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Published on: December 17, 2017
Age-Related Clinical Characteristics, Inflammatory Features, Phenotypes, and Treatment Response in Asthma
Ji Wang1, Xin Zhang2, Li Zhang2
1Department of Respiratory and Critical Care Medicine, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, China; Department of Respiratory and Critical Care Medicine, Clinical Research Center for Respiratory Disease, West China Hospital, Sichuan University, Chengdu, Sichuan, China; Laboratory of Pulmonary Immunology and Inflammation, Frontiers Science Center for Disease-Related Molecular Network, Sichuan University, Chengdu, Sichuan, China.
Background:
Emerging evidence suggests that aging affects asthma outcomes, but the mechanism remains largely unexplored.
Objective:
To explore age-related clinical characteristics, inflammatory features, phenotypes, and treatment response in asthma.
Methods:
This was a prospective cohort study of asthmatic patients with a 12-month follow-up in a real-world setting. Clinical inflammatory and phenotypic characteristics, future risk for exacerbations, and treatment response were assessed across different age groups (young was defined as age 18 to 39 years; middle-aged, 40 to 64 years; and elderly, 65 years or older).
Results:
Compared with young (n = 106) and middle-aged (n = 179) asthmatic patients, elderly patients (n = 55) had worse airway obstruction, more comorbidities including chronic obstructive pulmonary disease and diabetes, less atopy, and lower levels of IgE and FeNO, and were more likely to have late-onset and fixed airflow obstruction asthma and a reduced risk for having type 2 profile asthma. Levels of IFN-gamma, IL-17A, and IL-8 in induced sputum were significantly increased in elderly asthmatic patients (all P < .05). Path analysis indicated that age directly and significantly led to future exacerbations in asthma, partially mediated by an upregulation of airway IFN-gamma. Moreover, elderly patients with asthma had a reduced treatment response (improvement in FEV1 of 12% or greater, or 200 mL, and a reduction in Borg scores of 1 or greater) (adjusted odds ratio = 0.11; 95% CI, 0.02-0.52; and adjusted odds ratio = 0.12; 95% CI, 0.03-0.49, respectively).
Conclusions:
This study confirms that asthma in the elderly population represents a specific phenotype and indicates that aging can influence asthma in terms of clinical characteristics, inflammatory features, exacerbations, and treatment response.
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