Respiratory symptoms, spirometric respiratory impairment, and respiratory disease in middle-aged and older persons

Self-reported exposure to dust and diesel exhaust, respiratory symptoms, and use of respiratory protective equipment among Arctic miners

Arctic miners face significant risks from diesel exhaust and dust exposure, potentially leading to adverse respiratory health. Employers must limit harmful exposures, using personal protective equipment (PPE) as a last line of defense. This study explored the association between reported respiratory exposure and symptoms, and PPE training and usage. Data from the MineHealth study (2012-2014) included a total of 453 Arctic open pit miners in Norway, Sweden, and Finland. Participants answered questions on exposure to dust and diesel exhaust, respiratory symptoms, and PPE use, in addition to age, gender, BMI, smoking, and self-rated health. Estimated exposure to dust was common, reported by 91%, 80%, and 82% and that of diesel exhaust by 84%, 43%, and 47% of workers in Sweden, Finland, and Norway, respectively. Reported dust exposure was significantly related to respiratory symptoms (OR 2.2, 95% CI 1.3-3.7), diesel exposure increased the occurrence of wheezing (OR 2.6, 95% CI 1.3-5.4). PPE use varied between the studied mines. Non-use was common and related to reduced visibility, wetness, skin irritation and fogging of the respiratory PPE. Future research should employ more precise exposure assessment, respiratory function as well as explore the reasons behind the non-compliance of PPE use.

Association between body mass index and respiratory symptoms in US adults: a national cross-sectional study

The correlation between body mass index (BMI) and the development of cough, shortness of breath, and dyspnea is unclear. Therefore, this study aimed to investigate the association between these parameters. Data from individuals who participated in the National Health and Nutrition Examination Survey between 2003 and 2012 were analyzed. Weighted logistic regression analysis and smoothed curve fitting were used to examine the correlation between BMI and respiratory symptoms. In addition, the relationship between BMI, chronic obstructive pulmonary disease (COPD), and bronchial asthma was examined. Stratified analysis was used to discover inflection points and specific groups. Weighted logistic regression and smoothed curve fitting revealed a U-shaped relationship between BMI and respiratory symptoms. The U-shaped relationship in BMI was also observed in patients with bronchial asthma and COPD. Stratified analysis showed that the correlation between BMI and wheezing and dyspnea was influenced by race. In addition, non-Hispanic black individuals had a higher risk of developing cough than individuals of the other three races [OR 1.040 (1.021, 1.060), p < 0.0001], and they also exhibited an inverted U-shaped relationship between BMI and bronchial asthma. However, the association of BMI with cough, wheezing, dyspnea, COPD, and asthma was not affected by sex. High or low BMI was associated with cough, shortness of breath, and dyspnea, and has been linked to bronchial asthma and COPD. These findings provide new insights into the management of respiratory symptoms and respiratory diseases.

Inspiratory versus expiratory incentive spirometry: A randomised control trial study protocol

Background

Respiratory impairments refer to a reduction in pulmonary function, which may adversely affect an individual's health. Incentive spirometry is a technique designed to assist patients in achieving a pre-set airflow volume; the volume is determined from predicted values or baseline measurements. Our study aims to assess the effect of incentive spirometry on respiratory impairments.

Method

Fifty-four patients aged 40 years and above with obstructive, restrictive or mixed respiratory impairments attending the respiratory clinic at the Lagos State University Teaching Hospital, Ikeja (LASUTH), will be recruited and assigned to three groups of 18 participants based on the class of respiratory impairment. Participants in each category of respiratory impairment will be subdivided into three groups. A final group of six participants per class of impairment will participate in the experiment. Our study will be a double-blind, randomised control trial with two intervention groups and one parallel placebo control group. Pulmonary function will be assessed before and after every procedure while the six-minute walk test (6MWT), Medical Research Council dyspnoea scale and the Pulmonary Functional Status and Dyspnea Questionnaire-Modified will be assessed fortnightly during our study. Data will be analysed using descriptive and inferential statistics and a repeated MANOVA; p < 0.05.

