title: Clinical determinants of reduced physical activity in hemodialysis and peritoneal dialysis patients.
abstract: OBJECTIVE
  The phenotype associated to reduced physical activity (PA) in dialysis patients is poorly documented. We here evaluate weekly PA in two independent cohorts.
  
  
  METHODS
  Cross-sectional study with PA assessed by the number of steps/day measured by pedometer in two cohorts of prevalent dialysis patients: (1) peritoneal dialysis (PD) patients (n = 64; 62 ± 14 years; 70 % men) from Stockholm, Sweden using the pedometer for 7 consecutive days; (2) hemodialysis (HD) patients (n = 78; 63 ± 12 years; 65% men) from a single center in Madrid, Spain using the pedometer for 6 consecutive days: 2 HD days, 2 non-HD midweek days and 2 non-HD weekend days. In both cohorts, comorbidities, body composition, nutritional status, and related biomarkers were assessed. Cohorts were not merged; instead data were analyzed separately serving as reciprocal replication analyses.
  
  
  RESULTS
  Most patients (63% of PD and 71% of HD) were considered sedentary (<5,000 steps/day). PD patients had on average 4,839 ± 3,313 steps/day. HD patients had 3,767 ± 3,370 steps/day on HD-free days, but fewer steps/day on HD days (2,274 ± 2,048 steps/day; p < 0.0001). In both cohorts, and across increasing PA tertiles, patients were younger and had less comorbidities. Higher PA was also accompanied by better nutritional status (depicted by albumin, pre-albumin, creatinine and normalized protein catabolic rate in HD, and by albumin and subjective global assessment [SGA] in PD), higher lean body mass, and lower fat body mass (bioimpedance and/or dual-energy X-ray absorptiometry [DEXA]). Higher levels of PA were accompanied by lower levels of C-reactive protein in PD. Age and lean body mass were the strongest multivariate predictors of PA in both cohorts.
  
  
  CONCLUSIONS
  There is a high prevalence of sedentary behavior in dialysis patients. Better physical activity was consistently associated with younger age, lower presence of comorbidities and better nutritional status. Pedometers represent a simple and inexpensive tool to objectively evaluate physical activity in this patient population.
authors.affiliation: Department of Nephrology, Severo Ochoa Hospital, Leganes, Madrid, Spain.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Cobo
authors.forename: Paloma
authors.initials: P
authors.lastname: Gallar
authors.forename: Thiane
authors.initials: T
authors.lastname: Gama-Axelsson
authors.forename: Cristina
authors.initials: C
authors.lastname: Di Gioia
authors.forename: Abdul Rashid
authors.initials: AR
authors.lastname: Qureshi
authors.forename: Rosa
authors.initials: R
authors.lastname: Camacho
authors.forename: Ana
authors.initials: A
authors.lastname: Vigil
authors.forename: Olof
authors.initials: O
authors.lastname: Heimbürger
authors.forename: Olimpia
authors.initials: O
authors.lastname: Ortega
authors.forename: Isabel
authors.initials: I
authors.lastname: Rodriguez
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Herrero
authors.forename: Peter
authors.initials: P
authors.lastname: Bárány
authors.forename: Bengt
authors.initials: B
authors.lastname: Lindholm
authors.forename: Peter
authors.initials: P
authors.lastname: Stenvinkel
authors.forename: Juan Jesús
authors.initials: JJ
authors.lastname: Carrero
mesh_terms: D056044:Actigraphy / Q000295:instrumentation; D000367:Age Factors; D000368:Aged; D016009:Chi-Square Distribution; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D015999:Multivariate Analysis; D009752:Nutritional Status; D016017:Odds Ratio; D010530:Peritoneal Dialysis / Q000009:adverse effects*; D006435:Renal Dialysis / Q000009:adverse effects*; D051436:Renal Insufficiency, Chronic / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy*; D012307:Risk Factors; D057185:Sedentary Behavior; D013030:Spain / Q000453:epidemiology; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors; D016896:Treatment Outcome