Enderle Janna, Reljic Dejan, Jensen Björn, Peine Sven, Zopf Yurdagül, Bosy-Westphal Anja
Institute for Human Nutrition and Food Science, Christian-Albrechts-University, Düsternbrooker Weg 17, 24105 Kiel, Germany.
Hector-Center for Nutrition, Exercise and Sports, Department of Medicine 1, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg, Ulmenweg 18, 91054 Erlangen, Germany; German Center Immunotherapy (DZI), University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg, Ulmenweg 18, 91054 Erlangen, Germany.
Clin Nutr. 2023 May;42(5):644-652. doi: 10.1016/j.clnu.2023.03.006. Epub 2023 Mar 9.
BACKGROUND & AIMS: Reference values for body composition parameters like skeletal muscle mass index (SMI) depend on age and BMI. To ensure reference intervals reflect these changes, they have traditionally been separated into groups of young adults based on sex and BMI. However, this static stratification oversimplifies the dynamic and gradual changes of body composition with increasing age and BMI. The aim was therefore to provide continuous reference ranges for body composition parameters.
Cross-sectional data of 1958 healthy men and women with an age between 18 and 97 years and a BMI between 17.1 und 45.6 kg/m were obtained between 2011 and 2019. Multiple regression analyses stratified by sex with age, age and BMI as independent variables were conducted to predict fat mass index (FMI), visceral adipose tissue (VAT), SMI, appendicular lean soft tissue index (ALSTI) and the ratio between extracellular to total body water (ECW/TBW).
The regression models explained between 61 (VAT in women and ALSTI in men) and 93% of the variance in the respective body composition parameters (FMI in women). Age had only a minor impact (2-16%) whereas BMI substantially increased the explained variance of reference models for FMI, VAT and ALSTI (total explained variance 61-93%). In SMI, age is a major determinant of the explained variance (36% in men and 38% in women) with BMI equally contributing to the explained variance (total explained variance 72% in men and 75% in women). For ECW/TBW-ratio, age nearly completely explained the variance (79% in men and 74% in women) whereas BMI added only 2-3% to the explained variance.
In conclusion, the derived continuous reference ranges are expected to improve body composition evaluation especially in very overweight and very old persons. Future studies applying these reference equations need to validate these assumptions. STUDY REGISTRATION, CLINICALTRIALS.GOV: NCT01368640, NCT01481285, NCT03779932, NCT04028648.
骨骼肌质量指数（SMI）等身体成分参数的参考值取决于年龄和体重指数（BMI）。为确保参考区间反映这些变化，传统上会根据性别和BMI将其分为年轻成年人组。然而，这种静态分层过于简化了随着年龄和BMI增加身体成分的动态和渐进变化。因此，目的是提供身体成分参数的连续参考范围。
获取了2011年至2019年间1958名年龄在18至97岁之间、BMI在17.1至45.6kg/m之间的健康男性和女性的横断面数据。进行了以年龄、年龄和BMI为自变量的按性别分层的多元回归分析，以预测脂肪质量指数（FMI）、内脏脂肪组织（VAT）、SMI、四肢瘦软组织指数（ALSTI）以及细胞外液与总体液之比（ECW/TBW）。
回归模型解释了相应身体成分参数（女性的FMI）中61%（女性的VAT和男性的ALSTI）至93%的方差。年龄的影响较小（2% - 16%），而BMI显著增加了FMI、VAT和ALSTI参考模型的解释方差（总解释方差为61% - 93%）。在SMI中，年龄是解释方差的主要决定因素（男性为36%，女性为38%），BMI对解释方差的贡献相同（男性总解释方差为72%，女性为75%）。对于ECW/TBW比值，年龄几乎完全解释了方差（男性为79%，女性为74%），而BMI仅增加了2% - 3%的解释方差。
总之，得出的连续参考范围有望改善身体成分评估，尤其是在超重和高龄人群中。未来应用这些参考方程的研究需要验证这些假设。研究注册，ClinicalTrials.gov：NCT01368640、NCT01481285、NCT03779932、NCT04028648。