Discussion

The outcome of our study may reveal the effect of inspiratory and expiratory incentive spirometry on obstructive, restrictive or mixed respiratory impairments.

Conclusion

Our study may contribute to the body of knowledge on pulmonary rehabilitation.

Clinical implication

Our study results may indicate if inspiratory incentive spirometry or expiratory incentive spirometry is better suited for the treatment of the respiratory impairment.

Trial Registration

www.pactr.org: PACTR202005904039357.

Significant Spirometric Transitions and Preserved Ratio Impaired Spirometry Among Ever Smokers

BACKGROUND

Emerging data from longitudinal studies suggest that preserved ratio impaired spirometry (PRISm), defined by proportionate reductions in FEV₁ and FVC, is a heterogeneous population with frequent transitions to other lung function categories relative to individuals with normal and obstructive spirometry. Controversy regarding the clinical significance of these transitions exists (eg, whether transitions merely reflect measurement variability or noise).

RESEARCH QUESTION

Are individuals with PRISm enriched for transitions associated with substantial changes in lung function?

STUDY DESIGN AND METHODS

Current and former smokers enrolled in the Genetic Epidemiology of COPD (COPDGene) study with spirometry available in phases 1 through 3 (enrollment, 5-year follow-up, and 10-year follow-up) were analyzed. Postbronchodilator lung function categories were as follows: PRISm (FEV₁ < 80% predicted with FEV₁/FVC ratio ≥ 0.7), Global Initiative for Chronic Obstructive Lung Disease grade 0 (FEV₁ ≥ 80% predicted and FEV₁/FVC ≥ 0.7), and obstruction (FEV₁/FVC < 0.7). Significant transition status was affirmative if a subject belonged to two or more spirometric categories and had > 10% change in FEV₁ % predicted and/or FVC % predicted between consecutive visits. Ever-PRISm was present if a subject had PRISm at any visit. Logistic regression examined the association between significant transitions and ever-PRISm status, adjusted for age, sex, race, FEV₁ % predicted, current smoking, pack-years, BMI, and ever-positive bronchodilator response.

RESULTS

Among subjects with complete data (N = 1,775) over 10.1 ± 0.4 years of follow-up, the prevalence of PRISm remained consistent (10.4%-11.3%) between phases 1 through 3, but nearly one-half of subjects with PRISm transitioned into or out of PRISm at each visit. Among all subjects, 19.7% had a significant transition; ever-PRISm was a significant predictor of significant transitions (unadjusted OR, 10.3; 95% CI, 7.9-13.5; adjusted OR, 14.9; 95% CI, 10.9-20.7). Results were similar with additional adjustment for radiographic emphysema and gas trapping, when lower limit of normal criteria were used to define lung function categories, and when FEV₁ alone (regardless of change in FVC % predicted) was used to define significant transitions.

INTERPRETATION

PRISm is an unstable group, with frequent significant transitions to both obstruction and normal spirometry over time.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT000608764; URL: www.

CLINICALTRIALS

gov.

A novel locus for exertional dyspnoea in childhood asthma

Most children diagnosed with asthma have respiratory symptoms such as cough, dyspnoea and wheezing, which are also important markers of overall respiratory function. A decade of genome-wide association studies (GWAS) have investigated genetic susceptibility to asthma itself, but few have focused on important respiratory symptoms that characterise childhood asthma.Using whole-genome sequencing (WGS) data for 894 asthmatic trios from a Costa Rican cohort, we performed family-based association tests (FBATs) to assess the association between genetic variants and multiple asthma-relevant respiratory phenotypes: cough, phlegm, wheezing, exertional dyspnoea and exertional chest tightness. We tested whether genome-wide significant associations were replicated in two additional studies: 1) 286 asthmatic trios from the Childhood Asthma Management Program (CAMP), and 2) 2691 African American current or former smokers from the COPDGene study.In the 894 Costa Rican trios, we identified a genome-wide significant association (p=2.16×10^-9) between exertional dyspnoea and the single nucleotide polymorphism (SNP) rs10165869, located on chromosome 2q37.3, that was replicated in the CAMP cohort (p=0.023) with the same direction of association (combined p=3.28×10^-10). This association was not found in the African American participants from COPDGene. We also found suggestive evidence for an association between SNP rs10165869 and the atypical chemokine receptor 3 (ACKR3).Our finding encourages the secondary association analysis of a wider range of phenotypes that characterise respiratory symptoms in other airway diseases/studies.

