Effects of creatine supplementation on renal function: a randomized, double-blind, placebo-controlled clinical trial.
Creatine (CR) supplementation is commonly used by athletes. However, its effects on renal function remain controversial. The aim of this study was to evaluate the effects of creatine supplementation on renal function in healthy sedentary males (18-35 years old) submitted to exercise training. A randomized, double-blind, placebo-controlled trial was performed. Subjects (n = 18) were randomly allocated to receive treatment with either creatine (CR) ( approximately 10 g day(-1) over 3 months) or placebo (PL) (dextrose). All subjects undertook moderate intensity aerobic training, in three 40-min sessions per week, during 3 months. Serum creatinine, serum and urinary sodium and potassium were determined at baseline and at the end of the study. Cystatin C was assessed prior to training (PRE), after 4 (POST 4) and 12 weeks (POST 12). Cystatin C levels (mg L(-1)) (PRE CR: 0.82 +/- 0.09; PL: 0.88 +/- 0.07 vs. POST 12 CR: 0.71 +/- 0.06; PL: 0.75 +/- 0.09, P = 0.0001) were decreased over time, suggesting an increase in glomerular filtration rate. Serum creatinine decreased with training in PL but was unchanged with training in CR. No significant differences were observed within or between groups in other parameters investigated. The decrease in cystatin C indicates that high-dose creatine supplementation over 3 months does not provoke any renal dysfunction in healthy males undergoing aerobic training. In addition, the results suggest that moderate aerobic training per se may improve renal function.
Gualano
Bruno
B
Laboratory of Applied Nutrition and Metabolism, School of Physical Education and Sport, University of Sao Paulo, Sao Paulo, Brazil. gualano@usp.br
Ugrinowitsch
Carlos
C
Novaes
Rafael Batista
RB
Artioli
Guilherme Gianini
GG
Shimizu
Maria Heloisa
MH
Seguro
Antonio Carlos
AC
Harris
Roger Charles
RC
Lancha
Antonio Herbert
AH
D000293:Adolescent; D000328:Adult; D003401:Creatine / Q000008:administration & dosage / Q000494:pharmacology*; D003404:Creatinine / Q000097:blood; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology; D005919:Glomerular Filtration Rate / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007668:Kidney / Q000187:drug effects / Q000502:physiology*; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D011188:Potassium / Q000097:blood / Q000652:urine; D012964:Sodium / Q000097:blood / Q000652:urine
D012964:Sodium; D003404:Creatinine; D003401:Creatine; D011188:Potassium