Table 2.

Main findings of case studies reporting on creatine supplementation and kidney function.

Study	Study Design	Patient Characteristics	Creatine Supplementation Protocol	Concomitant Use of Other Substances	Main Findings
Pritchard & Kalra (1998) [15]	Retrospective	25-year-old man with FSG and frequently relapsing NS undergoing pre-season soccer training regime	L: 15 g∙day−1 for 1 week M: 2 g∙day−1 for 7 weeks	Cyclosporine	↓ mGFR ↑ Serum Crn ↓ Crn clearance
Koshy et al. (1999) [16]	Retrospective	20-year-old healthy man	Creatine monohydrate 20 g∙day−1 for 4 weeks	None	↑ Serum Crn ↑ Proteinuria ↑ Hematuria
Robinson et al. (2000) [17]	Retrospective	24-year-old healthy man Bodybuilder	25 g∙day−1 for 12 months	None	↔ Serum Crn ↔ BUN ↔ Electrolytes ↑ Proteinuria ↑ Hematuria Rhabdomyolysis
Barisic et al. (2002) [18]	Prospective	18-year-old sedentary man with mitochondrial encephalopathy and moderate renal insufficiency	Creatine monohydrate L: 20 g∙day−1 for 12 days M: 5 g∙day−1 for 28 months	Carbamazepine L-thyroxine Lamotrigine Coenzyme Q Riboflavin Vitamin K3 Ascorbic acid L-carnitine	↑ Serum Crn ↓ Crn clearance ↑ BUN ↑ Proteinuria
Révai et al. (2003) [19]	Retrospective	22-year-old man Supposedly bodybuilder	200 g∙day−1 continuously	Methandion	MPGN *
Thorsteinsdottir et al. (2006) [20]	Retrospective	24-year-old man Bodybuilder #	Creatine monohydrate 15 g∙day−1 for 6 months	Large amounts of dietary supplements for bodybuilding purposes, including multiple herbs, nonherbal supplements, and vitamins	↑ Serum Crn ↓ Crn clearance ↑ BUN ↑ Proteinuria ↑ Hematuria
Gualano et al. (2010) [72]	Prospective	20-year-old man with a single kidney and mild renal insufficiency submitted to resistance training and a high-protein diet (2.8 g∙kg−1∙day−1)	Creatine monohydrate L: 20 g∙day−1 for 5 days M: 5 g∙day−1 for 30 days	None	↔ mGFR ↑ Serum Crn ↓ Crn clearance ↓ BUN ↔ Electrolytes ↔ Proteinuria ↓ Albuminuria
Taner et al. (2010) [21]	Retrospective	18-year-old healthy man Supposedly bodybuilder	Creatine monohydrate L: 20 g∙day−1 for 5 days M: 1 g∙day−1 for 6 weeks	Not reported	↑ Serum Crn ↑ BUN ↑ Urate ↔ Electrolytes ↑ Proteinuria

BUN: blood urea nitrogen; Crn: creatinine; FSG: focal segmental glomerulosclerosis; L: loading phase; M: maintenance phase; mGFR: measured glomerular filtration rate; MPGN: membranoproliferative glomerulonephritis; NS: nephrotic syndrome. * the diagnosis was provided without any supporting test results being presented; ^# unusual high-intensity training regimen (3 h of strenuous exercise five times per week). Arrows indicate measured values above (↑), below (↓), or within (↔) normative range.