Growth processes leading to a large or small adult size

Background: The way in which a large size in anthropometric variables is ac hieved is a longstanding problem, since the pubertal spurt shows statistica lly and clinically little association with adult size (mostly studied for h eight). By analysing longitudinal growth of groups of subjects with a large or a small adult size separately for height, leg and sitting height, and b ihumeral and biiliac width, we studied this problem in some detail. Of inte rest are growth patterns specific for these variables and for boys or girls . Methods: The data consist of 120 boys and 112 girls followed longitudinally from 4 weeks until adulthood. Statistically, structural average velocity c urves were computed for each variable and each subgroup separately for comp arison. This velocity curve represents the average intensity and the averag e tempo of growth. Since the area under the velocity curve is adult size, d ifferences in the growth process can be visualized. Results: Both sexes show similar patterns in reaching a small or large adul t size. The different variables, however, show marked differences. Only for legs is the pubertal spurt delayed for the large groups (with additional g ains in prepubertal years). For sitting height and biiliac width, a slightl y elevated velocity all along development (after 2 years) leads to a larger size and for bihumeral width the size of the pubertal peak is decisive. Conclusions: The steering of growth to a certain target size is qualitative ly similar for boys and girls, but quite different for different anthropome tric variables. This leads to questions about endocrinological control for various parts of the body and differential bone growth in development.