title: "IDEAL" aging is associated with lower resting metabolic rate: the Baltimore Longitudinal Study of Aging.
abstract: OBJECTIVE
  To assess the associations among age, health status, and resting metabolic rate (RMR) in a large population of older adults.
  
  
  METHODS
  Cross-sectional analysis.
  
  
  METHODS
  Community-dwelling volunteers from the Baltimore Longitudinal Study of Aging (BLSA).
  
  
  METHODS
  Persons aged 40 to 96 (mean 68.2 ± 11.0) who underwent a comprehensive physical examination, cognitive assessment, RMR testing, body composition assessment, and physical function testing during a 3-day clinic visit (N = 420).
  
  
  METHODS
  Participants were assigned to Insight into the Determination of Exceptional Aging and Longevity (IDEAL) or non-IDEAL categories based on health status. IDEAL participants were defined according to the absence of physical and cognitive impairments, chronic conditions and comorbidities, and blood profile abnormalities. A three-stage linear regression model was used to assess the relationship between RMR and age, using IDEAL classification as a predictor and adjusting for sex and body composition.
  
  
  RESULTS
  Resting metabolic rate averaged 1,512.4 ± 442.9 kcal/d and was lower with older age (β = -8.55, P < .001). After adjusting for age, sex, and body composition, RMR was 109.6 kcal/d lower in IDEAL than non-IDEAL participants (P < .005).
  
  
  CONCLUSIONS
  Individuals who are fully functional and free of major medical conditions have lower RMR than those with disease and functional impairments. These findings suggest that health status plays a role in energy use and regulation independent of age and body composition and that elevated RMR may be a global biomarker of poor health in older persons.
authors.affiliation: Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland; Longitudinal Studies Section, Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, Maryland.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Schrack
authors.forename: Nicolas D
authors.initials: ND
authors.lastname: Knuth
authors.forename: Eleanor M
authors.initials: EM
authors.lastname: Simonsick
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferrucci
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D015142:Baltimore; D001481:Basal Metabolism / Q000502:physiology*; D001823:Body Composition / Q000502:physiology*; D002153:Calorimetry, Indirect; D003071:Cognition / Q000502:physiology; D003430:Cross-Sectional Studies; D002149:Energy Intake / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D012146:Rest / Q000502:physiology*; D055815:Young Adult
keywords: aging; comorbidities; resting metabolic rate