title: Metformin therapy increases insulin-stimulated release of D-chiro-inositol-containing inositolphosphoglycan mediator in women with polycystic ovary syndrome.
abstract: Some actions of insulin are mediated by putative inositolphosphoglycan mediators, and a deficiency in D-chiro-inositol-containing inositolphosphoglycan (DCI-IPG) may contribute to insulin resistance in women with polycystic ovary syndrome (PCOS). Furthermore, similar effects of DCI and metformin, an insulin-sensitizing drug, have been demonstrated in PCOS women. To determine whether metformin improves insulin actions by increasing biologically active DCI-IPG in women with PCOS, we analyzed DCI-IPG during an oral glucose tolerance test in 19 obese women with PCOS before and after 4-8 wk of metformin or placebo. After treatment, the mean (+/-SE) area under the curve (AUC) during the oral glucose tolerance test of insulin (AUC(insulin)) decreased significantly more in the metformin group, compared with the placebo group [-3574 +/- 962 vs. +1367 +/- 1021 micro IU/min.ml (-26 +/- 7 vs. +10 +/- 7 nmol/min.liter), P = 0.003], but the AUC of DCI-IPG (AUC(DCI-IPG)) decreased similarly in both groups (-1452 +/- 968 vs. -2207 +/- 1021%/min, P = 0.60). However, the ratio of AUC(DCI-IPG)/AUC(insulin) increased by 160% after metformin and decreased by 29% after placebo (P = 0.002 between groups). Moreover, metformin seemed to improve the positive correlation between AUC(DCI-IPG) and AUC(insulin) but not placebo (r = 0.32, P = 0.68 at baseline; r = 0.52, P = 0.12 after metformin; and r = -0.39, P = 0.30 after placebo). We conclude that in obese women with PCOS, metformin may improve the action of insulin in part by improving insulin-mediated release of DCI-IPG mediators, as evidenced by increased bioactive DCI-IPG released per unit of insulin.
authors.affiliation: Department of Medicine, Université de Sherbrooke, Sherbrooke, J1H SN4 Canada.
authors.forename: Jean-Patrice
authors.initials: JP
authors.lastname: Baillargeon
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Iuorno
authors.forename: Daniela J
authors.initials: DJ
authors.lastname: Jakubowicz
authors.forename: Teimuraz
authors.initials: T
authors.lastname: Apridonidze
authors.forename: Na
authors.initials: N
authors.lastname: He
authors.forename: John E
authors.initials: JE
authors.lastname: Nestler
mesh_terms: D000293:Adolescent; D000328:Adult; D019540:Area Under Curve; D015992:Body Mass Index; D001835:Body Weight; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D007295:Inositol Phosphates / Q000097:blood / Q000378:metabolism*; D007328:Insulin / Q000097:blood / Q000494:pharmacology*; D008687:Metformin / Q000627:therapeutic use*; D009765:Obesity / Q000150:complications / Q000503:physiopathology; D010919:Placebos; D011085:Polycystic Ovary Syndrome / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D011134:Polysaccharides / Q000097:blood / Q000378:metabolism*; D013739:Testosterone / Q000097:blood
chemical_list: D007004:Hypoglycemic Agents; D007295:Inositol Phosphates; D007328:Insulin; D010919:Placebos; D011134:Polysaccharides; C028039:inositol phosphate glycan; D013739:Testosterone; D008687:Metformin