Objective: Inhaled corticosteroids (ICS) is the mainstay therapy of childhood asthma, but side effects related to hypothalamic-pituitary-adrenal (HPA) axis suppression is a concern, especially when combined with Montelukast. HPA suppression is assessed by morning measuring serum cortisol level, which is invasive and inconvenient in children. Salivary cortisol is a non-invasive alternative. We aim to correlate serum with salivary cortisol levels in asthmatic children, and assess the effect of treatment with ICS alone or ICS with Montelukast. Methods: Morning serum and salivary cortisol levels were measured in asthmatic children (7– 12 years) who were treated with either ICS (IC group) or ICS plus Montelukast (ICM group). Salivary cortisol was also measured in age-matched healthy children (control group). We used Pearson coefficient to correlate between serum and salivary cortisol levels, and Student’s t -test or ANOVA for group comparisons as appropriate. We used multivariate regression analysis to evaluate predictors of salivary and serum cortisol levels. Results: A total of 150 children were recruited, 50 children in each study group. There was no difference between IC, ICM and control groups in age or BMI. Asthma groups had higher percentage of males (P= 0.01). We found positive correlation between serum and salivary cortisol levels (r = 0.29, p = 0.01). There was no difference in salivary cortisol levels between the 3 groups (7.30 ± 5.99 vs. 10.04 ± 11.6 vs. 10.7 ± 9.8, p = 0.76). There was no difference in serum cortisol levels between IC and ICM groups (249.03 ± 117.8 vs. 277.5 ± 123.9, p = 0.24). Age, gender, BMI, ICS dose and asthma severity did not affect serum or salivary cortisol levels. Conclusion: Salivary cortisol level correlates with serum cortisol in asthmatic children, but not different from level in controls, and not affected by treatment with ICS alone or with Montelukast. Keywords: asthma, children, inhaled corticosteroids, Montelukast, salivary cortisol, serum cortisol
AbdulWahab et al. (Mon,) studied this question.