What is diabetes risk in slim women with PCOS?
Q - If a woman has PCOS but remains slim, what are her chances of becoming diabetic with age?
A - PCOS is a very heterogeneous condition and each clinical profile has to be considered on its own merit. For instance, infertility is commonly presumed to affect many women with PCOS but only the minority with major menstrual disturbance face this prospect.
Similarly, transition to diabetes for women with PCOS has gained a lot of attention recently, particularly with the fashion for using metformin.
Many women have now gained the impression that diabetes and heart disease are inevitable late sequelae of the syndrome. Certainly, obese women with a first-degree relative with diabetes are at increased risk of acquiring type 2 diabetes perhaps greater than 70 per cent chance.
It is likely only a subgroup of women with PCOS have a 'metabolic syndrome' and many will escape insulin resistance which is probably genetically programmed separately from the inheritance of PCOS.
If insulin resistance and the polycystic morphology coexist then insulin drive to the ovary becomes clinically manifest. The physiological explanation is that insulin directly stimulates ovarian theca cells to make testosterone. Other women are programmed to have more impressive PCOS symptoms without the drive circulating insulin.
So, our slim women with PCOS should be assessed for other risk factors for diabetes, of which family history is the most important. Counselling on diabetes prevention should be done as her phenotype of being overweight may emerge later. In the absence of any other marker her risk of acquiring diabetes is probably not greatly raised.
Dr Gerard Conway is consultant endocrinologist, UCL Hospitals NHS Trust, The Middlesex Hospital, London