title: Self-reported physical activity and lung function two months after cardiac surgery--a prospective cohort study.
abstract: BACKGROUND
  Physical activity has well-established positive health-related effects. Sedentary behaviour has been associated with postoperative complications and mortality after cardiac surgery. Patients undergoing cardiac surgery often suffer from impaired lung function postoperatively. The association between physical activity and lung function in cardiac surgery patients has not previously been reported.
  
  
  METHODS
  Patients undergoing cardiac surgery were followed up two months postoperatively. Physical activity was assessed on a four-category scale (sedentary, moderate activity, moderate regular exercise, and regular activity and exercise), modified from the Swedish National Institute of Public Health's national survey. Formal lung function testing was performed preoperatively and two months postoperatively.
  
  
  RESULTS
  The sample included 283 patients (82% male). Two months after surgery, the level of physical activity had increased (p < 0.001) in the whole sample. Patients who remained active or increased their level of physical activity had significantly better recovery of lung function than patients who remained sedentary or had decreased their level of activity postoperatively in terms of vital capacity (94 ± 11% of preoperative value vs. 91 ± 9%; p = 0.03), inspiratory capacity (94 ± 14% vs. 88 ± 19%; p = 0.008), and total lung capacity (96 ± 11% vs. 90 ± 11%; p = 0.01).
  
  
  CONCLUSIONS
  An increased level of physical activity, compared to preoperative level, was reported as early as two months after surgery. Our data shows that there could be a significant association between physical activity and recovery of lung function after cardiac surgery. The relationship between objectively measured physical activity and postoperative pulmonary recovery needs to be further examined to verify these results.
authors.affiliation: Department of Physiotherapy, Örebro University Hospital, 701 85 Örebro, Sweden. marcus.jonsson@oru.se.
authors.forename: Marcus
authors.initials: M
authors.lastname: Jonsson
authors.forename: Charlotte
authors.initials: C
authors.lastname: Urell
authors.forename: Margareta
authors.initials: M
authors.lastname: Emtner
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Westerdahl
mesh_terms: D000368:Aged; D006348:Cardiac Surgical Procedures; D015331:Cohort Studies; D015444:Exercise; D005260:Female; D006801:Humans; D008019:Life Style; D008168:Lung / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D011446:Prospective Studies; D012129:Respiratory Function Tests; D057566:Self Report