Endocrine Abstracts

Four androgens are routinely measured in women: dehydroepiandrosterone sulfate (DHEAS), dehydroepiandrosterone (DHEA), androstenedione, and testosterone. The diagnosis of hyperandrogenemia in women is accompanied by many difficulties. One of them is the method used to measure androgens in the laboratory. In most laboratories, androgens are determined using various immuno-analytical methods. Recently, gas or liquid chromatography combined with mass spectrometry have begun to be use. These instrumental techniques should be prefered for androgen mesurement in women due to their low circulating levels. Another difficulty with androgen laboratory assays are reference ranges, which can not just be automatically taken from other references but should be tested and confirmed in each laboratory. We determined our laboratory reference range for DHEA, androstendione and testosterone quantified using newly developed LC-MS/MS method in fertile, postmenopausal and pregnant women and their newborns in plasma. DHEAS was also estimated (radioimunoassay). Moreover, we have calculated biologically available testosterone. SHBG and albumin (calculation of biologically available testosterone) and LH (phase of cycle) were measured using immunoanalysis. Reference ranges were calculated based on the 2.5th–97.5th percentiles of measured data. For calculating ranges in fertile women, 220 healthy woman samples were analyzed (average age 29.8 years). Dividing into four phases of the menstrual cycle was performed based on the day of the cycle and LH levels. Calculating of reference ranges in healthy postmenopausal woman was performed by analyzing 97 plasma samples (average age 58 years). Samples from 142 healthy women (average age 31.41 years) with physiological gravidity at the 37th week, during the first period of spontaneous labor, and from newborn mixed cord blood divided in two group according the fetal sex were used for calculating reference ranges. All probands were not using any medications, had no clinical signs of hyperandrogenemia. Androgens levels of fertile women change during menstrual cycle with higher levels in ovulation phase (for example: follicular phase testosterone: 0.10–1.53 nmol/l and ovulation phase testosterone: 0.28–2.02 nmol/l).Pregnant women at the 37th week carrying male fetus have higher levels of androgens (testosterone: 0.73–5.79 nmol/l)than pregnant women carrying female fetus (testosterone: 0.99–5.07 nmol/l). Using LC-MS/MS methods and determination of own reference ranges for these androgens could improve the diagnostics of hyperandrogenemia in women.

Acknowledgments: The study was supported by the project MHCZ-DRO (Institute of Endocrinology-EÚ, 00023761), and by the grant MHCR 17-30528A from the Czech Health Research Council.