September 10, 2018
2 min read

CoQ10 plus vitamin E improves metabolic profile in PCOS

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Women with polycystic ovary syndrome randomly assigned to 8 weeks of coenzyme Q10 plus vitamin E supplementation experienced an improvement in glycemic and anthropometric measures vs. women assigned to either supplement alone, according to findings published in The Journal of Clinical Endocrinology and Metabolism.

Recent research has suggested that serum concentrations of coenzyme Q10 (CoQ10) correlate with the alpha-tocopherol isoform of vitamin E, and that CoQ10 found in cellular membranes could prevent the oxidation of alpha-tocopherol and may be involved in its regeneration, Azimeh Izadi, PhD candidate in the department of biochemistry and diet therapy at Tabriz University of Medical Sciences in Tehran, Iran, and colleagues wrote in the study background.

“It is hypothesized that the co-supplementation of CoQ10 and vitamin E might have a strong, synergistic effect on metabolic profile and co-supplementation may work better than a single supplementation alone,” the researchers wrote. “Therefore, we evaluated the independent and additive effects of CoQ10 and vitamin E on insulin resistance and sex hormone concentrations among patients with PCOS.”

In a randomized, double-blind, placebo-controlled trial, Izadi and colleagues analyzed data from 86 women with PCOS who were assigned to one of four groups for 8 weeks: 200 mg daily CoQ10 plus vitamin E placebo (n = 22); 400 IU daily vitamin E plus CoQ10 placebo (n = 22); 200 mg CoQ10 plus 400 IU vitamin E daily (n = 21); and CoQ10 placebo plus vitamin E placebo (n = 21). All patients were prescribed metformin at baseline (1,500 mg daily). Researchers asked patients to maintain their diet and physical activity levels and avoid taking antioxidant supplements or anti-inflammatory medications for the duration of the study. Participants completed three 24-hour dietary recalls, completed physical activity questionnaires and provided fasting blood samples to measure serum glucose, insulin, follicle-stimulating hormone, luteinizing hormone, testosterone, sex hormone-binding globulin, progesterone and estradiol. Researchers also calculated free androgen index and insulin resistance via homeostatic model assessment of insulin resistance (HOMA-IR). Researchers used analysis of covariance to determine the effects of supplementation on anthropometric variables and hormone concentrations, and linear regression analysis to measure the association between changes in glucose homeostasis parameters and changes in free androgen index.

Researchers found CoQ10 supplementation, either alone or combined with vitamin E, was associated with an improved fasting blood glucose and improvement in insulin resistance vs. placebo. Results persisted after adjustment for age, BMI, physical activity and baseline values. CoQ10, vitamin E and co-supplementation, when compared with placebo, were associated with decreased total testosterone levels (P < .001), according to researchers. Additionally, CoQ10 supplementation, combined with vitamin E, was associated with improvement in SHBG vs. all other groups (P = .008); however, CoQ10 or vitamin E alone did not affect SMBG.


In linear regression analysis, researchers found that changes in fasting blood glucose, insulin and HOMA-IR were predictors of a change in free androgen index (P < .05).

“The current clinical trial showed that CoQ10 with or without vitamin E supplementation for 8 weeks among patients with PCOS resulted in a significant reduction in serum [fasting blood glucose] and HOMA-IR,” the researchers wrote. “However, the changes observed in glucose homeostasis parameters following vitamin E supplementation did not reach statistical significance.”

The researchers noted that changes in insulin resistance were associated with changes in free androgen index, confirming the hypothesis that insulin resistance is one of the major pathological mechanisms of PCOS. – by Regina Schaffer

Disclosures: The authors report no relevant financial disclosures.