title: Altered D-chiro-inositol urinary clearance in women with polycystic ovary syndrome.
abstract: OBJECTIVE
  Evidence suggests that some actions of insulin are effected by inositolphosphoglycan (IPG) mediators. We hypothesize that a deficiency in D-chiro-inositol (DCI) and/or a DCI-containing IPG (DCI-IPG) may contribute to insulin resistance in humans.
  
  
  METHODS
  To assess this possibility in polycystic ovary syndrome (PCOS), we determined insulin sensitivity (Si by frequently sampled intravenous glucose tolerance test), plasma and urinary DCI and myo-inositol (MYO) levels (by gas chromatography/mass spectrometry), and the release of insulin and DCI-IPG during the oral glucose tolerance test (area under the curve [AUC]) in 23 women with PCOS and 26 normal women.
  
  
  RESULTS
  Women with PCOS were heavier than control subjects (P = 0.002 for BMI), but also had decreased Si (P < 0.001) and increased AUC(insulin) (P < 0.001) compared with normal women, even when corrected for BMI. The urinary clearance of DCI (uCl(DCI)) was increased almost sixfold in PCOS compared with normal women (P = 0.001), but not MYO clearance (P = 0.10). uCl(DCI) correlated inversely with Si when all women were analyzed together (n = 49, r = -0.50, P < 0.001) and was one of the three best independent parameters predicting Si. Finally, the ratio of AUC(DCI-IPG) to AUC(insulin) was decreased threefold in women with PCOS (P < 0.001).
  
  
  CONCLUSIONS
  uCl(DCI) is inversely correlated with insulin sensitivity in women and is a strong independent predictor of insulin resistance in multivariate models. PCOS, which is characterized by insulin resistance, is associated with a selective increase in uCl(DCI) and impaired DCI-IPG release in response to insulin. These findings are consistent with a defect in tissue availability or utilization of DCI in PCOS that may contribute to the insulin resistance of the syndrome.
authors.affiliation: Department of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada. jp.baillargeon@usherbrooke.ca
authors.forename: Jean-Patrice
authors.initials: JP
authors.lastname: Baillargeon
authors.forename: Evanthia
authors.initials: E
authors.lastname: Diamanti-Kandarakis
authors.forename: Richard E
authors.initials: RE
authors.lastname: Ostlund
authors.forename: Teimuraz
authors.initials: T
authors.lastname: Apridonidze
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Iuorno
authors.forename: John E
authors.initials: JE
authors.lastname: Nestler
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001794:Blood Pressure; D015992:Body Mass Index; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007294:Inositol / Q000097:blood / Q000652:urine*; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance / Q000502:physiology*; D016015:Logistic Models; D015999:Multivariate Analysis; D011085:Polycystic Ovary Syndrome / Q000378:metabolism* / Q000503:physiopathology; D013739:Testosterone / Q000097:blood; D049629:Waist-Hip Ratio
chemical_list: D007328:Insulin; D013739:Testosterone; D007294:Inositol