Characterization of Insulin Resistance Syndrome in Children and Young Adults. When to Screen for Prediabetes

Context: Insulin resistance syndrome (IRS) is associated with the development of type 2 diabetes mellitus (DM2). However, it is unclear which individuals with insulin resistance will develop DM2. Aim: To study the prevalence of IRS in childhood and to identify the group with the highest risk of further progression to DM2. Methods: In a cross-sectional study, 86 obese individuals underwent an intravenous glucose tolerance test (IVGTT). Insulin resistance index (Si IVGTT), acute insulin response (AIR) and disposition index (DI) were calculated from IVGTT. Results: For analysis the participants were divided into insulin-sensitive (IS) (n = 25, 13.3 ± 5.9 yr) and insulin-resistant (IR) groups on the basis of having an Si IVGTT greater or lesser than 4.5 x 10 -4 mU/ml/min, respectively. The IR group was then subdivided according to DI, with the standard cut-off value of 0.13 min -1 , into compensated IR (CIR) (n = 37, 13.0 ± 3.5 yr) and decompensated IR (DIR) (n = 24, 21.9 ± 12.6 yr) groups. The frequency of IRS was 43% in children, 78% in adolescents and 83.6% in adults. Decompensated insulin response first appeared during adolescence. The frequency of decompensation increased from 22% in adolescence to 67% in adulthood. The DIR group had increased triglycerides (TG) and urinary free cortisol levels. Conclusions: The frequency and severity of IR increases with age. Decompensation first presents in adolescence with low AIR and elevated TG. Decompensated adolescents are the group at highest risk for further progression to DM2.