title: Interaction between body mass index and central adiposity and risk of incident cognitive impairment and dementia: results from the Women's Health Initiative Memory Study.
abstract: OBJECTIVE
  To assess the relationship between body mass index (BMI) and waist-hip ratio (WHR) and the clinical end points of cognitive impairment and probable dementia in a cohort of older women enrolled in the Women's Health Initiative Memory Study (WHIMS).
  
  
  METHODS
  Prospective, randomized clinical trial of hormone therapies with annual cognitive assessments and anthropometrics.
  
  
  METHODS
  Fourteen U.S. clinical sites of the WHIMS.
  
  
  METHODS
  Seven thousand one hundred sixty-three postmenopausal women aged 65 to 80 without dementia.
  
  
  METHODS
  Annual cognitive assessments, average follow-up of 4.4 years, including classification of incident cognitive impairment and probable dementia. Height, weight, waist, and hip measurements were assessed at baseline, and a waist-hip ratio (WHR) of 0.8 or greater was used as a marker of central adiposity.
  
  
  RESULTS
  There were statistically significant interactions between BMI and WHR and incident cognitive impairment and probable dementia with and without adjustment for a panel of cognitive risk factors. Women with a WHR of 0.80 or greater with a BMI of 20.0 to 24.9 kg/m² had a greater risk of cognitive impairment and probable dementia than more-obese women or women with a WHR less than 0.80, although women with a WHR less than 0.80 and a BMI of 20.0 to 24.9 kg/m² had poorer scores on cognitive assessments.
  
  
  CONCLUSIONS
  WHR affects the relationship between BMI and risk of cognitive impairment and probable dementia in older women. Underweight women (BMI < 20.0 kg/m²) with a WHR less than 0.80 had a greater risk than those with higher BMIs. In normal-weight to obese women (20.0-29.9 kg/m², central adiposity (WHR ≥ 0.80) is associated with greater risk of cognitive impairment and probable dementia than in women with higher BMI. These data suggest that central adiposity as a risk factor for cognitive impairment and probable dementia in normal-weight women.
authors.affiliation: Division of Geriatrics, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA. d-kerwin@northwestern.edu
authors.forename: Diana R
authors.initials: DR
authors.lastname: Kerwin
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Gaussoin
authors.forename: Rowan T
authors.initials: RT
authors.lastname: Chlebowski
authors.forename: Lewis H
authors.initials: LH
authors.lastname: Kuller
authors.forename: Mara
authors.initials: M
authors.lastname: Vitolins
authors.forename: Laura H
authors.initials: LH
authors.lastname: Coker
authors.forename: Jane M
authors.initials: JM
authors.lastname: Kotchen
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Nicklas
authors.forename: Sylvia
authors.initials: S
authors.lastname: Wassertheil-Smoller
authors.forename: Raymond G
authors.initials: RG
authors.lastname: Hoffmann
authors.forename: Mark A
authors.initials: MA
authors.lastname: Espeland
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D003072:Cognition Disorders / Q000453:epidemiology*; D003704:Dementia / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D056128:Obesity, Abdominal / Q000453:epidemiology; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D013851:Thinness / Q000453:epidemiology; D014481:United States / Q000453:epidemiology; D049629:Waist-Hip Ratio