title: Effect of self-reported walking difficulty on bone mass and bone resorption marker in Japanese people aged 40 years and over.
abstract: BACKGROUND
  This study aimed to examine the association of walking difficulty with bone mass or bone turnover among community-dwelling Japanese people aged 40 years and older.
  
  
  METHODS
  We studied 1097 community-dwelling Japanese people aged 40 years and older (379 men and 718 women) who were invited to participate in periodic health examinations in 2006-2009. Walking difficulty was defined as having difficulty walking 100 m on a level surface (self-administered questionnaire). Calcaneal stiffness index (bone mass) was measured by quantitative ultrasound. Spot urine samples were collected, and urinary N-terminal cross-linking telopeptide of type I collagen (NTx) was measured. Values were corrected for creatinine (Cre) concentration.
  
  
  RESULTS
  The prevalence of walking difficulty was significantly higher in women than in men (7.4 vs. 3.4 %, p = 0.011) and significantly increased with age in men (p for trend = 0.02) and women (p for trend <0.001). In univariate analysis, men and women with walking difficulty were older (p < 0.001) and had a lower stiffness index (p < 0.001), compared with those without walking difficulty. Among women, individuals with walking difficulty had significantly higher urinary NTx/Cre than those without walking difficulty (p < 0.001); however, this was not so among men (p = 0.39). Multiple regression analysis adjusted for age, weight, and menopausal status showed a significant association between walking difficulty and lower stiffness index in men (p = 0.004) and women (p = 0.005). In women, walking difficulty was significantly associated with higher NTx/Cre (p = 0.001), but not in men (p = 0.35).
  
  
  CONCLUSIONS
  Walking difficulty may contribute to low bone mass in both sexes but might cause high bone turnover in women only.
authors.affiliation: Department of Public Health, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan. yasuyo-a@nagasaki-u.ac.jp.
authors.forename: Yasuyo
authors.initials: Y
authors.lastname: Abe
authors.affiliation: Department of Public Health, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nishimura
authors.affiliation: Department of Public Health, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Arima
authors.affiliation: Department of Public Health, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.|Department of Rehabilitation, Nishi-Isahaya Hospital, Isahaya, Japan.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Kanagae
authors.affiliation: Department of Public Health, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.|Department of Rehabilitation, Nishi-Isahaya Hospital, Isahaya, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Mizukami
authors.affiliation: Department of Public Health, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.|Department of Rehabilitation, Nishi-Isahaya Hospital, Isahaya, Japan.
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Tomita
authors.affiliation: Department of Public Health, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.|Department of Rehabilitation, Nishi-Isahaya Hospital, Isahaya, Japan.
authors.forename: Takuhiro
authors.initials: T
authors.lastname: Okabe
authors.affiliation: Goto Health Care Office, Nagasaki, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Goto
authors.affiliation: Center for Public Relations Strategy, Nagasaki University, Nagasaki, Japan.
authors.forename: Itsuko
authors.initials: I
authors.lastname: Horiguchi
authors.affiliation: Department of Public Health, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Aoyagi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D015415:Biomarkers; D015519:Bone Density; D001862:Bone Resorption / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D016138:Walking / Q000502:physiology*
chemical_list: D015415:Biomarkers
keywords: Bone mass; Bone turnover; Calcaneal stiffness index; Walking difficulty