Dual energy X-ray absorptiometry body composition reference values of limbs and trunk from NHANES 1999–2004 with additional visualization methods

Body Mass Index has traditionally been used as a measure of health, but Fat Mass Index (FMI) and Lean Mass Index (LMI) have been shown to be more predictive of mortality and health risk. Total body FMI and LMI reference curves have particularly been useful in quantifying sarcopenia and sarcopenic obesity. Research has shown regional composition has significant associations to health outcomes. We derived FMI and LMI reference curves of the regions of the body (leg, arm, and trunk) for 15,908 individuals in the 1999–2004 National Health and Nutrition Examination Survey data for each sex and ethnicity using the Lambda-Mu-Sigma (LMS) method and developed software to visualize this regional composition. These reference curves displayed differentiation between males and females during puberty and sharper limb LMI declines during late adulthood for males. For adults ages 30–50, females had 39%, 83%, and 47% larger arm, leg, and trunk FMI values than males, respectively. Males had 49%, 20%, and 15% higher regional LMI values than females for the arms, legs, and trunk respectively. The leg FMI and LMI of black females were 14% and 15% higher respectively than those of Hispanic and white females. White and Hispanic males had 37% higher trunk FMI values than black males. Hispanic females had 20% higher trunk FMI than white and black females. These data underscore the importance of accounting for sex and ethnicity in studies of regional composition. This study is the first to produce regional LMI and FMI reference tables and curves from the NHANES dataset. These reference curves provide a framework useful in studies and research involving sarcopenia, obesity, sarcopenic obesity, and other studies of compositional phenotypes. Further, the software tool we provide for visualizing regional composition will prove useful in monitoring progress in physical therapy, diets, or other attempts to attain healthier compositions.体质量指数（Body Mass Index）传统上一直被用作健康评估指标，但脂肪质量指数（Fat Mass Index, FMI）与瘦体重指数（Lean Mass Index, LMI）已被证实可更精准地预测死亡率与健康风险。全身FMI与LMI参考曲线在量化肌肉减少症（sarcopenia）及肌肉减少性肥胖（sarcopenic obesity）方面尤为实用。研究表明，身体区域组成与健康结局存在显著关联。 本研究基于1999-2004年美国国家健康与营养检查调查（National Health and Nutrition Examination Survey, NHANES）的15908名受试者数据，采用Lambda-Mu-Sigma（LMS）方法，按性别与种族分层，构建了手臂、腿部、躯干三个身体区域的FMI与LMI参考曲线，并开发了用于可视化身体区域组成的配套软件。 这些参考曲线呈现出青春期男女的分化特征，且成年晚期男性的肢体LMI呈现更为显著的下降趋势。在30至50岁的成人群体中，女性的手臂、腿部与躯干FMI值分别较男性高出39%、83%与47%；而男性的手臂、腿部与躯干LMI值则分别较女性高出49%、20%与15%。黑人女性的腿部FMI与LMI值分别较西班牙裔及白人女性高出14%与15%；白人男性与西班牙裔男性的躯干FMI值则较黑人男性高出37%。西班牙裔女性的躯干FMI值较白人及黑人女性高出20%。 上述数据凸显了在身体区域组成相关研究中纳入性别与种族因素的重要性。本研究首次基于NHANES数据集生成了区域LMI与FMI参考表格及曲线，这些参考曲线可为肌肉减少症、肥胖、肌肉减少性肥胖及其他身体组成表型相关研究提供分析框架。此外，本研究开发的身体区域组成可视化工具，可用于监测物理治疗、膳食干预或其他旨在优化身体组成的干预措施的实施进展。