Lung Function and Respiratory Symptoms after Tuberculosis in an American Indian Population. The Strong Heart Study

Rationale: Permanent lung function impairment after active tuberculosis infection is relatively common. It remains unclear which spirometric pattern is most prevalent after tuberculosis.Objectives: Our objective was to elucidate the impact of active tuberculosis survival on lung health in the Strong Heart Study (SHS), a population of American Indians historically highly impacted by tuberculosis. As arsenic exposure has also been related to lung function in the SHS, we also assessed the joint effect between arsenic exposure and past active tuberculosis.Methods: The SHS is an ongoing population-based, prospective study of cardiovascular disease and its risk factors in American Indian adults. This study uses tuberculosis data and spirometry data from the Visit 2 examination (1993-1995). Prior active tuberculosis was ascertained by a review of medical records. Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV₁), and FEV₁/FVC were measured by spirometry. An additional analysis was conducted to evaluate the potential association between active tuberculosis and arsenic exposure.Results: A history of active tuberculosis was associated with reduced percent predicted FVC and FEV₁, an increased odds of airflow obstruction (odds ratio = 1.45, 95% confidence interval = 1.08-1.95), and spirometric restrictive pattern (odds ratio = 1.73, 95% confidence interval = 1.24-2.40). These associations persisted after adjustment for diabetes and other risk factors, including smoking. We also observed the presence of cough, phlegm, and exertional dyspnea after a history of active tuberculosis. In the additional analysis, increasing urinary arsenic concentrations were associated with decreasing lung function in those with a history of active tuberculosis, but a reduced odds of active tuberculosis was found with elevated arsenic.Conclusions: Our findings support existing knowledge that a history of active tuberculosis is a risk factor for long-term respiratory impairment. Arsenic exposure, although inversely associated with prior active tuberculosis, was associated with a further decrease in lung function among those with a prior active tuberculosis history. The possible interaction between arsenic and tuberculosis, as well as the reduced odds of tuberculosis associated with arsenic exposure, warrants further investigation, as many populations at risk of developing active tuberculosis are also exposed to arsenic-contaminated water.

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.

Association of Symptoms of Obstructive Lung Disease and All-Cause Mortality in Older Adult Smokers

OBJECTIVES

This study aims to investigate the impact of respiratory symptoms in current and former smokers with and without obstructive lung disease (OLD) on all-cause mortality.

DESIGN

Secondary analysis in a prospective cohort (the Health, Aging and Body Composition study).

SETTING

Memphis, Tennessee, and Pittsburgh, Pennsylvania.

PARTICIPANTS

Black and white men and women with a history of current and former smoking (N = 596; 63% male and 37% female) aged 70-79 years followed for 13 years. Participants were categorized into 4 mutually exclusive groups based on symptom profile and forced expiratory volume in the 1st second to forced vital capacity ratio. The groups were Less Dyspnea-No OLD (N = 196), More Dyspnea-No OLD (N = 104), Less Dyspnea-With OLD (N = 162), and More Dyspnea-With OLD (N = 134).

MEASUREMENTS

All-cause mortality.

RESULTS

Overall, 53% in Less Dyspnea-No OLD, 63% in More Dyspnea-No OLD, 67% in Less Dyspnea-With OLD, and 84% in More Dyspnea-With OLD died within the 13- year follow up period (log-rank χ²  = 44.4, P < .0001). The hazard ratio was highest for participants with OLD, both with (HR =1.91, 95% CI 1.44 - 2.54; P < .0001) and without dyspnea (HR = 1.52, 95% CI 1.15 - 2.02; p = .004). Participants without OLD but with dyspnea had a similar risk of death to subjects who had OLD but fewer symptoms.

