title: Interrelated factors favoring physical performance and activity in older adults from the NuAge cohort study.
abstract: OBJECTIVE
  Contribute evidence towards the complex interrelationships of body composition, physical performance and physical activity (PA) in an older population to assist in decisions for maintaining functional capacity in older adults.
  
  
  METHODS
  This is a cross-sectional analysis of an existing dataset in which a literature-supported model linking together the variables of interest is tested using path analysis. A proposed model with age, sex, energy intake and chronic diseases as predictors associated with body composition components, while the latter associated with physical performance and with PA acting both as a predictor and as an outcome of physical performance.
  
  
  METHODS
  A sample of 847, community dwellers, non-diabetic older men and women from the Quebec Longitudinal Study on Nutrition and Successful Aging (NuAge Study).
  
  
  METHODS
  Physical performance tests were reduced to two indices: strength and mobility. Muscle mass index (MMI; kg/height(2)) and % body fat were derived from DXA and bioimpedance analysis (BIA). PA was assessed by the Physical Activity Scale for the Elderly (PASE) and energy intakes were calculated from 24-hour food recalls. Data from the NuAge dataset served to test the relationships. The proposed model was evaluated using indices of fit.
  
  
  RESULTS
  Significant associations were found for MMI and % body fat with mobility (β -0.11 and -0.02, respectively), and for MMI with strength (β=0.60). PA was associated with MMI (β=0.02) and negatively with % body fat (β=-0.16), while mobility associated with PA (β=0.65). Our hypothesized model, with some paths added, fit the data: chi-square=4.64, root mean square error of approximation (RMSEA)=0.
  
  
  CONCLUSIONS
  PA has desirable associations with body composition in older adults and mobility is associated with PA. These results stress the importance of taking into account the prior level of mobility when recommending PA for this age group. This model could explain in part the complex interrelationships that occur with aging and the potential factors that could be targeted to assist older individuals in maintaining functional capacity.
authors.affiliation: Division of Geriatric Medicine, McGill University, Québec, Canada; School of Human Nutrition and Dietetics, McGill University, Québec, Canada.
authors.forename: Joane
authors.initials: J
authors.lastname: Matta
authors.affiliation: Division of Geriatric Medicine, McGill University, Québec, Canada; MUHC-Division of Clinical Epidemiology, Québec, Canada.
authors.forename: Nancy
authors.initials: N
authors.lastname: Mayo
authors.affiliation: CSSS-IUGS, Université de Sherbrooke, Québec, Canada.
authors.forename: Isabelle J
authors.initials: IJ
authors.lastname: Dionne
authors.affiliation: Department of Medicine and Research Centre of the Centre Hospitalier de l'Université de Montréal, Québec, Canada.
authors.forename: Pierrette
authors.initials: P
authors.lastname: Gaudreau
authors.affiliation: CSSS-IUGS, Université de Sherbrooke, Québec, Canada.
authors.forename: Tamàs
authors.initials: T
authors.lastname: Fülöp
authors.affiliation: CSSS-IUGS, Université de Sherbrooke, Québec, Canada.
authors.forename: Daniel
authors.initials: D
authors.lastname: Tessier
authors.affiliation: School of Human Nutrition and Dietetics, McGill University, Québec, Canada.
authors.forename: Katherine
authors.initials: K
authors.lastname: Gray-Donald
authors.affiliation: Department of Nutrition, Université de Montréal, Québec, Canada; Centre de recherche, Institut universitaire de gériatrie de Montréal, Québec, Canada.
authors.forename: Bryna
authors.initials: B
authors.lastname: Shatenstein
authors.affiliation: MUHC-Division of Clinical Epidemiology, Québec, Canada.
authors.forename: Susan
authors.initials: S
authors.lastname: Scott
authors.affiliation: Division of Geriatric Medicine, McGill University, Québec, Canada; School of Human Nutrition and Dietetics, McGill University, Québec, Canada. Electronic address: jose.morais@mcgill.ca.
authors.forename: José A
authors.initials: JA
authors.lastname: Morais
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D000886:Anthropometry / Q000379:methods; D001823:Body Composition / Q000502:physiology; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D002149:Energy Intake / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008954:Models, Biological; D009043:Motor Activity / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology; D010809:Physical Fitness / Q000502:physiology*; D012727:Sex Characteristics
keywords: Body composition; Path analysis; Physical activity; Physical performance