DiNicolantonio, J. J., & H O'Keefe, J. (2022). Myo-inositol for insulin resistance, metabolic syndrome, polycystic ovary syndrome and gestational diabetes. Open heart, 9(1). https://doi.org/10.1136/openhrt-2022-001989
DiNicolantonio JJ, H O'Keefe J. Myo-inositol for insulin resistance, metabolic syndrome, polycystic ovary syndrome and gestational diabetes. Open heart. 2022;9(1). doi:10.1136/openhrt-2022-001989
DiNicolantonio, J. J., and J. H O'Keefe. "Myo-inositol for insulin resistance, metabolic syndrome, polycystic ovary syndrome and gestational diabetes." Open heart, vol. 9, no. 1, 2022.
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RRM Academy Synopsis
Myo-inositol may improve ovulation and insulin resistance in PCOS
This paper summarizes results from other papers and presents no new study of its own. The authors gather trial results on myo-inositol for insulin resistance and PCOS, now also called PMOS, plus metabolic syndrome and gestational diabetes. Some small trials found that myo-inositol helped ovulation and blood sugar markers in women with PCOS.
Key Findings
Obese women with PCOS took D-chiro-inositol for eight weeks. 86% ovulated, versus 27% on placebo.
In a 12-week trial of 50 overweight women with PCOS, myo-inositol restored regular cycles in those with irregular or missing periods. Folic acid alone did not.
In another trial, 61.7% of women with PCOS ovulated after taking myo-inositol. Among those who did not respond, adding a fertility drug raised ovulation to 72.2%.
Among pregnant women with a close relative who had type 2 diabetes, myo-inositol lowered the gestational diabetes rate to 6.0%, versus 15.3% on placebo.
In an 80-woman trial of postmenopausal women with metabolic syndrome, myo-inositol led 8 women (20%) to no longer meet the criteria for it. Only 1 in the control group did.
Interpretation
This paper summarizes other research published in a heart journal and presents no trial of its own. The authors gather findings from earlier trials and reviews on myo-inositol. They do not re-check the studies or grade how strong each one is. Where a group size is given, the PCOS, gestational diabetes, and metabolic syndrome trials run from about 50 to 80 women. Some other trials named in the paper give no group size. Because this paper adds no new data, its claims rest entirely on those earlier trials; the paper can report only that some trials found the changes described, and it cannot prove that myo-inositol caused them.
RRM Context
Insulin resistance often stops ovulation in PCOS. PCOS is also called PMOS, short for polyendocrine metabolic ovarian syndrome. Fixing insulin resistance fits the root-cause approach Restorative Reproductive Medicine takes to this diagnosis. Cycle charting and hormone tests help show a woman's pattern in that approach. The paper centers on inositols and does not discuss charting or how a clinician should pick or order tools.
Our editorial summary of this paper, not the article's abstract.
Several inositol isomers and in particular myo-inositol (MI) and D-chiro-inositol (DCI), were shown to possess insulin-mimetic properties and to be efficient in lowering post-prandial blood glucose. In addition, abnormalities in inositol metabolism are associated with insulin resistance and with long term microvascular complications of diabetes, supporting a role of inositol or its derivatives in glucose metabolism. The aim of this review is to focus on the potential benefits of a dietary supplement of myo-inositol, by far the most common inositol isomer in foodstuffs, in human disorders associated with insulin resistance (polycystic ovary syndrome, gestational diabetes mellitus or metabolic syndrome) or in prevention or treatment of some diabetic complications (neuropathy, nephropathy, cataract). The relevance of such a nutritional strategy will be discussed for each context on the basis of the clinical and/or animal studies. The dietary sources of myo-inositol and its metabolism from its dietary uptake to its renal excretion will be also covered in this review. Finally, the actual insights into inositol insulin-sensitizing effects will be addressed and in particular the possible role of inositol glycans as insulin second messengers.
Metabolic and Endocrine Agents · Insulin Sensitizing Agents
To evaluate whether myo-inositol supplementation, an insulin sensitizer, reduces the rate of gestational diabetes mellitus (GDM) and lowers insulin resistance in obese pregnant women. In an open-label, randomized trial, myo-inositol (2 g plus 200 micrograms folic acid twice a day) or placebo (200 micrograms folic acid twice a day) was administered from the first trimester to delivery in pregnant obese women (prepregnancy body mass index 30 or greater. We calculated that 101 women in each arm would be required to demonstrate a 65% GDM reduction in the myo-inositol group with a statistical power of 80% (α=0.05). The primary outcomes were the incidence of GDM and the change in insulin resistance from enrollment until the diagnostic oral glucose tolerance test. From January 2011 to April 2014, 220 pregnant women at 12-13 weeks of gestation were randomized at two Italian university hospitals, 110 to myo-inositol and 110 to placebo. Most characteristics were similar between groups. The GDM rate was significantly reduced in the myo-inositol group compared with the control group, 14.0% compared with 33.6%, respectively (P=.001; odds ratio 0.34, 95% confidence interval 0.17-0.68). Furthermore, women treated with myo-inositol showed a significantly greater reduction in the homeostasis model assessment of insulin resistance compared with the control group, -1.0±3.1 compared with 0.1±1.8 (P=.048). Myo-inositol supplementation, started in the first trimester, in obese pregnant women seems to reduce the incidence in GDM through a reduction of insulin resistance. CLINICAL ClinicalTrials.gov, www.clinicaltrials.gov, NCT01047982.
