The effects of supplementation of creatine on total homocysteine

Background Small increases in homocysteine are associated with increased risk for cardiovascular events patients with end-stage renal disease (ESRD). Endogenous creatine intake may decrease homocysteine via negative feedback inhibition, as creatine is a by-product of methionine and homocysteine metabolism. Therefore, this study was conducted to examine whether oral supplementation of creatine would affect levels of plasma homocysteine in ESRD patients. Methods: 16 ESRD patients with hyperhomocysteinemia completed the study. Patients supplemented 5 g/day of creatine monohydrate for 30 days. Results: Homocysteine levels significantly increased (t=-2.315, p=0.035) in ESRD patients (pre-test 18.9±14.0 mg/dlitre, 139.80±103.56 μmol/litre; post-test 28.8±11.2 mg/dlitre, 213.03±82.85 μmol/litre). Conclusions: The current study suggests that ingestion of 5 g/day of creatine monohydrate in ESRD patients results in an increase in homocysteine. Combined with previous studies it appears that dosages ≥ 5 g/day of creatine increase homocysteine in patients with decreased renal function.