title: Obesity and Structural Brain Integrity in Older Women: The Women's Health Initiative Magnetic Resonance Imaging Study.
abstract: Midlife obesity has been linked to age-related brain atrophy and risk of dementia, but the relationships are less clear for older individuals. These associations may be explained by changes in appetite or metabolism in the dementia prodrome; thus, prospective studies with adequate follow-up are needed. We examined the associations that obesity (body mass index, BMI) and change in BMI over an average of 6.6 (1.0-9.1) years have with global and regional brain and white matter lesion volumes in a sample of 1,366 women aged 65-80.
  
  
  
  Least square means for regional brain volumes and white matter lesion loads for women grouped by BMI and changes in BMI were generated from multivariable linear models with and without adjustment for demographic and health covariates.
  
  
  
  Both global obesity and increase in BMI were associated with lower cerebrospinal fluid and higher specific brain volumes (ps < .05), after controlling for diabetes and other cerebrovascular disease risk factors. Obesity, but not change in BMI, predicted lower lesion loads for the total, parietal, and occipital white matter (ps < .05).
  
  
  
  Obesity in this cohort is associated with less brain atrophy and lower ischemic lesion loads. The findings are consistent with our previous report of worse cognitive performance in association with weight loss (probably not due to frailty) in this cohort and in line with the idea of the "obesity paradox" as differences in dementia risk vary across time, whereby midlife obesity seems to be a predictor of dementia, whereas weight loss seems to be a better predictor at older ages.
authors.affiliation: Psychology Department, University of Wisconsin-Milwaukee. driscoli@uwm.edu.
authors.forename: Ira
authors.initials: I
authors.lastname: Driscoll
authors.affiliation: Department of Biostatistical Sciences, Wake Forest School of Medicine, Winston-Salem, North Carolina.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Gaussoin
authors.affiliation: Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Wassertheil-Smoller
authors.affiliation: College of Medicine, University of Florida, Gainesville.
authors.forename: Marian
authors.initials: M
authors.lastname: Limacher
authors.affiliation: Department of Biostatistical Sciences, Wake Forest School of Medicine, Winston-Salem, North Carolina.
authors.forename: Ramon
authors.initials: R
authors.lastname: Casanova
authors.affiliation: Department of Psychiatry, Neurology, and Epidemiology and Biostatistics, University of California, San Francisco.
authors.forename: Kristine
authors.initials: K
authors.lastname: Yaffe
authors.affiliation: Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, Maryland.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Resnick
authors.affiliation: Department of Biostatistical Sciences, Wake Forest School of Medicine, Winston-Salem, North Carolina.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Espeland
keywords: Aging; BMI; Brain volume; Lesion volume; White matter hyperintensities