Coenzyme Q10 improves blood pressure and glycaemic control: a controlled trial in subjects with type 2 diabetes

Our objective was to assess effects of dietary supplementation with coenzyme Q10 (CoQ) on blood pressure and glycaemic control in subjects with type 2 diabetes, and to consider oxidative stress as a potential mechanism for any effects.

Seventy-four subjects with uncomplicated type 2 diabetes and dyslipidaemia were involved in a randomised double blind placebo-controlled 2x2 factorial intervention.

The study was performed at the University of Western Australia, Department of Medicine at Royal Perth Hospital, Australia.

Subjects were randomly assigned to receive an oral dose of 100 mg CoQ twice daily (200 mg/day), 200 mg fenofibrate each morning, both or neither for 12 weeks.

We report an analysis and discussion of the effects of CoQ on blood pressure, on long-term glycaemic control measured by glycated haemoglobin (HbA(1c)), and on oxidative stress assessed by measurement of plasma F2-isoprostanes.

Fenofibrate did not alter blood pressure, HbA(1c), or plasma F2-isoprostanes. There was a 3-fold increase in plasma CoQ concentration (3.4+/-0.3 micro mol/l, P<0.001) as a result of CoQ supplementation. The main effect of CoQ was to significantly decrease systolic (-6.1+/-2.6 mmHg, P=0.021) and diastolic (-2.9+/-1.4 mmHg, P=0.048) blood pressure and HbA(1c) (-0.37+/-0.17%, P=0.032). Plasma F2-isoprostane concentrations were not altered by CoQ (0.14+/-0.15 nmol/l, P=0.345).

These results show that CoQ supplementation may improve blood pressure and long-term glycaemic control in subjects with type 2 diabetes, but these improvements were not associated with reduced oxidative stress, as assessed by F2-isoprostanes.

This study was supported by a grant from the NH&MRC, Australia.