Effect of self-reported walking difficulty on bone mass and bone resorption marker in Japanese people aged 40 years and over

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. 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. 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