title: The prognostic value of body-mass index on mortality in older adults with dementia living in nursing homes.
abstract: A protective effect of obesity on death has been reported in the context of various co-morbidities. We studied if the obesity paradox applied to nursing home (NH) older residents according to dementia status.
  
  
  
  Prospective data from 3741 NH residents from France. All-cause mortality was the dependent measure. Subjects were categorized according with body mass index (BMI) as underweight, normal-weight, overweight, and obese. Dementia status was obtained from medical charts. Cox regressions were performed.
  
  
  
  There were 344 (9.2%) residents who were underweight, 1367 (43.8%) normal weight, 1069 (28.6%) overweight and 691 (18.5%) obese. 1083 (28.9%) people died during follow-up. In residents with dementia, mortality risk was reduced by almost half in overweight and obese people (HRs of 0.60 [0.48-0.76] and 0.53 [0.38-0.75], respectively; p < 0.001), and increased in underweight (HR = 1.65 [1.29-2.12]; p < 0.001) compared to normal-weight residents; moreover, each 1 kg/m2increase in BMI decreased the risk of death by 12% and 9% in underweight and normal-weight subjects with dementia. For people without dementia, mortality risk was reduced in overweight and obese people (HRs of 0.80 [0.65-0.99], p = 0.042, and 0.77 [0.60-0.99], p = 0.044, respectively) compared to normal-weight; the 1-unit increase in BMI reduced the risk of death (23% reduction) only in underweight people.
  
  
  
  This study showed that the presence of dementia amplifies the obesity paradox in very old and functionally limited NH residents. Therefore, weight loss in NH residents, particularly in people with dementia, should be considered with extreme caution even for obese people.
authors.affiliation: Gerontopole of Toulouse, Institute of Ageing, Toulouse University Hospital (CHU-Toulouse), Toulouse, France; UMR INSERM 1027, University of Toulouse III, Toulouse, France. Electronic address: philipebarreto81@yahoo.com.br.
authors.forename: Philipe
authors.initials: P
authors.lastname: de Souto Barreto
authors.affiliation: Clinique des Minimes, Toulouse, France.
authors.forename: Yves
authors.initials: Y
authors.lastname: Cadroy
authors.affiliation: Gerontopole of Toulouse, Institute of Ageing, Toulouse University Hospital (CHU-Toulouse), Toulouse, France.
authors.forename: Eirini
authors.initials: E
authors.lastname: Kelaiditi
authors.affiliation: Gerontopole of Toulouse, Institute of Ageing, Toulouse University Hospital (CHU-Toulouse), Toulouse, France; UMR INSERM 1027, University of Toulouse III, Toulouse, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Vellas
authors.affiliation: Gerontopole of Toulouse, Institute of Ageing, Toulouse University Hospital (CHU-Toulouse), Toulouse, France; UMR INSERM 1027, University of Toulouse III, Toulouse, France.
authors.forename: Yves
authors.initials: Y
authors.lastname: Rolland
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D001835:Body Weight; D015897:Comorbidity; D003704:Dementia / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D005602:France / Q000453:epidemiology; D006707:Homes for the Aged; D006801:Humans; D008297:Male; D009026:Mortality; D065228:Non-Randomized Controlled Trials as Topic; D009735:Nursing Homes; D009765:Obesity / Q000453:epidemiology*; D050177:Overweight / Q000453:epidemiology; D015995:Prevalence; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires
keywords: Mortality; Nursing home; Obesity paradox; Older adults; Overweight; Underweight