Effects of creatine supplementation on renal function:: a randomized, double-blind, placebo-controlled clinical trial - Gualano, Bruno; Ugrinowitsch, Carlos; Novaes, Rafael Batista; Artioli, G. G; Shimizu, Maria Heloisa; Seguro, Antonio Carlos; Harris, Roger Charles; Lancha Junior, Antonio Herbert (European Journal of Applied Physiology, 2008)