title: Racial and ethnic differences in the association of body mass index and survival in maintenance hemodialysis patients.
abstract: BACKGROUND
  In maintenance hemodialysis (HD) patients, overweight and obesity are associated with survival advantages. Given the greater survival of maintenance HD patients who are minorities, we hypothesized that increased body mass index (BMI) is associated more strongly with lower mortality in blacks and Hispanics relative to non-Hispanic whites.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  We examined a 6-year (2001-2007) cohort of 109,605 maintenance HD patients including 39,090 blacks, 17,417 Hispanics, and 53,098 non-Hispanic white maintenance HD outpatients from DaVita dialysis clinics. Cox proportional hazards models examined the association between BMI and survival.
  
  
  METHODS
  Race and BMI.
  
  
  RESULTS
  All-cause mortality.
  
  
  RESULTS
  Patients had a mean age of 62 ± 15 (standard deviation) years and included 45% women and 45% patients with diabetes. Across 10 a priori-selected BMI categories (<18-≥40 kg/m(2)), higher BMI was associated with greater survival in all 3 racial/ethnic groups. However, Hispanic and black patients experienced higher survival gains compared with non-Hispanic whites across higher BMI categories. Hispanics and blacks in the ≥40-kg/m(2) category had the largest adjusted decrease in death HR with increasing BMI (0.57 [95% CI, 0.49-0.68] and 0.63 [95% CI, 0.58-0.70], respectively) compared with non-Hispanic whites in the 23- to 25-kg/m(2) group (reference category). In linear models, although the inverse BMI-mortality association was observed for all subgroups, overall black maintenance HD patients showed the largest consistent decrease in death HR with increasing BMI.
  
  
  CONCLUSIONS
  Race and ethnicity categories were based on self-identified data.
  
  
  CONCLUSIONS
  Whereas the survival advantage of high BMI is consistent across all racial/ethnic groups, black maintenance HD patients had the strongest and most consistent association of higher BMI with improved survival.
authors.affiliation: Harold Simmons Center for Chronic Disease Research and Epidemiology, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA.
authors.forename: Joni
authors.initials: J
authors.lastname: Ricks
authors.forename: Miklos Z
authors.initials: MZ
authors.lastname: Molnar
authors.forename: Csaba P
authors.initials: CP
authors.lastname: Kovesdy
authors.forename: Joel D
authors.initials: JD
authors.lastname: Kopple
authors.forename: Keith C
authors.initials: KC
authors.lastname: Norris
authors.forename: Rajnish
authors.initials: R
authors.lastname: Mehrotra
authors.forename: Allen R
authors.initials: AR
authors.lastname: Nissenson
authors.forename: Onyebuchi A
authors.initials: OA
authors.lastname: Arah
authors.forename: Sander
authors.initials: S
authors.lastname: Greenland
authors.forename: Kamyar
authors.initials: K
authors.lastname: Kalantar-Zadeh
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D044383:Black People / Q000706:statistics & numerical data*; D015992:Body Mass Index; D002423:Cause of Death; D003953:Diagnosis-Related Groups; D005260:Female; D006630:Hispanic or Latino / Q000706:statistics & numerical data*; D006801:Humans; D053208:Kaplan-Meier Estimate; D007676:Kidney Failure, Chronic / Q000208:ethnology* / Q000401:mortality / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000208:ethnology; D050177:Overweight / Q000208:ethnology*; D016016:Proportional Hazards Models; D006435:Renal Dialysis; D012306:Risk; D014481:United States / Q000453:epidemiology; D044465:White People / Q000706:statistics & numerical data*; D001741:Black or African American