Researchers characterize patients who might benefit from early COPD intervention

Individuals with low FEV₁/FVC ratio plus low FVC lifetime trajectories were at an increased risk for COPD, according to a study in The Lancet Respiratory Medicine.

Further, those with both low FEV₁/FVC ratio and low FVC trajectories — which researchers defined as a “mixed” phenotype — had strong relationships to childhood risk factors and mental health disorders in adulthood, according to researchers. Patients with this mixed phenotype, as well as those with low FEV₁/FVC ratio only, or the “obstructive-only” phenotype, may benefit most from early interventions for COPD, results showed.

“Interest in lifetime lung function trajectories has increased in the context of emerging evidence that COPD can arise from multiple disadvantaged lung function pathways, including those that stem from poor lung function in childhood,” N. Sabrina Idrose, MSc, PhD candidate at University of Melbourne, told Healio. “This has highlighted the opportunity to identify pre-COPD, which are people on course to develop COPD.”

In a prospective cohort study, Idrose; Shyamali Dharmage, MBBS, MSc, MD, PhD; Dinh Bui, MPH, PhD; and colleagues evaluated 2,422 individuals from the Tasmanian Longitudinal Health Study who had spirometry measurements taken in childhood to middle age (7, 13, 18, 45, 50 and 53 years) to observe how FEV₁/FVC ratio trajectories, FVC trajectories, and their combinations related to static lung volume and gas transfer measurements. Researchers then sought out risk factors for the different groups of spirometry patterns.

Dharmage, Bui and colleagues grouped the six FEV₁/FVC ratio trajectories and five FVC trajectories they found into four patterns of lifetime spirometry: obstructive-only (low FEV₁/FVC ratio), restrictive-only (low FVC), mixed (low FEV₁/FVC ratio and low FVC) and reference (no low FEV₁/FVC ratio or low FVC).

Among the patients, 25.8% had the obstructive-only trajectory, 10.5% had the restrictive-only trajectory, 3.5% had the mixed trajectory and 60.2% were in the reference category.

Researchers found that individuals in the mixed (37%) and obstructive-only (22%) groups had the highest incidence of COPD at age 53 years.

With the highest rates observed in the mixed group, all three subnormal patterns showed higher incidence than the reference group of childhood asthma (reference, 13% vs. obstructive-only, 24%; P < .01; restrictive-only, 20%; P < .01; mixed, 39%; P < .001), bronchitis (reference, 46% vs. obstructive-only, 54%; P < .01; restrictive-only, 53%; P < .05; mixed, 68%; P < .001) and pneumonia (reference, 12% vs. obstructive-only, 16%; restrictive-only, 17%; mixed, 19%; P < .05 for all). Patients with the mixed pattern also had higher rates of parental asthma (27% vs. 17%; P < .05) and lower rates of breastfeeding (39% vs. 44%) than the reference group.

Researchers also found that individuals in the restrictive-only group struggled with lower total lung capacity and residual volume. This group also faced an increased risk for childhood underweight, “suggesting that the restrictive-only pattern might characterize individuals with poor lung development in childhood,” the researchers wrote. They also were more likely to have adult obesity, diabetes, cardiovascular conditions, hypertension and obstructive sleep apnea by age 53 years.

“Our study is novel because it is the first to identify and characterize lifetime patterns of obstruction and restriction, their risk factors and their consequences,” Idrose told Healio. “This could inform development of clinical algorithms for detection of individuals who are at risk of developing COPD, and those with established yet undiagnosed COPD, to enable precision preventive and tailored management strategies.”

This study by Dharmage, Bui and colleagues adds to the literature indicating that spirometry measurements of young patients should be considered in order to reduce serious risks, according to an accompanying editorial by Sonali Bose, MD, MPH, associate professor of medicine, pulmonary, critical care and sleep medicine at Icahn School of Medicine at Mount Sinai, Christopher Pascoe, PhD, assistant professor in the department of physiology and pathophysiology at University of Manitoba, and Cindy McEvoy, MD, MCR, professor of pediatrics at Oregon Health and Science University.

“Dharmage and colleagues reinforce a growing belief that early abnormalities in an apparently healthy population warrant risk modification at earlier points in the life course, opening the door even wider for opportunities to redirect abnormal lung health trajectories,” Bose, Pascoe and McEvoy wrote. “This finding is especially important as clinical approaches to chronic lung disease currently focus on therapeutic strategies implemented after diagnosis, rather than reducing early-life risks such as prematurity and prenatal exposures to prevent disease development.”

For more information:

N. Sabrina Idrose, MSc, can be reached at sabrina.idrose@unimelb.edu.au. 

Reference:

Bose S, et al. Lancet Respir Med. 2022;doi:10.1016/S2213-2600(22)00391-5.