Current Bronchodilator Responsiveness Criteria Underestimate Asthma in Older Adults.

BACKGROUND: Asthma is common in older adults and is confirmed by demonstration of variable expiratory air-flow limitations, typically evaluated by spirometric assessment of bronchodilator responsiveness. However, many patients with clinically suspected asthma and documented air-flow obstruction do not exhibit a post-bronchodilator response that meets or exceeds current established guidelines. We investigated if extending the time from bronchodilator administration to assessment of bronchodilator response increases the yield of spirometry for the diagnosis of asthma in older adults. METHODS: This was a cross-sectional study. The subjects were non-smokers, ≥ 60 y old, and with suspected asthma. Subjects were characterized as (1) those with a positive bronchodilator response on the 30-min post-bronchodilator spirometry, (2) those with a positive bronchodilator response on the 60-min post-bronchodilator spirometry, and (3) those without a positive bronchodilator response but with a positive methacholine challenge test. Factors associated with a late response to bronchodilator were evaluated by using bivariate analysis and by multivariate analysis by using a logistic regression model. RESULTS: This study enrolled 165 subjects. Of these, 81 (49.1%) had a positive bronchodilator response on 30-min post-bronchodilator spirometry; 25 (15.2%) had a positive bronchodilator response on the 1-h post-bronchodilator spirometry; and 59 (35.8%) had no positive bronchodilator response but had a positive methacholine challenge test. On multivariable regression analysis, those with a higher baseline percentage of predicted FEV1, higher scores on a standard asthma control test, and wheezing and/or cough after exercise were more likely to either have a late bronchodilator response or no bronchodilator response. CONCLUSIONS: Our study showed that a late positive response to bronchodilator use was more common than previously presumed in older subjects with suspected asthma. Pulmonary function testing laboratories should consider routinely reassessing spirometry at 1 h after bronchodilator use if the earlier assessment did not reveal a significant response.

Left heart function in COPD : Impact of lung deflation.

Chronic obstructive pulmonary disease (COPD) primarily affects the lungs; however, cardiovascular conditions are among the most common extrapulmonary comorbidities. Besides shared risk factors such as cigarette smoking, pathophysiological connections between the lung and the heart have been identified as mediators of reduced cardiac output. Recent research has focused on hyperinflation of the lung as a pulmonary cause for heart dysfunction. Hyperinflation is a typical lung abnormality seen in COPD; it is characterized by increased residual volume, intrathoracic gas volume, and total lung capacity while vital capacity is decreased. The degree of hyperinflation with airway obstruction is inversely related to left ventricular filling, stroke volume, and cardiac output. The underlying mechanisms are assumed to be compression of the pulmonary veins and thus reduced preload of the left heart as well as decreased pulmonary microvascular blood flow due to compression of the pulmonary vasculature. Treatment with a dual bronchodilator antagonizes this detrimental lung-heart unbalance effectively: Pulmonary blood flow, left ventricular end-diastolic volume, and stroke volume increase in COPD patients without cardiac abnormalities. Similar effects, yet less pronounced, were reported with single bronchodilator therapy. Future work needs to investigate whether these promising findings can be reproduced in COPD patients with cardiovascular diseases.

Effects of long-term bronchodilators in bronchiectasis patients with airflow limitation based on bronchodilator response at baseline.

PURPOSE: The association between positive bronchodilator response (BDR) at baseline and the effect of long-term bronchodilator therapy has not been well elucidated in patients with bronchiectasis. The aims of our study were to explore the association between positive BDR at baseline and lung-function improvement following long-term (3-12 months) bronchodilator therapy in bronchiectasis patients with airflow limitation. MATERIALS AND METHODS: The medical records of 166 patients with clinically stable bronchiectasis who underwent baseline pre- and postbronchodilator spirometry and repeated spirometry after 3-12 months of bronchodilator therapy were retrospectively reviewed. For analysis, patients were divided into two groups, responders and poor responders, based on achievement of at least 12% and 200 mL in forced expiratory volume in 1 second (FEV1) following bronchodilator therapy from baseline FEV1. RESULTS: A total of 57 patients (34.3%) were responders. These patients were more likely to have positive BDR at baseline than poor responders (38.6% [22 of 57] vs 18.3% [20 of 109], P=0.004). This association persisted after adjustment for other confounding factors (adjusted odds ratio 2.298, P=0.034). However, we found FEV1 improved significantly following long-term bronchodilator therapy, even in patients without positive BDR at baseline (change in FEV1 130 mL, interquartile range -10 to 250 mL; P<0.001). CONCLUSION: Positive BDR at baseline was independently associated with responsiveness to long-term bronchodilator therapy in bronchiectasis patients with airflow limitation. However, FEV1 improvement was also evident in bronchiectasis patients without positive BDR at baseline, suggesting that these patients can benefit from long-term bronchodilator therapy.

Early response to inhaled bronchodilators and corticosteroids as a predictor of 12-month treatment responder status and COPD exacerbations.

