Time-integrated measurement of corticosteroids in saliva by oral diffusion sink technology

Saliva, as a medium for assessing adrenocortical function in humans, has many advantages and a few distinct disadvantages. Interpretation of measurements of saliva cortisol is complicated by the contamination of saliva by steroid-binding proteins from blood plasma, enzyme activity in the salivary gland that converts cortisol to cortisone, and the amplification in saliva of the episodic fluctuations in systemic cortisol concentrations. We describe a new measurement technology that rejects artifacts from contamination of saliva by plasma protein, provides for measurement of both cortisol and cortisone, and integrates episodic fluctuations in concentration over a period of hours. This oral diffusion sink technology may greatly enhance the reliable interpretation of corticosteroid concentrations measured in saliva.