Studies Link Risk Factors for COPD Back to Childhood

Childhood factors such as asthma, maternal smoking, bronchitis, allergic rhinitis, and eczema predisposed children to lung function decline and chronic obstructive pulmonary disease (COPD) as adults, according to 2 recent studies. Risks might be minimized by reducing maternal smoking, encouraging immunizations, having good asthma control, and avoiding smoking, researchers said.

Both studies were published in the Lancet Respiratory Medicine.

One study said it was unique because it is the first to track lung function from childhood to the sixth decade in a large population sample.¹ Researchers followed 8583 participants in the Tasmanian Longitudinal Health Study and investigated mean forced expiratory volume in 1 second (FEV₁) trajectories from age 7 to age 53. Lung function measurements were taken at ages 7, 13, 18, 45, 50, and 53.

By adulthood, most COPD cases were clustered in participants whose FEV₁ fell into these categories: early below average, accelerated decline FEV₁, below average FEV₁, and persistently low FEV₁,

Predictors of these 3 trajectories included childhood asthma, bronchitis, pneumonia, allergic rhinitis, eczema, parental asthma, and maternal smoking. There were borderline associations with food allergy and childhood underweight. Additionally, asthma in combination with either eczema or allergic rhinitis had a multiplicative effect.

The researchers said their findings contradict beliefs that lung function established in childhood tracks throughout life.

Maternal smoking affects not only early lung function, but predisposes children to more rapid lung function decline if they, too, take up smoking. In addition, the researchers said their findings highlight the potential role of lifelong asthma control in promoting lung health and preventing COPD.

In another study, researchers studied trajectories of FEV₁ in 2 birth cohorts with repeat spirometry from 5 years to 24 years.² One group had 1046 participants aged 5 to 16 years and another group was made up of 1390 participants aged 8 to 24.

A third, smaller group was followed with repeat lung function measures from infancy and follow-up until age 18.

Of 4 FEV₁ trajectories, one (the persistently low trajectory) was marked by low FEV₁ from school age to adulthood. Factors associated with this group included recurrent wheeze with severe wheezing exacerbations, early allergic sensitization, and tobacco smoke exposure.

"Taken together, these findings clearly point towards the importance of early life for the development of COPD," wrote Erika von Mutius, MD, of Helmholtz Centre Munich in Germany, in an editorial. "Importantly, maternal smoking and childhood asthma not only adversely affected early lung function, but predisposed children to more rapid lung function decline if they still suffered from asthma or actively smoked as adults."

References

1. Bui DS, Lodge CJ, Burgess JA, et al. Childhood predictors of lung function trajectories and future COPD risk: a prospective cohort study from the first to the sixth decade of life. [published online 
April 5, 2018]. Lancet Respir Med. http://dx.doi.org/10.1016/S2213-2600(18)30100-0.

2. Belgrave CM, Granell R, Turner SW. Lung function trajectories from pre-school age to adulthood and their associations with early life factors: a retrospective analysis of three population-based birth cohort studies. [published online 
April 5, 2018]. Lancet Respir Med. https://doi.org/10.1016/S2213-2600(18)30099-7.

3. von Mutius E. Childhood origins of COPD. Lancet Respir Med. [published online 
April 5, 2018]. http://dx.doi.org/10.1016/ S2213-2600(18)30141-3.