LAUSR

The OGTT-GRCs [ I ncessant In crease (IIn), M ono ph asic (Mph), and B i ph asic (Bph)] reflect insulin sensitivity (IS) and β-cell function (BCF), being worse in the former and best in the latter. Accordingly, the prevalence of these GRCs differ in diabetic and nondiabetic individuals (Table). While islet cell Ab - obese youth CDX-T2D have worse IS, Ab + youth have severe impairment in BCF [Diabetes 58: 2009]. Here, we examined the prevalence of OGTT-GRC patterns, clamp-measured IS, and BCF in obese Ab + (GAD65 and IA2) vs. Ab - youth CDX-T2D. The dominant GRC was IIn in Ab + and Mph in Ab - youth while Bph was scarce in both (Table). In Ab + youth, 1st- (32.5 ± 5.6 vs. 40.2 ± 8.0 µU/mL, p=0.13) and 2nd-phase insulin (39.6 ± 8.6 vs. 62.8 ± 12.2 µU/mL, p=0.04), were 20% and 40% lower in IIn vs. the other two combined. In Ab - , while 1st- (67.3 ± 19.1 vs. 122.4 ± 28.3 µU/mL, p=0.049) and 2nd-phase insulin (110.3 ± 31.4 vs. 171.6 ± 28.6 µU/mL, p=0.054) were lower in IIn vs. Mph, overall BCF was less impaired than in Ab + youth. IS did not differ by GRC type in either group but was lower in Ab - vs. Ab + irrespective of GRC type. The prevalence of IIn-GRC is 3-fold higher in Ab + vs. Ab - obese youth CDX-T2D, and the prevalence in Ab - youth is similar to that in the TODAY study (Table). The higher prevalence of IIn-GRC in Ab + obese youth signifies the severe insulin deficiency characteristic of type 1 diabetes. Disclosure J. Kim: None. N. Gebara: None. H. Tfayli: Other Relationship; Self; Sanofi. F. Bacha: Research Support; Self; National Institute of Diabetes and Digestive and Kidney Diseases, Pediatric Diabetes Consortium. Other Relationship; Self; AstraZeneca, Jaeb Center for Health Research. S.A. Arslanian: None. Funding Eunice Kennedy Shriver National Institute of Child Health and Human Development (K24-HD01357, R01HD27503 to S.A.A.); National Center for Advancing Translational Sciences (UL1TR000005); National Center for Research Resources (UL1RR024153)