In our study, the presence of COPD was shown to increase with age, as expected, but undiagnosed airflow limitation was also seen in patients as young as 40–49 years. There were statistically significant differences observed between patients with and without airflow limitation, for parameters including age, smoking pack-years, CAT score, chronic bronchitis, and body mass index. In patients with chronic bronchitic symptoms, 33.5% had airflow limitation, suggesting that this history may be a useful predictor of COPD amongst patients with CVD. This has also been demonstrated recently in another study, which showed that underdiagnosis of COPD was particularly a problem in younger men with chronic bronchitic symptoms – a phenotype which is not usually recognized as COPD in Japan 25 because the Japanese COPD
Third, comparing patients with HF and COPD to those without COPD, the risk of mortality increased with more severe airflow limitation from GOLD stages 1 to 4. Other hospital studies have found no association between COPD in HF with mortality for mild(6,7) or moderate(10) airflow limitation or for overall COPD.(6,10) These studies used formal spirometry screening in patients with HF to identify and assess COPD severity and so included a much higher proportion of patients with mild severity COPD. In our community cohort of patients with COPD and spirometry data, just under half were in the most severe two stages which might partly explain these differences, combined with the higher power of a large sample. The lack of risk stratification using FEV 1 for the hospitalisation outcome
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Since time to initial treatment seems crucial for the long- term outcome, including decline of lung function, it is of outmost importance to intervene as early as possible in those individuals at risk of developing airflow limitation. The aim of the present study was, therefore, to identify, especially modifiable, factors, associated with airflow limitation in a well-characterized population-based cohort of adults and by that, potentially facilitate future interventions, which aim at reducing decline in lung function in individuals at high risk.
Results: Bronchodilation was obtained by additional medication. The mean values of PA evalu- ated by metabolic equivalents (METs) at $3.0 METs and the duration of PA at $3.0 METs and $3.5 METs were improved by medication. The % change in the duration of PA at $3.5 METs was significantly correlated with the baseline functional residual capacity (FRC), residual volume, and inspiratory capacity/total lung capacity. However, the % change in the duration of PA at any intensity was not correlated with the % changes of any values of the pulmonary function tests or incremental shuttle walking test except the PA at $2.5 METs with FRC. Conclusion: Medication could improve the PA in patients with COPD, especially at a relatively high intensity of activity when medication was administered based on airflow limitation and breathlessness. The improvement was seen in the patients with better baseline lung volume, but was not correlated with the improvements in the pulmonary function tests or exercise capacity.
Results: Fifty-four percent of patients had moderate COPD. Mean serum IL-6 levels were 15.01 ± standard deviation (SD) 0.61 pg/dL and 4.59 ± 3.40 pg/dL in the case and control groups, respectively (P = 0.03). There was a significant correlation between IL-6 levels and Global Initiative for Chronic Obstructive Lung Disease stage (r = 0.25, P = 0.04) and between IL-6 and BODE index (r = 0.38, P = 0.01). There was also a significant negative correlation between serum IL-6 and forced expiratory volume in one second (FEV 1 , r = −0.36, P = 0.016). Conclusion: Our findings suggest that serum IL-6 is increased in patients with sulfur mustard poisoning and COPD, and may have a direct association with airflow limitation.
population-based databases and subjects were not recruited as part of a study of airway disease. Therefore, the key variables for cluster analysis might not be enough to reflect the diverse aspects of airway disease. Nevertheless, our five clusters were very similar to clinical phenotypes in terms of distinct prescription patterns as well as distributions of age, sex, and smoking history. From a different prospective, population-based data were one of the strengths of the study. Since subjects with mild-to-moderate airflow limitation are frequently asymptomatic, 30,31 it is sometimes hard to recruit
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In conclusion, a significant relationship was found be- tween AL and the presence of comorbid lung cancer in men, hypertension in women, diabetes and hypergly- cemia, and MetS in men and women. Further research investigating gender-based difference of comorbidity is needed. Similarly, further research is required to fully understand the relationships and underlying mecha- nisms between airflow limitation and the comorbidities. Our findings could have implications in the management of subjects with AL on medical health checkups. Efforts aimed at the earlier detection of AL and the identifica- tion of comorbidities may become integral for the reduc- tion of the disease burden of COPD on the society. Knowledge of comorbidities associated with AL should be widely publicized to raise the awareness of COPD.
