Metabolic Effects of a Commonly Used Combined Hormonal Oral Contraceptive in Women With and Without Polycystic Ovary Syndrome.

BACKGROUND: Data on combined hormonal oral contraceptives' (OCs) effects on metabolic changes in women with polycystic ovary syndrome (PCOS) have been conflicting and were predominantly based on OCs with cyproterone acetate (unavailable in the United States) Most studies did not include normal women as controls. We compared metabolic changes before and after an OC commonly used in the United States between women with and without PCOS.
METHODS: Ten PCOS and 20 control women took ethinyl estradiol 35 μg and norgestimate 0.18/0.215/0.25 mg. Fasting glucose and insulin, area-under-the-curve (AUC) glucose and insulin, insulin sensitivity (homeostatic model assessment of insulin sensitivity index [HOMA-ISI] and Matsuda index), insulinogenic index (Δinsulin0-30 minutes/Δglucose0-30 minutes), blood pressure, and lipids were evaluated at baseline and after three cycles of OC.
RESULTS: At baseline, PCOS women had lower insulin sensitivity (Matsuda index p = 0.0093, HOMA-ISI p = 0.0397), higher fasting insulin (p = 0.0495), fasting glucose (p = 0.0393), AUC insulin (p = 0.0023), and triglycerides (p = 0.0044) versus controls. Baseline AUC glucose did not differ between PCOS women and controls. After 3 months of OC use, glucose tolerance worsened in PCOS women versus controls (p = 0.0468). Higher baseline androgens were predictive of worsened glucose tolerance, and a reduction of AUC insulin during OC use. The insulinogenic index significantly decreased in PCOS women (p < 0.01), while fasting insulin and insulin resistance significantly worsened in control women.
CONCLUSION: Women with PCOS exhibited worsened glucose tolerance (demonstrated by AUC glucose) after 3 months of a commonly used OC compared with control women. Larger studies with longer follow-up should confirm these findings.