Individuals with impaired FEV1/FVC trajectories often experience wheeze before middle age

Key takeaways:

• The most impaired lung function trajectories included rapid decline.
• Researchers found a link between rapidly declining trajectories and predominant wheeze in middle-aged adults.

Around 20% to 25% of individuals with rapidly declining FEV₁/FVC trajectories experienced wheezing and usual phlegm/bronchitis as adolescents/young adults, according to results published in The Lancet Respiratory Medicine.

“Clinicians usually think that COPD affects older people; however, our study suggests that COPD is not infrequent in middle-aged adults,” Jennifer L. Perret, MBBS, FRACP, PhD, respiratory physician-epidemiologist in the Allergy and Lung Health Unit at The University of Melbourne, told Healio. “Our findings would encourage primary care clinicians to actively look for COPD in their middle-aged patients, especially if they report wheezing.”

Using the Australian Tasmanian Longitudial Health Study (TAHS; n = 2,421) and the U.S. Coronary Artery Risk Development in Young Adults (CARDIA; n = 3,153) study, Perret and colleagues evaluated individuals with respiratory symptom and spirometry data from young ages (TAHS, 6 to 7 years; CARDIA mean age, 25 years) to middle ages (TAHS mean age, 53 years; CARDIA mean age, 55 years) to uncover if respiratory symptoms experienced during middle age are more frequently reported among those on impaired FEV₁/FVC trajectories.

Using FEV₁/FVC trajectories, researchers grouped patients in one of six groups, which slightly differed between the two cohorts. In TAHS, trajectories were classified as average; early high, normal decline; early low, catch-up, normal decline; early low, normal decline; early normal, rapid decline; or early low, rapid decline. In CARDIA, trajectories were classified as average; above average; below average; persistently low; normal peak, rapid decline; or low peak, rapid decline.

The study reported that the TAHS cohort had five symptom profiles via latent class analysis (predominant wheeze, predominant productive cough, predominant dry cough, nearly all respiratory symptoms and minimal), and the CARDIA cohort had six symptom profiles (all symptoms outlined above plus “some chesty colds”).

Spirometry-defined COPD in middle-aged individuals was found in similar proportions of the two cohorts (TAHS, n = 116 [5%]; CARDIA, n = 199 [6%]). Additionally, high proportions of individuals with spirometry-defined COPD in both studies reported at least one respiratory symptom (TAHS, 82%; CARDIA, 71%).

“It was important to find out that around 4% or 1 in 25 people aged in their 50s had lung-related symptoms and COPD which may or may not have been diagnosed by a doctor,” Perret told Healio. “So, it was surprisingly common to us.”

When evaluating symptom profiles in relation to FEV₁/FVC trajectories, a higher proportion of individuals with productive cough and individuals with dry cough had an average trajectory vs. individuals with wheeze (51% and 46% vs. 39%) in the TAHS cohort. For individuals in the CARDIA cohort, a higher proportion of those with dry cough and those with some chesty colds had an average FEV₁/FVC trajectory vs. those with wheeze and those with productive cough (44% and 43% vs. 38% and 38%).

Further, more individuals from the two most impaired rapid decline FEV₁/FVC trajectory groups first reported wheeze vs. bronchitis/phlegm or both wheeze and bronchitis/phlegm in the TAHS cohort at 40 to 55 years old (24% vs. 5% or 12%) and the CARDIA cohort at older than 30 years (27% vs. 2% or 9%).

“It was surprising that wheezing was the most common symptom of people on impaired lung function trajectories, rather than cough, phlegm or breathing difficulty,” Perret told Healio. “However, this made sense as the origin of COPD occurs in the small airways.”

In the TAHS analysis, researchers found a link between the early low, rapid decline FEV₁/FVC trajectory and predominant wheeze (multinominal OR [mOR] = 6.71; 95% CI, 4.1-10.9). Similarly, a link between the low peak, rapid decline FEV₁/FVC trajectory and predominant wheeze (mOR = 9.9; 95% CI, 4.52-21.7) was observed in the CARDIA analysis.

According to the study, with each poorer classification of FEV₁/FVC impairment in a set of the three most impaired trajectories, the odds for predominant wheeze rose. During an examination of only individuals without spirometry-defined COPD, this finding held true.

Researchers went on to find elevated odds for nearly all respiratory symptoms in middle age (51 to 55 years) among those with the early low, rapid decline FEV₁/FVC trajectory vs. the average trajectory in TAHS (mOR = 4.95; 95% CI, 2.52-9.74).

This was also true in CARDIA, as those with the low peak, rapid decline FEV₁/FVC trajectory vs. the average trajectory had heightened odds for nearly all respiratory symptoms in the middle age range of 47 to 64 years (mOR = 14.8; 95% CI, 5.97-36.6).

When assessing respiratory symptom data from younger ages, 20% of individuals in TAHS from either the early normal, rapid decline or early low, rapid decline FEV₁/FVC trajectory groups experienced wheezing and usual phlegm/bronchitis before turning 14 years old.

A slightly higher proportion (25%) of younger aged individuals (18 to 30 years) in CARDIA from the normal peak, rapid decline or low peak, rapid decline FEV₁/FVC trajectory classifications had these symptoms, according to the study.

“More work on identifying symptomatic patients on an impaired FEV₁/FVC trajectory via objective testing is needed,” Perret and colleagues wrote.