creatine-insulin

In healthy omnivorous men, creatine supplementation (20 g/day for 5 days followed by 2 g/day for 6 weeks) increased muscle creatine (31% after loading, 14% after maintenance) and glycogen (13.5% after loading, normalized after maintenance), without any change in ATP concentration or plasma insulin, and only a trend to increase GLUT4 (30%).

A loading phase of creatine followed by maintenance for 11 weeks in otherwise healthy sedentary males appears to reduce glucose following an oral glucose tolerance test (11-22%) with efficacy at 4 weeks and no further efficacy at 12 weeks; there was no significant influence on insulin sensitivity (assessed via HOMA) nor serum insulin.

5 g/day given to vegetarians for 42 days was associated with a nonsignificant elevation of blood glucose levels (both fasting and postprandial) and no alteration in insulin levels (both fasting and postprandial).