Correlation of BMI-related insulin resistance and cardiometabolic multimorbidity risk in the hypertension with sarcopenia adults

Background Cardiometabolic multimorbidity (CMM) and obesity are growing global public health burdens. The obesity paradox, however, obscures how insulin resistance (IR) shapes CMM risk in individuals with coexisting hypertension and sarcopenia, a question that remains unresolved.Methods Two body mass index (BMI)-adjusted IR indices – the estimated glucose disposal rate (eGDR) and the triglyceride glucose index (TyG) – were assessed in the China Health and Retirement Longitudinal Study (CHARLS) cohort over a median follow-up of 8 years.Results Cox regression revealed that eGDR–BMI and HDL-C were inversely associated with CMM risk, while TyG–BMI and platelet count were positively associated (all p < 0.05). Kaplan–Meier analysis demonstrated that elevated TyG–BMI conferred a stronger association with cumulative CMM incidence than reduced eGDR–BMI (HR > 1.5, p < 0.01). Restricted cubic spline modeling confirmed nonlinear dose–response relationships (p nonlinear < 0.05), yielding cutoff values of 7.5 for eGDR–BMI and 196.6 for TyG–BMI. The TyG–BMI-based model achieved superior predictive performance among all models evaluated (AUC = 0.702).Conclusions These findings establish clinically meaningful associations and threshold values of eGDR–BMI and TyG–BMI with CMM risk, highlighting the value of weight management and routine lipid and platelet monitoring in middle-aged and older adults with coexisting hypertension and sarcopenia.