Asymptomatic Volunteers with a Polycystic Ovary Are a Functionally Distinct but Heterogeneous Population

Context/Objective: Our objective was to determine the ovarian function of asymptomatic volunteers with a polycystic ovary (V-PCO). Participants: Non-hirsute eumenorrheic V-PCO (n = 32) and volunteers with ultrasonographically normal ovaries (V-NO) (n = 21) were compared with one another and with polycystic ovary syndrome (PCOS) patients who met National Institute of Health criteria (n = 90). Design/Setting/Interventions: GnRH agonist (GnRHag), ACTH, and oral glucose tolerance tests were prospectively performed in a General Clinical Research Center. Results: The distribution of 17-hydroxyprogesterone (17OHP) responses to GnRHag of V-PCO formed a distinct population intermediate between that of V-NO, the reference population, and PCOS. Nevertheless, the V-PCO population was heterogeneous. There were 53% (seventeen of 32) that were functionally normal, with 17OHP responses and free testosterone levels like V-NO. A total of 25% (eight of 32) had an elevated free testosterone, thus meeting Rotterdam criteria for PCOS; one third of these had 17OHP hyperresponsiveness to GnRHag testing. The remaining 22% (seven of 32) had 17OHP hyperresponsiveness to GnRHag, but normal free testosterone. Of PCOS, 69% had elevated 17OHP hyperresponsiveness to GnRHag. Ovarian volume correlated significantly with 17OHP responses only in PCOS, accounting for just 10% of the variance. Conclusions: Many asymptomatic volunteers have a PCO. They are a distinct, but heterogeneous, population with respect to ovarian function, ranging from normal (53%) to occult PCOS by Rotterdam criteria (25%). Nearly one quarter (22%) had the typical PCOS type of ovarian dysfunction without hyperandrogenemia, termed a "dysregulated PCO"; they or their offspring may be at risk for PCOS. Ovarian ultrasonographic characteristics must be considered when establishing norms for ovarian function. (J Clin Endocrinol Metab 94: 1579-1586, 2009)