D-pinitol improves glycemic control in diabetics.

Twenty patients (mean age, 65.5 years; mean body mass index, 26.3 kg/[m.sup.2]) with type 2 diabetes that was poorly controlled on sulfonylurea, Metformin, and/or insulin therapy received D-pinitol at a dose of 20 mg per kg of body weight per day for 12 weeks, while continuing their usual medication. The mean fasting plasma glucose concentration decreased from 200 mg/dl at baseline to 169 mg/dl after 12 weeks (15.5% decrease; p < 0.05). The mean hemoglobin A1c concentration decreased from 9.8% to 8.3% (15.3% decrease; p < 0.05).

Comment: D-chiro-inositol, a stereoisomer of myoinositol (commonly known as inositol), is a component of an endogenous phosphoglycan that has been reported to mediate the action of insulin. D-Pinitol (3-O-methyl-D-chiro-inositol) occurs naturally in several foods such as legumes and citrus fruits and has a chemical structure and biochemical actions similar to those of D-chiro-inositol. In addition, D-pinitol is probably converted to D-chiro-inositol in vivo, as demonstrated by a 14-fold increase in the mean serum concentration of D-chiro-inositol after administration of D-pinitol to diabetic patients. The results of the present study confirm an earlier report (Eur J Clin Nutr. 2005;59:456-458) showing that supplementation with D-pinitol improves glycemic control in patients with type 2 diabetes. Since D-pinitol appears to mediate the action of insulin, rather than enhance the binding of insulin to its receptor, D-pinitol's effects on glycemic control might be additive to those of chromium, which is believed to work by facilitating insulin binding to its receptor.

Kim MJ, et al. Effect of pinitol on glucose metabolism and adipocytokines in uncontrolled type 2 diabetes. Diabetes Res Clin Pract. 2007;77(Suppl 1):S247-S251.