Endocrine Abstracts

Introduction: Impaired glucose regulation (IGR) is usually defined as impaired fasting glucose (IFG, fasting plasma glucose (FPG) is between 6.1 to 6.9 mmol/L) and/or impaired glucose tolerance (IGT, 2 hour postprandial glucose (PPG) is 7.8 to 11 mmol/L). More recently, a haemoglobin A1c (HbA1c) ≥ 42 but <47 mmol/mol has been suggested to indicate an increased diabetes risk. Women with polycystic ovary syndrome (PCOS) are strongly associated with insulin resistance and a family history of diabetes, and are at risk of diabetes. Early recognition of IGR and appropriate intervention are essential to prevent or delay the onset of diabetes. We therefore investigated the usefulness of HbA1c in diagnosing IGR in PCOS. Methods Sixty-one sequential, treatment naïve, women with PCOS and 21 controls who have had an OGTT and a HbA1c test were included.

Results: PCOS patients and healthy controls were well matched for age (mean ±SD) 32.3±7.1 vs 30.1± 8.0 years (P=0.2) and body mass index (BMI) 33.2± 5.7 vs 30.5± 7.17 kg/m2 (P=0.1). FPG (4.9± 0.6vs 4.9± 0.5 mmol/L, P=0.7) were comparable between groups. PPG (6.1± 1.8 vs 5.1± 1.9 mmol/L), triglycerides (TG) (1.2± 0.5 vs 1.0± 0.5 mmol/L) were significantly higher and high density lipoprotein -cholesterol (HDL) (1.1± 0.3 vs 1.3± 0.4 mmol/L) lower in PCOS than in controls (P<0.05). HbA1c correlated with FPG (r=0.46 P<0.001), PPG(r=0.29 P=0.02), TG (r=0.19 P=0.05), HDL(r=−0.3 P=0.02) and BMI (r=0.56, P<0.001) in PCOS. All the subjects without IGR except one PCOS patient had HbA1c <42 mMol/mol. Thirteen of 61 (IFG =3, IGT = 9, DM=1) in PCOS and 2 of 21(all IGT) in controls had IGR. None of PCOS patients with IGR had HbA1c above 42 mMol/mol. One control with IGT had HbA1c >42 mMol/mol.

Conclusion: HbA1c was insensitive in detecting IGR amongst PCOS patients in this study and so is not suited to detecting small degrees of dysglycaemia in this population.

Declaration of interest: There is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.

Funding: No specific grant from any funding agency in the public, commercial or not-for-profit sector.