Accommodating planned exercise in type I diabetic patients on intensive treatment

Area of Science:

• Endocrinology
• Metabolic Disorders
• Exercise Physiology

Background:

• Optimal metabolic control in type 1 diabetes requires insulin adjustments for exercise.
• Exercise is a normal daily activity for individuals with type 1 diabetes.
• Both continuous subcutaneous insulin infusion (CSII) and multiple subcutaneous injections (MSI) require careful insulin management during physical activity.

Purpose of the Study:

• To investigate the effects of pre-exercise insulin dose modifications on glucose regulation in adolescents with type 1 diabetes.
• To compare the responses of patients using CSII versus MSI to altered insulin regimens before postprandial exercise.

Main Methods:

• Seven adolescents using CSII and six using MSI participated.
• Subjects underwent five conditions: resting control and exercise with usual, 1/2, 2/3 usual, or no insulin dose adjustment.
• Exercise consisted of 45 minutes of cycle ergometry at 55% VO2, 2 hours after breakfast and insulin administration.

Main Results:

• Performing exercise without adjusting the usual insulin dose led to a significant decrease in blood glucose levels in both CSII and MSI groups.
• Hypoglycemia occurred in four patients on CSII (plasma glucose 57 ± 5 mg/dl) and three patients on MSI (plasma glucose 65 ± 10 mg/dl).
• These results highlight the risk of hypoglycemia when insulin doses are not modified before exercise.

Conclusions:

• Significant glucose lowering effects and hypoglycemia risk observed when usual insulin doses are maintained during postprandial exercise.
• Insulin dose modification prior to exercise is essential for preventing hypoglycemia in type 1 diabetes patients on CSII and MSI.
• Further research is needed to establish optimal insulin adjustment strategies for exercise in type 1 diabetes.