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We found that patients with more severe airflow limitation had a significant decrease in the RA of Treponema and a progressive increase in the RA of Pseudomonas . These results suggest that severity-related changes in the respiratory microbiome are based on a decrease in specific genera, which are partially substituted by Pseudomonas . This change may be partly related to recurrent antibiotic exposure in previous years, considering the antibiotic sensitivity of the micro- organisms part of Treponema genus. Previous cross- sectional studies evaluating the relation between bacter- ial diversity and more severe airway limitation have mostly showed a decline in advanced stages [26–28], associated with changes in the RAs of specific genera such as Haemophilus [28, 29]. These partly discordant results may be due to patient selection, considering that most of the previous studies have focused on a restricted number of patients with moderate or severe disease [26, 27] or an overrepresentation of patients with moderate disease  whereas we studied a wider range of disease severity (GOLD 1–4). Our results, therefore, support a significant role for Pseudomonas as the severity of the disease increases to higher lung function impairment.
follow-up duration was relatively short. This is largely attrib- utable to high number of cancer-related deaths, which also contributed to the limited duration of anticoagulation in our study with a median duration of 4 months. However, analysis in which death was included as a competing risk of recurrence did not show a difference. Last, inclusion of patients with valid spirometry test results would have introduced selection bias. It is possible that PE patients in our study were more likely to have preexisting respiratory symptoms than PE patients who were not included in this study. Further pro- spective study with a larger and more heterogeneous cancer population is necessary to assess the generalizability of our results. Despite these limitations, our study used validated and standardized measurements to define airflow limitation and the diagnosis of PE and included cancer-related factors as well as treatment in the analyses.
Materials and methods: Subjects aged 50–64 years (n=1,050) were investigated with forced expiratory volume in 1 s (FEV 1 ) and forced vital capacity (FVC). Airflow limitation was defined as FEV 1 /FVC ,0.7 before bronchodilation. Chronic airflow limitation was defined after bronchodilation either according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) as FEV 1 /FVC ,0.7 or according to the lower limit of normal (LLN) approach as FEV 1 /FVC , LLN. COPD was defined as chronic airflow limitation (GOLD) in combina- tion with dyspnea, wheezing, or chronic bronchitis. Emphysema was classified according to findings from computed tomography of the lungs. Occupational exposure was defined as self- reported occupational exposure to vapor, gas, dust, or fumes (VGDF). Odds ratios (OR) were calculated in models adjusted for age, gender, and smoking; population-attributable fractions and 95% CI were also calculated.
As patients with persistent airflow limitation, either asthma or COPD patients, usually need long-term inha- lation treatments and should then be familial with their device(s) for long periods, their PUP represent a crucial point indeed in terms of their therapeutic strategy. Unfor- tunately, the patient’ s opinion was only episodically regarded as a crucial variable which can influence the effectiveness of their treatment, even substantially [17 – 20]. This aspect is of greater value when considering that, at present, the majority of molecules available on the market Table 2 Predictors of proper inhalation achieving: results of univariate and multivariate linear regressions on patients characteristics and tested devices
Our study had several strengths. This study targeted the population with emphysema but normal spirometric values. Previously, subjects with morphological emphysema but no definite spirometric abnormalities were excluded in COPD studies based on current diagnostic criteria. Yuan et al performed a similar study on 143 subjects without airflow limitations. However, they did not reveal the relationship between emphysema on CT and the annual rate of FEV 1 decline, although only half of the participants were scanned twice, and the difference in the annual FVC decline rates was also not analyzed. 9 More recently, a subgroup analysis
To the best of our knowledge, this is the first study to perform a risk assessment for COPD on current smokers in Malaysia. We found a high prevalence of airflow limitation. The predictors of airflow limitation were Indian ethnicity, LFQ ≤ 18 and a long smoking history in pack-years. In addition, the awareness of COPD and the intention to quit smoking were both low among current smokers. Such findings should alert us to look out for more smokers who are at a high risk of COPD and subsequently to raise their awareness and to motivate them to quit smoking.
