{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,4]],"date-time":"2026-09-04T07:14:24Z","timestamp":1788506064052,"version":"build-2803163510"},"reference-count":43,"publisher":"MJS Publishing, Medical Journals Sweden AB","license":[{"start":{"date-parts":[[2026,9,4]],"date-time":"2026-09-04T00:00:00Z","timestamp":1788480000000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JRM"],"abstract":"<jats:p>Background: Relative fat mass is a novel anthropometric indicator that outperforms body mass index in assessing obesity. Although obesity is a known risk factor for knee osteoarthritis, the prospective association between relative fat mass and symptomatic knee osteoarthritis in middle-aged and older adults with metabolic syndrome remains unclear.\nMethods: This prospective cohort study used CHARLS data, including 3,301 middle-aged and older metabolic syndrome patients free of knee osteoarthritis at baseline. Participants were grouped into relative fat mass quartiles. Incident symptomatic knee osteoarthritis was the primary outcome. Multivariable Cox models, restricted cubic spline analyses, subgroup analyses, and receiver operating characteristic curves were used to assess associations and predictive performance.\nResults: Knee osteoarthritis incidence increased across relative fat mass quartiles (Q1: 21%; Q4: 37%). In fully adjusted models, those in the highest relative fat mass quartile had a 50% higher knee osteoarthritis risk compared with the lowest quartile (HR\u2009=\u20091.50, 95% CI: 1.18\u20131.90), with a significant dose\u2013response trend. Restricted cubic spline analysis indicated a non-linear association. The relationship was stronger among rural residents. Relative fat mass demonstrated better predictive ability than body mass index (AUC: 0.587 vs 0.532).\nConclusions: Among Chinese middle-aged and older adults with metabolic syndrome, higher relative fat mass was independently and non-linearly associated with an increased risk of incident symptomatic knee osteoarthritis. Relative fat mass outperformed body mass index as a predictive measure, supporting its use as a simple and effective tool to identify high-risk individuals and guide targeted prevention strategies.<\/jats:p>","DOI":"10.2340\/jrm.v58.45354","type":"journal-article","created":{"date-parts":[[2026,9,4]],"date-time":"2026-09-04T06:56:36Z","timestamp":1788504996000},"page":"jrm45354","source":"Crossref","is-referenced-by-count":0,"title":["Relative fat mass predicts symptomatic knee osteoarthritis in older adults with metabolic syndrome: a longitudinal cohort study"],"prefix":"10.2340","volume":"58","author":[{"given":"Lei","family":"Huang","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuhui","family":"Wang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuhao","family":"Chen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Weilong","family":"Yao","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xianxu","family":"Zhang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shicheng","family":"Li","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yong","family":"Sun","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Changlin","family":"Zhou","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bin","family":"Qian","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhiqiang","family":"Luo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pandeng","family":"Wei","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1183","published-online":{"date-parts":[[2026,9,4]]},"reference":[{"key":"167357","doi-asserted-by":"crossref","unstructured":"Sharma L. 