LOS ANGELES — Can identification of early airflow abnormalities predict future clinically important respiratory-related outcomes, including development of COPD?
That is the question raised in a recent study published in the journal Chest. A study team led by researchers from the David Geffen School of Medicine at the University of California, Los Angeles, noted, “Small airways are known to be affected early in the course of chronic obstructive pulmonary disease (COPD); however, traditional spirometric indices may not accurately identify small airways disease.”1
The VA HSR&D Center for the Study of Healthcare Innovation, Implementation, and Policy at the Greater Los Angeles Veterans Affairs Healthcare System, the Center for Access & Delivery Research & Evaluation (CADRE) at the Iowa City, IA, VA Health Care System, Iowa City, IA, and the VA Ann Arbor, MI, Healthcare System participated in the research.
Included in their study were 832 current and former smokers with post-bronchodilator FEV1/FVC ≥0.7 from the SPIROMICS cohort. Participants were classified as having a reduced pre-bronchodilator FEV3/FEV6 based on lower limit of normal (LLN) values and repeatability analysis was performed for FEV3 and FEV6. Researchers sought to determine the relationship between baseline FEV3/FEV6 and outcome measures including functional small airways disease on thoracic imaging and respiratory exacerbations.
Results indicated that the measures, FEV3/FEV6 <LLN at baseline, defined as reduced compared to FEV3/FEV6 ≥LLN, were associated with lower FEV1, poorer health status based on St. George’s Respiratory Questionnaire score, more emphysema and more functional small airways disease on quantitative imaging.
“FEV3 and FEV6 showed excellent agreement between repeat measurements,” the authors advised. “Reduced FEV3/FEV6 was associated with increased odds of a severe respiratory exacerbation within the first year of follow-up and decreased time to first exacerbation. A low FEV3/FEV6 was also associated with development of COPD by spirometry (post-bronchodilator FEV1/FVC <0.7) during study follow-up.”
Researchers explained that FEV3/FEV6 is “a routinely available and repeatable spirometric index which can be useful in the evaluation of early airflow obstruction in current and former smokers without COPD. A reduced FEV3/FEV6 can identify those at risk for future development of COPD and respiratory exacerbations.”
- Yee N, Markovic D, Buhr RG, Fortis S, et al. Significance of FEV3/FEV6 in recognition of early airway disease in smokers at risk of development of COPD: Analysis of the SPIROMICS cohort. Chest. 2021 Nov 9:S0012-3692(21)04276-8. doi: 10.1016/j.chest.2021.10.046. Epub ahead of print. PMID: 34767825.