Medscape Medical News
Childhood Asthma Linked to Early COPD
Veronica Hackethal, MD
Although COPD rarely develops before the fourth decade of life
and typically affects current or former smokers, 11% of the children in this
study met Global Initiative for Chronic Obstructive Lung Disease (GOLD)
criteria for COPD by age 30 years. Children with a decreased pattern of lung
growth or decreased lung function at study entry and males were at increased
"Our data support
the hypothesis that both reduced growth and an early decline are trajectories
leading to an asthma–COPD overlap syndrome and complement the recent
observation that in older patients, a rapid decline in lung function can lead
to COPD," write Michael J McGeachie, PhD, from Brigham and Women's
Hospital, Harvard Medical School, Boston, Massachusetts, and colleagues.
Past studies have
linked early decline in lung function and a pattern of decreased lung growth to
the development of COPD. A recent study found that
poorer lung function in early adulthood is associated with the development of
COPD later in life. However, long-term data on the issue are limited in
children with asthma, who are already at increased risk for airflow obstruction.
The current analysis
was part of the randomized placebo-controlled CAMP study, which enrolled
children aged 5 to 12 years with mild to moderate asthma and followed them into
the third decade of life. The larger CAMP study found that inhaled anti-inflammatory
agents were no better than placebo in terms of their long-term effects on lung
function growth. During the study, participants underwent annual spirometry
lung function assessments.
684 CAMP participants who had mild to moderate persistent asthma despite
medication use. They separated these children into four groups, based on their
trajectories of lung growth and decline in lung function, as measured by forced
expiratory volume in 1 second (FEV1). FEV1is a measure of
lung function that usually peaks in late adolescence or early adulthood, but
then remains stable for many years before starting a gradual decline. The four
categories included normal growth with normal peak, normal growth and early
decline, reduced growth and normal peak, and reduced growth and early decline.
By about age 26 years,
11% (n = 73) of participants had lung impairment suggestive of COPD, as defined
by the GOLD criteria. Thirty-six percent of participants with a reduced lung
growth pattern and 8% of those with a normal growth pattern met GOLD criteria
for COPD (P < .001).
commented: "These findings have critical implications in terms of tertiary
prevention because they indicate that interventions aimed at reducing the
long-term sequelae of childhood asthma need to start early in life and to
target patients years before they enter adulthood."
The authors note that
more studies are needed to identify interventions that could improve outcomes
in children with mild to moderate persistent asthma.