CONCLUSIONS

OLD is associated with high risk of death with different risk profiles based on symptom group. Patients with symptoms of shortness of breath without OLD should be considered an at-risk group given their similar mortality to those with OLD with minimal symptoms. J Am Geriatr Soc 67:2116-2122, 2019.

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.

Longitudinal Phenotypes and Mortality in Preserved Ratio Impaired Spirometry in the COPDGene Study

RATIONALE

Increasing awareness of the prevalence and significance of Preserved Ratio Impaired Spirometry (PRISm), alternatively known as restrictive or Global Initiative for Chronic Obstructive Lung Disease (GOLD)-unclassified spirometry, has expanded the body of knowledge on cross-sectional risk factors. However, longitudinal studies of PRISm remain limited.

OBJECTIVES

To examine longitudinal patterns of change in lung function, radiographic characteristics, and mortality of current and former smokers with PRISm.

METHODS

Current and former smokers, aged 45 to 80 years, were enrolled in COPDGene (phase 1, 2008-2011) and returned for a 5-year follow-up (phase 2, 2012-2016). Subjects completed questionnaires, spirometry, chest computed tomography scans, and 6-minute-walk tests at both study visits. Baseline characteristics, longitudinal change in lung function, and mortality were assessed by post-bronchodilator lung function categories: PRISm (FEV1/FVC < 0.7 and FEV1 < 80%), GOLD0 (FEV1/FVC > 0.7 and FEV1 > 80%), and GOLD1-4 (FEV1/FVC < 0.7).

MEASUREMENTS AND MAIN RESULTS

Although the prevalence of PRISm was consistent (12.4-12.5%) at phases 1 and 2, subjects with PRISm exhibited substantial rates of transition to and from other lung function categories. Among subjects with PRISm at phase 1, 22.2% transitioned to GOLD0 and 25.1% progressed to GOLD1-4 at phase 2. Subjects with PRISm at both phase 1 and phase 2 had reduced rates of FEV1 decline (-27.3 ± 42.1 vs. -33.0 ± 41.7 ml/yr) and comparable proportions of normal computed tomography scans (51% vs. 52.7%) relative to subjects with stable GOLD0 spirometry. In contrast, incident PRISm exhibited accelerated rates of lung function decline. Subjects with PRISm at phase 1 had higher mortality rates relative to GOLD0 and lower rates relative to the GOLD1-4 group.

CONCLUSIONS

PRISm is highly prevalent, is associated with increased mortality, and represents a transitional state for significant subgroups of subjects. Additional studies to characterize longitudinal progression in PRISm are warranted.

[Characteristics of non-pharmacological interventions in the elderly with COPD. Smoking cessation, pulmonary rehabilitation, nutritional management and patient education]

Chronic obstructive pulmonary disease (COPD) is a respiratory disorder responsible for a high mortality and disability. People older than 65 years are more commonly affected than younger people and tend to present with more symptoms and a greater level of disability. Non-pharmacological interventions play an important role in the management of all patients with COPD and this is particularly true in the elderly. Given the improvement in quality of life and risk of hospitalization, smoking cessation should be promoted to patients of all ages. Increased physical activity is associated with reduced respiratory symptoms. Tests such as the "Short Physical Performance Battery" can be useful in frailer older people with COPD, while walking tests such as the 6-minute walk test are used as an assessment before pulmonary rehabilitation. Increased physical activity should be combined with nutritional management. Screening for undernutrition by questionnaire, body mass index and albumin quantification is recommended in the elderly. In case of undernutrition, oral supplementation seems to reduce the risk of re-admission. All these measures must be included in an education program adapted to the elderly comorbidities (hearing loss, isolation…).

Diagnosis of the cause of chronic dyspnoea in primary and tertiary care: characterizing diagnostic confidence

Background

Chronic dyspnoea (breathlessness) in adults is a common symptom, the exact cause of which may be difficult to diagnose on initial presentation. We characterised the diagnostic complexity of chronic dyspnoea in primary care and tertiary care.

