The potential cardio-metabolic benefits of replacing time in less-for more-active behaviors in adults with type 2 diabetes

Purpose: To examine the cross-sectional associations of objectively derived physical activity and sedentary time with cardiometabolic biomarkers, including the potential collective impact of shifting time use from less towards more active behaviors.

Methods: Overweight/obese and/or physically inactive adults with type 2 diabetes (n=294; mean age = 58.0 [SD 8.5] years) wore Actigraph GT1M accelerometers for seven days to assess moderate-to-vigorous physical activity (MVPA), light-intensity activity, and sedentary time (segregated into non-prolonged [sedentary time accumulated in bouts <30mins] and prolonged[sedentary time accumulated in bouts ≥30mins]). Using isotemporal modelling, associations of these activity variables (30 mins/day increments) with waist circumference, BMI, fasting blood (HbA1C, glucose, triglycerides, HDLcholesterol), and blood pressure were examined: In isolation (adjusted for confounders); independently (also adjusted for other activities); and, interdependently (i.e., by reallocating time from less- to more-active behaviors).

Results: Significant (p<0.05) associations (in isolation) were observed with waist circumference and BMI for prolonged (detrimental) and non-prolonged (beneficial) sedentary time, and with diastolic blood pressure (beneficial) for non-prolonged sedentary time. No outcome was significantly associated with light-intensity activity or MVPA. Reallocating 30 mins/day of prolonged sedentary time to either non-prolonged sedentary time or light-intensity activity was associated with significantly lower average waist circumference and BMI. Associations were strongest when considered interdependently.

Conclusions: Additional to existing physical activity messages, shifts away from prolonged sedentary time (e.g., getting up at least every 30 minutes) should be investigated as a potentially achievable strategy to improve body composition in adults with type 2 diabetes.