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Sex‐specific functional adaptation of the femoral diaphysis to body composition
Author(s) -
Lacoste Jeanson Alizé,
Santos Frédéric,
Dupej Ján,
Velemínská Jana,
Brůžek Jaroslav
Publication year - 2018
Publication title -
american journal of human biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.559
H-Index - 81
eISSN - 1520-6300
pISSN - 1042-0533
DOI - 10.1002/ajhb.23123
Subject(s) - diaphysis , femur , apposition , anatomy , sexual dimorphism , fat mass , resorption , bone mass , cortical bone , biology , lean body mass , medicine , obesity , osteoporosis , endocrinology , body weight , surgery
Objectives The human femoral diaphysis is often used to reconstruct loading histories (mobility, activity, body mass). The proximal femur is known to be differentially affected by changes in total fat‐mass (FM), fat‐free mass (FFM), and body fat percentage (BF%), but the adaptation of the entire diaphysis to body composition has not been thoroughly characterized to date. Understanding how the femoral diaphysis adapts to body components would benefit biomechanical interpretations of the femoral variation and nutrition‐related studies. Methods Combining various methods from clinical nutrition, biological anthropology, and geometric morphometrics, we evaluated the correlation of measures taken on the entire femoral diaphysis with estimated FM, FFM, and BF% from 61 CT scans (17 females, 44 males). The sample was predominantly composed of people with obesity. Results Cortical area of the cross‐sections and local cortical thickness showed high correlation with BF% in particular, in females only. The curvature significantly decreased with FM and BF% in both sexes. The lowest correlations are found with FFM. Conclusions The observed sexual dimorphism is consistent with differing aging processes; cortical bone decreases in females through endosteal resorption while it remains almost constant in males who compensate for endosteal resorption by periosteal apposition on the diaphyseal surface. The functional adaptation to compressive forces indicates a systemic endosteal apposition of bone material with increased BF% and FM in females only. FM and BF% are linked to a straighter femur in both sexes, suggesting an optimization of the resistance to compressive loads by distributing them more linearly along the entire diaphysis.