Methods

This retrospective observational study screened consecutive referral letters of all adult patients referred to cardiology or respiratory clinics at a tertiary referral hospital, during May to June 2015. For patients referred due to chronic dyspnoea, data were analysed from the initial referral letter and subsequent specialist clinic letters for the 6-month time period after referral.

Results

Of 1,370 patient referrals, 122 patients (mean age 63 y, 55% female) were referred due to chronic dyspnoea. One hundred and five patients (86%) were referred from primary care and 17 (14%) from other hospital clinics. Sixty-one percent were referred with an evident diagnosis (referrer was confident of the initial diagnosis), whereas 39% had non-evident or unclear diagnoses. By 6 months after referral, a definitive final diagnosis had been determined by the specialist clinics in 62% of patients. The majority of patients had been referred appropriately to a cardiology or respiratory clinic, based on the final diagnosis. However, only 26% of diagnoses were fully concordant between the initial referrer diagnosis and the final specialist clinic diagnosis, with 26% being partially concordant and 48% non-concordant. Diagnostic certainty of the referrer was associated with concordance of diagnosis between the referrer and specialist clinic (P<0.001).

Conclusions

In adult patients referred due to chronic dyspnoea to hospital specialist clinics, there is considerable diagnostic uncertainty about its aetiology, for both referring doctors and specialist clinics. These results demonstrate the current difficulty in diagnosing the cause of chronic dyspnoea in adults, and highlight the need for evidence-based diagnostic pathways.

The outcome and the influencing factors of the age of onset in post-mortem of chronic bronchitis patients: a retrospective study

Purpose

Chronic bronchitis is thought to occur in elderly patients, and smoking seems to be an important risk factor. The outcomes related to the age of onset in patients with chronic bronchitis are still unclear.

Patients and methods

A retrospective study was conducted on deceased patients whose diagnosis included bronchitis from 2010 to 2016. Patients were separated into two groups according to the age of onset (Group I, age ≤50 years old; Group II, age >50 years old). Information regarding disease course, smoking history, death age, number of admissions per year, Hugh Jones Index, and self-reported comorbidities of the patients was recorded.

Results

The courses of chronic cough and sputum were 33.38±7.73 years and 14.44±8.60 years in Group I and Group II, respectively (p<0.05). The death ages of Group I and Group II were 77.65±7.87 years and 84.69±6.67 years, respectively (p<0.05). There was a significant negative correlation between the number of hospital admissions per year and the age of onset. The age of onset was negatively associated with daily smoking count (r=−0.210) and total smoking count (r=−0.146). In Group I, there were fewer cases of coronary heart disease (OR =0.41 [0.24–0.71]), neurological diseases (OR =0.48 [0.24–0.97]), and total comorbidities (OR =0.67 [0.54–0.85]) than in Group II.

Conclusion

Patients with early onset chronic bronchitis had a longer history, younger death age, poorer health status, and lower incidence of comorbidities.

Correlates of dyspnoea and its association with adverse outcomes in a cohort of adults aged 80 and over

Background

adults aged 80 and over, a fast growing age-group, with increased co-morbidity and frailty have not been the focus of previous research on dyspnoea. We investigate the correlates of dyspnoea and its association with adverse outcomes in a cohort of adults aged 80 and over.

Methods

about 565 community-dwelling adults aged 80 and over of the BELFRAIL prospective cohort had assessment of Medical Research Council dyspnoea scale (MRC), forced expiratory volume in 1 s (FEV1), N-terminal pro-brain natriuretic peptide (NT-proBNP), physical performance tests, grip strength, 15 items geriatric depression scale, activities of daily living (ADL), body mass index (BMI) and demographics data. Kaplan-Meier survival curves, Cox and logistic multivariable regression, classification and regression tree (CART) analysis assessed association of dyspnoea (MRC 3-5) with time-to-cardiovascular and all-cause death (5 years), time to first hospitalisation (3 years), new/worsened ADL disability (2 years), and its correlates.

