During a median of 11 years, 56 patients (60.2 percent) experienced at least one severe asthma exacerbation -- defined as being admitted to the hospital for worsening asthma or as a significant and reversible reduction in FEV1 -- a standard measure of lung function.
Dr. T. R. Bai, of the University of British Columbia, Vancouver, Canada, and colleagues examined the long-term impact of asthma flares on annual lung function decline in 93 non-smoking asthmatic patients with moderate-to-severe asthma.
Intermittent periods of worsening airway inflammation, indicated by exacerbations in asthma, lead to excess lung function decline, according to a study published this month.
Decline in lung function was much more pronounced in those individuals with frequent asthma attacks relative to individuals with infrequent asthma attacks, Bai and colleagues report.
It's been proposed, they note, that worsening of airway inflammation associated with asthma exacerbations fuel potentially harmful structural changes in the airway that occur as asthma progresses.
The current results, they add, "provide additional rationale for the notion that the prevention of exacerbations should be the primary end-point in trials of asthma therapy."