Circadian Rhythm of Salivary Cortisol, 17α-Hydroxyprogesterone, and Progesterone in Healthy Children

Very few reference intervals for salivary steroids in children have been established to date (1). Even the manufacturers of salivary steroid assays do not provide sufficient reference data for their products. This lack of information is surprising because the measurement of salivary steroids has been accepted as being noninvasive and stress-free (2)(3). In particular, psychiatric and neuro-endocrinologic experiments are frequently designed with saliva as the medium of choice for steroid analysis (4)(5)(6). A large variety of stressors can rapidly affect the adrenal cortex, causing increased adrenal steroid concentrations. For example, hypoglycemia (7) or physical exercise (8) are potent physiologic stressors, whereas fear (9), feelings of inferiority (10)(11), or experiences at school (12)(13) can affect the adrenal cortex activity as psychologic stressors. The taking of blood can also influence adrenal steroid concentrations in children; saliva collection, however, is almost stress-free (14). The use of saliva for steroid analysis in children is therefore an excellent alternative to blood.