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study, a history of diabetes mellitus, hyperlipidemia, depres- sion, hypertension, arteriosclerosis or osteoporosis was not associated with AL in multivariate analysis, whereas the relationships with these diseases except for osteoporosis were significant before adjustment (Table S1). These findings suggest that valid evaluation of the links between COPD and these chronic diseases, which would be trivial under the influ- ence of covariates such as smoking history and age, could be difficult. The discrepancy between the present study and previous studies may be explained in part by differences in the experimental design or the study population (described in the “Limitation” section). Owing to the nature of the university hospital, many referred patients in our hospital have more advanced disease and need advanced therapy. Thus, this study may have underestimated the prevalence of the early stages of these chronic diseases, which may influence our findings.
Abstract: Chronic obstructive pulmonary disease (COPD) is frequently under-recognized and underdiagnosed. To determine the natural history of recognized and unrecognized COPD, we studied the rate of diagnosis, health care utilization, and mortality in patients with airflow limitation (AFL). Three hundred forty-seven outpatients at the Cincinnati Veterans Administration Medical Center performed spirometry and completed a respiratory questionnaire. Patients were followed for a minimum of 30 months and medical records were reviewed for COPD diagnosis, mortality, respiratory-related health care utilization, comorbidities, and respiratory medications. Three hundred twenty-five of 347 (94%) patients performed technically adequate spirometry and completed questionnaires. When AFL was defined by fixed ratio (FR, forced expiratory volume in 1 second [FEV 1 ]/forced vital capacity [FVC] , 0.7), patients with AFL and a diagnosis of COPD had a higher annual mortality rate (7.1% ± 2% versus 2.4% ± 0.8%, P = 0.01), more hospitalizations per year (0.2 ± 0.06 versus 0.04 ± 0.01, P , 0.001 mean ± standard error of the mean), increased respiratory symptoms (12.0 ± 0.9 versus 7.2 ± 0.6, P , 0.0001), and higher Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage compared with undiagnosed patients. Ninety-two of 137 patients with AFL (67%) had unrecognized AFL; 16 (17%) of the 92 were subsequently diagnosed. When AFL was defined by the lower limit of normal (LLN, FEV 1 /FVC , LLN), 67 of 103 patients (65%) had unrecognized AFL; 12 (18%) of the 67 were subsequently diagnosed. Patients with AFL defined by FR who were subsequently diagnosed had more emergency department visits per year (0.33 ± 0.11 versus 0.11 ± 0.05, P = 0.009), increased respiratory symptoms (10.2 ± 1.6 versus 6.5 ± 0.7, P , 0.05), and higher GOLD stage, but similar mortality and hospitalizations compared with the persistently undiagnosed patients. The annual rate of documented COPD diagnosis was 7% for both FR and LLN definitions. Patients with AFL and a diagnosis of COPD have more severe disease, higher health care utilization, and mortality than undiagnosed patients. The annual rate of COPD diagnosis is 7% among individuals with unrecognized AFL. Worse AFL, increased respiratory symptoms, and ED visits are associated with a subsequent COPD diagnosis in individuals with unrecognized AFL.
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Our study found that in patients with severe airflow limitation (severe and very severe categories) % predicted PEFR underestimated % predicted FEV 1 , whereas the exact opposite happened in patients with less severe airflow limitation (mild to moderate categories). It is clear from these results that if GOLD guidelines are followed and % predicted PEFR is used as a surrogate for that of FEV 1 , then severity of obstruction would be wrongly categorized in a large proportion of patients and could result in inappropriate diagnosis, severity classification, and management. Because of strong correlations, % predicted PEFR should be used as a surrogate for % predicted FEV 1 . However, the limits of agreement were wide and resulted in a significant discordance in the severity categories of airflow limitation according to GOLD classification. These values render substitution of % predicted PEFR for % predicted FEV 1 “ruling out” or “ruling in” severe airflow limitation.
