biostudies-literatureUnknown24(1)He A<h4>Introduction</h4>Body composition has been associated with various health outcomes, but its specific relationship with arthritis risk remains unclear. The study aimed to examine the associations between lean body mass (LBM) and fat mass (FM) with arthritis risk in men and women and to identify their threshold values.<h4>Methods</h4>The data were obtained from the CHARLS, a prospective cohort study from 2011 to 2018. Multivariate Cox regression models evaluated the associations between LBM and FM and arthritis risk. Smoothing curves and two-piece linear regression models were applied to identify the inflection points of LBM and FM associated with arthritis risk.<h4>Results</h4>A total of 6,761 participants were included in this study. During a mean follow-up period of 6.66 years, 944 paLipids in health and disease124https://www.ebi.ac.uk/biostudies/studies/S-EPMC11960006biostudies-literatureThe non-linear relationships between fat mass and lean body mass with arthritis.PMC11960006Li YCui YCui ZHe AChang JZhou XXu ZfalseThe non-linear relationships between fat mass and lean body mass with arthritis.<h4>Introduction</h4>Body composition has been associated with various health outcomes, but its specific relationship with arthritis risk remains unclear. The study aimed to examine the associations between lean body mass (LBM) and fat mass (FM) with arthritis risk in men and women and to identify their threshold values.<h4>Methods</h4>The data were obtained from the CHARLS, a prospective cohort study from 2011 to 2018. Multivariate Cox regression models evaluated the associations between LBM and FM and arthritis risk. Smoothing curves and two-piece linear regression models were applied to identify the inflection points of LBM and FM associated with arthritis risk.<h4>Results</h4>A total of 6,761 participants were included in this study. During a mean follow-up period of 6.66 years, 944 pa2025-01-01T00:00:00Z2025 Apr2025-06-28T03:05:13.342Z2025-06-28T03:05:13.342ZS-EPMC119600064017004310.1186/s12944-025-02525-6