Endocrine Abstracts

The hormone assessment in saliva is emerging as a new valuable tool for clinical and research purposes. Salivary levels are supposed to reflect the free fraction of circulating steroids, thus representing a more informative indicator of their activity. Moreover, saliva collection is not stressful and does not require medical assistance, allowing reliable and multiple sampling in a day. Liquid chromatography–tandem mass spectrometry (LC–MS/MS) technology offers high sensitivity and specificity to detect small concentration, and allows multi-analyte quantitation. In this study, we developed and validated a LC–MS/MS method for the simultaneous measurement of salivary testosterone, androstenedione, DHEA and 17OHProgesterone (17OHP), achieving a functional sensitivity (imprecision, accuracy) of 0.95pg/ml (2.3–108%), 1.95pg/ml (14.1–104%), 78.1pg/ml (8.1–102%) and 15.6pg/ml (13.2–89%) for testosterone, androstenedione, DHEA and 17OHP, respectively. For biological validation, paired serum and saliva samples were collected from 12 males and seven females healthy, normal weight adult volunteers, at 800, 1200, 1600, and 2000h of a regular day. We measured saliva androgen by the novel assay and serum androgens with a dedicated LC–MS/MS method previously validated. Free testosterone was calculated by the Vermeulen formula, by measuring SHBG and albumin concentrations at each time point. Salivary androgens were highly correlated to serum androgens (A: r=0.919; DHEA: r=0.771; 17OHP: r=0.875; female T: r=0.842 and male T: r=0.874). Moreover, a high correlation was observed also between salivary testosterone and free testosterone both in females (r=0.886) and males (r=0.860). Our assay displayed the sensitivity, accuracy and precision needed for a proper measurement of low salivary androgens concentrations and for its application in epidemiological studies or in routine settings. Moreover, the multi-analytical profiling allows a more effective evaluation of androgen status and will be used to define the reference ranges and circadian rhythm in healthy as well as in hypogonadic or hyperandrogenic subjects.