RADIAL BONE-MINERAL CONTENT OF NORMAL JAPANESE INFANTS AND PREPUBERTAL CHILDREN - INFLUENCE OF AGE, SEX AND BODY-SIZE

The present study was performed to measure appendicular bone mass of J apanese infants and children, and to assess the influence of age, sex and body size on bone mass during the period of bone growth. The bone mineral content (BMC) and bone width (BW) at the distal third of the r adius were measured by single photon absorptiometry (SPA) in 229 healt hy Japanese infants and children aged 0-12 years, and the BMC/BW ratio was calculated to give the bone mineral density (BMD). BMC and BW inc reased with age until 2 years, while BMD did not obviously change unti l 2 years. After 2 years of age, the overall effect of aging appeared more prominent in BMC and BMD than in BW. There were no significant di fferences in BMC, BW and BMD between males and females aged 0-12 years . Age, body height, and body weight were strongly correlated with thre e parameters of bone mass (BMC, BW, and BMD). Among the three paramete rs of bone mass, BMC showed the highest Pearson coefficient of correla tion with age (r=0.955), body height (r=0.957) and body weight (r=0.96 6), as compared with BW and BMD. The present cross-sectional study pro vides normative data of the appendicular bone mass in healthy Japanese children, which may serve as a standard for assessment of bone minera lization in Japanese infants and children with medical problems.