| Methods |
Randomized, placebo‐controlled, double blind cross‐over trial. |
| Participants |
30 patients (15 men, 15 women) with metabolic syndrome and inadequate BP control (SBP ≥ 140 or ≥ 130 for patients with type 2 diabetes) on an unchanged, anti‐hypertensive regimen. Patients with significant comorbidities (cardiovascular, renal, hepatic, metabolic, etc.) were excluded. |
| Interventions |
Cross‐over with CoQ10 (100 mg BID) and placebo added to current, unchanged, conventional hypertensive regimen. Patients taking antioxidant vitamin supplementation, including CoQ10, before the trial were excluded (no washout period). A washout period of 4 weeks was present between treatment periods. |
| Outcomes |
Mean 24‐hour ambulatory SBP and DBP, MAP, pulse pressure, HR, mean daytime and nighttime BP and HR, clinic BP (sitting, mean of 3 measurements after 5 minutes of rest) and HR, plasma CoQ10 levels. |
| Notes |
Compliance, safety data and adverse events also documented. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
"Randomization was performed in permutation blocks of six from a computer‐generated randomization list by a statistician with no clinical involvement in the study." |
| Allocation concealment (selection bias) |
Low risk |
"The study treatments were dispensed by an independent pharmacist in identical numbered bottles with the lowest available number allocated to each sequential participant." |
| Blinding (performance bias and detection bias)
Blood Pressure |
Low risk |
"Participants and investigators administering the treatment and assessing outcomes were blinded to treatment assignment and to plasma coenzyme Q10 levels." "Both Q‐Gel and placebo were supplied by Tishcon (Salisbury, MD), and were identical in appearance and taste." |
| Incomplete outcome data (attrition bias)
Blood Pressure |
Low risk |
The authors performed a modified intention‐to‐treat analysis: "Of 60 potential participants screened, 31 entered and 30 completed the study and were included in the analysis." The reason for withdrawal from the study of the 1 study participant was obtained by electronic communication from the study authors ‐ the patient had an increase in BP medication during the study. |
| Selective reporting (reporting bias) |
Low risk |
All primary and secondary outcomes were reported. |
| Other bias |
Low risk |
Research was supported by a grant from the National Heart Foundation of New Zealand (Grant Number 1155). Coenzyme Q10 (Q‐Gel) and placebo capsules were supplied by Tishcon, Salisbury, MD. Authors declared no conflicts of interest. |
