title: Longitudinal assessment of physical activity in women undergoing Roux-en-Y gastric bypass.
abstract: BACKGROUND
  Patients undergoing bariatric surgery do not seem to increase objectively measured physical activity (PA) after surgery, despite substantial weight loss. The aims of the present study were (i) to objectively characterize 3 months pre-surgery to 9 months postsurgery PA and sedentary behavior changes in women undergoing Roux-en-Y gastric bypass (RYGB) using tri-axial accelerometers and (ii) to examine associations between pre-surgery versus postsurgery PA and sedentary behavior with anthropometric measures taken in home environment.
  
  
  METHODS
  Fifty-six women, with an average pre-surgery body mass index (BMI) of 37.6 (SD 2.6) and of age 39.5 years (SD 5.7), were recruited at five Swedish hospitals. PA was measured for 1 week by the Actigraph GT3X+ accelerometer, and anthropometric measures were taken at home visits 3 months pre-surgery and 9 months postsurgery, thus limiting seasonal effects.
  
  
  RESULTS
  Average BMI loss, 9 months postsurgery, was 11.7 (SD 2.7) BMI units. There were no significant pre- to postsurgery differences in PA or sedentary behavior. However, pre-surgery PA showed negative association with PA change and positive association with postsurgery PA. Adjustments for pre-surgery BMI had no impact on these associations.
  
  
  CONCLUSIONS
  No significant differences were observed in objectively measured changes in PA or time spent sedentary from 3 months pre-surgery to 9 months postsurgery among women undergoing RYGB. However, women with higher pre-surgery PA decreased their PA postsurgery while women with lower pre-surgery PA increased their PA.
authors.affiliation: Department of Public Health Sciences, Karolinska Institutet, Tomtebodavägen 18A, Widerströmska Huset, 171 77, Stockholm, Sweden.
authors.forename: Daniel
authors.initials: D
authors.lastname: Berglind
authors.forename: Mikaela
authors.initials: M
authors.lastname: Willmer
authors.forename: Ulf
authors.initials: U
authors.lastname: Eriksson
authors.forename: Anders
authors.initials: A
authors.lastname: Thorell
authors.forename: Magnus
authors.initials: M
authors.lastname: Sundbom
authors.forename: Joanna
authors.initials: J
authors.lastname: Uddén
authors.forename: Mustafa
authors.initials: M
authors.lastname: Raoof
authors.forename: Jakob
authors.initials: J
authors.lastname: Hedberg
authors.forename: Per
authors.initials: P
authors.lastname: Tynelius
authors.forename: Erik
authors.initials: E
authors.lastname: Näslund
authors.forename: Finn
authors.initials: F
authors.lastname: Rasmussen
mesh_terms: D000328:Adult; D015992:Body Mass Index; D005260:Female; D015390:Gastric Bypass; D006801:Humans; D007702:Kinetocardiography; D008137:Longitudinal Studies; D008875:Middle Aged; D009043:Motor Activity; D009767:Obesity, Morbid / Q000503:physiopathology / Q000601:surgery*; D011184:Postoperative Period; D015431:Weight Loss