Effect Of Co-enzyme Q10 Supplementation On Muscle Blood Flow And Metabolism In Type 2 Diabetics With Peripheral Artery Disease

Abstract

The dietary supplement co-enzyme Q10 (CoQ10) is a potent antioxidant and a component of the electron transport chain which has been shown to improve muscle metabolism and blood flow. PURPOSE: The purpose of this study was to determine the impact of CoQ10 supplementation on muscle metabolism and blood flow in type II diabetes (T2D) patients with mild peripheral artery disease (PAD) compared to a non-diabetic control group. METHODS: Seven T2D patients (69.9±5.1 years) and 7 matched controls (67.0±8.9) were tested 2 weeks post placebo (week 2) and 2 weeks post CoQ10 supplementation (week 4). During each testing session the participants performed a 12 s dynamic plantar flexion exercise during which medial gastrocnemius muscle PCr and pH were measured using 31P magnetic resonance spectroscopy. Muscle oxygen saturation and blood flow were simultaneously measured using near infrared spectroscopy. The placebo and CoQ10 dosage was 200 mg/day. Two-way ANOVA and Newman-Keuls post-hoc tests were used to determine differences. RESULTS: Comparing the T2D patients to the controls in the placebo trial, there were no differences in resting PCr (37.8±3.2 vs. 41.1±2.1 mM), end exercise PCr (17.2±6.5 vs. 20.6±5.8 mM), or resting pH (7.02±0.02 vs. 7.01±0.04). However, end exercise pH (6.98±0.07 vs. 7.00±0.04), PCr recovery rate after exercise (22.3±13.4 vs. 49.4±36.6 mM/kg/min), and blood flow index (5.3±2.9 vs. 9.7±2.9%/s) were lower for the T2D patients (p<0.03). The time for muscle oxygen saturation recovery to 50% (70.9±52.1 vs. 31.8±8.4 s) was longer for the T2D patients (p<0.01). Comparing the placebo trial to the CoQ10 trial, there were no differences (p=0.96 to 0.47) between any of the variables measured for either the T2D patients or the control group. CONCLUSIONS: Our results show that there are significant muscle metabolic and hemodynamic differences between T2D patients and controls as expected. Two weeks of CoQ10 supplementation at 200 mg/day however, did not significantly impact these metabolic or hemodynamic measures in either group. The lack of significance may be due to the relatively short supplementation period and low dosage. When blood flow is severely compromised, studies suggest that a higher CoQ10 dose and/or a longer dosing period may be needed to elicit a significant impact on physiology.