Effect of Acute Creatine Supplementation on Arterial Stiffness and Muscle Oxygen Saturation

Abstract

ObjectiveTo determine the effects of acute creatine monohydrate supplementation on arterial stiffness (AS) and skeletal muscle oxygen saturation (SmO2). There is a void in our knowledge on the impact of acute creatine monohydrate supplementation on AS in the major elastic arteries. In addition, there is a dearth of findings on the effects of creatine supplementation on SmO2 in the lower leg. Data have indicated that creatine supplementation can result in an increase in lower leg anterior compartment pressure at rest and post exercise. Although the increased pressures seen during these studies were not pathological, this and additional factors associated with creatine supplementation could possibly effect SmO2 during exercise and recovery.Methods20 male, physically active participants were randomized in a double‐blind fashion to placebo (PL) (n=10, 22.9±3.1 yrs.) or creatine (CM) (n=10, 21.3±1.8 yrs.) groups. Subjects received 0.3 g/kg/day creatine monohydrate or placebo in gelatin capsules for 7 days. Ultrasonography of the carotid artery, applanation tonometry, submaximal exercise tests (10 minute treadmill activity at 3.7 mph and 9% incline), SmO2, and lower leg pain (analog visual scale and pain test algometer) assessments were conducted at baseline and on day 7 of the study period.ResultsThere were baseline differences in central systolic blood pressure (cSBP) (mean difference, 109; 95% confidence interval (CI) 105 to 113, vs. mean difference, 130; 95% CI 114 to 146, p < 0.05) between the PLA and CM groups, respectively. Following the intervention, there were no significant differences between PL and CM in arterial stiffness indices between the groups. There was a significant group effect (P<0.03) but no significant effect of supplementation (P>0.05) on the % change in SmO2 during the exercise tests (CM: pre 66.49 ± 30.54; post 59.61 ± 23.87 vs. PL: pre 39.87 ± 16.72; post 38.51 ± 26.95 % change SmO2; M ± SD). Percent fat free mass (FFM) was significantly increased (mean, 68.5±7.5%; 95% CI 62.1% to 72.9%, to mean 69.3±7.5% 95% CI 62.9% to 73.6%, P<0.05) in the CM group only. There were no other significant changes in anthropometric measurements.ConclusionsUsing a randomly controlled, double‐blind trial with validated measurements of AS and SmO2, acute creatine supplementation does not appear to impact vascular compliance or oxygen saturation in skeletal muscle in young, healthy males.