Effects of D-chiroinositol added to a meal on plasma glucose and insulin in hyperinsulinemic rhesus monkeys.

We have previously demonstrated that D-chiroinositol, administered intravenously to insulin-resistant monkeys, increases the rate of disappearance of plasma glucose and insulin. The purpose of the present study was to determine whether orally administered D-chiroinositol might also similarly improve the postprandial plasma glucose profile of hyperinsulinemic insulin-resistant monkeys. A complete liquid diet meal (15 ml/kg body weight) was ingested by each of six monkeys on two occasions separated by 10 days, with conditions identical except D-chiroinositol (500 mg/kg body weight) was added to the second meal. At 110 minutes following each meal, the monkeys were anesthetized and blood samples obtained at 120, 150, 180, 210, 240, 270 and 300 minutes. Plasma glucose and insulin concentrations were determined. The mean plasma glucose concentration (120-300 minutes) was significantly lower after the meal containing D-chiroinositol compared to the control meal (7.1 +/- 1.2 vs. 7.8 +/- 1.2 mM) (p < 0.05). Plasma insulin concentrations tended to be lower after the meal containing D-chiroinositol compared to the control meal (3930 +/- 1068 vs. 4518 +/- 1200 pM) (p < 0.15, ns). We conclude that in hyperinsulinemic monkeys, D-chiroinositol added to a meal lowers postprandial plasma glucose without an increase in plasma insulin, and therefore may be a useful agent for reducing meal-induced hyperglycemia without inducing hyperinsulinemia.