Anthropometry-adjusted TyG indices improve insulin resistance estimation: an exploratory euglycemic–hyperinsulinemic clamp study in Japanese adults without diabetes
摘要
We evaluated the diagnostic performance of anthropometry-adjusted triglyceride-glucose (TyG)-derived indices for assessing insulin resistance (IR) in Japanese adults without diabetes, using the euglycemic–hyperinsulinemic clamp (EHC) as the reference standard.
MethodsA total of 61 Japanese individuals without diabetes underwent insulin sensitivity assessment using the gold standard EHC. IR was defined as an insulin sensitivity index (ISI) below the 25th percentile. Surrogate IR indices, including Homeostasis Model Assessment of Insulin Resistance (HOMA-IR), the original TyG index, and anthropometry-adjusted TyG-derived indices (TyG-BMI, TyG-WC, TyG-WHtR), were calculated. Correlations between these indices and the ISI were evaluated using Spearman’s rank correlation. Receiver operating characteristic (ROC) analysis and linear regression were used to compare diagnostic accuracy and predictive ability. Pairwise DeLong tests were used to assess differences in the area under the curve (AUC) values.
ResultsTyG-BMI and TyG-WHtR showed the stronger associations with ISI (ρ = − 0.544 and − 0.546, respectively) than both HOMA-IR and the original TyG index. TyG-BMI and TyG-WHtR had the highest AUCs (0.810 and 0.829, respectively) for identifying clamp-defined IR. The optimal cutoff value for HOMA-IR was approximately 2.5. The optimal cutoff for TyG-BMI was 203.7. Pairwise DeLong tests supported the higher diagnostic performance of selected anthropometry-adjusted TyG-derived indices compared with conventional markers.
ConclusionsAnthropometry-adjusted TyG-derived indices, particularly TyG-BMI and TyG-WHtR, showed strong associations with IR as assessed by the gold standard EHC in Japanese adults without diabetes. These findings suggest that these indices may serve as practical surrogate markers for IR in settings where direct clamp measurements are not feasible.