Effects of ubiquinol on metabolic profile in prediabetic patients: A randomized, double-blinded, placebo-controlled pilot study

Background/objectives: Prediabetes not only increase the risk of developing diabetes, but it is also associated with the development of cardiovascular disease, chronic kidney disease, neuropathy, and retinopathy. Oxidative stress is a well-known contributor to its pathogenesis. This study aimed to examine the potential benefit effect of ubiquinol supplementation, a lipophilic antioxidant, on metabolic profile in prediabetic patients. Methods: This prospective, randomized, double-blind, placebo-controlled pilot study enrolled 20 adults with impaired fasting plasma glucose (FPG), who were randomly assigned to receive ubiquinol (100 mg per day) or placebo. Metabolic profile including FPG, hemoglobin A1C (HbA1C), fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR), total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglyceride (TG) was assessed after 12-week treatment period. Between-group differences were analyzed according to the intention-to-treat principle, with effect sizes calculated to estimate the magnitude of observed effects. Results: HOMA-IR was significantly lower in ubiquinol group compared to placebo group at week 12 (P = 0.028), with a moderate effect size (r =0.490). Median (range) HOMA-IR reduced from 2.23 (0.97) to 1.66 (0.39) for ubiquinol group while increased from 2.20 (0.90) to 2.35 (1.90) for placebo group. No significant difference in other outcome was reported. However, moderate-to-large effect sizes were observed for FPG, HbA1C, and fasting insulin. Conclusions: Daily supplementation of 100-mg ubiquinol for 12 weeks improves insulin sensitivity for prediabetic patients with a favorable safety profile. The observed effect sizes support further investigation in larger, adequately powered trials to confirm the metabolic effects of ubiquinol.