592-P: The Association of the Timing and Magnitude of Peak Physical Activity with Cardiometabolic Health Outcomes in People with Diabetes

Introduction & Objective: To investigate the association of the timing and magnitude of peak physical activity with cardiometabolic outcomes, such as glycated haemaglobin (HbA1c) and body mass index (BMI), in people with type 1 and type 2 diabetes.

Methods: We recruited 810 people with type 1 diabetes and 1381 people with type 2 diabetes to the study. Participants wore a wrist-worn accelerometer for a 7 day and the start time of the most active 5 hours (M5time) and the acceleration (physical activity) performed in this 5 hour period (M5value) quantified. Outcome variables recorded were HbA1c, total cholesterol, HDL cholesterol, LDL cholesterol, waist circumference and BMI. Associations were assessed by linear regression after adjustment for sex, age and total (24 hour) physical activity levels.

Results: In people with type 1 diabetes the M5 time was no associated with any of the outcome variables, but the M5value was associated with HbA1c (β-coefficient [95%CI], -0.19[-0.05,-0.32], p-value 0.005), HDL cholesterol (0.004,[0.001,0.007], p-value 0.016) and LDL cholesterol (-0.008[-0.001,-0.016], p-value 0.034). In people with type 2 diabetes both the M5time 0.45[0.05,0.85], p-value 0.028) and M5value (-0.23[-0.03,-0.43], p-value 0.032) were associated with HbA1c. No other associations were observed.

Conclusions: A greater amount of physical activity during the peak activity time was associated with better glycaemic control in people with type 1 and 2 diabetes, even after adjusting for total physical activity levels. Performing peak physical activity levels earlier in the day was also associated with better glycaemic control, only in people with type 2 diabetes.