title: Association of physical activity with survival among ambulatory patients on dialysis: the Comprehensive Dialysis Study.
abstract: OBJECTIVE
  Despite high mortality and low levels of physical activity (PA) among patients starting dialysis, the link between low PA and mortality has not been carefully evaluated.
  
  
  METHODS
  The Comprehensive Dialysis Study was a prospective cohort study that enrolled patients who started dialysis between June 2005 and June 2007 in a random sample of dialysis facilities in the United States. The Human Activity Profile (HAP) was administered to estimate PA among 1554 ambulatory enrolled patients in the Comprehensive Dialysis Study. Patients were followed until death or September 30, 2009, and the major outcome was all-cause mortality.
  
  
  RESULTS
  The average age was 59.8 (14.2) years; 55% of participants were male, 28% were black, and 56% had diabetes mellitus. The majority (57.3%) had low fitness estimated from the HAP score. The median follow-up was 2.6 (interquartile range, 2.2-3.1) years. The association between PA and mortality was linear across the range of scores (1-94). After multivariable adjustment, lower adjusted activity score on the HAP was associated with higher mortality (hazard ratio, 1.30; 95% confidence interval, 1.23-1.39 per 10 points). Patients in the lowest level of fitness experienced a 3.5-fold (95% confidence interval, 2.54-4.89) increase in risk of death compared with those with average or above fitness.
  
  
  CONCLUSIONS
  Low levels of PA are strongly associated with mortality among patients new to dialysis. Interventions aimed to preserve or enhance PA should be prospectively tested.
authors.affiliation: Nephrology Section, San Francisco Veterans Affairs Medical Center, San Francisco, CA 94121, USA. Kirsten.johansen@ucsf.edu
authors.forename: Kirsten L
authors.initials: KL
authors.lastname: Johansen
authors.forename: George A
authors.initials: GA
authors.lastname: Kaysen
authors.forename: Lorien S
authors.initials: LS
authors.lastname: Dalrymple
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Grimes
authors.forename: David V
authors.initials: DV
authors.lastname: Glidden
authors.forename: Shuchi
authors.initials: S
authors.lastname: Anand
authors.forename: Glenn M
authors.initials: GM
authors.lastname: Chertow
mesh_terms: D015331:Cohort Studies; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000401:mortality* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D011446:Prospective Studies; D006435:Renal Dialysis; D015996:Survival Rate