Division of Kinesiology, Health and Sport Studies, Wayne State University, Detroit, MI USA.
Division of Kinesiology, Health and Sport Studies, Wayne State University, Detroit, MI USA.
J Clin Densitom. 2022 Jul-Sep;25(3):384-391. doi: 10.1016/j.jocd.2021.11.008. Epub 2021 Nov 24.
Accurate assessment of total body composition in tall (>1.96m) individuals using dual energy x-ray absorptiometry (DXA) scans is problematic due to current height restrictions of the scan table. The aim of this investigation was to quantify absolute and relative contributions of fat, bone and lean mass, of the feet and head regions, to whole-body composition DXA scan totals. Whole-body DXA scans were performed in collegiate athletes. Athlete DXA scans were included in data analyses if the entire body fit within the confines of scan table area. The feet region of interest (ROI) was delineated at the ankle joint mortise, marked superiorly by the inferior margin of the tibial plafond and encompassing all inferior anatomical structures. The head region was calculated by the DXA scan software. Both absolute (kg) and relative (feet/whole-body x 100 = feet mass %) contributions to body composition were calculated. Data presented as mean±SD. 132 National Collegiate Athletic Association (NCAA) athletes (85 female) underwent DXA scans which met the inclusion criteria. The feet region represented: 1.9±0.3kg (2.6±0.3%) of total mass; 0.4±0.3kg (2.6±0.5%) of fat mass; 1.3±0.3kg (2.5±0.3%) of lean mass; and 0.14±0.0kg (5.4±0.6%) of bone mineral content (BMC). The head region represented: 4.8±0.5kg (6.9±0.8%) of total mass; 1.2±0.2kg (8.2±3.0%) of fat mass; 3.2±0.5kg (6.1±0.9%) of lean mass; and 0.48±0.07kg (18.7±2.7%) of BMC. Significant negative relationships were found between head% versus whole-body BMC (r=-0.54;p < 0.0001), lean mass (r=-0.57;p<0.0001), and fat mass (r=-0.81;p<0.0001) and between feet% versus fat mass (r=-0.68;p<0.0001). A significant positive relationship was noted between feet% versus whole-body BMC (r=0.18;p=0.04) but not versus lean mass (r=0.15;p=0.09). Removing the feet from whole-body composition analyses reduces lean, fat and bone mass compartment totals by 3%-5%. Removing the head region reduces body composition compartments by 6%-19%, from whole-body DXA scan totals.
使用双能 X 射线吸收法（DXA）扫描对身高超过 1.96 米的个体进行全身成分的准确评估存在问题，因为目前扫描台的高度限制。本研究的目的是定量分析足部和头部区域的脂肪、骨骼和瘦体重的绝对和相对贡献，以了解全身 DXA 扫描总量。对大学生运动员进行全身 DXA 扫描。如果运动员的整个身体都在扫描台区域内，则将其 DXA 扫描纳入数据分析中。感兴趣的足部区域（ROI）在踝关节窝处划定，由胫骨平台的下缘标记为上方，包括所有下方解剖结构。头部区域由 DXA 扫描软件计算。计算身体成分的绝对（kg）和相对（足部/全身 x 100=足部质量%）贡献。数据以平均值±标准差表示。132 名符合纳入标准的美国大学生体育协会（NCAA）运动员（85 名女性）接受了 DXA 扫描。足部区域代表：1.9±0.3kg（2.6±0.3%）的总质量；0.4±0.3kg（2.6±0.5%）的脂肪质量；1.3±0.3kg（2.5±0.3%）的瘦体重；和 0.14±0.0kg（5.4±0.6%）的骨矿物质含量（BMC）。头部区域代表：4.8±0.5kg（6.9±0.8%）的总质量；1.2±0.2kg（8.2±3.0%）的脂肪质量；3.2±0.5kg（6.1±0.9%）的瘦体重；和 0.48±0.07kg（18.7±2.7%）的 BMC。头部%与全身 BMC（r=-0.54;p < 0.0001）、瘦体重（r=-0.57;p<0.0001）和脂肪质量（r=-0.81;p<0.0001）之间存在显著负相关，而足部%与脂肪质量（r=-0.68;p<0.0001）之间存在显著负相关。足部%与全身 BMC（r=0.18;p=0.04）呈显著正相关，但与瘦体重（r=0.15;p=0.09）无相关性。从全身 DXA 扫描总量中去除足部会使瘦体重、脂肪和骨量的总和减少 3%-5%。从全身 DXA 扫描总量中去除头部区域会使身体成分减少 6%-19%。
