During growth, the shape, architecture, and strength of bones are modulated by three major processes: growth, modelling, and remodelling. Modelling is of particular interest as it appears that bone is much more capable of responding to external loads during growth than at any other time. Remodelling also occurs during growth, but the net result of remodelling is to lose or maintain, but not to gain bone. Information on the pattern of bone mineral accrual is illustrated in Figs. 20.1 and 20.2, which show plots and velocity curves of total body bone mineral content during growth. The authors of these longitudinal studies of boys and girls have also shown that, on average, 26 % of adult total bone mineral was accrued during the 2 years around peak bone mineral content velocity, at age 12.5 for girls and 14.1 for boys. Furthermore, it is of interest that true bone density does not increase with size or age, and reported increases in BMD with age are a reflection of growth and an increase in size rather than an increase in bone mineral per unit volume.
KeywordsLactate Osteoporosis Fluoride Glucocorticoid Tral
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