Abstract and Introduction
Polycystic ovary syndrome (PCOS) and Type 2 diabetes mellitus (T2D) are both obesity-related conditions that share epidemiological and pathophysiological factors. Insulin resistance is a key factor whereby obesity influences the expression of each condition. However, the mechanisms by which insulin resistance contributes towards the manifestation of PCOS and T2D differ in important ways: in PCOS, compensatory hyperinsulinemia results in pleiotropic effects including co-gonadotrophic stimulation of ovarian and adrenal steroidogenesis; in T2D, insulin resistance contributes towards β-cell exhaustion and ultimately to hyposecretion of insulin with resultant dysglycemia. The link between PCOS and Type 1 diabetes mellitus is believed to implicate supraphysiological concentrations of insulin within the systemic circulation. Further progression of the obesity epidemic will ensure even greater prominence of important obesity-related conditions such as PCOS and T2D. Research to gain a clearer understanding of the mechanisms linking each condition should be a priority.
Polycystic ovary syndrome (PCOS) is a common condition with prevalence among Caucasian premenopausal women between 6–10%. PCOS affects women of premenopausal age and is characterized by hyperandrogenic features (e.g., hirsutism, acne and alopecia) that result from hyperandrogenemia, and menstrual disturbance including subfertility. PCOS is associated with obesity: between 38 and 88% of women with PCOS are overweight or obese, although PCOS can also manifest in lean women. PCOS also associates with other features of the metabolic syndrome including Type 2 diabetes mellitus (T2D), hypertension, dyslipidemia and insulin resistance, although long-term prospective data are lacking.[3–5] Estimates of prevalence of metabolic syndrome in women with PCOS are between 34 and 46%, using the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATPIII) criteria.[3–6] It is also clear that hyperandrogenism is frequently associated with T2D in women.
The importance of obesity stems from its association with comorbidities and other obesity-related conditions. As the obesity epidemic ensues, obesity-related conditions will become ever more prevalent. Obesity-related conditions are therefore relevant to all healthcare professionals and will assume even greater relevance in the future provision of healthcare. Given the frequent concurrence of PCOS and T2D and the similarities between these two common conditions, it is important to examine the link between them. In this article, we discuss the epidemiological, pathophysiological and genetic links between diabetes (both T2D and Type 1 diabetes mellitus [T1D]) and PCOS.
Women's Health. 2012;8(2):147-154. © 2012 Future Medicine Ltd.