Reduced Form of Coenzyme Q10 Relieves Daily Life Stress and Improves Sleep Quality in Healthy Subjects with High Stress Sensitivity ―A Randomized, Double—blind, Parallel—group Study―

Objective　This randomized, double-blind, parallel-group study examined the effects of a reduced form of coenzyme Q10（ubiquinol）on stress and sleep in healthy subjects. Methods　Subjects were randomly allocated to two groups and received test food containing 100 mg ubiquinol or placebo every day for 8 weeks. Primary outcome measures were scores on the Brief Job Stress Questionnaire and the Japanese version of the Epworth Sleepiness Scale. Secondary outcome measures were OSA sleep inventory MA version（OSA-MA）scores; visual analogue scale （VAS）scores for stress, sleep, and fatigue; and autonomic nervous system activity and pulse wave data from a wearable monitoring system. Laboratory tests were performed and adverse events（AEs）analyzed. Results　Safety data were evaluated for 30 subjects from each group（16 males）who completed the study. Data from 24 （ubiquinol group）and 28（placebo group）subjects were evaluated for efficacy after exclusion of subjects who deviated from the study protocol. Ubiquinol produced statistically significant changes from baseline values, but the effects were not significantly greater than the placebo effects. In contrast, stratified analysis of subjects with VAS stress scores≥70 demonstrated that ubiquinol had a significantly greater effect than placebo on VAS stress score; OSA-MA initiation╱maintenance of sleep, frequent dreaming, and refreshing scores, and VAS sleep quality score. Neither clinically relevant AEs nor abnormal laboratory test values were observed. Conclusions　Ubiquinol reduced stress and improved sleep-related problems in subjects with high stress sensitivity. Additional extended studies on ubiquinol are warranted（. UMIN Clinical Trail Registry ID：000032233）