Functional and endocrine-metabolic oligomenorrhea: proposal of a new diagnostic assessment tool for differential diagnosis in adolescence

Background: To develop a diagnostic assessment tool, using clinical, biochemical and sonographic markers, to help clinicians in the differential diagnosis of functional oligomenorrhea (FO) and endocrine-metabolic oligomenorrhea (EMO). Methods: Sixty-two adolescents with oligomenorrhea without evident hormonal imbalances or severe energy deficit were selected. They were divided into two groups (EMO and FO) and they all underwent the following assessment: physical examination (height, weight, presence of hirsutism or acne), blood exams and transabdominal ultrasonography. The biochemical markers included: hemoglobin, thyrotropin stimulating hormone (TSH), prolactin (PRL), follicle stimulating hormone (FSH), luteinizing hormone (LH), free (FT) and total testosterone (TT), androstenedione (A), dehydroepiandrosterone sulfate (DHEAS) and sex hormone binding globulin (SHBG). Uterine and ovarian volume, ovarian morphology, endometrial thickness and pulsatility index (PI) of uterine arteries were evaluated with ultrasound. Results: Body mass index (BMI), hemoglobin, LH levels and LH/FSH ratio were significantly higher in women with EMO than in those with FO. Increased androgens values were found in the EMO group, but only A and FT were significantly different (p = 0.04). Ovarian volume and uterine artery PI were the only ultrasound features significantly different, with higher values in the EMO population (p <0.05). Considering these variables, with a receiving characteristic operating curve, new cut-offs were calculated, and a diagnostic assessment tool elaborated (area under curve [AUC] 0.88, specificity 99%, sensibility 59%, p <0.001]. Conclusions: This diagnostic tool, specific for adolescents, could be useful in the management of oligomenorrhea. Recognizing and distinguishing EMO and FO is very important in order to establish an appropriate treatment and a correct follow-up.