Genetic and environmental factors combine with potential other contributors, including ovarian dysfunction, hyperandrogenism and hypothalamic pituitary abnormalities, to contribute to the aetiology of PCOS. Although no single genetic abnormality has been identified in PCOS, a family history of type 2 diabetes is common.

Most women with PCOS have insulin resistance. This plays a key aetiological role, contributing to reproductive (hyperandrogenism, anovulation and infertility) and metabolic features (type 2 diabetes, metabolic syndrome and cardiovascular risk factors). Insulin resistance is both genetic and lifestyle related, yet specific causes of insulin resistance and optimal therapies to address it remain unclear.

As noted, elevated insulin levels drive androgen production (table 2) and increase free androgen levels by reducing sex-hormone-binding globulin (SHBG) level. The combination of increased levels of androgens and insulin underpin the features of PCOS (figure 1).

Figure 1: Basic schema of aetiology and clinical features including reproductive, metabolic and psychosocial features of PCOS.

(Teede et al.³ Reproduced with permission.)

This article first appeared in Australian Doctor, How to treat on 29 August 2008 and has been reproduced here with permission.

 Australian Doctor, How to treat: Polycystic ovary syndrome 437.44 Kb

Content Updated 20 November, 2009