Even after treatment with inhaled corticosteroids alone or in combination with long-acting antagonists, lung function decline continues in uncontrolled asthma.
Patients with uncontrolled asthma continue to experience significant declines in lung function over time despite receipt of asthma controller therapy, according to findings presented at CHEST 2024.
“Various studies reported the annual decline in forced expiratory volume in one second (FEV1) in patients with moderate-to-severe asthma ranging from 13 mL (patients with no history of exacerbations) to 77 mL (among those with ≥2 exacerbations),” Lucia De Prado Gomez, PharmD, and colleagues wrote. “However, it remains unclear if patients with uncontrolled asthma develop a persistent decline in FEV1.”
Dr. De Prado Gomez and colleagues examined longitudinal change in lung function over 12 months among patients with uncontrolled asthma using data from a prospective cohort. If a patient had a history of one or more severe asthma exacerbations, the researchers included them in the study. Recruitment occurred from November 2021 to October 2023 in outpatient practices at a large health system. Participants completed a baseline interview to collect sociodemographic information and asthma history, as well as follow-up visits at 3, 6, and 12 months. At each visit, the researchers obtained spirometry with pre- and post-bronchodilators (BD). The researchers evaluated the annualized rate of change from baseline to month 12 in pre- and post-BD FEV1 and pre- and post-BD FEV1% predicted, using the FEV1 parameter as a response variable and time as a continuous variable.
Post-Treatment Differences in FEV1
The analysis included 159 patients with uncontrolled asthma (mean age, 58.5; 70.0% women), most of whom (72.0%) had never smoked. Most patients (79.0%) received asthma controller treatment using inhaled corticosteroids (ICS) alone or a combination of ICS with a long-acting β2 agonist and/or a long-acting muscarinic antagonist. The mean Asthma Control Questionnaire and Asthma Quality of Life scores were 1.3 and 4.8, respectively.
At baseline, the mean FEV1 for pre-BD (n=125) and post-BD (n=124) measured 2,050 mL and 2,120 mL, respectively. The mean FEV1% predicted pre- and post-BD was 77.3 and 80.4, respectively.
During the 12-month study period, Dr. De Prado Gomez and colleagues found that the pre- and post-BD FEV1 (n=80 for both) dropped significantly, with a slope estimate (95% CI) of negative 84.2 mL (−142.8 to −25.6) and negative 112.6 mL (−185.4 to −39.8). Predicted Pre-BD and post-BD FEV1% also dropped, with a slope estimate (95% CI) of negative 2.0 (−4.7 to 0.6) and negative 3.1 (−5.7 to −0.4).
Clinically Meaningful Changes
The study results provide evidence of the natural course of lung function decline over time among patients with uncontrolled asthma, according to the researchers.
As a result, the findings “may help identify the risk factors associated with FEV1 decline and determine the clinically meaningful change for FEV1 in patients with asthma,” Dr. De Prado Gomez and colleagues wrote.
