Effects of Glutamine on Glycemic Control During and After Exercise in Adolescents With Type 1 Diabetes: A pilot study

OBJECTIVE: To investigate if oral glutamine ameliorates exercise and postexercise nighttime hypoglycemia in type 1 diabetic adolescents. RESEARCH DESIGN AND METHODS: Ten adolescents (15.2 ± 1.4 years [SD], A1C 6.9 ± 0.9%) on insulin pumps were studied. The subjects were randomized to receive a glutamine or placebo drink pre-exercise and at bedtime (0.25 g/kg/dose). A 3:00 p.m. exercise session consisted of four 15-min treadmill/5-min rest cycles. Pre-exercise blood glucose was 140–150 mg/dl and was monitored throughout the night. Studies were randomized crossover over 3 weeks. RESULTS: Blood glucose levels dropped comparably (52%) during exercise on both days. However, the overnight number of hypoglycemic events was higher on glutamine than placebo (≤70 mg/dl, P = 0.03 and ≤60, P = 0.05). The cumulative probability of nighttime hypoglycemia was increased on glutamine days (80%) versus placebo days (50%) (P = 0.02). CONCLUSIONS: Glutamine increased the cumulative probability of postexercise overnight hypoglycemia compared with placebo in adolescents with type 1 diabetes. Whether glutamine may enhance insulin sensitivity postexercise requires further study in type 1 diabetes.