Center for Health, Exercise and Sport Sciences, Belgrade, Serbia.
Int J Med Sci. 2013;10(2):141-7. doi: 10.7150/ijms.5125. Epub 2013 Jan 3.
Guanidinoacetic acid (GAA) is a natural precursor of creatine, yet the potential use of GAA as a nutritional additive for restoring creatine availability in humans has been limited by unclear efficacy and safety after exogenous GAA administration. The present study evaluated the effects of orally administered GAA on serum and urinary GAA, creatine and creatinine concentration, and on the occurrence of adverse events in healthy humans.
Twenty-four healthy volunteers were randomized in a double-blind design to receive either GAA (2.4 grams daily) or placebo (PLA) by oral administration for 6 weeks.
www.clinicaltrials.gov, identification number NCT01133899. Serum creatine and creatinine increased significantly from before to after administration in GAA-supplemented participants (P < 0.05). The proportion of participants who reported minor side effects was 58.3% in the GAA group and 45.5% in the placebo group (P = 0.68). A few participants experienced serum creatine levels above 70 µmol/L.
Exogenous GAA is metabolized to creatine, resulting in a significant increase of fasting serum creatine after intervention. GAA had an acceptable side-effects profile with a low incidence of biochemical abnormalities.
胍基乙酸（GAA）是肌酸的天然前体，但由于外源性 GAA 给药后疗效和安全性不明确，其作为一种恢复人体肌酸供应的营养添加剂的潜在用途受到限制。本研究评估了口服 GAA 对健康人体血清和尿液 GAA、肌酸和肌酐浓度的影响，以及不良事件的发生情况。
24 名健康志愿者采用双盲设计随机分为 GAA（每日 2.4 克）或安慰剂（PLA）组，通过口服给药，为期 6 周。
www.clinicaltrials.gov，注册号 NCT01133899。GAA 补充组的血清肌酸和肌酐在给药后与给药前相比显著增加（P < 0.05）。GAA 组报告轻微副作用的参与者比例为 58.3%，安慰剂组为 45.5%（P = 0.68）。少数参与者的血清肌酸水平超过 70 µmol/L。
外源性 GAA 代谢为肌酸，干预后空腹血清肌酸显著增加。GAA 的副作用谱可接受，生化异常发生率低。