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Association of sarcopenia and its prognostic value in symptomatic knee osteoarthritis among older people in China: the first longitudinal evidence from CHARLS. BMC Geriatr 2024; 24: 977.","DOI":"10.1186\/s12877-024-05556-3"},{"key":"167361","doi-asserted-by":"crossref","unstructured":"Wu Y, Boer CG, Hofman A, Schiphof D, van Middelkoop M, Szilagyi IA, et al. Weight-bearing physical activity, lower-limb muscle mass, and risk of knee osteoarthritis. JAMA Netw Open 2024; 7: e248968.","DOI":"10.1001\/jamanetworkopen.2024.8968"},{"key":"167362","doi-asserted-by":"crossref","unstructured":"Chang AH, Lee JJ, Chmiel JS, Almagor O, Song J, Sharma L. Association of Long-term Strenuous Physical Activity and Extensive Sitting With Incident Radiographic Knee Osteoarthritis. JAMA Netw Open 2020; 3: e204049.","DOI":"10.1001\/jamanetworkopen.2020.4049"},{"key":"167363","doi-asserted-by":"crossref","unstructured":"Salis Z, Driban JB, McAlindon TE. Predicting the onset of end-stage knee osteoarthritis over two- and five-years using machine learning. Semin Arthritis Rheum 2024; 66: 152433.","DOI":"10.1016\/j.semarthrit.2024.152433"},{"key":"167364","doi-asserted-by":"crossref","unstructured":"Batushansky A, Zhu S, Komaravolu RK, South S, Mehta-D\u2019souza P, Griffin TM. Fundamentals of OA. An initiative of Osteoarthritis and Cartilage. Obesity and metabolic factors in OA. Osteoarthritis Cartilage 2022; 30: 501\u2013515.","DOI":"10.1016\/j.joca.2021.06.013"},{"key":"167365","doi-asserted-by":"crossref","unstructured":"Zhou C, Zhang Y, Liu X, He C, Li S. Relationship of METS-IR with cardiometabolic multimorbidity in China: a nationwide longitudinal cohort study. Front Nutr 2025; 12: 1518840.","DOI":"10.3389\/fnut.2025.1518840"},{"key":"167366","doi-asserted-by":"crossref","unstructured":"Li K, Leng Y, Lei D, Zhang H, Ding M, Lo WLA. Causal link between metabolic related factors and osteoarthritis: a Mendelian randomization investigation. Front Nutr 2024; 11: 1424286.","DOI":"10.3389\/fnut.2024.1424286"},{"key":"167367","doi-asserted-by":"crossref","unstructured":"Yu L, Tian D, Su Z, Zhang L, Jie L, Guo S, et al. Mechanical stress overload promotes NF-\u03baB\/NLRP3-mediated osteoarthritis synovitis and fibrosis through Piezo1. Cell Signal 2025; 132: 111786.","DOI":"10.1016\/j.cellsig.2025.111786"},{"key":"167368","doi-asserted-by":"crossref","unstructured":"Li X, Lu Z, Qi Y, Chen B, Li B. The role of polyunsaturated fatty acids in osteoarthritis: insights from a Mendelian randomization study. Nutrients 2023; 15: 4787.","DOI":"10.3390\/nu15224787"},{"key":"167369","doi-asserted-by":"crossref","unstructured":"Sampath SJP, Venkatesan V, Ghosh S, Kotikalapudi N. Obesity, metabolic syndrome, and osteoarthritis: an updated review. Curr Obes Rep 2023; 12: 308\u2013331.","DOI":"10.1007\/s13679-023-00520-5"},{"key":"167370","doi-asserted-by":"crossref","unstructured":"Dickson BM, Roelofs AJ, Rochford JJ, Wilson HM, De Bari C. The burden of metabolic syndrome on osteoarthritic joints. Arthritis Res Ther 2019; 21: 289.","DOI":"10.1186\/s13075-019-2081-x"},{"key":"167371","doi-asserted-by":"crossref","unstructured":"Zeng P, Li M, Cao J, Zeng L, Jiang C, Lin F. Association of metabolic syndrome severity with frailty progression among Chinese middle and old-aged adults: a longitudinal study. Cardiovasc Diabetol 2024; 23: 302.","DOI":"10.1186\/s12933-024-02379-9"},{"key":"167372","doi-asserted-by":"crossref","unstructured":"Yu H, Wang J, Xu X, Li H, Guo J. Revealing the mediating mechanisms between BMI and osteoarthritis: a Mendelian randomization and mediation analysis. 