Background. A deficiency of D-
chiro-inositol-
inositolphosphoglycan mediator (DCI-IPG) may contribute to
insulin resistance in
polycystic ovary syndrome (PCOS). Whether the relationship between impaired DCI-IPG release and
insulin resistance is specific to PCOS rather than
obesity is unknown. We assessed
insulin-released DCI-IPG and its relationship to
insulin sensitivity at baseline and after
weight loss in obese women with and without PCOS. Methods. Obese PCOS (n = 16) and normal (n = 15) women underwent 8 weeks of a hypocaloric diet. The Matsuda index, area under the curve DCI-IPG (AUCDCI-IPG), AUCinsulin, and AUCDCI-IPG/AUCinsulin were measured during a 2 hr OGTT at baseline and 8 weeks. Results. PCOS women had lower AUCDCI-IPG/AUCinsulin at baseline and a significant relationship between AUCDCI-IPG/AUCinsulin and Matsuda index (p = 0.0003), which was not present in controls.
Weight loss was similar between PCOS (-4.08 kg) and normal women (-4.29 kg, p = 0.6281).
Weight loss in PCOS women did not change the relationship between AUCDCI-IPG/AUCinsulin and Matsuda index (p = 0.0100), and this relationship remained absent in control women. Conclusion. The association between AUCDCI-IPG/AUCinsulin and
insulin sensitivity was only found in PCOS but not in normal women, and this relationship was unaffected by
weight loss. DCI and its messenger may contribute to
insulin resistance in PCOS independent of
obesity.