Clinically useful predictors of conversion to abnormal glucose tolerance in women with polycystic ovary syndrome.

Objective: To determine clinically useful predictors of conversion from normal to abnormal glucose tolerance (AGT) in women with polycystic ovary syndrome (PCOS) during regular follow-up, considering that optimal timing for retesting with an oral glucose tolerance test (OGTT) is unknown.

Design: Retrospective cohort study.

Setting: Reproductive endocrinology clinic of an academic center.

Patient(s): Glucose-tolerant PCOS women having a follow-up OGTT≥1 year later.

Intervention(s): Regular clinical follow-up.

Main Outcome Measure(s): Sets of criteria associated with the lowest false negative rate and an optimal specificity.

Result(s): Out of 83 women with PCOS, 24.1% converted to AGT during a median follow-up of 3.0 years, including 3.6% who converted to diabetes. Conversion to AGT was significantly associated with glucose excursion and 2-hour glucose during the normal OGTT, increase in fasting glucose (FG) and body mass index during follow-up, and homeostasis model-assessment insulin resistance and FG at follow-up. The best predictive set of criteria was a baseline glucose excursion of >25 mg/dL or an increase in FG of ≥5%. Using these criteria would have saved 45% of the OGTTs, without missing any conversion to AGT.

Conclusion(s): Although our results need to be validated, we determined that using glucose excursion during the previously normal OGTT in combination with another predictor (e.g., increase in FG or glycosylated hemoglobin), could greatly reduce the number of OGTTs performed in PCOS women during their regular follow-ups, with a minimal rate of missed cases.