The novel nutritional metabolic risk index and established triglyceride-glucose indices in type 2 diabetes: modifying role of biological aging assessed by telomere length.

<h4>Background</h4>Triglyceride-glucose (TyG) derivatives are recognized markers of type 2 diabetes (T2DM) risk. However, the association between composite indices integrating nutritional and metabolic status and biological aging in T2DM patients remains unclear.<h4>Methods</h4>Data from 4,572 adults were analyzed to evaluate the association between four indices, including the geriatric nutritional risk index (GNRI), TyG, triglyceride glucose-waist-to-height ratio (TyG-WHtR), and the composite nutritional metabolic risk index (NMRI), and T2DM prevalence using logistic regression and restricted cubic spline analysis. The potential mediating and moderating roles of relative telomere(definition) length (RTL) were also explored.<h4>Results</h4>TyG and TyG-WHtR were strongly associated with higher odds of T2DM, with TyG-WHtR presenting the strongest association (odds ratio [OR] = 10.20; 95% confidence interval [CI]: 8.64-12.10). NMRI was independently inversely associated with T2DM in a non-linear manner, and the inverse association was stronger among participants with shorter RTL (interaction OR = 1.007; 95% CI: 1.000-1.014; <i>p</i> = 0.041). RTL did not mediate but moderated the NMRI-T2DM link. GNRI exhibited no significant association with T2DM.<h4>Conclusion</h4>TyG and TyG-WHtR may serve as useful indicators of T2DM risk, while NMRI is inversely associated with T2DM. RTL appeared to modify the association between NMRI and T2DM, suggesting potential value for individualized metabolic risk stratification, which warrants further investigation in longitudinal studies. These findings suggest that the interplay between nutritional-metabolic indices and biological aging in diabetes pathogenesis warrants further investigation.