Bronchial hyperresponsiveness and the development of asthma and COPD in asymptomatic individuals: SAPALDIA Cohort Study

Abstract

Background: Bronchial hyperresponsiveness (BHR) is a common feature of asthma. However, BHR is also present in asymptomatic individuals and its clinical and prognostic significance is unclear. We hypothesised that BHR might play a role in the development of chronic obstructive pulmonary disease (COPD) as well as asthma. Methods: In 1991 respiratory symptoms and BHR to methacholine were evaluated in 7126 of the 9651 participants in the SAPALDIA cohort study. Eleven years later 5825 of these participants were reevaluated, of whom 4852 performed spirometric tests. COPD was defined as an FEV 1 /FVC ratio of ,0.70. Results: In 1991 17% of participants had BHR, of whom 51% were asymptomatic. Eleven years later the prevalence of asthma, wheeze, and shortness of breath in formerly asymptomatic subjects with or without BHR was, respectively, 5.7% v 2.0%, 8.3% v 3.4%, and 19.1% v 11.9% (all p,0.001). Similar differences were observed for chronic cough (5.9% v 2.3%; p = 0.002) and COPD (37.9% v 14.3%; p,0.001). BHR conferred an adjusted odds ratio (OR) of 2.9 (95% CI 1.8 to 4.5) for wheezing at follow up among asymptomatic participants. The adjusted OR for COPD was 4.5 (95% CI 3.3 to 6.0). Silent BHR was associated with a significantly accelerated decline in FEV 1 by 12 (5-18), 11 (5-16), and 4 (2-8) ml/year in current smokers, former smokers and never smokers, respectively, at SAPALDIA 2. Conclusions: BHR is a risk factor for an accelerated decline in FEV 1 and the development of asthma and COPD, irrespective of atopic status. Current smokers with BHR have a particularly high loss of FEV 1 .

Integrated effect of EGFR and PAR-1 signaling crosstalk on airway hyperresponsiveness

“…The causal relationship between an individual gene (molecule) and the phenotype (AHR) may be unclear because of its complex pathological processes in advanced patients with asthma, such as airway inflammation and structural remodeling. Besides the symptomatic patients, prospective studies revealed that some of the asymptomatic young adults also exhibit AHR (25) and it is thought to be a possible risk factor for future onset of asthma (26,27). In addition, associated factors such as atopy may partly contribute to the relationship (28).…”

Predictors of Severe Dyspnea in Patients With Moderate-to-Severe Chronic Obstructive Pulmonary Disease

“…Отсюда следует, что, будучи предиктором тяжести течения ХОБЛ, ОФВ1 не является маркером активности заболевания, которую, вероятнее всего, следует отождествлять со скоростью снижения ОФВ1 [3,7]. Установлено, что факторами, влияющими на прогрессирование ХОБЛ, являются табакокурение [8], гиперреактив-ность бронхов (БГР) [9], частота обострений заболе-ваний [10], выраженность эмфиземы и бронходила-тационного ответа [3], а также фармакотерапия [11,12]. Следует отметить также, что, помимо ОФВ1, предикторами прогрессирования и летальности при ХОБЛ выступают и другие клинико-функциональ-ные признаки заболевания.…”

Asthma, Chronic Obstructive Pulmonary Disease (COPD), and the Overlap Syndrome

“…Asymptomatic AHR is a risk factor for the development of asthma and COPD and is associated with new symptoms of wheeze, chronic cough, and annual loss of forced expiratory volume in 1 second (FEV 1 ). 16,17 Furthermore, AHR has been shown to be an important risk factor in patients with established asthma and COPD: more severe AHR is associated with more severe symptoms and a more rapid decline in FEV 1 .…”