Actigraph Calibration in Obese/Overweight and Type 2 Diabetes Mellitus Middle-Aged to Old Adult Patients

BACKGROUND: Several methods exist to asses and control physical intensity levels of subjects engaged in physical activities programs, accelerometry is a method that could be easily used in the field. The purposes were: to calibrate Actigraph in middle-aged to old obese/overweight and DM2 adult patients; and to determine the threshold counts for sedentary, light, moderate, and vigorous physical activity (PA). METHODS: Sample comprise 26 participants (62.6 +/- 6.5 years of age) of both gender. Counts and VO2 were simultaneously assessed during: resting, seating, standing, walking at 2.5 km x h(-1), 5 km x h(-1), and 6 km x h(-1). A hierarchical linear model was used to derive a regression equation between MET and counts. Receiver operating characteristics (ROC) analysis was used to define thresholds for PA levels. RESULTS: The regression equation was: MET 1.388400490262 + 0.001312683420044 (counts x min(-1)), r = .867. The threshold counts for sedentary-light, light-moderate and moderate-vigorous PA were: 200, 1240, 2400 counts-min(-1) respectively. CONCLUSION: The Actigraph is a valid and useful device for the assessment of the amount of time spent in each PA intensity levels in obese/overweight and DM2 middle-aged to old adult patients.