title: Personality typology in relation to muscle strength.
abstract: BACKGROUND
  Physical inactivity plays a central role in the age-related decline in muscle strength, an important component in the process leading to disability. Personality, a significant determinant of health behaviors including physical activity, could therefore impact muscle strength throughout adulthood and affect the rate of muscle strength decline with aging. Personality typologies combining "high neuroticism" (N ≥ 55), "low extraversion" (E < 45), and "low conscientiousness" (C < 45) have been associated with multiple risky health behaviors but have not been investigated with regards to muscle strength.
  
  
  OBJECTIVE
  The purpose of this study is to investigate associations between individual and combined typologies consisting of high N, low E, and low C and muscle strength, and whether physical activity and body mass index act as mediators.
  
  
  METHODS
  This cross-sectional study includes 1,220 participants from the Baltimore Longitudinal Study of Aging.
  
  
  RESULTS
  High N was found among 18%, low E among 31%, and low C among 26% of the sample. High levels of N, particularly when combined with either low E or low C, were associated with lower muscle strength compared with having only one or none of these personality types. Facet analyses suggest an important role for the N components of depression and hostility. Physical activity level appears to partly explain some of these associations.
  
  
  CONCLUSIONS
  Findings provide support for the notion that the typological approach to personality may be useful in identifying specific personality types at risk of low muscle strength and offer the possibility for more targeted prevention and intervention programs.
authors: Clinical Research Branch, Longitudinal Studies Section, National Institute on Aging, Baltimore, MD, USA. toleam@mail.nih.gov
authors: Magdalena I
authors: MI
authors: Tolea
authors: Antonio
authors: A
authors: Terracciano
authors: Yuri
authors: Y
authors: Milaneschi
authors: E Jeffrey
authors: EJ
authors: Metter
authors: Luigi
authors: L
authors: Ferrucci
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