The Circadian Variation in Anti-Mu ¨ llerian Hormone in Patients with Polycystic Ovary Syndrome Differs Significantly from Normally Ovulating Women Leif Bungum 1 *, Florencia Franssohn 1 , Mona Bungum 1 , Peter Humaidan 2 , Aleksander Giwercman 1 1 Reproductive Medicine Center, Ska ˚ne University Hospital, Lund University, Malmo ¨ , Sweden, 2 Fertility Clinic, Odense University Hospital, Odense, Denmark Abstract Obective: To improve the biologic understanding of the Polycystic Ovarian Syndrome (PCOS) condition by examining the circadian variation and relationship between Anti Mu ¨ llerian Hormone (AMH), gonadotropins and ovarian steroids in PCOS patients compared to normally ovulating and menstruating women. By comparing the pattern of co-variation between AMH and Luteinizing Hormone, two compounds closely linked to hyperandrogenism and anovulation in PCOS, the involvement of the Hypothalamic-Pituitary-Ovarian axis in PCOS pathology could be elucidated. Patients: Eight normal-weighted young, anovulatory PCOS-women as study group and ten normal menstruating and ovulating women as controls. Interventions: Observational prospective study of the circadian variation in AMH, gonadotropins, sex steroids and androgens in a study and a control group. A circadian profile was performed in each study and control subject during a 24-h period by blood sampling every second hour, starting at 8:00 a.m. and continuing until 8:00 a.m. the following day. Result(s): Significant differences in hormonal levels were found between the groups, with higher concentrations of AMH, LH and androgens in the PCOS group and lower amounts of FSH and progesterone. A distinct difference in the circadian variation pattern of AMH and LH between PCOS patients and normal controls was seen, with PCOS patients presenting a uniform pattern in serum levels of AMH and LH throughout the study period, without significant nadir late-night values as was seen in the control group. In PCOS women, a significant positive association between LH/ FSH and testosterone was found opposite to controls. Main outcome measures: Circadian variation in Anti-Mu ¨ llerian Hormone, gonadotropins and ovarian steroids and the covariation between them. Conclusion: A significant difference in the circadian secretion of LH and AMH in PCOS women compared to normally ovulating women indicate an increased GnRH pulse, creating high and constant LH serum concentrations. A significant co- variation between LH and AMH may suggest LH as a factor involved in the control of AMH secretion. Citation: Bungum L, Franssohn F, Bungum M, Humaidan P, Giwercman A (2013) The Circadian Variation in Anti-Mu ¨ llerian Hormone in Patients with Polycystic Ovary Syndrome Differs Significantly from Normally Ovulating Women. PLoS ONE 8(9): e68223. doi:10.1371/journal.pone.0068223 Editor: Samuel Kim, University of Kansas Medical Center, United States of America Received February 23, 2013; Accepted May 28, 2013; Published September 4, 2013 Copyright: ß 2013 Bungum et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: The study was supported by an unconditional grant from Merck-Serono. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The study was supported by an unconditional grant from Merck-Serono. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. This does not alter the authors’ adherence to all the PLOS ONE policies on sharing data and materials. * E-mail: Leif.bungum@med.lu.se Introduction Polycystic ovary syndrome (PCOS), anovulation and clinical or biochemical hyperandrogenism, are phenotypically heterogenic endocrine disorders, affecting women of reproductive age with a prevalence of 6–10% [1]. Obesity, insulin resistance and the metabolic syndrome may also be related to PCOS. Polycystic ovaries as a central feature of PCOS are secondary to follicular arrest interfering with normal folliculogenesis, including follicle recruitment, follicle dominance and ovulation. Although there is no consensus as to an explanation of the biological mechanisms behind PCOS, the condition seems to be at least two- factorial [2]. Firstly, the intra-ovarian hyperandrogenism promotes early follicular growth and leads to an excess in follicles measuring from 2–5 mm. Secondly, a low aromatase activity caused by insufficient Follicle Stimulating Hormone [3] activity impairs estrogen synthesis interfering with the selection and growth of a dominant follicle [4]. Insulin resistance, secondary to both genetic and lifestyle related factors as e.g. overweight is associated with anovulation, but is probably not the primary cause of PCOS [5– 8]. Androgen production is driven by Luteinizing Hormone (LH)- stimulated steroidogenesis in theca interna cells [9] and hyperan- drogenism may have both an extra- and intra-ovarian origin. An PLOS ONE | www.plosone.org 1 September 2013 | Volume 8 | Issue 9 | e68223