It should be “considered only a pilot study with preliminary data,” cautioned Dr. Rosario D’Anna in an email to Reuters Health. “However, inositol seems to be an interesting supplementation, even if is usually produced by our metabolism.”
The findings are reported in a September 8 online issue of Menopause by Dr. D’Anna at the University of Messina, and colleagues. In their paper, the authors note that “inositol (either in the isoform D-chiro-inositol or as myo-inositol) has been reported to improve insulin sensitivity and ovulatory function in young women affected by polycystic ovary syndrome.”
The team tested the effect of myo-inositol in 80 postmenopausal women with metabolic syndrome. The subjects were randomized to myo-inositol 2g BID plus diet or placebo plus diet for 6 months.
The improvement in blood pressure, insulin resistance, cholesterol and triglycerides was significantly greater with myo-inositol supplements than placebo, the investigators found.
For example, the HOMA insulin resistance index dropped from 9.4 to 2.2 and from 10.6 to 7.9 in the two groups, respectively. Corresponding increases in HDL cholesterol were 9.1 mg/dL and 0.2 mg/dL, while triglycerides dropped by 54 mg/dL and 8 mg/dL.
In discussing the results, the authors suggest that certain populations may respond more to inositol supplementation than others. “Probably, people with genetic or metabolic impairment have a reduced production of endogenous inositol, and consequently might benefit of inositol supplementation,” Dr. D’Anna suggested.
Nonetheless, she and her colleagues conclude, “This first report concerning myo-inositol supplementation for 6 months in postmenopausal women affected by metabolic syndrome demonstrated that it may improve some of the metabolic features of the syndrome such as carbohydrate metabolism, lipid profile, and blood pressure.”