Impaired glucose tolerance and polycystic ovary syndrome

• prevalence study of a cohort of women with PCOS (1)
• 122 women with PCOS were recruited from hospital clinics
  • a prospective study was undertaken with a subset of 25 women to determine the natural history of glucose intolerance in PCOS.
• an oral glucose tolerance test was undertaken - 10% of women had type 2 diabetes and 35% had impaired glucose tolerance.
• a repeat oral glucose tolerance test was performed on the subset of 25 women after a mean follow-up of 2.4 years; two-hour glucose levels were higher (significance level p<0.02) but in some of the women glucose tolerances had improved

There is evidence that for patients with PCOS, Sex hormone binding globulin (SHBG) is an integrated marker of insulin resistance that may be of use to identify insulin-resistant individuals (2).

Screening for glucose intolerance (3):

• it is recommended that women presenting with PCOS, particularly if they are obese (BMI>30), have a strong family history of type 2 diabetes, or are over the age of 40 years, be offered a glucose tolerance test as they are at increased risk for type 2 diabetes
• annual fasting glucose may be useful in screening for diabetes in women with PCOS. If the fasting glucose is >=5.6 mmol/l and the patient has other risk factors for diabetes, an oral glucose tolerance test is recommended

Reference:

• (1) Diabetes Care (1999), 22, 141-6.
• (2) J Clin Endocrinol Metab. 2003 Apr;88(4):1528-33.
• (3) RCOG (2007) Long-term consequences of polycystic ovary syndrome.