Fasting and post-prandial glucagon like peptide 1 and oral contraception in polycystic ovary syndrome.

Objective: We aimed to investigate whether fasting and meal regulated glucagon like peptide 1 (GLP-1) secretion are altered in patients with polycystic ovary syndrome (PCOS) compared to healty women and whether oral contraceptive use influence GLP-1 secretion dynamics in the syndrome.

Design: Prospective observational study.

Patients: Fourteen lean normal glucose tolerant patients with PCOS and 11 age- and body mass index (BMI)-matched healthy women.

Measurements: Glucagon like peptide 1, glucose and insulin levels were measured during a standardized meal tolerance test and area under the curves (AUCs) were calculated. Whereas healthy controls were assessed at baseline, all tests were repeated in women with PCOS after treatment with ethinyl estradiol 30 μg/drospirenone 3 mg (EE/DRSP) for 3 months.

Results: Both fasting and post-meal levels of GLP-1 were significantly reduced in women with PCOS compared to controls (P = 0·022 and P = 0·028, respectively). AUC for GLP-1 was also lower in PCOS (P = 0·012). Glucose and insulin measurements did not show a significant change between the groups. In the PCOS group, GLP-1, glucose and insulin levels did not show any change after 3 months of EE/DRSP use.

Conclusion: GLP-1 levels both at fasting and in response to a meal are blunted in lean women with PCOS compared to healthy women. Short term oral contraception do not alter GLP-1 secretion in PCOS. Disturbance in incretin secretion dynamics might contribute to the risk of impaired glucose tolerance and type 2 diabetes in PCOS.