Association between metabolic score for insulin resistance and future stroke risk in patients with cardiovascular-kidney-metabolic syndrome stages 0-3: a longitudinal analysis based on CHARLS.

Background: Metabolic disorders, cardiovascular diseases, and chronic kidney diseases are closely interrelated, and the proposal of cardiovascular-kidney-metabolic (CKM) syndrome concept has received extensive attention.The disease burden of CKM is heavy, with stroke being a significant contributor, and CKM staging is bidirectional.A large body of evidence has demonstrated that insulin resistance is closely associated with diseases such as stroke, obesity and chronic kidney disease. While the metabolic score for insulin resistance (METS-IR) serves as an important indicator for evaluating insulin resistance, the relationship between METS-IR and stroke incidence remains unclear in the population defined by CKM syndrome stages 0-3.

Methods: In this study, data on individuals with CKM syndrome stages 0-3 without stroke at baseline were collected from China Health and Retirement Longitudinal Study (CHARLS).Self-reported stroke was used as the primary outcome, with METS-IR at baseline as the exposure factor. Logistic regression was performed to analyze the effect of METS-IR on the incidence of stroke among participants with CKM, and restricted cubic spline (RCS) regression was utilized to explore the potential nonlinear relationship between them. To evaluate the predictive value of METS-IR for stroke risk in individuals with CKM syndrome stages 0-3, we applied receiver operating characteristic (ROC) analysis.

Results: A total of 5009 participants were included in this study, with a mean age of 60.48 ± 8.81 years. Over a 5-year follow-up, 339 participants in this study developed incident stroke. Participants were stratified into METS-IR quartiles (Q1-Q4). In the fully adjusted model, compared with Q1 (the lowest quartile), the odds ratio (OR) for Q3 was 1.88 (95% CI: 1.25-2.81; P = 0.002), and the OR for Q4 was 1.72 (95% CI: 1.08-2.76; P = 0.02). RCS analysis revealed a nonlinear relationship between METS-IR and stroke risk among participants with CKM syndrome stages 0-3 (P-overall < 0.05; P-nonlinearity < 0.05). ROC analysis showed an area under the curve (AUC) of 0.726 (95% CI: 0.699-0.752), with an optimal METS-IR cutoff value of 29.58.

Conclusions: In individuals with CKM syndrome stages 0-3, elevated METS-IR levels may be associated with an increased stroke risk. Furthermore, METS-IR demonstrates moderate predictive value for stroke risk in this population. Monitoring METS-IR may therefore aid in their early identification.