title: Effect of short-term high-dose creatine supplementation on measured GFR in a young man with a single kidney.
abstract: It currently is unknown whether creatine supplementation is safe for people with or at risk of kidney disease. We report on the short-term effects of creatine supplementation on kidney function in a young man with a single kidney and mildly decreased glomerular filtration rate (GFR). A 20-year-old man who had undergone unilateral nephrectomy and presented with mildly decreased GFR without kidney damage underwent a trial with 35 days of creatine supplementation (20 g/d for 5 days followed by 5 g/d for the next 30 days) and had his kidney function monitored. After the intervention, (51)Cr-EDTA clearance (pre, 81.6 mL/min/1.73 m(2); post, 82.0 mL/min/1.73 m(2)), proteinuria (protein excretion: pre, 130 mg/d; post, 120 mg/d), and electrolyte levels were unchanged. Albuminuria, serum urea level, and estimated creatinine clearance were decreased (pre, 4.6 mg/d; post, 2.9 mg/d; pre, 37 mg/d; post, 28 mg/dL; and pre, 88 mL/min/1.73 m(2); post, 71 mL/min/1.73 m(2), respectively), whereas serum creatinine level was slightly increased (pre, 1.03 mg/dL; post, 1.27 mg/dL), falsely suggesting kidney function impairment. This prospective report suggests that short-term creatine supplementation may not affect kidney function in an individual with a single kidney, mild decreased GFR, and ingesting a high-protein diet (ie, 2.8 g/kg/d). This finding has great relevance considering that creatine-induced kidney disease has been a growing concern, even for healthy people.
authors.affiliation: Laboratory of Nutrition and Metabolism Applied to Exercise, School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil. gualano@usp.br
authors.forename: Bruno
authors.initials: B
authors.lastname: Gualano
authors.forename: Desire Coelho
authors.initials: DC
authors.lastname: Ferreira
authors.forename: Marcelo Tatit
authors.initials: MT
authors.lastname: Sapienza
authors.forename: Antonio Carlos
authors.initials: AC
authors.lastname: Seguro
authors.forename: Antonio Herbert
authors.initials: AH
authors.lastname: Lancha
mesh_terms: D003401:Creatine / Q000008:administration & dosage* / Q000494:pharmacology; D005919:Glomerular Filtration Rate / Q000187:drug effects*; D006801:Humans; D007668:Kidney / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D009392:Nephrectomy; D013997:Time Factors; D055815:Young Adult
chemical_list: D003401:Creatine