title: Actigraph calibration in obese/overweight and type 2 diabetes mellitus middle-aged to old adult patients.
abstract: 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Dept. of Sport Science, Polytechnic Institute of Bragança, Portugal.
authors.forename: Vitor Pires
authors.initials: VP
authors.lastname: Lopes
authors.forename: Pedro
authors.initials: P
authors.lastname: Magalhães
authors.forename: José
authors.initials: J
authors.lastname: Bragada
authors.forename: Catarina
authors.initials: C
authors.lastname: Vasques
mesh_terms: D056044:Actigraphy; D000368:Aged; D002138:Calibration; D003924:Diabetes Mellitus, Type 2 / Q000534:rehabilitation*; D015444:Exercise; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000534:rehabilitation*; D050177:Overweight / Q000534:rehabilitation; D010807:Physical Endurance; D012372:ROC Curve