posted on 2015-04-10, 11:14authored byTim J. Cole, Emily RoushamEmily Rousham, Nicola L. Hawley, Noel Cameron, Shane A. Norris, John M. Pettifor
Aim To examine ethnic and sex differences in the pattern of skeletal maturity from adolescence to adulthood using a novel longitudinal analysis technique (SuperImposition by Translation And Rotation (SITAR)).
Setting Johannesburg, South Africa.
Participants 607 boys and girls of black as well as white ethnicity from the Birth to Twenty bone health study, assessed annually from 9 to 20 years of age.
Outcome measure Bone maturity scores (Tanner–Whitehouse III radius, ulna, and short bones (TW3 RUS)) assessed longitudinally from hand-wrist radiographs were used to produce individual and mean growth curves of bone maturity and analysed by the SITAR method.
Results The longitudinal analysis showed that black boys matured later by 7.0 SE 1.6 months (p<0.0001) but at the same rate as white boys, whereas black girls matured at the same age but at a faster rate than white girls (by 8.7% SE 2.6%, p=0.0007). The mean curves for bone maturity score consistently showed a midpubertal double kink, contrasting with the quadratic shape of the commonly used reference centile curves for bone maturity (TW3).
Conclusions Skeletal maturity was reached 1.9 years earlier in girls than boys, and the pattern of maturation differed between the sexes. Within girls, there were no ethnic differences in the pattern or timing of skeletal maturity. Within boys, however, skeletal maturity was delayed by 7 months in black compared with white ethnicity. Skeletal maturation, therefore, varies differentially by sex and ethnicity. The delayed maturity of black boys, but not black girls, supports the hypothesis that boys have greater sensitivity to environmental constraints than girls.
Funding
The Birth to Twenty cohort and Bone Health study were funded by the Wellcome Trust, South African Medical Research Council, National Research Foundation and the University of the Witwatersrand.
History
School
Sport, Exercise and Health Sciences
Published in
ARCHIVES OF DISEASE IN CHILDHOOD
Volume
100
Issue
2
Pages
138 - 143 (6)
Citation
COLE, T.J. ... et al., 2015. Ethnic and sex differences in skeletal maturation among the Birth to Twenty cohort in South Africa. Archives of Disease in Childhood, 100 (2), pp. 138 - 143.
This work is made available according to the conditions of the Creative Commons Attribution 4.0 International (CC BY 4.0) licence. Full details of this licence are available at: http://creativecommons.org/licenses/ by/4.0/
Acceptance date
2014-09-02
Publication date
2014-11-19
Copyright date
2015
Notes
This is an Open Access article distributed in accordance withunder the terms of the Creative Commons Attribution (CC BY 4.0) license, which permits others to distribute, remix, adapt and build upon this work, for commercial use, provided the original work is properly cited. See: http://creativecommons.org/licenses/by/4.0/