title: Knee extensor strength is associated with Mini-Mental State Examination scores in elderly men.
abstract: The present study examined whether the strength capability of knee extensor muscles is associated with global cognitive function, assessed by Mini-Mental State Examination (MMSE), in non-disabled elderly men. Isometric torques during maximal voluntary knee extension, plantar flexion, and elbow flexion and MMSE scores were determined in 39 non-disabled men aged 61-79 years and used for the cross-sectional analysis examining the associations among the measured variables. Moreover, 27 of the subjects participated in a training program consisted of body mass-based exercises (sitting down onto and standing up from a chair, hip joint extension and flexion, calf raises, side leg raises, and trunk flexion and extension) 6 days a week for 3 months. Isometric torques and MMSE scores were determined after the intervention. Among the data before intervention, only knee extension torque (KET) and KET relative to body mass (KET/BM) significantly correlated to the MMSE scores: r = 0.579 (P < 0.0001) for KET and r = 0.520 (P < 0.001) for KET/BM. After the intervention, KET and KET/BM increased significantly, but MMSE score did not. However, the absolute change in MMSE scores was significantly associated with that in KET (r = 0.381, P < 0.05) and KET/BM (r = 0.422, P < 0.05). These findings indicate that the strength capability of knee extensors is associated with global cognitive function in non-disabled elderly men, and provide a new perspective to a general concept that exercises strengthening knee extensor muscles should be included in resistance training programs for elderly individuals.
authors.affiliation: National Institute of Fitness and Sports in Kanoya, 1 Shiramizu, Kanoya, Kagoshima 891-2393, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Nakamoto
authors.forename: Yasuhide
authors.initials: Y
authors.lastname: Yoshitake
authors.forename: Yohei
authors.initials: Y
authors.lastname: Takai
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kanehisa
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kitamura
authors.forename: Masashi
authors.initials: M
authors.lastname: Kawanishi
authors.forename: Shiro
authors.initials: S
authors.lastname: Mori
mesh_terms: D000368:Aged; D003071:Cognition / Q000502:physiology*; D003430:Cross-Sectional Studies; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008137:Longitudinal Studies; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D016059:Range of Motion, Articular; D019415:Torque