Oral glucose tolerance test curve shape in Mexican children and adolescents with and without obesity

Mexican children with obesity are at a higher risk of developing type 2 diabetes mellitus (T2DM). Objectives To compare oral glucose tolerance test (OGTT) characteristics: time of peak glucose, glucose level ≥155 mg/dL at 1 h, presence of metabolic syndrome (MetS), sensitivity, secretion, and oral disposition index (oDI) in children with and without obesity, according to oral glucose tolerance curve shape: monophasic or biphasic. Methods Cross-sectional study including 143 children. Groups were divided into (a) obese: biphasic (B-Ob) (n=55) and monophasic (M-Ob) (n=50), (b) without obesity: biphasic (B-NonOb) (n=20) and monophasic (M-NonOb) (n=18). Results Late glucose peak was more frequent in the M-Ob group (p<0.001). Glucose levels ≥155 mg/dL and MetS were more frequent in the M-Ob group but did not show significance. The groups with obesity (biphasic and monophasic) had higher indices of insulin resistance and insulin secretion compared to the nonobese groups (biphasic and monophasic) (p<0.001). AUC glucose was higher in the M-Ob group (p<0.05), and AUC insulin was higher in the M-NonOb group. oDI (Matsuda) was significantly lower in the M-Ob group compared to the other groups (p<0.001), and oDI-HOMA IR was higher in M-NonOb group (p=0.03). Conclusions All OGTT parameters could help to identify Mexican children at increased risk of developing T2DM, not only fasting plasma glucose and 2 h glucose. M-Ob in non-T2DM Mexican children reflects an early defect in glucose metabolism. Higher level of IR indexes in M-NonOb vs. B-NonOb could indicate an increased risk for T2DM of genetic origin.