Incidence of menstrual cycle abnormalities and polycystic ovary syndrome in female Japanese patients with type 1 diabetes mellitus. The role of androgens

Type 1 diabetes mellitus (T1DM) adversely affects gonadal function. This study aimed to define the characteristics and factors associated with menstrual cycle abnormalities and polycystic ovary syndrome (PCOS) in Japanese patients with T1DM. Our study enrolled 157 patients, including 55 with oligomenorrhea (prolonged menstrual cycle) and 102 without oligomenorrhea. LH/FSH ratio (p = 0.04) and total testosterone levels (p = 0.03) were significantly higher in the oligomenorrhea group than in the non-oligomenorrhea group. No significant differences were found between the two groups regarding age at menarche, age at T1DM diagnosis, treatment, glycated hemoglobin, or total daily insulin dose. Of the 55 patients in the oligomenorrhea group, 27 were diagnosed with PCOS based on the Rotterdam criteria. We concluded that female patients with T1DM, as well as abnormal menstrual cycles and hyperandrogenism, may suffer from undiagnosed PCOS and should be referred to a gynecologist for full assessment, diagnosis, and treatment.