Endocrine Abstracts

Polycystic ovary syndrome (PCOS) has an early onset. However, its prevalence in the youngest age groups has not been assessed, mostly due to the poor specificity of the criteria for defining PCOS in adolescents, including the testosterone references generated only on adult women. Moreover, the current references for testosterone were mostly built by immunoassays, known to have poor accuracy. This study was aimed at defining androgen and pro-androgen reference intervals in 149 healthy normal weight and drug-free young women, aged 16–20 y, by using liquid chromatography–tandem mass spectrometry (LC–MS/MS). All had 11–13 menses/year and no signs of hyperandrogenism. Median values (2.5th–97.5th centiles, ng/ml) for testosterone, androstenedione, DHEA, 17OHprogesterone and progesterone were 0.275 (0.129–0.519), 0.898 (0.407–1.665), 6.78 (2.58–18.34), 0.646 (0.210–2.443) and 0.132 (0.049–13.950) respectively. After excluding 36 subjects who did not report their last bleeding day and 9 subjects in ovulatory peak, subjects were sub-grouped according to menstrual phases: follicular phase (day 1–13, LH <20 μU/ml, estradiol <100 pg/ml, FSH <10 uU/ml, n=48); luteal phase (day 14 on, LH <20 uU/ml, estradiol <100 pg/ml, FSH <10 uU/ml, n=56). Follicular and luteal phase median values (2.5th–97.5th centiles, ng/ml) were: 0.247 (0.126–0.416) and 0.274 (0.131–0.553) for testosterone, 0.884 (0.384–1.514) and 0.839 (0.317–1.556) for androstenedione, 6.91 (2.84–21.09) and 7.01 (2.29–17.23) for DHEA, 0.375 (0.160–0.847) and 1.275 (0.261–2.516) for 17OHprogesterone, 0.067 (0.049–0.337) and 4.177 (0.060–14.575) for progesterone respectively. Confirming higher progesterone (P<0.0001) and 17OHprogesterone (P<0.0001), increased testosterone was found in the luteal compared to the follicular phase (P=0.037). Within the luteal phase subgroup, 23 anovulatory (progesterone <2 ng/ml) and 20 normo-ovulatory subjects (progesterone >7 ng/ml) were found. Notably, testosterone was significantly higher in anovulatory than ovulatory subgroup (P=0.021). Using LC– MS/MS, we defined androgen and pro-androgen reference intervals in young females according to menstrual phase, highlighting the link between testosterone and ovulatory efficiency.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This work was supported, however funding details unavailable.