Patterns of Timing and Intensity of Physical Activity and HbA1c Levels in Hispanic/Latino Adults With or at Risk of Type 2 Diabetes

Background: Despite the clear benefits of increased physical activity (PA) on glycemic control, little is known about the importance of the timing of exercise among people with diabetes. Our objective was to compare the time of day of PA with concurrent HbA1c levels and body mass index (BMI) among Hispanic/Latino adults with or at risk of type 2 diabetes (T2D). Methods: Monitored activity data obtained from Hispanic/Latino adults were summarized as number of steps per day, moderate-to vigorous-intensity physical activity (MVPA), and energy expenditure (kcals/day). We next examined the association between PA measures and participants' HbA1c. K-means clustering analysis was applied to identify daily PA patterns by time of day and intensity. Results: Three dominant clusters were identified: low-intensity PA, and early and late PA by time of day. The step counts were correlated with HbA1c in the late-active group (P = .01). Furthermore, independently in younger adults (age <= 50 years) and in overweight adults 25 <= BMI < 30 kg/m2), there was an association between HbA1c and step counts (P < .01 and P < .005, respectively) as well as HbA1c and MVPA (P < .05 and P < .035, respectively). Conclusions: For Hispanic/Latino adults with or at risk of T2D, there appears to be clustering of PA by intensity and time of day which, in turn, may influence achieved HbA1c and BMI. Our findings demonstrate that the amount of activity is more efficacious on HbA1c in participants who are more active later during the day and separately in overweight and younger individuals. This finding may help design more personalized PA recommendations in this population.