Περίληψη:
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.
RESEARCH DESIGN AND 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 S-1 (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(DCl)) 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 S-1 when all
women were analyzed together (n = 49, r = 0.50, P < 0.001) and was one
of the three best independent parameters predicting S-1. Finally, the
ratio of AUC(DCl-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.
Συγγραφείς:
Baillargeon, JP
Diamanti-Kandarakis, E
Ostlund, RE and
Apridonidze, T
Iuorno, MJ
Nestler, JE