Results

participants with dyspnoea MRC 3-5 (29.9%) had increased hazard ratios for cardiovascular mortality 2.85 (95% confidence interval 1.93-4.20), all-cause mortality 2.04 (1.58-2.64), first hospitalisation 1.72 (1.35-2.19); and increased odds ratio for new/worsened disability 2.49 (1.54-4.04), independent of age, sex and smoking status. Only FEV1, physical performance, BMI and NT-proBNP (in order of importance) were selected in the tree-based classification model for dyspnoea.

Conclusions

in a cohort of adults aged 80 and over, dyspnoea was common and an independent predictor of adverse outcomes, with cardio-respiratory and physical performance impairments as key independent correlates. Its routine and comprehensive evaluation in primary care could be very valuable in caring for this age-group.

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 in Elderly Patients

Chronic obstructive pulmonary disease (COPD) is prevalent in the elderly population, with high impact on quality of life, morbidity, and mortality. The diagnosis is usually made based on symptoms and spirometry values that support the presence of airflow obstruction. However, the condition is frequently underdiagnosed. COPD is associated with premature aging and several other medical conditions that can partially explain its underdiagnosis and management. There are several pharmacologic and nonpharmacologic interventions proven to be effective in ameliorating the symptoms of COPD. Appropriate drug delivery and reduction of side effects is also pivotal in the management of patients with COPD.

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).

Health-related quality of life and risk factors associated with spirometric restriction

The restrictive spirometric pattern is associated with a substantial morbidity and mortality burden. We sought to determine to what extent spirometric restriction is associated with impaired quality of life.We used data from two large population-based European cohorts: 6698 European Community Respiratory Health Survey (ECRHS) and 6069 Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults (SAPALDIA) adult participants. The restrictive pattern was defined as forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC) ≥lower limit of normal (LLN) and FVC <LLN; an obstructive pattern was defined as FEV₁/FVC <LLN independent of FVC. The Physical Component Summary and Mental Component Summary of quality of life were computed using the Short Form-36 questionnaire.In both cohorts, the restrictive pattern was associated with heavy smoking, being underweight or obese and the coexistence of respiratory symptoms. In univariate analyses, compared with the normal group, both the restrictive and obstructive pattern had significant Physical Component Summary deficits (-2.77 and -2.08, respectively, in ECRHS; -3.25 and -2.14, respectively, in SAPALDIA; all p-values <0.001). However, in models adjusted for sex, age, education, body mass index, smoking, comorbidities and respiratory symptoms, only the restrictive pattern remained significantly associated with Physical Component Summary deficits (p=0.004 in ECRHS; p=0.001 in SAPALDIA).The restrictive spirometric pattern is associated with deficits in the physical component of quality of life that are partly independent of the presence of respiratory symptoms.

Health-related quality of life and physiological measurements in achalasia

The diagnosis of achalasia is generally made based on patient symptoms, the appearance of the esophagus on endoscopy and barium esophagogram, and esophageal manometry. In addition, timed barium esophagography (TBE) can give useful information on the clearance of liquid barium over a 10 minute period and the passage of a barium tablet. What is unclear is how well these physiological measurements of esophageal function correlate with patient-perceived health-related quality of life. Our aim was to assess whether objective physiological measurements of high-resolution manometry (HRM) and TBE will correlate with quantitative achalasia-related health-related quality of life (HRQoL) measurements. Patients referred for possible surgical treatment of achalasia were assessed preoperatively in the following manner. A gastroenterologist and surgeon clinically evaluated all patients. In addition to history and physical examination, patients underwent further testing with TBE, upper gastrointestinal endoscopy, and HRM. The diagnosis of achalasia was based on HRM. Prior to surgical treatment, patients completed the 'Measure of Achalasia Disease Severity' (ADS) which is a validated instrument assessing the severity of achalasia-associated HRQoL. Hundred and twenty patients were included in this study. The mean ADS score was 24.9 ± 3.6. There was no statistically significant difference in score among the achalasia types: I, 24.0 ± 4.3; II, 25.4 ± 3.2; III, 24.3 ± 4.6. Using linear regression analysis, there was no statistically significant correlation between ADS scores and TBE column height or width at 1 and 5 minutes. There was no statistically significant difference between patients who could pass a 13 mm barium tablet (26.4 ± 3.4) and those who could not (24.9 ± 3.6). There was no statistically significant correlation between LES pressure and IRP with ADS scores. There is poor correlation between patient-perceived health-related quality of life and objective physiological measurements of achalasia. Therefore, the assessment of treatment outcomes of achalasia will need to require both an assessment of esophageal physiology as well as HRQoL.

