Table 1_Insulin resistance, metabolic phenotypes, and the obesity paradox: a triglyceride glucose-body mass index framework in partial kidney diseases.docx

In early-stage or metabolically heterogeneous populations, elevated TyG-BMI consistently predicts higher disease risk. Conversely, in advanced stages (e.g., end-stage renal disease, stage 4 CKM), the association frequently becomes U-shaped, with low TyG-BMI paradoxically linked to excess mortality. This reflects its dual nature: the TyG component captures ‘metabolic toxicity’, while BMI proxies ‘nutritional reserve’.

Thus, the ‘obesity paradox’ may represent a metabolic phenotype spectrum—from metabolically healthy obesity (MHO) to metabolically unhealthy lean (MUL)—that the combination of its TyG and BMI components helps differentiate. For disease incidence prediction, TyG-BMI is often outperformed by indices of central obesity (e.g., Triglyceride-Glucose-Waist Circumference Index(TyG-WC), Triglyceride-Glucose–Waist-to-Height Ratio(TyG-WHtR); for mortality in advanced illness, the standalone TyG index may be superior.</p>Conclusion<p>TyG-BMI is a valuable tool for metabolic phenotyping and risk stratification in kidney disease, with its paradoxical associations highlighting the complex interplay between metabolic health and nutritional reserve.

Future research must establish context-specific clinical thresholds. TyG-BMI is preferentially useful in settings where waist circumference is unavailable, in early CKD screening, and in select type 2 diabetes mellitus (T2DM) subgroups. In advanced CKD, dialysis, critical illness, and CKM stage 4, alternative indices such as TyG index, TyG-WC, or TyG-WHtR should be prioritized due to the confounding effects of fluid overload and catabolic state.</p>