The 87th Annual Meeting of the American Association of Physical Anthropologists (2018)


Girl, you’ll be a woman soon: Examining associations between pelvic dimensions and body composition in growing girls living in London

SARAH-LOUISE DECRAUSAZ1, JANE E. WILLIAMS2, MARY S. FEWTRELL2, JAY T. STOCK1 and JONATHAN CK. WELLS2.

1Department of Archaeology, University of Cambridge, 2Childhood Nutrition Research Centre, University College London Institute of Child Health

April 14, 2018 1, Zilker 1/2/3 Add to calendar

The relationship between body composition and pelvic dimensions in women is unclear, principally with regards to preparing the body for reproduction. Previous work has demonstrated that pelvic breadth increases more slowly overall than linear growth and that girls reach their mother’s height before they reach their mother’s pelvic breadth. Fat mass increases as girls enter puberty; however precocious development as a result of increased adiposity in girls is unconfirmed. This study examines the interaction between pelvic breadth and changing adiposity that could impact pelvic dimensions as girls grow into women.

Body composition data and pelvic dimensions were collected from dual energy x-ray absorptiometry (DXA) scans from 286 girls and women living in London today between the ages of 4 and 22 years. Body composition data collected were four-component model lean mass and fat mass. Measures of adiposity collected were subscapular, suprailiac, tricep and bicep skinfolds and waist circumference. Tanner development stages and age at first menses were also collected. Outcome pelvic dimensions collected from DXA scans were bi-iliac breadth, mediolateral inlet breadth and biacetabular breadth. Variables were converted to age-adjusted z-scores to enable accurate body composition comparison between women and growing girls.

Multiple regression analyses demonstrate that only biacetabular breadth and mediolateral inlet breadth were associated significantly with both fat and lean mass. Tanner development stage and waist circumference associated significantly with mediolateral inlet breadth. These results suggest that bony pelvic dimensions vary in association with body composition and adiposity, potentially as part of preparing the female body for reproduction.

This research was made possible with support from the Parkes Foundation.