Dyspnea in Community-Dwelling Older Persons: A Multifactorial Geriatric Health Condition

OBJECTIVES

To evaluate the associations between a broad array of cardiorespiratory and noncardiorespiratory impairments and dyspnea in older persons.

DESIGN

Cross-sectional.

SETTING

Cardiovascular Health Study.

PARTICIPANTS

Community-dwelling persons (N = 4,413; mean age 72.6, 57.1% female, 4.5% African American, 27.2% <high school education, 54.7% ever-smokers).

MEASUREMENTS

Dyspnea severity (moderate to severe defined as American Thoracic Society Grade ≥2) and several impairments, including those established using spirometry (forced expiratory volume in 1 second (FEV₁ )), maximal inspiratory pressure (respiratory muscle strength), echocardiography, ankle-brachial index, blood pressure, whole-body muscle mass (bioelectrical impedance), single chair stand (lower extremity function), grip strength, serum hemoglobin and creatinine, Center for Epidemiologic Studies Depression Scale (CES-D), Mini-Mental State Examination, medication use, and body mass index (BMI).

RESULTS

In a multivariable logistic regression model, impairments that had strong associations with moderate to severe dyspnea were FEV₁ less than the lower limit of normal (adjusted odds ratio (aOR) = 2.88, 95% confidence interval (CI) = 2.37-3.49), left ventricular ejection fraction less than 45% (aOR = 2.12, 95% CI = 1.43, 3.16), unable to perform a single chair stand (aOR = 2.10, 95% CI = 1.61-2.73), depressive symptoms (CES-D score ≥16; aOR = 2.02, 95% CI = 1.26-3.23), and obesity (BMI ≥30; aOR = 2.07, 95% CI = 1.67-2.55). Impairments with modest but still statistically significant associations with moderate to severe dyspnea included respiratory muscle weakness, diastolic cardiac dysfunction, grip weakness, anxiety symptoms, and use of cardiovascular and psychoactive medications (aORs = 1.31-1.71).

CONCLUSION

In community-dwelling older persons, several cardiorespiratory and noncardiorespiratory impairments were significantly associated with moderate to severe dyspnea, akin to a multifactorial geriatric health condition.

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.

Phenotype of normal spirometry in an aging population

RATIONALE

In aging populations, the commonly used Global Initiative for Chronic Obstructive Lung Disease (GOLD) may misclassify normal spirometry as respiratory impairment (airflow obstruction and restrictive pattern), including the presumption of respiratory disease (chronic obstructive pulmonary disease [COPD]).

OBJECTIVES

To evaluate the phenotype of normal spirometry as defined by a new approach from the Global Lung Initiative (GLI), overall and across GOLD spirometric categories.

METHODS

Using data from COPDGene (n = 10,131; ages 45-81; smoking history, ≥10 pack-years), we evaluated spirometry and multiple phenotypes, including dyspnea severity (Modified Medical Research Council grade 0-4), health-related quality of life (St. George's Respiratory Questionnaire total score), 6-minute-walk distance, bronchodilator reversibility (FEV1 % change), computed tomography-measured percentage of lung with emphysema (% emphysema) and gas trapping (% gas trapping), and small airway dimensions (square root of the wall area for a standardized airway with an internal perimeter of 10 mm).

