Respiratory symptoms, exacerbations and sleep disturbances are more common among participants with asthma and chronic airflow limitation : an epidemiological study in Estonia, Iceland and Sweden

• Published in: BMJ Open Respiratory Research
• Main Authors: Mindus, Stephanie, Gislason, Thorarinn, Benediktsdottir, Bryndis, Jogi, Rain, Movérare, Robert, Malinovschi, Andrei, Janson, Christer
• Format: Article in Journal/Newspaper
• Language: English
• Published: Uppsala universitet, Lung- allergi- och sömnforskning 2024
• Subjects: Asthma; Asthma Epidemiology; COPD epidemiology; Respiratory Medicine and Allergy; Lungmedicin och allergi; Iceland
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-524063; https://doi.org/10.1136/bmjresp-2023-002063

BACKGROUND: Chronic airflow limitation (CAL) is a hallmark of chronic obstructive pulmonary disease but is also present in some patients with asthma. We investigated respiratory symptoms, sleep and health status of participants with and without CAL with particular emphasis on concurrent asthma using data from adult populations in Iceland, Estonia and Sweden investigated within the Burden of Obstructive Lung Disease study. METHODS: All participants underwent spirometry with measurements of forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) before and after bronchodilation. CAL was defined as postbronchodilator FEV1/FVC below the lower limit of normal. IgE-sensitisation and serum concentrations of eosinophil-derived neurotoxin (S-EDN) were assessed in a subsample. The participants were divided into four groups: no self-reported doctor's diagnosed asthma or CAL, asthma without CAL, CAL without asthma and asthma and CAL: χ2 test and analysis of variance were used in bivariable analyses and logistic and linear regression when analysing the independent association between respiratory symptoms, exacerbations, sleep-related symptoms and health status towards CAL, adjusting for centre, age, sex, body mass index, smoking history and educational level. RESULTS: Among the 1918 participants, 190 (9.9%) had asthma without CAL, 127 (6.6%) had CAL without asthma and 50 (2.6%) had CAL with asthma. Having asthma with CAL was associated with symptoms such as wheeze (adjusted OR (aOR) 6.53 (95% CI 3.53 to 12.1), exacerbations (aOR 12.8 (95% CI 6.97 to 23.6), difficulties initiating sleep (aOR 2.82 (95% CI 1.45 to 5.48), nocturnal gastro-oesophageal reflux (aOR 3.98 (95% CI 1.79 to 8.82)) as well as lower physical health status. In these analyses, those with no asthma and no CAL were the reference group. The prevalence of IgE-sensitisation was highest in both asthma groups, which also had higher levels of S-EDN. CONCLUSION: Individuals with self-reported asthma with CAL suffer from a higher burden of ...