title: The number of years lived with obesity and the risk of all-cause and cause-specific mortality.
abstract: BACKGROUND
  The role of the duration of obesity as an independent risk factor for mortality has not been investigated. The aim of this study was to analyse the association between the duration of obesity and the risk of mortality.
  
  
  METHODS
  A total of 5036 participants (aged 28-62 years) of the Framingham Cohort Study were followed up every 2 years from 1948 for up to 48 years. The association between obesity duration and all-cause and cause-specific mortality was analysed using time-dependent Cox models adjusted for body mass index. The role of biological intermediates and chronic diseases was also explored.
  
  
  RESULTS
  The adjusted hazard ratio (HR) for mortality increased as the number of years lived with obesity increased. For those who were obese for 1-4.9, 5-14.9, 15-24.9 and ≥ 25 years of the study follow-up period, adjusted HRs for all-cause mortality were 1.51 [95% confidence interval (CI) 1.27-1.79], 1.94 (95% CI 1.71-2.20), 2.25 (95% CI 1.89-2.67) and 2.52 (95% CI 2.08-3.06), respectively, compared with those who were never obese. A dose-response relation between years of duration of obesity was also clear for all-cause, cardiovascular, cancer and other-cause mortality. For every additional 2 years of obesity, the HRs for all-cause, cardiovascular disease, cancer and other-cause mortality were 1.06 (95% CI 1.05-1.07), 1.07 (95% CI 1.05-1.08), 1.03 (95% CI 1.01-1.05) and 1.07 (95% CI 1.05-1.11), respectively.
  
  
  CONCLUSIONS
  The number of years lived with obesity is directly associated with the risk of mortality. This needs to be taken into account when estimating its burden on mortality.
authors.affiliation: Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia. Asnawi_Abdullah@yahoo.com
authors.forename: Asnawi
authors.initials: A
authors.lastname: Abdullah
authors.forename: Rory
authors.initials: R
authors.lastname: Wolfe
authors.forename: Johannes U
authors.initials: JU
authors.lastname: Stoelwinder
authors.forename: Maximilian
authors.initials: M
authors.lastname: de Courten
authors.forename: Christopher
authors.initials: C
authors.lastname: Stevenson
authors.forename: Helen L
authors.initials: HL
authors.lastname: Walls
authors.forename: Anna
authors.initials: A
authors.lastname: Peeters
mesh_terms: D000328:Adult; D002318:Cardiovascular Diseases / Q000150:complications / Q000401:mortality; D002423:Cause of Death; D015331:Cohort Studies; D015986:Confounding Factors, Epidemiologic; D005260:Female; D006801:Humans; D008297:Male; D008404:Massachusetts / Q000453:epidemiology; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications / Q000401:mortality; D009765:Obesity / Q000150:complications / Q000401:mortality*; D016016:Proportional Hazards Models; D012307:Risk Factors; D013997:Time Factors; D055815:Young Adult