Endocrine Abstracts

Background: Cortisol is inactivated to cortisone in the salivary gland by 11β-HSD type 2. Concentrations of cortisone and cortisone in saliva correlate strongly with serum cortisol concentrations (1). Only free, biologically active hormone is measured in saliva, testing is non-invasive and can be performed at home/school, reducing cost and inconvenience to families and NHS resources. We previously reported pilot data from healthy children and young people (CYP) (1). Here we describe salivary cortisol (SC), and cortisone (SCn) concentrations, and SCn:SC ratios in a larger cohort.

Methods: Healthy CYP children aged 5-18 years old participated. Exclusion criteria: Medical conditions and medications that may affect cortisol concentrations, family history of inherited adrenal disorders and oral lesions. Samples were collected 30 mins after waking and at 2-hour intervals thereafter, until sleep. Patients did not clean their teeth or eat one hour before sampling. Samples were analysed by LC-MS/MS.

Results: 86 (49M) participants, median age for males was 10.8years (IQR=5.6), median female age was 11.0 years (IQR=4.7). 7 samples at 7 time-points collected. 8hours after waking, SC was undetectable in 3 samples (3.5%), after 10 hours in 11 samples (12.9%) and in 24(28.3%) samples after 12hours. SCn was always detectable. SCn:SC was 4.2 (1.60) on the waking sample and increased throughout the day to peak 10 hours after waking, 9.8 (3.62).

Using a generalised linear model with repeated measures, neither age or sex were found associated with cortisol (p-values: age – 0.67 sex – 0.29) or with cortisone levels (p-values: age – 0.70 sex – 0.85).

Conclusion: Data from this larger cohort confirm our previous findings. SC is often undetectable and SCn may be a more reliable measure. SC and SCn are neither related to sex nor age. The ratio of SCn:SC increases through the day, suggesting that the circadian cortisol profile is regulated partly by changes in the relative activity of 11β-HSD type 1 and 2.

Reference

1. Titman A, et al. 2020. Clin. Endocrinol. (Oxf):93(5):572-8.