A Randomized, Double-Blind, Placebo-Controlled Crossover Study of Coenzyme Q10 Therapy in Hypertensive Patients With the Metabolic Syndrome

BACKGROUND Our aim was to examine the effects of adjunctive coenzyme Q(10) therapy on 24-h ambulatory blood pressure (BP) in subjects with the metabolic syndrome and inadequate BP control. METHODS In a randomized, double-blind, placebo-controlled 12-week crossover trial, coenzyme Q(10) (100 mg twice daily) or placebo was administrated to 30 subjects with the metabolic syndrome, and inadequate BP control (an average clinic BP of >= 140 systolic mm Hg or >= 130 mm Hg for patients with type 2 diabetes) while taking an unchanged, conventional antihypertensive regimen. Clinic and 24-h ambulatory BP were assessed pre- and post-treatment phases. The primary outcomes were the changes in 24-h systolic and diastolic BP during adjunctive therapy with coenzyme Q(10) vs. placebo and prespecified secondary outcomes included changes in BP loads. RESULTS Compared with placebo, treatment with coenzyme Q(10) was not associated with statistically significant reductions in systolic (P = 0.60) or diastolic 24-h ambulatory BP (P = 0.12) or heart rate (P = 0.10), although daytime diastolic BP loads, were significantly lower during coenzyme Q(10) administration with thresholds set at >90 mm Hg (P = 0.007) and 85 mm Hg (P = 0.03). Coenzyme Q(10) was well tolerated and was not associated with any clinically relevant changes in safety parameters. CONCLUSIONS Although it is possible that coenzyme Q(10) may improve BP control under some circumstances, any effects are likely to be smaller than reported in previous meta-analyses. Furthermore, our data suggest that coenzyme Q(10) is not currently indicated as adjunctive antihypertensive treatment for patients with the metabolic syndrome whose BP control is inadequate, despite regular antihypertensive therapy.