Metabolic and Endocrine Agents · Insulin Sensitizing Agents
Santamaria A et al., 2015·J Matern Fetal Neonatal Med
To evaluate whether myo-inositol supplementation may reduce gestational diabetes mellitus (GDM) rate in overweight women. In an open-label, randomized trial, myo-inositol (2 g plus 200 μg folic acid twice a day) or placebo (200 μg folic acid twice a day) was administered from the first trimester to delivery in pregnant overweight non-obese women (pre-pregnancy body mass index ≥ 25 and < 30 kg/m(2)). The primary outcome was the incidence of GDM. From January 2012 to December 2014, 220 pregnant women were randomized at two Italian University hospitals, 110 to myo-inositol and 110 to placebo. The incidence of GDM was significantly lower in the myo-inositol group compared to the placebo group (11.6% versus 27.4%, respectively, p = 0.004). Myo-inositol treatment was associated with a 67% risk reduction of developing GDM (OR 0.33; 95% CI 0.15-0.70). Myo-inositol supplementation, administered since early pregnancy, reduces GDM incidence in overweight non-obese women.
Metabolic and Endocrine Agents · Insulin Sensitizing Agents
Greff D et al., 2023·Reprod Biol Endocrinol·Free full text on PubMed Central
Metformin is the gold standard insulin sensitizer, which is widely used to treat insulin resistance in polycystic ovary syndrome (PCOS). However, metformin may induce gastrointestinal side effects. Inositols have long been debated as a potential alternative for metformin in treating PCOS. Therefore, the present systematic review aimed to evaluate the efficacy and safety of inositols in treating PCOS. The present systematic search was performed in CENTRAL, MEDLINE, and Embase from the inception until October 20th, 2021. Eligible randomized controlled trials (RCTs) included women diagnosed with PCOS and compared any inositols with metformin or placebo. Our primary outcome was cycle normalization, whereas secondary outcomes were body mass index (BMI), parameters of carbohydrate metabolism and clinical and laboratory hyperandrogenism. Results are reported as risk ratios or mean differences (MDs) with 95% confidence intervals (CIs). Twenty-six RCTs were identified, including data of 1691 patients (806 inositol, 311 with placebo, and 509 metformin groups). In patients treated with inositols, the risk (CI: 1.13; 2.85) of having a regular menstrual cycle was found by 1.79 higher than in the case of placebo. Moreover, the inositols showed non-inferiority compared to metformin in this outcome. In the case of BMI (MD = -0.45; CI: -0.89; -0.02), free testosterone (MD = -0,41, CI: -0.69; -0.13), total testosterone (MD = -20.39, CI: -40.12; -0.66), androstenedione (MD = -0.69, CI: -1,16; -0.22), glucose (MD = -3.14; CI: -5.75; -0.54) levels and AUC insulin (MD = -2081.05, CI: -2745.32; -1416.78) inositol treatment induced greater decrease compared to placebo. Inositol increased sex-hormone-binding globulin significantly compared to placebo (MD = 32.06, CI:1.27; 62.85). Inositol is an effective and safe treatment in PCOS. Moreover, inositols showed non-inferiority in most outcomes compared to the gold standard treatment; metformin. PROSPERO registration number: CRD42021283275.
Therapeutics › Metabolic and Endocrine Agents › Insulin Sensitizing Agents · Lifestyle and Environment › Nutrition and Metabolic Health › Blood Sugar and Insulin
PMID 35236761 35236761 DOI 10.1136/openhrt-2022-001989 10.1136/openhrt-2022-001989 DiNicolantonio et al. 2022, DiNicolantonio 2022
Cite this article
DiNicolantonio, J. J., & H O'Keefe, J. (2022). Myo-inositol for insulin resistance, metabolic syndrome, polycystic ovary syndrome and gestational diabetes. Open heart, 9(1). https://doi.org/10.1136/openhrt-2022-001989
DiNicolantonio JJ, H O'Keefe J. Myo-inositol for insulin resistance, metabolic syndrome, polycystic ovary syndrome and gestational diabetes. Open heart. 2022;9(1). doi:10.1136/openhrt-2022-001989
DiNicolantonio, J. J., and J. H O'Keefe. "Myo-inositol for insulin resistance, metabolic syndrome, polycystic ovary syndrome and gestational diabetes." Open heart, vol. 9, no. 1, 2022.