title: Cognitive Decline, Body Mass Index, and Waist Circumference in Community-Dwelling Elderly Participants.
abstract: OBJECTIVE
  The aim of this study was to explore the association of body mass index (BMI), waist circumference (WC), and BMI and WC changes over time with cognitive decline in a nationally representative sample.
  
  
  METHODS
  A total of 5239 participants (≥65 years) were followed for 3 years as part of the National Health and Aging Trends Study. Cox proportional hazard regression was applied to model the risk of cognitive decline.
  
  
  RESULTS
  BMI, after adjusting for WC and main confounders, was associated with reduced risk of cognitive decline (hazard ratio [HR] 0.97 for each unit BMI increase, 0.95-0.99). After stratifying by gender and age, this effect remained significant among females and young elders ≤80 years. A BMI decrease and WC increase >10% over the study period were associated with increased risk of cognitive decline (HR 1.98, 1.16-3.38; HR 1.30, 1.04-1.62, respectively).
  
  
  CONCLUSIONS
  In the elderly individuals, lean mass, as measured by BMI adjusted for WC, was associated with reduced risk of cognitive decline. Loss of lean mass and gain of fat mass, as measured by WC adjusted for BMI, were associated with elevated risk of cognitive decline.
authors.affiliation: 1 Department of Psychiatry, New York State Psychiatric Institute, Columbia University, New York, NY, USA.
authors.forename: Jorge Mario
authors.initials: JM
authors.lastname: Rodríguez-Fernández
authors.affiliation: 1 Department of Psychiatry, New York State Psychiatric Institute, Columbia University, New York, NY, USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Danies
authors.affiliation: 1 Department of Psychiatry, New York State Psychiatric Institute, Columbia University, New York, NY, USA.
authors.forename: José
authors.initials: J
authors.lastname: Martínez-Ortega
authors.affiliation: 2 Department of Neurosurgery, University of California, San Francisco, CA, USA.
authors.forename: William C
authors.initials: WC
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D015992:Body Mass Index; D003072:Cognition Disorders / Q000209:etiology* / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000523:psychology*; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012307:Risk Factors; D055105:Waist Circumference
keywords: adiposity; cognitive impairment; dementia; fat mass; lean mass