Cause-specific mortality in old age in relation to body mass index in middle age and in old age: follow-up of the Whitehall cohort of male civil servants

Int J Epidemiol. 2006 Feb;35(1):169-78. doi: 10.1093/ije/dyi212. Epub 2005 Nov 12.


Background: The relevance of body mass index (BMI) to cause-specific mortality in old age is uncertain.

Objectives: To examine cause-specific 5 year mortality in old age by BMI in old age and middle age (40-69 years).

Methods: Cox proportional hazards for mortality rates among 4862 former male civil servants in relation to quartiles of BMI measured when screened in 1968-70 and when resurveyed in 1997-98 (median age 76 years).

Results: The association between all-cause mortality after resurvey and BMI in old age was U-shaped with hazard ratios (HRs) of 1.3 (95% CI 1.1-1.5) for the lightest and heaviest categories relative to the middle two. Among 'healthy' men the lightest (<22.7 kg/m2) had greatest all-cause mortality. The heaviest men (>26.6 kg/m2) had increased risk of cardiovascular disease (CVD) mortality in the first two years or for the whole period if never-smokers. Respiratory mortality was inversely associated with BMI in old age [adjusted HR for trend per BMI category increase 0.6 (0.5-0.7)] but cancer mortality lacked a clear pattern. Net gain or loss of 10 kg or more between middle and old age was a strong predictor of all-cause and CVD mortality.

Conclusions: The shape of the association between BMI in old age and mortality differs by cause of death. Major weight change over time is a warning signal for higher CVD mortality. Having BMI<22.7 kg/m2 in old age is associated with above-average mortality rates even if apparently healthy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Aging / physiology*
  • Body Mass Index*
  • Cardiovascular Diseases / mortality
  • Cause of Death*
  • England
  • Follow-Up Studies
  • Government*
  • Health Surveys
  • Humans
  • Lung Diseases / mortality
  • Male
  • Middle Aged
  • Nutritional Status
  • Proportional Hazards Models
  • Prospective Studies
  • Thinness