Lung Function Decline in Relation to COVID-19 in the General Population: A Matched Cohort Study With Prepandemic Assessment of Lung Function

Abstract

Objective To quantify the potential decline in dynamic lung volumes following coronavirus disease 2019 (COVID-19) in the general population. Methods A prospective matched cohort study of adult Copenhagen General Population Study (CGPS) participants with a pre-pandemic spirometry available. CGPS individuals with a positive SARS-CoV-2 polymerase chain reaction (PCR) test performed a repeat spirometry, a questionnaire regarding respiratory symptoms and a diffusing capacity test for carbon monoxide. A matched uninfected CGPS control sample was used, and simple regression and linear mixed effect models were computed to study lung function decline. Results A total of 606 were included. 92/107 (85.9%) of individuals with a positive SARS-CoV-2 PCR test experienced COVID-19 symptoms and 12 (11.2%) were hospitalized. Spirometry was performed at a median (interquartile range) of 5.6 (3.9-12.8) months after positive SARS-CoV-2 PCR test. COVID-19 was associated with an adjusted 7.3 mL (95%CI: 0.3-14.3) and 22.6 mL (95%CI: 13.1-32.0) steeper decline in annual FEV1 and FVC or a total of 113.8 and 301.3 ml lower FEV1 and FVC from baseline to follow up. Results were robust in analyses restricted to individuals not requiring hospitalization. Conclusion COVID-19 related decline of dynamic lung volumes in the general population not requiring hospitalization were small but measurable.

Interstitial lung disease following coronavirus disease 2019

“…An interesting study used prepandemic lung function tests in SARS-CoV-2-positive individuals and matched controls, and evaluated lung volume decline following asymptomatic to mild COVID-19. The results showed that COVID-19 was associated with an accelerated decline in FEV1 and FVC independent of tobacco smoking [21 ▪▪ ]. Unfortunately, DLco was not available in that study [21 ▪▪ ].…”

Restrictive spirometry versus restrictive lung function using the GLI reference values

“…Restrictive lung function is common in several conditions and diseases including lung and pleural diseases but also obesity, deformities of thorax and neuromuscular disease, and notably, other conditions than lung and pleural (Bradley et al, 2008; Stansbury & Mannino, 2009). In addition, the COVID‐19 pandemic may increase the global prevalence of restrictive lung function due to inflammatory response in the lungs (E. et al, 2021; Iversen et al, 2022; Torres‐Castro et al, 2021). On a population level, prevalence estimates of restrictive lung function using dynamic spirometry, that is, restrictive spirometry pattern (RSP), based on normal forced expiratory volume in a one second (FEV 1 )/forced vital capacity (FVC) (or VC) ratios and decreased FVC (or VC) have yielded results between 6% and 8% in the United States (Ford et al, 2013; Kurth & Hnizdo, 2015), from 5% to 19% in Spain (Scarlata et al, 2008), and in Sweden about 10% (Backman et al, 2016).…”

Lung Function After Coronavirus Disease 2019: Some Answers, More Questions

“…In this issue of The Journal of Infectious Diseases , Iverson et al [ 5 ] begin to address some of the outstanding gaps in our understanding of pulmonary impairment after COVID-19. They leveraged the Copenhagen General Population Study, an ongoing, population-based prospective cohort study of the Danish population residing in the Copenhagen area.…”

“…To assess the impact of COVID-19 on lung function, Iverson et al [ 5 ] first performed repeated-measures linear mixed-effects modeling to determine the mean yearly change in lung function between those with and without COVID-19. Of note, the mean time between baseline and follow-up spirometry sessions for cases and controls was 6.4 and 8.4 years, respectively (although the earliest baseline visit was in December 2003, 16 years before the COVID-19 pandemic began).…”

“…Third, and not specific to this study, there continue to be challenges and uncertainty about how best to describe changes in lung function after an acute insult such as COVID-19. In this case, Iverson et al [ 5 ] chose to leverage mixed-effects models and report the primary outcome of lung function as a rate of annual decline. However, this approach implies that declines in lung function were consistent between the baseline and follow-up assessments, an assumption that is unlikely in the case of COVID-19.…”