Responsiveness to parenteral corticosteroids may aid in predicting lung function trajectory

In adults with moderate to severe asthma, responsiveness to parenteral corticosteroids may be useful to predict lung function decline.

“In patients with moderate to severe asthma on stable medical therapy, the responsiveness to parenteral corticosteroids has not been evaluated as a predictor of lung function decline in a cohort with more than 1 year of follow-up,” Loren C. Denlinger, MD, PhD, with the division of allergy, pulmonary and critical care medicine at the School of Medicine and Public Health at the University of Wisconsin, and colleagues wrote in the American Journal of Respiratory Critical Care Medicine.

Researchers evaluated 396 adults from the National Heart, Lung, and Blood Institute (NHLBI) Severe Asthma Research Program III who underwent a course of intramuscular triamcinolone at baseline and at least two or more follow-up visits. Researchers collected participants’ post-bronchodilator FEV₁ percent predicted, which was categorized as a severe decline (> 2% loss per year), mild decline (> 0.5%-2% loss per year), no change (0.5% loss to < 1% gain per year) or improvement ( 1% gain per year).

The study included 396 participants. Of those, 78 (mean age, 50 years; 66.7% women) had severe decline, 91 (mean age, 47.5 years; 68.1% women) had mild decline, 114 (mean age, 46.9 years; 64% women) had no change and 113 (mean age, 46.9 years; 69% women) had improvement in airway function, according to the results.

In univariable models, the researchers found a relationship between the triamcinolone-induced difference in post-bronchodilator FEV₁ percent predicted and change in lung function or FEV₁ slope category over 4 years (P < .001).

After adjusting for baseline FEV₁, asthma exacerbation history, blood eosinophils and BMI, researchers observed a 50% increase in odds for participants being categorized as having severe airway function decline (OR = 1.5; 95% CI, 1.3-1.8) for each 5% decrement in triamcinolone-induced difference in FEV₁ percent predicted.

“[U]sing a unique biomarker, airway response to parenteral corticosteroids, we were able to identify individuals most likely to experience a decline in airway function. The ability to identify that group prospectively will allow us to examine the pathology of progressive loss of airway function and perhaps identify interventions to prevent permanent disability,” the researchers wrote.