Testosterone, androstenedione, cortisol and cortisone levels in human unstimulated, stimulated and parotid saliva

Background: Recently, measurements of steroids like testosterone, androstenedione, cortisol and cortisone in saliva are more and more applied in diagnostics and scientific studies. This is mainly due to the simple and non-invasive collection of saliva. We aimed to evaluate the optimal way to collect saliva for steroid hormone measurement. Methods: We investigated in twenty volunteers whether there is a difference between steroid hormone concentrations in unstimulated and stimulated saliva collected while chewing, using cotton and synthetic Salivettes (R), citric acid or chewing gum. Furthermore, total unstimulated saliva was compared to parotid gland saliva. Testosterone, androstenedione, cortisol and cortisone were measured using Liquid-Chromatography Tandem Mass Spectrometry (LC-MS/MS). Results: Salivary testosterone, androstenedione and cortisol concentrations were unaffected by stimulation upon mouth and tongue movements, cortisone levels were on average 16% lower. Concentrations of all hormones were lower in parotid gland saliva compared to total unstimulated saliva (on average 51%, 26%, 66% and 49% lower, for testosterone, androstenedione, cortisol and cortisone, respectively). Concentrations of testosterone as well as androstenedione were lower when using synthetic Salivettes (R) (58% and 41%, respectively) and were higher when using cotton Salivettes (R) (217% and 46%, respectively). Cortisol levels in saliva were unaffected by using Salivettes (R). However, cortisol and testosterone levels were higher in with chewing gum stimulated saliva (16% and 55%, respectively). Cortisone concentrations were lower in all types of stimulations (on average 25%-35%). Conclusion: The way saliva is collected should be considered when analysing and interpreting salivary hormone concentrations. We advocate unstimulated saliva collection in simple polypropylene tubes for all steroid measurements.