Lifetime asthma incidence is related to age at onset and allergies in western Sweden
Reshed Abohalaka, Selin Ercan, Lauri Lehtimäki, Linda Ekerljung, Helena Bäckman, Fatma Zehra Uslu, Saliha Selin Özuygur Ermiş, Madeleine Rådinger, Bright I. Nwaru, Hannu Kankaanranta
Abstract
Although asthma is more frequently diagnosed in childhood, a substantial proportion of cases manifests in adulthood. Nonetheless, few studies have comprehensively examined asthma incidence across different ages, genders, and asthma phenotypes. We conducted a retrospective evaluation of asthma incidence from birth to late adulthood, stratified by age, gender, and the presence or absence of allergies. Our analysis indicates that a significant number of asthma cases emerged in adulthood, particularly among middle-aged women, with adult-onset asthma surpassing childhood-onset asthma after the age of 35 years. Additionally, allergic asthma was more common in younger than older individuals but decreases with age, ultimately leading to a higher proportion of non-allergic asthma in older than younger individuals. These findings underscore the predominance of adult-onset asthma among females and confirm the majority of allergic asthma in children, which declines with age. Additionally, increasing age is associated with increased incidence of non-allergic asthma. Asthma heterogeneity should be considered in both clinical management and research.