Sex Differences in Glycemia and Self-Management Strategies for Exercise in an Active Adults Cohort with Type 1 Diabetes.

Objective: To examine potential differences in glucose levels during and after exercise between sexes in adults with type 1 diabetes.

Methods: The T1DEXI study was a prospective, 4-week free-living observational study in adults with type 1 diabetes. Ninety-one females were matched on age and insulin-modality to 91 males. Participants completed exercise study videos and personal exercise sessions. Study-collected food, insulin, exercise, and glucose data surrounding exercise and on sedentary days were compared between sexes to examine how they impact glucose levels during and after exercise.

Results: Female participants had higher glucose levels than male participants when starting study exercise (8.5 ± 2.8 vs. 8.0 ± 2.8 mmol/L, p=0.01) and when starting personal exercise activities (8.4 ± 2.9 vs. 7.8 ± 2.7 mmol/L, p=0.05). Glucose declines during study exercise were comparable between female and male participants (adjusted mean: -0.8 vs. -1.0 mmol/L respectively, p=0.11), but smaller in female participants during personal exercise (adjusted mean: -0.9 vs. -1.4 mmol/L, p<0.001). 24-hour mean glucose levels were also higher in female participants on sedentary days (p=0.04). Daily macronutrient consumption was similar between sexes after adjusting for weight, as were food, exercise, and insulin habits surrounding exercise.

Conclusions: Female participants had higher pre-exercise glucose levels compared to male participants, and smaller glucose declines during personal exercise, but there were no observable differences in food, exercise, and insulin habits.