title: Does the obesity survival paradox of dialysis patients differ with age?
abstract: BACKGROUND
  The obesity paradox of hemodialysis patients (the association between obesity and survival) could be modified by age. We hypothesize that whereas obesity associates with survival in elderly patients, it behaves as a mortality risk marker in younger individuals.
  
  
  METHODS
  Retrospective study of 2002-2010 adult incident hemodialysis to analyze the relationship between body mass index (BMI) and annual body weight changes with mortality in different age strata.
  
  
  RESULTS
  Included in the study were 6,290 individuals. A progressive decrease in mortality was associated with increasing BMI ranges. Both annual body weight gains and losses were associated with mortality. Similar results were observed in elderly individuals, but in the BMI values of young patients, there were no significant differences in mortality.
  
  
  CONCLUSIONS
  There is a survival benefit with increasing BMI in patients overall. However, while these results persist in patients >65 years, in young people there are no changes in mortality. Patients with the highest inter-annual variability in weight have an increased risk.
authors.forename: Jordi
authors.initials: J
authors.lastname: Calabia
authors.forename: Emma
authors.initials: E
authors.lastname: Arcos
authors.forename: Juan Jesús
authors.initials: JJ
authors.lastname: Carrero
authors.forename: Jordi
authors.initials: J
authors.lastname: Comas
authors.forename: Martí
authors.initials: M
authors.lastname: Vallés
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D016016:Proportional Hazards Models; D065840:Protective Factors; D006435:Renal Dialysis / Q000401:mortality*; D012189:Retrospective Studies; D012307:Risk Factors; D016019:Survival Analysis; D015430:Weight Gain