Olga S Palamarchuk, Oleh O Moroz, Volodymyr P Feketa
{"title":"Unmasking covert metabolic syndrome in normal-weight women: regional adiposity and muscle quality outperform BMI in a temporally validated machine learning triage framework.","authors":"Olga S Palamarchuk, Oleh O Moroz, Volodymyr P Feketa","doi":"10.1007/s00592-026-02815-0","DOIUrl":null,"url":null,"abstract":"<p><strong>Aims: </strong>Traditional screening based on body mass index (BMI) fails to identify the metabolically obese normal-weight (MONW) phenotype. We aimed to develop and temporally validate an interpretable machine learning framework utilizing non-invasive surrogate markers of central adiposity (waist-to-height ratio, WHtR) and relative functional muscle capacity (relative handgrip strength, RHGS) for cross-sectional triage of prevalent metabolic syndrome (MetS) in women.</p><p><strong>Methods: </strong>In 2,418 women (NHANES 2011-2014), we excluded pregnant women and applied independent K-nearest neighbors imputation (k = 5) without data leakage. Using XGBoost, we evaluated baseline M1 (Age + BMI), intermediate M2 (Age + BMI + RHGS), and proposed M3 (Age + WHtR + RHGS). Following TRIPOD Type 3 temporal validation, we trained models on Cycle 2011-2012 (N = 1,167) and tested them on Cycle 2013-2014 (N = 1,251). SHapley Additive exPlanations (SHAP) extracted exploratory, model-dependent decision reference points.</p><p><strong>Results: </strong>In the unstratified cohort, M3 achieved comparable discrimination to M2 (AUC 0.782 vs. 0.769, DeLong p = 0.117). However, in normal-weight women (n = 371), M3 demonstrated marked superiority over M1 (AUC 0.855 [95% CI 0.800-0.910] vs. 0.757 [95% CI 0.678-0.835], p < 0.001) and M2 (AUC 0.801, p = 0.015), with near-perfect calibration (Brier score = 0.068), high rule-out reliability (NPV = 98.9%), and a negative likelihood ratio (LR-) of 0.12 (95% CI 0.06-0.22). SHAP dependence analysis illustrated non-additive muscle-fat interactions, where lower strength (< 0.891 kg/kg) amplified risk primarily when WHtR exceeded 0.529.</p><p><strong>Conclusions: </strong>Replacing BMI with indices of visceral adiposity and relative strength markedly improves MetS triage in normal-weight women. This temporally validated framework provides a non-invasive pre-laboratory triage tool to prioritize high-risk MONW individuals for comprehensive clinical evaluation.</p>","PeriodicalId":6921,"journal":{"name":"Acta Diabetologica","volume":" ","pages":""},"PeriodicalIF":3.1000,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Acta Diabetologica","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1007/s00592-026-02815-0","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENDOCRINOLOGY & METABOLISM","Score":null,"Total":0}
引用次数: 0
Abstract
Aims: Traditional screening based on body mass index (BMI) fails to identify the metabolically obese normal-weight (MONW) phenotype. We aimed to develop and temporally validate an interpretable machine learning framework utilizing non-invasive surrogate markers of central adiposity (waist-to-height ratio, WHtR) and relative functional muscle capacity (relative handgrip strength, RHGS) for cross-sectional triage of prevalent metabolic syndrome (MetS) in women.
Methods: In 2,418 women (NHANES 2011-2014), we excluded pregnant women and applied independent K-nearest neighbors imputation (k = 5) without data leakage. Using XGBoost, we evaluated baseline M1 (Age + BMI), intermediate M2 (Age + BMI + RHGS), and proposed M3 (Age + WHtR + RHGS). Following TRIPOD Type 3 temporal validation, we trained models on Cycle 2011-2012 (N = 1,167) and tested them on Cycle 2013-2014 (N = 1,251). SHapley Additive exPlanations (SHAP) extracted exploratory, model-dependent decision reference points.
Results: In the unstratified cohort, M3 achieved comparable discrimination to M2 (AUC 0.782 vs. 0.769, DeLong p = 0.117). However, in normal-weight women (n = 371), M3 demonstrated marked superiority over M1 (AUC 0.855 [95% CI 0.800-0.910] vs. 0.757 [95% CI 0.678-0.835], p < 0.001) and M2 (AUC 0.801, p = 0.015), with near-perfect calibration (Brier score = 0.068), high rule-out reliability (NPV = 98.9%), and a negative likelihood ratio (LR-) of 0.12 (95% CI 0.06-0.22). SHAP dependence analysis illustrated non-additive muscle-fat interactions, where lower strength (< 0.891 kg/kg) amplified risk primarily when WHtR exceeded 0.529.
Conclusions: Replacing BMI with indices of visceral adiposity and relative strength markedly improves MetS triage in normal-weight women. This temporally validated framework provides a non-invasive pre-laboratory triage tool to prioritize high-risk MONW individuals for comprehensive clinical evaluation.
期刊介绍:
Acta Diabetologica is a journal that publishes reports of experimental and clinical research on diabetes mellitus and related metabolic diseases. Original contributions on biochemical, physiological, pathophysiological and clinical aspects of research on diabetes and metabolic diseases are welcome. Reports are published in the form of original articles, short communications and letters to the editor. Invited reviews and editorials are also published. A Methodology forum, which publishes contributions on methodological aspects of diabetes in vivo and in vitro, is also available. The Editor-in-chief will be pleased to consider articles describing new techniques (e.g., new transplantation methods, metabolic models), of innovative importance in the field of diabetes/metabolism. Finally, workshop reports are also welcome in Acta Diabetologica.