Lung function decline in young adulthood ups CAC progression in midlife

Young adults with a faster decline in lung function, as measured by forced vital capacity (FVC) or forced expiratory volume in 1 second (FEV1), are at greater risk of coronary artery calcium (CAC) progression in midlife, as shown in a study.

“This emphasizes the significance of preserving lung function in early adulthood to potentially reduce the risk of subclinical coronary atherosclerosis and improve future cardiovascular health,” the researchers said.

The study included a total of 2,694 participants (mean age 40.4 years, 44.7 percent men) from the Coronary Artery Risk Development in Young Adults (CARDIA). The researchers calculated the rates of decline in FVC and FEV1 over a 20-year period for each participant and categorized into quartiles. CAC progression served as the primary endpoint.

Of the participants, 455 (16.9 percent) had CAC progression during a mean follow-up of 8.9 years. [Am J Med 2023;136:910-917.E4]

Participants in the second (Q2; hazard ratio [HR], 1.366, 95 percent confidence interval [CI], 1.003‒1.861), third (Q3; HR, 1.412, 95 percent CI, 1.035‒1.927) and highest quartiles (Q4; HR, 1.789, 95 percent CI, 1.318‒2.428) of FVC decline had the highest risk of CAC progression compared with those in the lowest quartile (Q1) after adjusting for traditional cardiovascular risk factors.

These associations persisted across a series of sensitivity analyses and all subgroups.

“Environmental and behavioural factors, as well as genetics, contribute to the speed of lung function decline,” the researchers said. “However, our study found that the increased risk of CAC progression in individuals with lung function decline was consistent across all subgroups, regardless of smoking status.” [Am J Respir Crit Care Med 2020;202:210-218]

Previous studies have shown the association of rapid lung function decline with systemic inflammation, endothelial dysfunction, and impaired vascular reactivity, which are common pathways that contribute to a higher cardiovascular disease (CVD) risk. [N Engl J Med 2004;350:1387-1397; J Intern Med 2017;281:471-482; Am J Epidemiol 2003;158:1171-1181; Arterioscler Thromb Vasc Biol 2014;34:715-723]

Mendelian randomization studies also provide genetic evidence supporting the cause relationship between lung function decline and CVD risk. [Eur Respir J 2021;582003196; Circ Genom Precis Med 2018;11e001952; Thorax 2022;77:164-171]

Better predictor

“The evidence on whether FEV1 or FVC is a stronger predictor of cardiovascular disease is mixed and may vary depending on the population being studied and the cardiovascular outcome being assessed,” the researchers said. [Int J Chron Obstruct Pulmon Dis 2020;15:1135-1142; Thorax 2011;66:49-54; BMC Med 2021;19:153; J Am Coll Cardiol 2018;72:1109-1122; Trends Cardiovasc Med 2021;31:93-98]

“Both measures are widely used in clinical trials and epidemiological studies. Specifically, FEV1 provides information on how well the large airways are functioning, while FVC provides information on overall lung function. Neither measure is necessarily better than the other, as they serve different purposes and are often used together to provide a more complete picture of lung function,” they added.