title: Differences in physical function by body mass index in elderly Japanese individuals: The Fujiwara-kyo Study.
abstract: OBJECTIVE
  This study examined differences in physical function according to body mass index (BMI) in elderly Japanese individuals.
  
  
  METHODS
  Participants (1754 men and 1795 women aged ≥65 years) were divided into the following five BMI groups: low BMI (≤20.0), low-medium BMI (20.1-22.5), medium BMI (22.6-25.0), medium-high BMI (25.1-27.5) and high BMI (≥27.6). Physical function was measured according to BMI and sex, and associations between BMI and physical function were examined.
  
  
  RESULTS
  Compared with the medium BMI group, handgrip strength (HGS), knee extension torque (KET), and knee flexion torque (KFT) were significantly lower in both sexes in the low BMI group, while KET and KFT were significantly higher among men in the high BMI group. One-leg standing time (OLST) with open eyes was significantly shorter among men in the high BMI group than in the medium BMI group. The high BMI group was significantly inferior to the medium BMI group in 10m gait time (10MGT), OLST, and maximum one-step length to height ratio among women. All physical functions, except for 10MGT in men, were associated with BMI adjusted age and/or sex. Muscle strength showed a positive association with BMI in both sexes. There was a stronger association between BMI and physical performance in women compared to men.
  
  
  CONCLUSIONS
  We found that BMI influences a variety of factors related to muscle strength and physical performance. Our findings may help contribute to the prevention of mobility impairments in elderly Japanese individuals.
authors.affiliation: Department of Physical Therapy, Faculty of Health and Science, Kio University, Japan. Electronic address: a.minematsu@kio.ac.jp.
authors.forename: Akira
authors.initials: A
authors.lastname: Minematsu
authors.affiliation: Faculty of Biomedical Engineering, Osaka Electro-Communication University, Japan.
authors.forename: Kan
authors.initials: K
authors.lastname: Hazaki
authors.affiliation: Department of Orthopedics, Yamato Takada Municipal Hospital, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Harano
authors.affiliation: Department of Community Health and Epidemiology, Nara Medical University School of Medicine, Japan.
authors.forename: Nozomi
authors.initials: N
authors.lastname: Okamoto
authors.affiliation: Department of Community Health and Epidemiology, Nara Medical University School of Medicine, Japan.
authors.forename: Norio
authors.initials: N
authors.lastname: Kurumatani
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology*; D044466:Asian People; D015992:Body Mass Index; D001835:Body Weight; D015444:Exercise; D005260:Female; D018737:Hand Strength / Q000502:physiology; D006801:Humans; D007717:Knee / Q000502:physiology; D016014:Linear Models; D008297:Male; D053580:Muscle Strength / Q000502:physiology
keywords: Body mass index (BMI); Elderly Japanese; Physical function