Urinary chiro-inositol excretion is an index marker of insulin sensitivity in Japanese type II diabetes

Abstract

Objective: To determine the relationship between urinary chiro-inositol excretion and insulin sensitivity in Japanese type II diabetic patients.

Research design and methods: Eighteen subjects were age-matched, nonobese, type II diabetic patients. Eight subjects had impaired glucose tolerance (IGT), and 10 had normal glucose tolerance (NGT). We quantified urinary chiro-inositol excretion using gas chromatography-mass spectrometry and the insulin sensitivity index (SI), and glucose effectiveness (SG) using Bergman's modified minimal model method.

Results: The urinary excretion of chiro-inositol was much lower in the diabetic patients (32.3 +/- 16.0 mumol/day, means +/- SD) than in the NGT subjects (96.0 +/- 17.6; P < 0.0001) and IGT subjects (58.9 +/- 11.6; P < 0.0001). SI was much lower in the diabetic patients (3.81 +/- 1.49) than in the NGT subjects 6.30 +/- 1.59, P < 0.0005). SG was much lower in the diabetic patients (2.14 +/- 0.56) than in the NGT subjects (3.07 +/- 0.38, P < 0.0001). There was a significant correlation between urinary chiro-inositol excretion and SI (r = 0.766), as well as a significant correlation between urinary chiro-inositol excretion and SG (r = 0.747).