Oral glucose tolerance test should be recommended as the screening method for dysglycaemia in all Southern Chinese women with polycystic ovary syndrome

Abstract

OBJECTIVES: Polycystic ovary syndrome (PCOS) is commonly associated with abnormal glucose metabolism. There have been debates on whether fasting glucose (FG) or an oral glucose tolerance test (OGTT) should be used as a screening method for dysglycaemia in this group of women. There has been little evidence on the screening strategy for dysglycaemia in women with PCOS in the Southern Chinese population. This study reviewed the performance of FG and OGTT in diagnosing dysglycaemia in a cohort of Hong Kong Chinese women with PCOS, with or without additional consideration of BMI and family history of DM. METHOD: We prospectively recruited 467 Hong Kong Chinese women diagnosed with PCOS by the Rotterdam criteria during April 2011 to March 2013. All subjects attended the clinic within the first 5 days of spontaneous or induced menstruation after overnight fasting for a 75g 2-hour OGTT. Impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and diabetes mellitus (DM) were defined according to the American Diabetes Association (2010) criteria; these categories were collectively referred to as dysglycaemia (i.e. FG≥5.6 mmol/l or 2h glucose ≥7.8 mmol/l) in the current study. Individuals with IFG and/or IGT were referred to as having pre-diabetes. RESULTS: Among the recruited subjects, 58 (12.4%) had dysglycaemia (46 pre-diabetes and 12 DM, including 4 having pre-existing DM). Out of the 46 subjects with pre-diabetes, 25 (54.3%) had normal FG, and of the 8 subjects with screened DM in this study, 1 (12.5%) had normal FG. The sensitivity of FG alone in screening for pre-diabetes, DM and overall dysglycaemia were 45.7%, 87.5% and 48.1% respectively. Among the 58 subjects with screened dysglycaemia, 20 (34.5%) had BMI <25 kg/m2 and 35 (60.3%) had no family history of DM. CONCLUSIONS: The use of FG alone could miss 54.3% of pre-diabetes and 12.5% of DMcases among Chinese women with PCOS. A full OGTT should be recommended as the screening method for dysglycaemia in women with PCOS regardless of the BMI or family history of DM.