Low physical activity in patients with type 2 diabetes: the role of obesity

Few studies have described ambulatory activity in free-living individuals with type 2 diabetes mellitus (T2DM) using motion sensors, and none included a control group. For this reason, our study compared the physical-activity levels of outpatients with T2DM with subjects without diabetes, and examined the relationship between body mass index (BMI) and physical-activity parameters.

Physical-activity levels in 70 outpatients with T2DM and 30 age-, gender- and employment-matched individuals without diabetes were measured using the SenseWear Armband™, a monitoring device validated against doubly labelled water, to assess total energy expenditure. Patients wore the SenseWear Armband™ on their right arm continuously every day for 1 week.

Total energy expenditure (<300 kcal/day), number of steps (<1500/day), physical-activity duration (<130 min/day) and active energy expenditure/day (<300 kcal) were all significantly lower (P<0.05) in patients with T2DM. These measures were inversely correlated with BMI, and remained significant after adjusting for age, gender, employment status and the presence of diabetes.

Outpatients with T2DM have lower physical-activity levels than their matched controls, a characteristic that is related to their higher BMI.