Attenuated salivary cortisol response after exercise test in children with asthma.

OBJECTIVE

The clinical relevance of lower basal cortisol levels in children with asthma is unclear. We compared the salivary cortisol response after a standardized exercise test in children with asthma versus the salivary cortisol response in healthy children.

METHODS

Nineteen prepubertal children with asthma and 20 prepubertal healthy children performed a standardized exercise test twice. Salivary cortisol levels were determined before exercise and immediately and 15 min after exercise. Morning salivary cortisol levels were determined from saliva collected at home.

RESULTS

Salivary cortisol levels increased in 84.2% of the healthy children compared to 35.0% in children with asthma after the 20-m shuttle-run test. Median increase in salivary cortisol levels was 200.3% [95% confidence interval (CI), 141.8-346.1] in healthy children compared to 89.8% (95% CI, 56.9-181.6) in children with asthma. The response was not related to the morning salivary cortisol level or maintenance dose of inhaled corticosteroids. The mean time to exhaustion of both shuttle-run tests was significantly shorter in children with asthma (mean difference 1.4 min; 95% CI, 0.7-2.3). None of the children had to stop because of dyspnea.

CONCLUSION

Our study demonstrates that children with asthma using a maintenance dose of inhaled corticosteroids (ICS) have an attenuated salivary cortisol response compared with healthy children.