In this chapter, we present bone growth patterns among rural Chinese children based on both cross-sectional and 6-year follow-up data. The bone parameters examined were whole-body bone area (BA), bone mineral content (BMC), and bone mineral density (BMD), with a particular focus on (1) attained levels and the timing of peak growth by age, gender, and Tanner pubertal stage; (2) bone growth "tracking": the influence of bone ranking early in life on that attained at an older age; and (3) the influence of timing of puberty on attained levels and the timing of peak BA, BMC, and BMD growth. Our cross-sectional studies have shown that the bone parameters examined herein tended to increase linearly from early childhood until early adolescence, where it began to slow and then plateau in late adolescence to young adulthood. The increase in BA and BMC across age was similar between males and females prior to age 15, but after age 15, BA and BMC leveled-off in females, but continued to increase in males. However for BMD, female levels were higher between ages 13-17, but after age 17, male BMD continued to increase and eventually surpassed female BMD levels by age 18 (or Tanner stage IV). Our longitudinal studies have demonstrated that female peak bone growth precedes that in males by 1-3 years, with males having ~2 extra years of prepubertal bone accretion. In both genders, peak growth in height (linear bone growth) is first achieved and was, in order, followed by peak BA, BMC, and BMD. Children with a relatively low rank in their baseline, BA, BMC, and BMD distribution tended to be low ranked at 6-year follow-up, but a considerable proportion shifted ranks between baseline and follow-up. Notably, those with relatively low BMC and BA at baseline had decreased bone growth up to ages 14-15, but their "post-peak" growth deceleration was less steep than those with higher baseline bone rankings.
|Original language||English (US)|
|Title of host publication||Handbook of Growth and Growth Monitoring in Health and Disease|
|Publisher||Springer New York|
|Number of pages||15|
|State||Published - Jan 1 2012|
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