Age-related differences in associations between uncontrolled asthma, comorbidities and biomarkers in adult-onset asthma

ObjectiveAdult-onset asthma is a recognized but heterogeneous phenotype and has been described to associate with poor asthma control. Knowledge about associations between clinical characteristics including comorbidities and control of adult-onset asthma is limited, especially in older populations. We aimed to study how clinical biomarkers and comorbidities are associated with uncontrolled asthma among middle-aged and older individuals with adult-onset asthma.MethodsClinical examinations including structured interview, asthma control test (ACT), spirometry, skin prick test (SPT), blood sampling, and measurement of exhaled fractional nitric oxide (FeNO) was performed in a population-based adult-onset asthma cohort in 2019-2020 (n = 227, 66.5% female). Analyses were performed among all included, and separately in middle-aged (37-64 years, n = 120) and older (& GE;65 years, n = 107) participants.ResultsIn bivariate analysis, uncontrolled asthma (ACT & LE; 19) was significantly associated with a blood neutrophil count & GE;5/& mu;l, BMI & GE;30, and several comorbidities. In multivariable regression analysis, uncontrolled asthma was associated with neutrophils & GE;5/& mu;l (OR 2.35; 95% CI 1.11-4.99). In age-stratified analysis, BMI & GE;30 (OR 3.04; 1.24-7.50), eosinophils & GE;0.3/& mu;l (OR 3.17; 1.20-8.37), neutrophils & GE;5/& mu;l (OR 4.39; 1.53-12.62) and allergic rhinitis (OR 5.10; 1.59-16.30) were associated with uncontrolled asthma among the middle-aged. Among the older adults, uncontrolled asthma was only associated with comorbidities: chronic rhinitis (OR 4.08; 1.62-10.31), ischemic heart disease (OR 3.59; 1.17-10.98), malignancy (OR 3.10; 1.10-8.73), and depression/anxiety (OR 16.31; 1.82-146.05).ConclusionsIn adult-onset asthma, comorbidities were strongly associated with uncontrolled asthma among older adults, while clinical biomarkers including eosinophils and neutrophils in blood were associated with uncontrolled asthma among middle-aged.

Automated summary

This study investigated the associations between clinical characteristics, biomarkers, comorbidities, and control of adult-onset asthma in middle-aged and older individuals. The results showed that comorbidities were strongly associated with uncontrolled asthma among older adults, while clinical biomarkers such as eosinophils and neutrophils in blood were associated with uncontrolled asthma among middle-aged individuals.