Prediction equations for appendicular skeletal muscle mass validated in 13,582 Asian adults
In this abstract, a three-phase study tested and developed equations estimating appendicular skeletal muscle mass from accessible measures in Asian adults; the new equation was then externally validated in an independent Japanese cohort. [1]
Automatic summary · not editorially reviewed
The key findings
Phase 1 tested existing NHANES-derived equations in three cohorts from Taiwan and Japan totalling 13,582 people. [1]
The newly developed NAHSIT-based Equation 4 reached R = 0.90 and an AUC of 0.90 in both sexes for detecting low muscle mass. [1]
In Phase 3 external validation in the independent Japanese NILS-LSA cohort, Equation 4 achieved AUC values of 0.90 in males and 0.85 in females. [1]
The source at a glance
- Study type / format
- Three-phase prediction-equation development and validation study (abstract).
- Population / context
- 13,582 Asian adults in three cohorts from Taiwan (ILAS, NAHSIT) and Japan (NILS-LSA).
- Summary based on
- Study abstract
- Original publication
- October 1, 2026
Existing equations tested in three Asian cohorts
Phase 1 tested existing equations derived from NHANES data in three cohorts totalling 13,582 people: ILAS from Taiwan (n = 2,780), NAHSIT from Taiwan (n = 6,853) and NILS-LSA from Japan (n = 3,949). The abstract reports acceptable to strong predictive accuracy (R = 0.52–0.89). Equation 4, using sex, age, height and weight, performed robustly in ILAS (R = 0.80), NILS-LSA (R = 0.86) and NAHSIT (R = 0.89). For detecting low muscle mass by AWGS 2019 criteria, AUC values ranged from 0.79 to 0.91 in males and 0.76 to 0.89 in females across cohorts.
Supporting source [1]
New NAHSIT-derived equation and its external validation
Phase 2 developed new population-based equations using the NAHSIT cohort. The new Equation 4 reached R = 0.90 and RMSE = 1.45, with a median error of 0.06 (IQR 1.81). Its AUC for detecting low muscle mass was 0.90 in both sexes; sensitivity/specificity was 0.85/0.80 in males and 0.87/0.80 in females. Phase 3 externally validated this equation in the independent Japanese NILS-LSA cohort, where it achieved the highest AUC values: 0.90 in males and 0.85 in females.
Supporting source [1]
Abstract-only scope of the equation study
This explainer is based on the abstract only; the full text was not reviewed. The abstract does not report how muscle mass was measured as the reference standard, the age range of participants, or how the cohorts were sampled. The authors describe the equations as clinically accessible and suited to large-scale screening in community settings; these are the authors' conclusions, and the abstract does not report a comparison with routine device-based measurement in practice.
Supporting source [1]
How to interpret this
Abstract only; the full text was not reviewed. The abstract does not report the reference measurement method for muscle mass, participant age range or cohort sampling. Reported accuracy and screening suitability are the authors' findings and conclusions, not an independent practical comparison.
Based on the study abstract; the full paper, tables and supplementary data were not reviewed.
Source & supporting passages
Lai HY, Zhang S, Chen IT, Otsuka R, Lee WJ, Liang CK, Yen KH, Arai H, Hsiao FY, Chen LK. · europepmc.org · October 1, 2026