Body weight variability in midlife and risk for dementia in old age.

Abstract

To analyze the relationship between body weight variability and dementia more than 3 decades later. The measurement of body weight variability was based on 3 successive weight recordings taken from over 10,000 apparently healthy tenured working men participating in the Israel Ischemic Heart Disease study, in which cardiovascular risk factors and clinical status were assessed in 1963, 1965, and 1968, when subjects were 40-70 years of age. Groups of men were stratified according to quartiles of SD of weight change among 3 measurements (1963/1965/1968): ≤ 1.15 kg, 1.16-1.73 kg, 1.74-2.65 kg, and ≥ 2.66 kg. The prevalence of dementia was assessed more than 36 years later in approximately one-sixth of them who survived until 1999/2000 (minimum age 76 years) and underwent cognitive evaluation (n = 1,620). Survivors' dementia prevalence rates were 13.4%, 18.4%, 20.1%, and 19.2% in the first to fourth quartiles of weight change SD, respectively (p for trend = 0.034). Compared to the first quartile of weight change SD and adjusted for diabetes mellitus, body height, and socioeconomic status, a multivariate analysis demonstrated that the odds ratio for dementia was 1.42 (95% confidence interval [CI] 0.95-2.13), 1.59 (95% CI 1.05-2.37), and 1.74 (95% CI 1.14-2.64) in quartiles 2-4 of weight change SD respectively. This relationship was independent of the direction of weight changes. Midlife variations in weight may antecede late-life dementia.