Methods: Demographic and medical claims data were retrospectively analyzed from the 4 th KNHANES along with NHI claims. Eligible patients were aged ≥ 40 years, who underwent complete pulmonary function tests (PFTs), and had at least one inpatient or outpatient claim coded as COPD between January 1, 2007 and December 31, 2010. Results: Among 6,663 eligible participants, 897 (13.5%) had airway obstruction. Self-reported physician-diagnosed COPD comprised only 3%, and there were 870 undiagnosed COPD patients (97%). Self-reported physician- diagnosed asthma made up 3.7%. Of the 897 respondents, 244 (27.2%) used COPD-related healthcare services. The frequency of healthcare visits increased with increasing severity of airway obstruction. After a 3-year follow-up period, 646 (74.2% of those initially undiagnosed) remained undiagnosed and only 224 (25.8%) were diagnosed and treated for COPD. Only 27.5% of the 244 participants with airway obstruction who used COPD-related healthcare underwent PFTs during the study period. The percentage of prescribed medications associated with COPD increased in accordance with the severity of the COPD. Inhaled long-acting anticholinergics were prescribed for 10.9% of patients with moderate airway obstruction and for 52.4% of patients with severe obstruction. Inhaled long-acting β -agonists combined with corticosteroids were prescribed for 50% of patients with severe airway obstruction. Conversely, 44.6% of healthcare users were prescribed oral theophylline for COPD treatment, and 21.7% were also prescribed an oral corticosteroid. The determinants of COPD-associated healthcare use in respondents with obstructive lung disease were advanced age, severe airflow limitation, presence of comorbidities, and self-reported physician diagnosis of COPD.
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Thus, the conventional cutoffs of both the fixed ratio and the Z-score of FEV 1 /FVC may be biased in the elderly population and the over- and underdiagnosis of the airflow limitation might be affected by not only the innate characteristics of each method but also the biased cutoffs. However, we could not determine a single best cutoff from our study because the optimal cutoffs varied with the outcomes and because there was no consensus regarding the desirable clinical outcome for the comparison. Nevertheless, we believe that our findings are meaningful since they raise the awareness of the uncertain optimality of the conventional cutoffs.
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a decrease in VC of the dependent lung in the lateral posi- tion, which can be associated with the mediastinum located upward, compared with the supine or prone positions, or to the presumed physiological difference between the unilateral dependent lung in the lateral position and the bilateral lungs in the sitting position for spirometry. Interestingly, in the nondependent lung, the increase in MLD in the early expira- tory phase negatively correlated with FEV 1 /FVC, suggesting that the proximal airway closure is delayed in COPD to obtain larger expiratory lung movements. This was also supported by the nondependent/dependent ratio of MLD change in the early-expiratory phase, which was larger in patients with more severe airflow limitation. In addition, the MLD change in the total expiratory phase also correlated negatively with FEV 1 / FVC. These observations suggest the existence of comple- mentary ventilation in the nondependent lung, which would appear to compensate insufficient ventilation in the dependent lung in patients with COPD to some extent. This indicates that the less affected lung may be placed uppermost in COPD patients in the lateral position to improve ventilation in part when the patient has large atelectasis or pneumonia. If this result is validated by other large study populations in the future, this knowledge would also be applicable to pulmonary rehabilitation in the lateral position and important for better understanding of the pathogenesis of COPD.
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Purpose: A new spirometric reference equation was recently developed from the first national chronic obstructive pulmonary disease (COPD) survey in Korea. How- ever, Morris’ equation has been preferred for evaluating spirometric values instead. The objective of this study was to evaluate changes in severity staging in Korean COPD patients by adopting the newly developed Korean equation. Materials and Methods: We evaluated the spirometric data of 441 COPD patients. The presence of airflow limitation was defined as an observed post-bronchodilator forced expiratory volume in one second/forced vital capacity (FEV1/FVC) less than 0.7, and the sever- ity of airflow limitation was assessed according to GOLD stages. Spirometric values were reassessed using the new Korean equation, Morris’ equation and other refer- ence equations. Results: The severity of airflow limitation was differently graded in 143 (32.4%) patients after application of the new Korean equation when compared with Morris’ equation. All 143 patients were reallocated into more severe stages (49 at mild stage, 65 at moderate stage, and 29 at severe stage were changed to moder- ate, severe and very severe stages, respectively). Stages according to other reference equations were changed in 18.6-49.4% of the patients. Conclusion: These results in- dicate that equations from different ethnic groups do not sufficiently reflect the air- flow limitation of Korean COPD patients. The Korean reference equation should be used for Korean COPD patients in order to administer proper treatment.