MEASUREMENTS AND MAIN RESULTS

Among 5,100 participants with GLI-defined normal spirometry, GOLD identified respiratory impairment in 1,146 (22.5%), including a restrictive pattern in 464 (9.1%), mild COPD in 380 (7.5%), moderate COPD in 302 (5.9%), and severe COPD in none. Overall, the phenotype of GLI-defined normal spirometry included normal adjusted mean values for dyspnea grade (0.8), St. George's Respiratory Questionnaire (15.9), 6-minute-walk distance (1,424 ft [434 m]), bronchodilator reversibility (2.7%), % emphysema (0.9%), % gas trapping (10.7%), and square root of the wall area for a standardized airway with an internal perimeter of 10 mm (3.65 mm); corresponding 95% confidence intervals were similarly normal. These phenotypes remained normal for GLI-defined normal spirometry across GOLD spirometric categories.

CONCLUSIONS

GLI-defined normal spirometry, even when classified as respiratory impairment by GOLD, included adjusted mean values in the normal range for multiple phenotypes. These results suggest that among adults with GLI-defined normal spirometry, GOLD may misclassify normal phenotypes as having respiratory impairment.

Epidemiology of Chronic Obstructive Pulmonary Disease (COPD) in Aging Populations

Current epidemiologic practice evaluates COPD based on self-reported symptoms of chronic bronchitis, self-reported physician-diagnosed COPD, spirometry confirmed airflow obstruction, or emphysema diagnosed by volumetric computed chest tomography (CT). Because the highest risk population for having COPD includes a predominance of middle-aged or older persons, aging related changes must also be considered, including: 1) increased multimorbidity, polypharmacy, and severe deconditioning, as these identify mechanisms that underlie respiratory symptoms and can impart a complex differential diagnosis; 2) increased airflow limitation, as this impacts the interpretation of spirometry confirmed airflow obstruction; and 3) "senile" emphysema, as this impacts the specificity of CT-diagnosed emphysema. Accordingly, in an era of rapidly aging populations worldwide, the use of epidemiologic criteria that do not rigorously consider aging related changes will result in increased misidentification of COPD and may, in turn, misinform public health policy and patient care.

Lower Extremity Proximal Muscle Function and Dyspnea in Older Persons

OBJECTIVES

To evaluate the association between performance on a single chair stand and moderate to severe exertional dyspnea.

DESIGN

Cross-sectional.

SETTING

Cardiovascular Health Study.

PARTICIPANTS

Community-dwelling individuals aged 65 and older (N = 4,413; mean age 72.6; female, n = 2,518 (57.1%); nonwhite, n = 199 (4.5%); obese, n = 788 (17.9%); history of smoking, n = 2,410 (54.6%)).

MEASUREMENTS

Performance on single chair stand (poor (unable to rise without arm use) vs normal (able to rise without arm use)), moderate to severe exertional dyspnea (American Thoracic Society grade ≥2), age, sex, ethnicity, obesity, smoking, frailty status (Fried-defined nonfrail, prefrail, frail), high cardiopulmonary risk (composite of cardiopulmonary diseases and diabetes mellitus), spirometric impairment, arthritis, depression, stroke, and kidney disease.

RESULTS

Poor performance on the single chair stand was established in 369 (8.4%) and moderate to severe exertional dyspnea in 773 (17.5%). Prefrail status was established in 2,210 (50.1%), frail status in 360 (8.2%), arthritis in 2,241 (51.4%), high cardiopulmonary risk in 2,469 (55.9%), spirometric impairment in 1,076 (24.4%), kidney disease in 111 (2.5%), depression in 107 (2.4%), and stroke in 93 (2.1%). In multivariable regression models, poor performance on the single chair stand was associated with moderate to severe exertional dyspnea (unadjusted odds ratio (OR) = 3.48, 95% confidence interval (CI) = 2.78-4.36; adjusted OR = 1.85, 95% CI = 1.41-2.41).

CONCLUSION

Poor performance on a single chair stand was associated with an adjusted 85% greater likelihood of moderate to severe exertional dyspnea than normal performance. These results suggest that reduced proximal muscle function of the lower extremities is associated with moderate to severe exertional dyspnea, even after adjusting for multiple confounders.