Salivary cortisol monitoring: Determination of reference values in healthy children and application in asthmatic children

Venipuncture testing of adrenocortical function in asthmatic infants and young children receiving inhaled corticosteroids can raise cortisol levels and mask physiological responses. This study aimed to establish reference ranges for salivary cortisol levels and evaluate the safety and effects of jet-nebulized budesonide inhalation suspension (BIS) on salivary cortisol levels and patient outcomes in infants and young children with mild or persistent asthma. Reference salivary cortisol levels were determined in healthy children aged 6 months to 4 years old. A 12-week multicenter, randomized, parallel-group, open-label study was performed involving 53 age-matched asthmatic children who received either 0.5 mg/day of BIS or 40‐60 mg/day of cromolyn sodium inhalation suspension (CIS) via compressor nebulizer. The effective measuring range of salivary cortisol concentration in asthmatic children was 0.12‐3.00 micrograms/dL. The upper and lower limits of the reference range were 0.827 and 0.076 micrograms/dL, respectively. No significant difference was seen from baseline through week 12 in the CIS and BIS groups. BIS was safe in these patients, with no inhibitory effects on adrenocortical function. Salivary cortisol measurement offers a useful and accurate tool for testing adrenocortical function in infants and young children. Longer-term studies that incorporate testing of the hypothalamic‐pituitary‐adrenal axis are warranted to confirm our findings.