Effect of Creatine Supplementation on Functional Capacity and Muscle Oxygen Saturation in Patients with Symptomatic Peripheral Arterial Disease: A Pilot Study of a Randomized, Double-Blind Placebo-Controlled Clinical Trial.

The aim of the study was to verify the effects of creatine (Cr) supplementation on functional capacity (walking capacity; primary outcome) and calf muscle oxygen saturation (StO2) (secondary outcome) in symptomatic peripheral arterial disease (PAD) patients. Twenty-nine patients, of both sexes, were randomized (1:1) in a double-blind manner for administration of placebo (PLA, n = 15) or creatine monohydrate (Cr, n = 14). The supplementation protocol consisted of 20 g/day for 1 week divided into four equal doses (loading phase), followed by single daily doses of 5 g in the subsequent 7 weeks (maintenance phase). Functional capacity (total walking distance) was assessed by the 6 min walk test, and calf muscle StO2 was assessed through near infrared spectroscopy. The measurements were collected before and after loading and after the maintenance phase. The level of significance was p < 0.05. No significant differences were found for function capacity (total walking distance (PLA: pre 389 ± 123 m vs. post loading 413 ± 131 m vs. post maintenance 382 ± 99 m; Cr: pre 373 ± 149 m vs. post loading 390 ± 115 m vs. post maintenance 369 ± 115 m, p = 0.170) and the calf muscle StO2 parameters (p > 0.05). Short- and long-term Cr supplementation does not influence functional capacity and calf muscle StO2 parameters in patients with symptomatic PAD.

Does Creatine Supplementation Affect Renal Function in Patients with Peripheral Artery Disease? A Randomized, Double Blind, Placebo-controlled, Clinical Trial.

BACKGROUND: Case studies and reviews have shown that creatine supplementation can affect kidney function. The objective of this study is to verify the effects of 8 weeks of creatine supplementation on renal function (creatinine clearance: primary outcome) in patients with symptomatic peripheral arterial disease. METHODS: Twenty-nine patients, of both genders, were randomized (1:1) in a double-blind manner for administration of Placebo (PLA; n = 15) or creatine monohydrate (Cr; n = 14). The supplementation protocol consisted of 20 g/day for 1 week divided into 4 equal doses (loading phase), followed by single daily doses of 5 g in the subsequent 7 weeks (maintenance phase). Before and after the supplementation period, markers of renal function, serum creatinine, creatinine excretion rate, and creatinine clearance were evaluated. The Generalized Estimation Equation Model was used for comparison between groups. The level of significance was P < 0.05. RESULTS: No significant differences were found between groups before and after the intervention for serum creatinine (Cr: pre 1.00 ± 0.15 mL/dL vs. post 1.07 ± 0.16 mL/dL; PLA: pre 1.30 ± 0.53 mL/dL vs. post 1.36 ± 0.47 mL/dL, P = 0.590), creatinine excretion rate (Cr: pre 81.73 ± 43.80 mg/dL vs. post 102.92 ± 59.57 mg/dL; PLA: pre 74.37 ± 38.90 mg/dL vs. post 86.22 ± 39.94 mg/dL, P = 0.560), or creatinine clearance (Cr; pre 108 ± 59 mL/min/1.73 m2 vs. post 117 ± 52 mL/min/1.73 m2; PLA: pre 88 ± 49 mL/min/1.73 m2 vs. post 82 ± 47 mL/min/1.73 m2, P = 0.366). CONCLUSIONS: Eight weeks of creatine supplementation is safe and does not compromise the renal function of patients with peripheral arterial disease.