The human body shape index (HBSI): An anthropometric measure based on an age-related model of human growth

Abstract

Body shape during age-related human growth is customarily described using either the body mass index (BMI) or the Ponderal Index (PI). These indices describe the human body shape (HBS) with different proportions between body mass (M) and body height (H). Both indices are affected by age during childhood. The establishment and maintenance of age- and sex-specific databases is time consuming and an expensive process. The lack of a general model for abnormal HBS makes the comparison of different populations (both in respect to time and location) very difficult. Efforts to evaluate the epidemic status of childhood obesity would benefit from the development of new tools and the refining of existing simple, reliable tools to evaluate and monitor HBS. An age invariant, sex-specific human body shape index (HBSI) has been recently introduced as an alternative to age-specific BMI and PI models. The HBSI was based on a mathematical model of human growth of Polish children (5-18 year old) between years 1985 and 1990. The sample was characterized by ideal fat composition (judged by 95th percentile of BMI values). To model growth, the best fit between individual body height (h) and body mass (m) was calculated separately between sexes with the function M = cpHx. The models of growth were M = 13.11 H 2.84 (R2 = 0.9) and M = 13.64 H 2.68 (R2 = 0.91) in girls and boys respectively. The HBSIs were calculated as (HBSIp = M/Hc), where HBSIB = 13.74 ± 1.72 (in boys), HBSIG = 13.21 ± 1.73 (in girls) and HBSI = 13.47 ± 1.74 (for both sexes). While the sensitivity and specificity of HBSI in the classification of the pathological changes in human body shape has not been explored, HBSI may be beneficial over other age-specific indices in the comparative analysis of HBS in children originating from different populations (location, diversity, and time periods) over long periods of growth.