BackgroundTo investigate the relationship between triglyceride glucose-body mass index (TyG-BMI) and ischemic stroke.MethodsLeveraging two Chinese general population surveys, the Northeast China Rural Cardiovascular Health Study (NCRCHS, N = 11,097) and the National Stroke Screening and Intervention Program in Liaoning (NSSIPL, N = 10,862), we evaluated the relationship between TyG-BMI and ischemic stroke by a restricted cubic spline and multivariate logistic regression after adjusting age, sex, level of education, exercise regularly, current smoking, current drinking, atrial fibrillation, hypertension, coronary artery disease, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol. The category-free analysis was used to determine whether TyG-BMI enhanced the capacity of estimating ischemic stroke.ResultsA total of 596 and 347 subjects, respectively, from NSSIPL and NCRCHS were survivors of ischemic stroke. In NSSIPL, the relationship between TyG-BMI and ischemic stroke was linear and did not have a threshold or saturation effect according to the results of the restricted cubic spline. The regression analysis indicated that the risk of ischemic stroke increased 20% for per SD increase of TyG-BMI after multivariate adjustment [odds ratio (OR): 1.20, 95% confidence interval (CI): 1.10–1.32]. Compared with those in the lowest tertile, the risk of ischemic stroke in subjects with intermediate and high TyG-BMI was significantly higher [OR (95% CI): 1.39 (1.10–1.74); OR (95% CI) 1.72 (1.37–2.17), respectively]. Category-free analysis indicated that TyG-BMI had a remarkable improvement in the ability to estimate prevalent ischemic stroke [NRI (95% CI): 0.188 (0.105–0.270)]. These abovementioned relationships were confirmed in NCRCHS.ConclusionsThe present study found the robust correlation between TyG-BMI and ischemic stroke, independently of a host of conventional risk factors. Meanwhile, our findings also suggested the potential usefulness of TyG-BMI to improve the risk stratification of ischemic stroke.