BACKGROUND: Early treatment response markers, for example, improvement in forced expiratory volume in 1 second (FEV1) and St George's Respiratory Questionnaire (SGRQ) total score, may help clinicians to better manage patients with chronic obstructive pulmonary disease (COPD). We investigated the prevalence of clinically important improvements in FEV1 and SGRQ scores after 2-month budesonide/formoterol or formoterol treatment and whether such improvements predict subsequent improvements and exacerbation rates. METHODS: This post hoc analysis is based on data from three double-blind, randomized studies in patients with moderate-to-very-severe COPD receiving twice-daily budesonide/formoterol or formoterol alone for 6 or 12 months. Prebronchodilator FEV1 and SGRQ total score were measured before treatment and at 2 and 12 months; COPD exacerbation rates were measured during months 2-12. Responders were defined by ≥100 mL improvement in prebronchodilator FEV1 and ≥4-point decrease in SGRQ total score. RESULTS: Overall, 2,331 and 1,799 patients were included in the 0-2- and 0-12-month responder analyses, respectively, and 2,360 patients in the 2-12-month exacerbation rate analysis. At 2 months, 35.1% of patients were FEV1 responders and 44.3% were SGRQ responders. The probability of response was significantly greater with budesonide/formoterol than with formoterol or placebo for both parameters. Two-month responders had a greater chance of 12-month response than 2-month nonresponders for both FEV1 (odds ratio, 5.57; 95% confidence interval, 4.14-7.50) and SGRQ (odds ratio, 3.87; 95% confidence interval, 2.83-5.31). Two-month response in FEV1 (P<0.001), but not SGRQ (P=0.11), was associated with greater reductions in exacerbation risk. CONCLUSION: Early FEV1 and SGRQ treatment responses relate to their changes at 12 months. FEV1 response, but not SGRQ response, at 2 months predicts the risk of a future COPD exacerbation in some, but not all patients. This is potentially useful in clinical practice, although more sensitive and specific markers of favorable treatment response are required.

Fractional exhaled nitric oxide and impulse oscillometry in children with allergic rhinitis.

PURPOSE: Airway inflammation, bronchial hyper-responsiveness (BHR), and bronchodilator response (BDR) are representative characteristics of asthma. Because allergic rhinitis (AR) is a risk factor for asthma development, we evaluated these 3 characteristics in AR using measurement of fractional exhaled nitric oxide (FeNO), a methacholine challenge test (MCT), and impulse oscillometry (IOS). METHODS: This study included 112 children with asthma (asthma group), 196 children with AR (AR group), and 32 control subjects (control group). We compared pulmonary function parameters and FeNO levels among the 3 groups. The AR group was subdivided into 2 categories: the AR group with BHR and the AR group without, and again pulmonary function and FeNO levels were compared between the 2 subgroups. RESULTS: FeNO levels were more increased in the AR and asthma groups than in the control group; within the AR group, FeNO was higher in the AR group with BHR than in the AR group without. The BDR was more increased in the AR group than in the control group when percent changes in reactance at 5 Hz (Δ X5) and reactance area (Δ AX) were compared. In the AR group, however, there was no difference in Δ X5 and Δ AX between the AR group with BHR and the AR group without. CONCLUSIONS: Reversible airway obstruction on IOS and elevated FeNO levels were observed in children with AR. Because elevated FeNO levels can indicate airway inflammation and because chronic inflammation may lead to BHR, FeNO levels may be associated with BHR in AR. IOS can be a useful tool for detecting lower airway involvement of AR independent of BHR assessed in the MCT.

Fractional Exhaled Nitric Oxide and Impulse Oscillometry in Children With Allergic Rhinitis

PURPOSE: Airway inflammation, bronchial hyper-responsiveness (BHR), and bronchodilator response (BDR) are representative characteristics of asthma. Because allergic rhinitis (AR) is a risk factor for asthma development, we evaluated these 3 characteristics in AR using measurement of fractional exhaled nitric oxide (FeNO), a methacholine challenge test (MCT), and impulse oscillometry (IOS). METHODS: This study included 112 children with asthma (asthma group), 196 children with AR (AR group), and 32 control subjects (control group). We compared pulmonary function parameters and FeNO levels among the 3 groups. The AR group was subdivided into 2 categories: the AR group with BHR and the AR group without, and again pulmonary function and FeNO levels were compared between the 2 subgroups. RESULTS: FeNO levels were more increased in the AR and asthma groups than in the control group; within the AR group, FeNO was higher in the AR group with BHR than in the AR group without. The BDR was more increased in the AR group than in the control group when percent changes in reactance at 5 Hz (Delta X5) and reactance area (Delta AX) were compared. In the AR group, however, there was no difference in Delta X5 and Delta AX between the AR group with BHR and the AR group without. CONCLUSIONS: Reversible airway obstruction on IOS and elevated FeNO levels were observed in children with AR. Because elevated FeNO levels can indicate airway inflammation and because chronic inflammation may lead to BHR, FeNO levels may be associated with BHR in AR. IOS can be a useful tool for detecting lower airway involvement of AR independent of BHR assessed in the MCT.