The prevalence of polycystic ovaries in women with type 2 diabetes mellitus

OBJECTIVE Polycystic ovary syndrome (PCOS) and type 2 diabetes mellitus are both common conditions associated with insulin resistance and compensatory hyperinsulinaemia. Previous reports have noted that impaired glucose tolerance and diabetes are common in women with PCOS. In this report we present the results of the converse study: the prevalence of polycystic ovaries in premenopausal women presenting with type 2 diabetes mellitus. SUBJECTS Subjects were recruited from a hospital Diabetes Clinic. A search of computerized records identified 49 premenopausal women with type 2 diabetes mellitus being treated with diet alone or oral hypoglycaemic agents of whom 38 (76%) patients agreed to be studied. DESIGN A cross-sectional study recording clinical, demographic and anthropometric data. Measurements of fasting metabolic parameters, reproductive endocrine profiles and ovarian dimensions were taken. RESULTS Eighty-two percent of women with type 2 diabetes mellitus had polycystic ovaries on ultrasound. Of these women, 52% had clinical evidence of cutaneous hyperandrogenism and/or menstrual disturbance. Correlations between metabolic and reproductive parameters were consistent with a stimulatory action of insulin on the ovary. There was no significant difference between the PCO and non-PCO groups with respect to metabolic profiles. CONCLUSIONS Women with type 2 diabetes mellitus have a higher prevalence of polycystic ovaries than that reported in the general population. Not all women with hyperinsulinaemia due to type 2 diabetes mellitus, however, develop PCO suggesting that hyperinsulinaemia alone is not sufficient for the expression of this ovarian morphology.