OR31-5 Characterization of the One-Hour Plasma Glucose and Plasma Insulin during an Oral Glucose Tolerance Test (OGTT) in Obese Hispanic Children and Adolescents Diagnosed with Prediabetes (Hba1c ≥ 5.7% & ≤ 6.4%)

Abstract

Background: OGTT is still considered the gold standard test to detect prediabetes and /or Type 2 diabetes (T2D). American Diabetes Association criteria for prediabetes: a) Hba1c 5.7- 6.4% b) fasting plasma glucose (FPG) ≥ 100 mg/dl and/or post-prandial PG ≥ 140, Impaired glucose tolerance (IGT) during an OGTT. In adults the 1-hour(1hr) glucose level (≥ 155 mg/dl) is a strong predictor of future T2D risk than the two-hour level and is associated with diabetes complication. The ideal cut-off for pediatrics is not established though studies have found 1hPG ≥ 132.5 mg/dl, as predictive for risk of T2D (1) Objective: a. To study the dynamic profile of Plasma Glucose (PG) and plasma Insulin (PI) values at time 0,1 and 2 hour during an OGTT b. to assess whether degree of insulin resistance in Hispanic children and adolescents can be predict an abnormal I hr glucose level. Methods: We reviewed OGTT results of 43 obese Hispanic youths; 7-18 years of age with prediabetes. PG and PI values were obtained at 0, 1 and 2hr during OGTT (glucola: dose of 1.75 g/kg body weight up to a maximum of 75 g). The Homeostasis Model Assessment of fasting insulin resistance (HOMA-IR), an index of insulin resistance was calculated using (fasting glucose (mg/dl) X fasting insulin(µIU/ml)/405) and values ≥3.4 were taken as insulin resistance(2). Independent T test was used to study differences between means for group1: HOMA-IR< 3.4 and group 2: HOMA-IR≥ 3.4. Results: Forty-three obese Hispanic youths; 7-18 years of age; mean age of 11.5 ± 0.7; BMI=42.2 ± 4.9; 47% male and 53% female. a) OGTT results: Only one subject had abnormal fasting plasma glucose, 3 subjects had IGT (7%), and 11(26%) had an abnormal 1 h PG during the OGTT b) 1hr glucose and 1hr insulin was different between HOMA-IR groups (p=0.001) even though 2-hr was not. PG: grp#1: 1hr=108 ± 27, 2hr=107 ± 33 mg/dl; grp #2: 1hr=136 ± 33, 2hr=120 ± 32. PI: grp#1: 1hr= 80 ± 61, 2hr= 78 ± 70; grp#2: 1hr= 213 ±171, 2hr= 99 ± 375. Conclusion: In our Hispanic children and adolescents, 1& 2-hr plasma insulin and plasma glucose were clearly abnormal, more so, in the HOMA- IR group ≥ 3.4. This demonstrate that at least in the IR children and adolescents, 1-hour values add value to the interpretation of the OGTT. 26 % of Hispanic children and adolescents had an abnormal 1-hr glucose which is a novel finding of our study. These results validate the recent reports of the plasma 1-hr glucose threshold ≥132.5 mg/dl in Pediatrics and prospective follow up of these Hispanic patients will be able to demonstrate the predictive value of 1 hr values of insulin and glucose to development of T2D.Reference: ADDIN EN.REFLIST 1. Manco M, Miraglia Del Giudice E, et al. 1-Hour plasma glucose in obese youth. Acta diabetologica. 2012;49(6):435-43. 2. Brar PC, Screening obese children and adolescents for prediabetes and/or type 2 diabetes in pediatric practices: a validation study. Clinical pediatrics. 2014;53(8):771-6.