Coenzyme Q10 improves endothelial dysfunction in statin-treated type 2 diabetic patients.
OBJECTIVE
The vascular benefits of statins might be attenuated by inhibition of coenzyme Q(10) (CoQ(10)) synthesis. We investigated whether oral CoQ(10) supplementation improves endothelial dysfunction in statin-treated type 2 diabetic patients.


METHODS
In a double-blind crossover study, 23 statin-treated type 2 diabetic patients with LDL cholesterol <2.5 mmol/l and endothelial dysfunction (brachial artery flow-mediated dilatation [FMD] <5.5%) were randomized to oral CoQ(10) (200 mg/day) or placebo for 12 weeks. We measured brachial artery FMD and nitrate-mediated dilatation (NMD) by ultrasonography. Plasma F(2)-isoprostane and 24-h urinary 20-hydroxyeicosatetraenoic acid (HETE) levels were measured as systemic oxidative stress markers.


RESULTS
Compared with placebo, CoQ(10) supplementation increased brachial artery FMD by 1.0 +/- 0.5% (P = 0.04), but did not alter NMD (P = 0.66). CoQ(10) supplementation also did not alter plasma F(2)-isoprostane (P = 0.58) or urinary 20-HETE levels (P = 0.28).


CONCLUSIONS
CoQ(10) supplementation improved endothelial dysfunction in statin-treated type 2 diabetic patients, possibly by altering local vascular oxidative stress.
Hamilton
Sandra J
SJ
School of Medicine and Pharmacology, Royal Perth Hospital Unit, University of Western Australia, Perth, Australia.
Chew
Gerard T
GT
Watts
Gerald F
GF
D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity / Q000187:drug effects / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects; D001916:Brachial Artery / Q000187:drug effects / Q000503:physiopathology; D008078:Cholesterol, LDL / Q000097:blood; D018592:Cross-Over Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology*; D004311:Double-Blind Method; D004730:Endothelium, Vascular / Q000187:drug effects / Q000503:physiopathology*; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000652:urine; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use*; D008875:Middle Aged; D018384:Oxidative Stress / Q000187:drug effects; D010919:Placebos; D014451:Ubiquinone / Q000031:analogs & derivatives* / Q000627:therapeutic use; D014664:Vasodilation / Q000187:drug effects
D008078:Cholesterol, LDL; D006893:Hydroxyeicosatetraenoic Acids; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D010919:Placebos; D014451:Ubiquinone; C055987:20-hydroxy-5,8,11,14-eicosatetraenoic acid; C024989:coenzyme Q10