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Lipids Health Dis 2024; 23: 354.","DOI":"10.1186\/s12944-024-02351-2"},{"key":"167376","doi-asserted-by":"crossref","unstructured":"Zhu X, Yue Y, Li L, Zhu L, Cai Y, Shu Y. The relationship between depression and relative fat mass (RFM): a population-based study. J Affect Disord 2024; 356: 323\u2013328.","DOI":"10.1016\/j.jad.2024.04.031"},{"key":"167377","doi-asserted-by":"crossref","unstructured":"Li Z, Yin T, Chen Y, Huang J, Jiang Y, Deng W. Association between relative fat mass and osteoarthritis in American adults. Front Nutr 2025; 12: 1610950.","DOI":"10.3389\/fnut.2025.1610950"},{"key":"167378","doi-asserted-by":"crossref","unstructured":"Chen Z, Chen H, Chen X, Chen Y, Wang J, Ou Y. Exploring the association between relative fat mass and psoriasis risk: insights from the NHANES data. Lipids Health Dis 2025; 24: 210.","DOI":"10.1186\/s12944-025-02615-5"},{"key":"167379","doi-asserted-by":"crossref","unstructured":"Wu X, Song Y, Wu S. The development and evaluation of nine obesity-based indices for gallstones in U.S. adults. Int J Surg 2025; 111: 2348\u20132357.","DOI":"10.1097\/JS9.0000000000002237"},{"key":"167380","doi-asserted-by":"crossref","unstructured":"Jiang Z, Cai X, Yao X, Lan W, Yao X, Tang F, et al. Body roundness index and the risk of knee osteoarthritis: evidence from the China Health and Retirement Longitudinal Study. Front Nutr 2025; 12: 1533966.","DOI":"10.3389\/fnut.2025.1533966"},{"key":"167381","doi-asserted-by":"crossref","unstructured":"Woolcott OO, Bergman RN. Defining cutoffs to diagnose obesity using the relative fat mass (RFM): association with mortality in NHANES 1999\u20132014. Int J Obes (Lond) 2020; 44: 1301\u20131310.","DOI":"10.1038\/s41366-019-0516-8"},{"key":"167382","doi-asserted-by":"crossref","unstructured":"Shahid A, Thirumaran AJ, Christensen R, Venkatesha V, Henriksen M, Bowden JL, et al. Comparison of weight loss interventions in overweight and obese adults with knee osteoarthritis: a systematic review and network meta-analysis of randomized trials. Osteoarthritis Cartilage 2025; 33: 518\u2013529.","DOI":"10.1016\/j.joca.2024.08.012"},{"key":"167383","doi-asserted-by":"crossref","unstructured":"Sanchez-Lopez E, Coras R, Torres A, Lane NE, Guma M. Synovial inflammation in osteoarthritis progression. Nat Rev Rheumatol 2022; 18: 258\u2013275.","DOI":"10.1038\/s41584-022-00749-9"},{"key":"167384","doi-asserted-by":"crossref","unstructured":"Nedunchezhiyan U, Varughese I, Sun AR, Wu X, Crawford R, Prasadam I. Obesity, inflammation, and immune system in osteoarthritis. Front Immunol 2022; 13: 907750.","DOI":"10.3389\/fimmu.2022.907750"},{"key":"167385","doi-asserted-by":"crossref","unstructured":"Chu X, Niu H, Wang N, Wang Y, Xu H, Wang H, et al. Triglyceride-glucose-based anthropometric indices for predicting incident cardiovascular disease: relative fat mass (RFM) as a robust indicator. Nutrients 2025; 17: 2212.","DOI":"10.3390\/nu17132212"},{"key":"167386","doi-asserted-by":"crossref","unstructured":"Liu L, Wu A, Yang S. Association between relative fat mass and cognitive function among US older men: NHANES 2011\u20132014. Lipids Health Dis 2025; 24: 166.","DOI":"10.1186\/s12944-025-02593-8"},{"key":"167387","doi-asserted-by":"crossref","unstructured":"Woolcott OO, Bergman RN. Relative fat mass (RFM) as a new estimator of whole-body fat percentage: a cross-sectional study in American adult individuals. Sci Rep 2018; 8: 10980.","DOI":"10.1038\/s41598-018-29362-1"},{"key":"167388","doi-asserted-by":"crossref","unstructured":"Zhang H, Mei J. The association between relative fat mass (RFM) and lumbar bone density in US adults: insight from 2011\u20132018 NHANES. 