The efficacy and safety of coenzyme Q10 in Parkinson's disease: a meta-analysis of randomized controlled trials.

The objective of this meta-analysis was to evaluate the effects of coenzyme Q10 (CoQ10) for the treatment of Parkinson's disease (PD) patients in order to arrive at qualitative and quantitative conclusions about the efficacy of CoQ10. Databases searched included PubMed, Google scholar, CNKI, Wan-Fang, and the Cochrane Library from inception to March 2016. We only included sham-controlled, randomized clinical trials of CoQ10 intervention for motor dysfunction in patients with PD. Relevant measures were extracted independently by two investigators. Weighted mean differences (WMD) were calculated with random-effects models. Eight studies with a total of 899 patients were included. Random-effects analysis revealed a pooled WMD of 1.02, indicating no significant difference when CoQ10 treatment compared with placebo in terms of UPDRS part 3 (p = 0.54). Meanwhile, the effect size of UPDRS part 1, UPDRS part 2, and total UPDRS scores were similar in CoQ10 group with in placebo group (p > 0.05). Moreover, we found CoQ10 was well tolerated compared with placebo group. Subgroup analysis showed that the effect size of CoQ10 in monocentric studies was larger than in multicenter studies. Using the GRADE criteria, we characterized the quality of evidence presented in this meta-analysis as moderate to high level. The current meta-analysis provided evidence that CoQ10 was safe and well tolerated in participants with PD and no superior to placebo in terms of motor symptoms. According to these results, we cannot recommend CoQ10 for the routine treatment of PD right now.