Childhood Risk Factors for Chronic Lung Disease in Adulthood Identified

Shyamali Dharmage, MD, PhD

In a recently published study, compromised lung function during childhood has been found to be associated with an increased risk of developing chronic obstructive pulmonary disease (COPD) as an adult.

The study retrieved data from the Tasmanian Longitudinal Health Study (TAHS), a population-based cohort study with multiple assessments of lung function. This allowed researchers to access lung function data from a large pool of participants over the course of 6 decades.

“We identified childhood factors that predict three adverse lung function trajectories that increase COPD risk, which provide insight into pathways toward development of COPD,” study author Shyamali Dharmage, MD, PhD, a professor at the School of Population and Global Health, the University of Melbourne, Australia, told MD Magazine.

The TAHS study began in 1968 and included 8583 Tasmanian children. At age 7, the children were given a clinical examination that involved pre-bronchodilator spirometry and a questionnaire completed by their parents. Follow-up assessments were conducted at ages 13, 18, 45, and 50 years, and featured measurements of pre-bronchodilator spirometry. The most recent follow-up took place in 2015 when the remaining 2438 subjects (age 53) were invited to participate in this clinical study.

Childhood factors included asthma, bronchitis, eczema, allergic rhinitis, food allergy, pneumonia, breast feeding, weight status, parental asthma, and parental smoking. COPD was defined as post-bronchodilator FEV₁/FVC less than the lower limit of normal at the final assessment at age 53.

Results showed 6 lung function trajectories among subjects: below average, accelerated decline (4%); persistently low (6%); early low, accelerated growth, normal decline (8%); persistently high (12%); below average (32%); and average (39%).

Three of these trajectories — below average, accelerated decline; persistently low; and below average — were linked to 75% of COPD cases by age 53. This was compared to the average group (early below average, accelerated decline: odds ratio [OR] 35.0; 95% CI; 19.5 - 64.0; persistently low: 9.5, 4.5 - 20.6; and below average: 3.7; 1.9 - 6.9).

Personal smoking and adult asthma further escalated the impact of maternal smoking and childhood asthma, on the early below average, accelerated decline trajectory.

“As the long-term adverse effects of early exposures such as maternal smoking and asthma on lung function are augmented by personal smoking and adult active asthma, optimal asthma control through life and avoiding personal smoking would minimize these effects,” Dharmage said.

Some childhood risk factors can be avoided as well. Dharmage encourages parents to get their children vaccinated to prevent pneumonia, avoid/quit smoking, and discourage their children from taking up smoking. Parents of children with asthma should ensure that their asthma is in optimal control.

Dharmage said further research should explore the factors that contribute to favorable lung function trajectories in order to guide interventions that promote lung health. Studying interventions are also worthwhile to broaden options for asthma management in the hopes of preventing adverse lung function trajectories and COPD.

The study, "Childhood predictors of lung function trajectories and future COPD risk: a prospective cohort study from the first to the sixth decade of life," was published online in The Lancet Respiratory Medicine this month.