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J Orthop Translat 2025; 52: 209\u2013219.","DOI":"10.1016\/j.jot.2025.03.022"},{"key":"167392","doi-asserted-by":"crossref","unstructured":"Ezzat AM, Li LC. Occupational physical loading tasks and knee osteoarthritis: a review of the evidence. Physiother Can 2014; 66: 91\u2013107.","DOI":"10.3138\/ptc.2012-45BC"},{"key":"167393","doi-asserted-by":"crossref","unstructured":"Jiang M, He J, Sun Y, Dong X, Yao J, Gu H, et al. Leptin induced TLR4 expression via the JAK2-STAT3 pathway in obesity-related osteoarthritis. Oxid Med Cell Longev 2021; 2021: 7385160.","DOI":"10.1155\/2021\/7385160"},{"key":"167394","doi-asserted-by":"crossref","unstructured":"Jiang M, He J, Gu H, Yang Y, Huang Y, Xu X, et al. Protective effect of resveratrol on obesity-related osteoarthritis via alleviating JAK2\/STAT3 signaling pathway is independent of SOCS3. Toxicol Appl Pharmacol 2020; 388: 114871.","DOI":"10.1016\/j.taap.2019.114871"},{"key":"167395","doi-asserted-by":"crossref","unstructured":"Catheline SE, Bell RD, Oluoch LS, James MN, Escalera-Rivera K, Maynard RD, et al. IKK\u03b2-NF-\u03baB signaling in adult chondrocytes promotes the onset of age-related osteoarthritis in mice. Sci Signal 2021; 14: eabf3535.","DOI":"10.1126\/scisignal.abf3535"},{"key":"167396","doi-asserted-by":"crossref","unstructured":"Cai H, Que Z, Chen J, Chen D, Rui G, Lan W. Association between different insulin resistance surrogates and osteoarthritis: a cross-sectional study from NHANES 1999-2018. BMC Musculoskelet Disord 2024; 25: 901.","DOI":"10.1186\/s12891-024-08027-3"},{"key":"167397","doi-asserted-by":"crossref","unstructured":"Lee H-A, Lee J-K, Han J-S. Betulinic acid improves TNF-\u03b1-induced insulin resistance by inhibiting negative regulator of insulin signalling and inflammation-activated protein kinase in 3T3-L1 adipocytes. Arch Physiol Biochem 2024; 130: 452\u2013459.","DOI":"10.1080\/13813455.2022.2120503"},{"key":"167398","doi-asserted-by":"crossref","unstructured":"Jin X, Dong X, Sun Y, Liu Z, Liu L, Gu H. Dietary fatty acid regulation of the NLRP3 inflammasome via the TLR4\/NF-\u03baB signaling pathway affects chondrocyte pyroptosis. Oxid Med Cell Longev 2022; 2022: 3711371.","DOI":"10.1155\/2022\/3711371"},{"key":"167399","doi-asserted-by":"crossref","unstructured":"Sakalyte R, Denkovskij J, Bernotiene E, Stropuviene S, Mikulenaite SO, Kvederas G, et al. The expression of inflammasomes NLRP1 and NLRP3, toll-like receptors, and vitamin D receptor in synovial fibroblasts from patients with different types of knee arthritis. Front Immunol 2021; 12: 767512.","DOI":"10.3389\/fimmu.2021.767512"}],"container-title":["Journal of Rehabilitation Medicine"],"original-title":[],"link":[{"URL":"https:\/\/medicaljournalssweden.se\/jrm\/article\/download\/45354\/55373","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/medicaljournalssweden.se\/jrm\/article\/download\/45354\/55374","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/medicaljournalssweden.se\/jrm\/article\/download\/45354\/55373","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,4]],"date-time":"2026-09-04T06:56:43Z","timestamp":1788505003000},"score":1,"resource":{"primary":{"URL":"https:\/\/medicaljournalssweden.se\/jrm\/article\/view\/45354"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,4]]},"references-count":43,"URL":"https:\/\/doi.org\/10.2340\/jrm.v58.45354","relation":{},"ISSN":["1651-2081"],"issn-type":[{"value":"1651-2081","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,4]]}}}