Creatine Supplementation Affects Glucose Homeostasis but Not Insulin Secretion in Humans

• Published in: Annals of nutrition and metabolism 2003-01, Vol.47 (1), p.11-15
• Main Authors: Rooney, Kieron B., Bryson, Janet M., Digney, Alison L., Rae, Caroline D., Thompson, Campbell H.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Blood Glucose - drug effects; Blood Glucose - metabolism; Body Weight - drug effects; Creatine - pharmacology; Diet, Vegetarian; Dietary Supplements; Exercise; Female; Glucose; Homeostasis; Homeostasis - drug effects; Human physiology applied to population studies and life conditions. Human ecophysiology; Humans; Insulin; Insulin - blood; Insulin - metabolism; Insulin Secretion; Male; Medical sciences; Metabolism; Musculoskeletal system; Nutritional survey. Food supply and nutritional requirement; Original Paper; Physical fitness; Plasma; Reference Values; Statistical significance; Time Factors; Vegetarianism
• ISSN: 0250-6807; 1421-9697
• DOI: 10.1159/000068908

Aims: In this study, it was investigated whether the glucose homeostasis is affected by dietary creatine supplementation. For this purpose, the plasma glucose concentration and the plasma insulin response to an oral glucose load were measured in creatine-supplemented vegetarians. Methods: The subjects were supplemented with either 5 g of creatine monohydrate (creatine-treated group, CREAT) or 5 g of maltodextrin (control group, CON) per day for 42 days. On days 0 and 43, blood samples were collected before as well as 10, 20, and 30 min following an oral glucose load and analyzed for plasma creatine, insulin, and glucose levels. Results: Creatine supplementation resulted in an increase in plasma creatine (CREAT 92.7 ± 14.6 µM vs. CON 31.2 ± 3.2 µM; p = 0.001). There was a trend (p = 0.07) towards elevated fasting plasma glucose levels following creatine supplementation, while the plasma glucose response to the glucose load was enhanced (CREAT 168.2 ± 5.3 mM· min vs. CON 129.6 ± 14.7 mM ·min; p = 0.05). There was no difference observed in the plasma insulin response to the glucose load between the groups. Conclusion: This study shows that creatine supplementation may result in abnormalities in glucose homeostasis in the absence of changes in insulin secretion.