevalent disability in ADLs and limitations in mobility and social/recreational activities (adjusted odds ratios [adjORs]: 1.91–3.98), as well as with higher odds of incident limitations in mobility and social/recreational activities, disability days in bed, and respiratory-based outpatient and ED visits, and hospitalization (adjORs: 1.86–2.35). In addition, ACOS had significantly worse physical and mental health scores than asthma alone (P-values <0.0001). Relative to COPD alone, ACOS was significantly associated with higher odds of prevalent limitations in mobility and social/recreational activities (adjORs: 1.68–2.06), as well as with higher odds of incident disability days in bed and respiratory-based outpatient and ED visits (adjORs: 1.48–1.74). In addition, ACOS had a significantly worse physical health score, but similar mental health score, as compared with COPD alone (P-values 0.0025 and 0.1578, respectively).

Conclusion

In the US, ACOS is associated with a greater health burden, including patient-reported outcomes and health care utilization, relative to asthma alone and COPD alone.

Phenotype of Spirometric Impairment in an Aging Population

RATIONALE

The Global Lung Initiative (GLI) provides age-appropriate criteria for establishing spirometric impairment, including mild, moderate, and severe chronic obstructive pulmonary disease (COPD) and restrictive pattern, but its association with respiratory-related phenotypes has not been evaluated.

OBJECTIVES

To evaluate respiratory-related phenotypes in GLI-defined spirometric impairment.

METHODS

In COPDGene (N = 10,131 patients; age range, 45-81 yr; average smoking history, 44.3 pack-years), we evaluated spirometry, dyspnea (modified Medical Research Council grade, ≥2), poor respiratory health-related quality of life (St. George's Respiratory Questionnaire total score, ≥25), poor exercise performance (6-minute-walk distance, <391 m), bronchodilator reversibility (FEV1 change, >12% and ≥200 ml), and computed tomography-diagnosed emphysema and gas trapping (>5% and >15% of lung, respectively).

MEASUREMENTS AND MAIN RESULTS

GLI established normal spirometry in 5,100 patients (50.3%), mild COPD in 669 (6.6%), moderate COPD in 865 (8.5%), severe COPD in 2,522 (24.9%), and restrictive pattern in 975 (9.6%). Relative to normal spirometry, graded associations with respiratory-related phenotypes were found for mild, moderate, and severe COPD, with respective adjusted odds ratios (95% confidence intervals) as follows: dyspnea-1.31 (1.10-1.56), 2.20 (1.81-2.68), and 10.73 (8.04-14.33); poor respiratory health-related quality of life-1.49 (1.28-1.75), 2.69 (2.08-3.47), and 14.61 (10.09-21.17); poor exercise performance-1.11 (0.94-1.31), 1.58 (1.33-1.88), and 4.58 (3.42-6.12); bronchodilator reversibility-2.76 (2.24-3.40), 5.18 (4.29-6.27), and 6.21 (5.06-7.62); emphysema-4.86 (3.16-7.47), 6.41 (4.09-10.05), and 17.79 (10.79-29.32); and gas trapping-3.92 (3.12-4.93), 5.20 (3.82-7.07), and 16.28 (9.71-27.30). Restrictive pattern was also associated with multiple respiratory-related phenotypes at a level similar to moderate COPD, but it was otherwise not associated with emphysema (0.89 [0.60-1.32]) or gas trapping (1.15 [0.92-1.42]).

CONCLUSIONS

GLI-defined spirometric impairment establishes clinically meaningful respiratory disease, as validated by graded associations with respiratory-related phenotypes.

Comparison of NHANES III and ERS/GLI 12 for airway obstruction classification and severity

The diagnosis and severity categorisation of obstructive lung disease is determined using reference values. The American Thoracic Society/European Respiratory Society in 2005 recommended the National Health and Nutrition Examination Survey (NHANES) III spirometry prediction equations for patients in USA aged 8–80 years. The Global Lung Initiative 2012 (GLI 12) provided spirometry prediction equations for patients aged 3–95 years. Comparison of the NHANES III and GLI 12 prediction equations for diagnosing and categorising airway obstruction in patients in USA has not been made.

We aimed to quantify the differences between NHANES III and GLI 12 predicted values in Caucasians aged 18–95 years, using both mathematical simulation and clinical data. We compared predicted forced expiratory volume in 1 s (FEV1) and lower limit of normal (LLN) FEV1/forced vital capacity (FVC) % for NHANES III and GLI 12 prediction equations by applying both a simulation model and clinical spirometry data to quantify differences in the diagnosis and categorisation of airway obstruction.

Mathematical simulation revealed significant similarities and differences between prediction equations for both LLN FEV1/FVC % and predicted FEV1. There are significant differences when using GLI 12 and NHANES III to diagnose airway obstruction and severity in Caucasian patients aged 18–95 years.

Similarities and differences exist between NHANES III and GLI 12 for some age and height combinations. The differences in LLN FEV1/FVC % and predicted FEV1 are most prominent in older taller/shorter individuals. The magnitude of the differences can be large and may result in differences in clinical management.