Work

Associations between insulin resistance surrogate indices and risk of incident symptomatic knee osteoarthritis: insights from a 9-year Chinese cohort

Year: 2026

Type: article

Abstract: Insulin resistance (IR) is increasingly recognized as a potential correlate of knee osteoarthritis (KOA); however, prospective evidence supporting this association remains limited. This study aimed to investigate the association between various surrogate markers of IR and the risk of incident KOA in a large prospective cohort. This prospective cohort study used CHARLS data from 2011 with follow-up in 2013, 2015, 2018, and 2020. Six surrogate IR indices—estimated glucose disposal rate (eGDR), Chinese visceral adiposity index (CVAI), triglyceride-glucose index (TyG), TyG-body mass index (TyG-BMI), metabolic score for insulin resistance (METS-IR), and atherogenic index of plasma (AIP)—were evaluated in relation to incident self-reported symptomatic KOA using multivariable Cox regression and restricted cubic splines. Sensitivity analyses addressed early incident cases, multiple testing, BMI overlap in adiposity-based indices, and potential selection bias. A total of 5871 participants free of KOA at baseline were included. During follow-up, 2143 participants (36.5%) developed incident KOA. In multivariable Cox regression, nominal P for trend values were observed for eGDR (P for trend = 0.046) and CVAI (P for trend = 0.044), while AIP showed nominally elevated hazard ratios (HRs) in the second (HR = 1.14, 95% confidence interval [CI]: 1.02 to 1.26) and third (HR = 1.15, 95% CI: 1.03 to 1.27) quartiles without a statistically significant trend (P for trend = 0.798). After FDR correction of the six fully adjusted trend tests, none remained statistically significant. Quartile comparisons were not included in this correction and are reported as nominal, exploratory findings. RCS analysis did not demonstrate statistically significant non-linearity for any of the six indices. The sensitivity analyses yielded a consistent overall pattern of estimates, including attenuation after full adjustment. Among the six surrogate markers examined, nominal findings included the eGDR and CVAI trend tests and the intermediate AIP quartile contrasts, whereas none of the six fully adjusted trend tests remained statistically significant after FDR correction. The quartile findings were not subjected to multiplicity correction and remain exploratory. The observed patterns were small in magnitude and should be regarded as hypothesis-generating rather than as evidence of indicator-specific risk stratification. Not applicable.

Source: BMC Endocrine Disorders

DOI: 10.1186/s12902-026-02526-1