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Assessing somatic maturity in children and adolescents : relevance to pediatric bone health

University of British Columbia

All healthy children pass through the same stages of growth, yet they do so at distinct times and tempos. Consequently, there can be large maturational differences between children of the same chronological age. Thus, it is essential to measure maturity as study results may be confounded by biological age. Yet assessing maturity is difficult. As a result, methods to predict maturity exist, however, the validity of these models have been questioned. Further, the influence of maturational timing on bone mass, density, structure, and strength remains unclear. In this dissertation, I utilized data from healthy children who were participants in the Healthy Bones Study III (HBSIII). Three studies comprise my dissertation. First, given the need for accurate prediction of maturity, in Chapter 5 I assessed the utility of models that estimate maturity offset (MO) and age at peak height velocity (APHV), common indicators of somatic maturity. I discovered errors in the development of the original equations and subsequently, I developed and validated new models. Second, given known growth and maturation differences between ethnicities, in Chapter 6 I examined whether there were differences between Asian and white children who lived in the same community (Metro Vancouver). I observed that growth and maturation differences existed between Asian and white children, despite living in the same neighborhoods. I also assessed the validity of new maturity prediction equations for Asian children, as previous equations were developed in white children. I recalibrated the equations to better predict MO and APHV in this ethnic group. Third, given the unknown influence of maturity on post-pubertal bone health, in Chapter 7 I examined the relationship between maturational timing and bone mass, density, structure, and strength in late adolescence. Though some evidence suggests naturally delayed maturation is deleterious to bone in post-puberty, I found that post-pubertal adolescents who were considered late-maturing youth (mostly) ‘caught-up’ with those that were considered early-maturing, although there were sex- and site-related differences. Collectively these studies enhance our understanding of maturation, provide maturity prediction models for both white and Asian children, and clarify the complex relationship between maturational timing and bone mass, density, structure, and strength.

Text

2018-08-10

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/66728

Experimental Medicine

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/