Validation of Physical Activity Monitors in Individuals with Diabetes: Energy Expenditure Estimation by the Multisensor SenseWear Armband Pro3 and the Step Counter Omron HJ-720 Against Indirect Calorimetry During Walking

Background: The purpose of this study is to test the agreement between energy expenditure estimate of the SenseWear (R) Armband Pro3 (SWA) (BodyMedia, Pittsburgh, PA) and the Omron HJ-720 (Omron Healthcare, Kyoto, Japan) step counter with indirect calorimetry (IC) as a gold standard in older individuals with type 1 and type 2 diabetes mellitus while walking on a treadmill. Subjects and Methods: In total, six men (60.3 +/- 3.1 years old) and 13 women (51.1 +/- 11.0 years old) with type 1 or type 2 diabetes mellitus were included in the study. Each subject performed three 15-min walking sessions with different combinations of speed and incline (3 km/h, 0%; 4 km/h, 0%; 5 km/h, 5%) on a treadmill. Energy expenditure (EE) was simultaneously measured by the SWA, Omron, and IC. Mean over-/underestimation and Pearson's correlation coefficients were used for statistical evaluation of the agreement between tested methods and IC. Results: At the speed of 3 km/h with 0% incline, mean overestimation of +81.19 +/- 23.81% was found for SWA (r = 0.79, P < 0.001) and +70.51 +/- 20.91% for Omron (r = 0.77, P < 0.001). At the speed of 4 km/h and 0% incline, mean overestimation found for SWA was +78.18 +/- 33.96% (r = 0.63, P < 0.01) and +75.77 +/- 33.36% for Omron (r = 0.52, P < 0.05). At the level of high-intensity exercise at the speed of 5 km/h and 5% incline, mean underestimation was -7.88 +/- 16.86% for SWA (r = 0.74, P < 0.001) and -7.37 +/- 16.07% for Omron (r = 0.75, P < 0.001). Conclusions: Both methods led to considerable overestimation of calculated EE in level walking and a relatively minor underestimation during fast uphill walking.