title: Associations of Brain Structure With Adiposity and Changes in Adiposity in a Middle-Aged and Older Biracial Population.
abstract: BACKGROUND
  Studies of adiposity and brain pathology in African Americans (AA) are sparse despite higher rates of obesity, dementia, and dementia-associated brain pathology in AA. This study examined relations of adiposity to white matter hyperintensities (WMH) and total brain volume (TBV) in AA and non-Hispanic whites (NHW).
  
  
  METHODS
  Waist circumference (WC) and body mass index (BMI) were measured in the Genetic Epidemiology Network of Arteriopathy study at Visits 1 (mean age 57 [±11]) and 2 (mean age 61 [±10], mean 5.2 years later). Brain MRIs were obtained shortly after Visit 2 in 1,702 participants (64% women, 48% AA). Multilevel linear regression using generalized estimating equation estimated associations of adiposity (cross-sectional) or adiposity changes with WMH (accounting for intracranial size) or TBV adjusting for demographics, cardiovascular risk factors, and incorporating adiposity-by-race interactions. Adiposity-by-age interactions were examined.
  
  
  RESULTS
  Concurrent TBV was inversely associated with BMI (β = -2.76 [95% confidence interval (CI): -4.99, -0.53]) and WC (β = -2.19 [CI: -4.04, -0.34]). Concurrent WMH were negatively associated with BMI (β = -0.04 [CI: -0.06, -0.01]) and, among NHW, with WC (β = -0.04 [CI: -0.06, -0.02]) but not with changes in BMI or WC. BMI increases were associated with lower TBV (β = -16.20, [CI: -30.34, -2.06]) in AA but not in NHW (β = -2.76 [CI: -14.02, 8.51]), although race-by-adiposity interactions were not supported. WC increases were not associated with MRI outcomes.
  
  
  CONCLUSIONS
  Greater measures of obesity and increases in measures of obesity, which are common in mid-life, could be detrimental to brain health, particularly in AA.
authors.affiliation: Department of Medicine-Geriatrics, University of Mississippi Medical Center, Jackson.
authors.forename: B Gwen
authors.initials: BG
authors.lastname: Windham
authors.affiliation: Center of Biostatistics, Jackson, Mississippi.
authors.forename: Seth T
authors.initials: ST
authors.lastname: Lirette
authors.affiliation: Institute of Molecular Medicine, Health Science Center at Houston, University of Texas.
authors.forename: Myriam
authors.initials: M
authors.lastname: Fornage
authors.affiliation: Department of Medicine, Boston University, Massachusetts.
authors.forename: Emelia J
authors.initials: EJ
authors.lastname: Benjamin
authors.affiliation: Department of Medicine-Geriatrics, University of Mississippi Medical Center, Jackson.|Center of Biostatistics, Jackson, Mississippi.
authors.forename: Kirby G
authors.initials: KG
authors.lastname: Parker
authors.affiliation: Mayo Clinic, Rochester, Minnesota.
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Turner
authors.affiliation: Mayo Clinic, Rochester, Minnesota.
authors.forename: Clifford R
authors.initials: CR
authors.lastname: Jack
authors.affiliation: Center of Biostatistics, Jackson, Mississippi.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Griswold
authors.affiliation: Department of Medicine-Geriatrics, University of Mississippi Medical Center, Jackson.
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Mosley
mesh_terms: D001741:Black or African American; D000375:Aging; D015992:Body Mass Index; D001921:Brain / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D008922:Mississippi / Q000453:epidemiology; D009765:Obesity / Q000453:epidemiology*; D055105:Waist Circumference; D066127:White Matter / Q000000981:diagnostic imaging*; D044465:White People
keywords: Longitudinal; MRI; Obesity; Race