Surrogate indices for insulin resistance of various insulin-responsive tissues are critical in epidemiological studies of youth at risk for developing type 2 diabetes (T2D) . Having established surrogate indices for peripheral insulin sensitivity (JCEM 2011; 96:2136) , we aimed to develop HIR-I in youth spanning from normal-weight (NW) to obese and from normal glucose tolerance to impaired glucose tolerance to T2D, and assessed potential race-related differences. A total of 287 youth (146 black, 141 white) had [6,6-2H2]glucose tracer-measured HIR (hepatic glucose production x fasting insulin [FI]) , lipids and DXA body composition. To develop HIR-I, multiple stepwise linear regression was performed with variables showing r >0.2 with tracer-measured HIR (Diabetologia, 2011;54:540) in each race (Table) . In black youth, HIR-I was generated from (fasting glucose [FG], FI, fat mass and VLDL) while in whites from (FG, FI and BMI) (Figure) . HIR-I correlated with tracer-measured HIR in blacks (r=0.915) and whites (r=0.923, both p<0.001) (Figure) . In both black and white youth, HIR-I was lowest in NW and highest in T2D (Figure) .

In conclusion, different physical and laboratory biomarkers contribute to race-specific formulas of HIR-I with strong correlations with tracer-measured HIR in both. Race-specific HIR-I and its change across the gamut of glycemia may shed light in epidemiological studies of the development of youth T2D.

Disclosure

W. Cho: None. F. Bacha: Other Relationship; AstraZeneca, Takeda Pharmaceutical Company Limited, Research Support; National Institute of Diabetes and Digestive and Kidney Diseases, U. S. Department of Agriculture. H. M. Tfayli: Advisory Panel; Novo Nordisk, Research Support; Novartis Pharmaceuticals Corporation, Sanofi. S. Lee: None. S. Michaliszyn: None. J. Kim: n/a. S. A. Arslanian: Advisory Panel; Eli Lilly and Company, Novo Nordisk, Other Relationship; AstraZeneca, Research Support; Eli Lilly and Company, Novo Nordisk.

Funding

American Diabetes Association (7-08-JF-27) , National Institute of Child Health and Human Development grants (K24-HD01357, R01-HD27503) , National Center for Advancing Translational Sciences Clinical and Translational Science Award (UL1TR000005) , National Center for Research Resources grant (UL1RR024153) , National Institute of Diabetes and Digestive and Kidney Diseases (R21DK083654-01A1)

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