Asthma exacerbations are associated with faster lung function decline, particularly in young adults aged 18 to 30 years, according to study findings published recently in BMJ Thorax.
Although asthma exacerbations are thought to be a potentially modifiable cause of lung function decline, previous research has shown mixed results. In the current study, researchers sought to determine whether exacerbations are associated with age-specific, long-term changes in lung function over time. Lung function was assessed based on changes in the rates of peak expiratory flow (PEF) and forced expiratory volume in 1 second (FEV1).
The researchers conducted an observational, historical population-based study of patients with active asthma according to the UK Optimum Patient Care Research Database (OPCRD) between June 2019 and November 2019. The database included 109,182 patients with follow-up from 5 to 50 years of age, including 75,280 patients who had at least 3 PEF and FEV1 measures taken after the age of 18 years. Researchers used adjusted linear growth models to assess the association between lung function trajectory and mean annual exacerbation rate (AER).
The study found that for each exacerbation, patients lost an estimated additional -1.34 L/min PEF per year (95% CI, −1.23 to –1.50). Patients aged 18 to 24 years at baseline with AERs of 2 or more/year lost an additional −5.95 L/min PEF/year (95% CI, −8.63 to –3.28) compared with patients who did not experience any exacerbations. Increasing age at baseline correlated with progressively smaller differences in the rate of lung function decline between AER groups. A similar analysis of FEV1 measurements showed consistent results.
Study limitations include the inability to assess causality, the lack of accounting for childhood risk factors, lack of data on smoking and body mass index, inclusion of some patients who also had COPD without controlling for this, and misclassification of electronic medical record data.
Researchers concluded that asthma exacerbations are associated with faster lung function decline. “This was more prominent in younger patients but was evident in older patients when it was related to lower starting [lung function], suggesting a persistent deteriorating phenotype that develops in adulthood over time.” The investigators suggested that excessive lung function decline might be prevented to some degree through early intervention efforts aimed at young adults with asthma.
Disclosure: This research was supported by Optimum Patient Care Global and AstraZeneca Ltd. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
Soremekun S, Heaney LG, Skinner D, et al. Asthma exacerbations are associated with a decline in lung function: A longitudinal population-based study. Thorax. Published online August 3, 2022. doi:10.1136/thorax-2021-217032