TOPLINE

Patients with asthma and preserved ratio impaired spirometry (PRISm) experienced severe acute exacerbations more than twice as often as those with normal lung function. This exacerbation burden was comparable to that seen in patients with obstructive ventilatory defects, despite the absence of overt airflow obstruction.

METHODOLOGY

• Researchers conducted a retrospective analysis of 1411 adult patients with asthma in Japan.
• Based on spirometry, patients were categorized into control (normal % forced expiratory volume in 1 second [FEV1] and preserved FEV1/forced vital capacity [FVC], n=1102), PRISm (reduced %FEV1 with preserved FEV1/FVC, n=133), and airflow obstruction (reduced %FEV1 and reduced FEV1/FVC, n=176).
• Primary outcomes included the frequency of severe acute exacerbations (defined as events requiring emergency room visits, hospitalization, or systemic corticosteroid treatment for ≥ 3 days) assessed over the 2 years preceding enrollment, along with clinical characteristics and treatment patterns.

TAKEAWAY

• Severe acute exacerbations occurred in 40% of the PRISm group compared with 24% of the control group and 30% of the airflow obstruction group.
• Compared with the control group, patients with PRISm had higher BMI (adjusted odds ratio [aOR], 1.08; P = .003), longer asthma duration (aOR, 1.02; P = .030), and more than double the odds of severe acute exacerbations (aOR, 2.31; P < .001).
• Compared with the airflow obstruction group, patients in the PRISm group had higher BMI (aOR, 1.15; P < .001) and shorter asthma duration (aOR, 0.97; P = .003), while the frequency of severe acute exacerbations did not differ significantly (aOR, 1.39; P = .267).
• Obesity (BMI ≥ 25) was present in 43% of the PRISm group, significantly higher than in the control (28%) and airflow obstruction (24%) groups (P = .001).

IN PRACTICE

"Our study identifies asthma with coexisting PRISm as a clinically important phenotype characterized by increased exacerbation burden," the authors wrote. "Recognition of asthma with coexisting PRISm may have potential clinical implications for identifying patients who may benefit from closer monitoring and more proactive optimization of management."

SOURCE

The study was led by Masako To, Department of Laboratory Medicine, Dokkyo Medical University, Saitama Medical Center in Koshigaya, Japan. It was published online on July 17 in Journal of Asthma and Allergy.

LIMITATIONS

The single-center retrospective study design and inclusion of a Japanese population could limit generalizability. PRISm classification was based on spirometry at a single timepoint, and treatment intensity could not be objectively defined as a covariate, potentially leaving residual confounding.

DISCLOSURES

No specific funding was reported. One author reported receiving lecture fees from AstraZeneca, GlaxoSmithKline, Novartis Pharma, and Sanofi, unrelated to this work. All other authors reported no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.