Aim: A 12-mo follow-up observation was performed to evaluate the tibial cortical bone properties of preadolescent children and their mothers in a densely populated area of Tokyo in association with their lifestyle in the context of healthy bone development of urban children.
Methods: Fifty-four volunteer mother-child pairs were examined twice: once in the 1st grade of elementary school and once in the following year. Tibial cortical speed of sound (TCSOS) was measured by non-invasive quantitative ultrasonometry. Nutritional intake and recreational activity were examined using a structured interview.
Results: TCSOS of the children showed a positive association with intake of vegetables, including potatoes and fruits (1st grade, r = 0.31, p < 0.05; 2nd grade, r = 0.33, p < 0.05), and inversely correlated with indoor recreational activities (1st grade, r = -0.28, p < 0.05). The z-score of TCSOS of the mothers was correlated with intake of milk, dairy products and eggs (r = 0.35, p < 0.001). However, there were no statistically significant correlations in TCSOS between children and their mothers.
Conclusion: A 1-y longitudinal study in urban children indicated the effects of specific types of food intake and recreational activities of children on tibial bone properties.