Effects of creatine supplementation on renal function: a randomized, double-blind, placebo-controlled clinical trial
- 1.7k Downloads
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) (∼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.
KeywordsAdverse effects Kidneys Cystatin C Exercise
We are grateful to Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) for financial support. We would also like to express our thanks to the subjects who took part in the study.
- Gualano B, Novaes RB, Shimuzu HM, Artioli GG, Rogeri PS, Ugrinowitsch C, Seguro AC, Lancha AH Jr (2006) Aerobic training improves renal function and decreases oxidative stress in healthy sedentary males, despite high-dose creatine supplementation. J Am Soc Nephrol 203AGoogle Scholar
- Gualano B, Novaes RB, Artioli GG, Freire TO, Coelho DF, Scagliusi FB, Rogeri PS, Roschel H, Ugrinowitsch C, Lancha AH Jr (2008) Effects of creatine supplementation on glucose tolerance and insulin sensitivity in sedentary healthy males undergoing aerobic training. Amino Acids (in press)Google Scholar
- Harris RC, Soderlund K, Hultman E (1992) Elevation of creatine in resting and exercised muscle of normal subjects by creatine supplementation. Clin Sci (Lond) 83:367–374Google Scholar
- Kuehl K, Goldberg L, Elliot D (1998) Renal insufficiency after creatine supplementation in a college football athlete (abstract). Med Sci Sports Exerc 30:S235Google Scholar
- Littell RC, Milliken GA, Stroup WW, Wolfinger RD, Schabenberger O (2006) SAS system for mixed models. SAS Institute, CaryGoogle Scholar
- Sewell DA, Harris RC (1995) Effect of creatine supplementation in the Thoroughbred horse. Equine Vet J 18:239–242Google Scholar
- Terjung RL, Clarkson P, Eichner ER, Greenhaff PL, Hespel PJ, Israel RG, Kraemer WJ, Meyer RA, Spriet LL, Tarnopolsky MA, Wagenmakers AJ, Williams MH (2000) American College of Sports Medicine roundtable. The physiological and health effects of oral creatine supplementation. Med Sci Sports Exerc 32:706–717PubMedCrossRefGoogle Scholar