Prevalence of endocrine disorders in 304 premenopausal women referred with oligomenorrhoea.

Introduction: We aimed to evaluate 304 premenopausal women admitted to our clinic for oligomenorrhoea, and to screen for Cushing's syndrome (CS) in this population.

Material and methods: The study included 304 premenopausal women referred to our clinic for oligomenorrhoea. Anthropometric measurements and Ferriman-Gallwey score were evaluated, and thyroid hormone, follicle-stimulating hormone (FSH), luteinizing hormone (LH), total testosterone, prolactin, dehydroepiandrosterone sulphate (DHEA-S), and 17-hydroxyprogesterone (17-OHP) levels were measured in all patients. If basal 17-OHP was > 2 ng/mL, we evaluated adrenocorticotropic hormone (ACTH)-stimulated 17-OHP levels. CS was screened by 1 mg-dexamethasone suppression test, and if the cortisol value was > 1.8 μg/dL, we performed additional confirmatory tests, and if necessary, pituitary magnetic resonance imaging (MRI) and inferior petrosal sinus sampling (IPSS) were performed.

Results: The most common cause of oligomenorrhoea was polycystic ovary syndrome (PCOS) that was detected in 81.57% of cases, followed by hyperprolactinemia at 7.23% and hypothalamic anovulation at 5.26%. The prevalence of premature ovarian failure (POF) was 1.6%, and non-classical congenital adrenal hyperplasia (NCAH) was 1.97%. CS was detected in 7 (2.30%) patients. All the patients with CS were found to have Cushing's disease (CD). Although 3 patients with CD had classical signs and symptoms, 4 had none. Patients with CD had similar total testosterone values to those in the PCOS and NCAH groups, but they had significantly higher DHEA-S compared to both groups (CD vs. PCOS, p = 0.001 and CD vs. NCAH, p = 0.030).

Conclusions: We found higher prevalence of CS in patients with oligomenorrhoea even in the absence of clinical signs. Therefore, we suggest routine screening for CS during the evaluation of patients with oligomenorrhoea and/or PCOS. The likelihood of CS is greater in patients with high androgen, especially DHEA-S levels.