PCOS is reported in 5% to 20% of reproductive aged women, making it the most common endocrine disorder and one of the most common causes of infertility in women.
According to a recent study published in Reproductive Biology and Endocrinology, inositol is safe and effective against polycystic ovary syndrome (PCOS).1
PCOS is reported in 5% to 20% of reproductive aged women, making it the most common endocrine disorder and one of the most common causes of infertility in women. It is diagnosed if 2 of the 3 criteria are met: hyperandrogenism, ovulatory dysfunction, and polycystic ovary morphology.
While the pathogenesis of PCOS is not fully understood, insulin resistance (IR) is vital to its pathogenesis. Data has indicated IR in 75% of lean and 95% of overweight women with PCOS, with 60% to 70% of women with PCOS being overweight and IR being more severe in obese women.
Inositols, insulin sensitizers in the vitamin B complex group, have positive effects on menstrual cycle regularity, carbohydrate metabolism, and laboratory and clinicalsymptoms of hyperandrogenism. However, evidence supporting inositol for treating PCOS is lacking.
To determine the safety and efficacy of inositol against PCOS, investigators conducted a systematic review and meta-analysis. Menstrual cycle normalization was measured as the primary outcome of the analysis. Secondary outcomes included pregnancy rate, body mass index (BMI), carbohydrate metabolism, clinical and laboratory hyperandrogenism, and treatment side effects.
Eligibility criteria for randomized controlled trials (RCTs) included comparing the safety and efficacy of inositols vs placebo or metformin in women with PCOS, diagnosing PCOS based on Rotterdam or corresponding criteria, and having monotherapy inositol or inositol in combination with dietary supplements or aromatase inhibitors as the primary intervention.
RCTs were found through searches of MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases through October 20th, 2021. Articles were extracted by 2 independent reviewers, with screening being initially based on the title and abstract, then the full text through eligibility criteria.
Data extracted included title, first author, year of publication, countries, number of centers, study design, main study findings, patient demographics, inclusion and exclusion criteria, details regarding the population, intervention, comparator, and outcome, and event rates.
There were 26 RCTs included in the final analysis, containing 1691 women with PCOS. On average, women were aged between 30 and 39 years and had a BMI under 30 kg/m2. Differences in the dose and length of intervention administration were observed between trials.
The inositol group showed increased rates of cycle normalization compared to the placebo, with a relative risk of 1.79. Inositol also showed a greater reduction in BMI compared to placebo, especially when myoinositol was administrated. The mean differences (MDs) in BMI reduction for inositol and myoinositol were -0.45 kg/m2 and -0.71 kg/m2 respectively.
Total testosterone levels were significantly reduced by inositol, with an MD of -20.39. Inositol also significantly reduced fasting plasma glucose levels, with an MD of -3.14. Significant decreases in the area under the receiver operating characteristic curve insulin levels were observed among patients receiving inositol.
Eight RCTs reported pregnancy rates.Inositols without additional therapy did not significantly impact pregnancy rates compared to placebo, nor did inositol followed by additional therapy. Similar outcomes were also observed when comparing inositol to metformin.
Adverse events were less common in the inositol group than the metformin group. Side effects of metformin included nausea, bloating, and generalized weakness.
These results indicated positive outcomes from inositol against PCOS. Investigators recommended inositols be included in the guidelines for treating PCOS.