Background: Obesity epidemic is associated with diabetes and its complications at young age. Meanwhile, there is no recommendation concerning stratification as a risky for the overweight without dysglycemia by WHO criteria.
Objective and hypotheses: Insulin response during OGTT might be dependent on BMI and can reflect preclinical stage of dysglycemia
Method: 72 otherwise healthy adolescents aged 13.56±2.47 y.o. were examined with standard 2-hrs oral glucose tolerance test (OGTT). Subjects were grouped by BMI Z-score: −<1 S.D. low weight (LW, n=11), ±1 S.D., normal weight (NW, n=16),+12 S.D., overweight (OW, n=14),+2.13.0 S.D., obese (OB 1, n=18),+>3 S.D., obese (OB2, n=13).
Results: Dysglycemia by the WHO standards was registered in 37.09% of subjects with excessive body mass: 24.19% of IFG (OW, OB1, OB2), 6.4% IGT (OB 2) and 6.4% IFG+IGT (OB 1, OB 2). Its about 51.11% of total overweight. All of them were insulin resistant. No one case of diabetes revealed.
Fasting insulin was gradually increasing from group to group (6.91; 10.17; 25.84; 30.71; 41.23 μIU/ml; P<0.01) as well as HOMA-IR (1.75; 2.69; 5.62; 6.85; 8.56; P<0.01) and average insulin concentration during the test (P<0.01). Peak insulin response was registered in LW at 30 min and in NW, OW, OB1 and OB2 at 15 min. Afterwards insulin levels were decreasing in LW and NW. Meanwhile it was tendency for insulin level to grow up in all overweight and obese. Insulin dropped down in all subjects at 120 min. Simultaneously, insulin at 120 min was higher than fasting at 387% in LW, 67% in NW, 156% in OW, for 100% in all obese (P<0.01). Insulin dynamic demonstrates high variability in LW and OW together with least result in OB2.
Conclusion: There is a linear dependence of fasting and average insulin concentration on BMI. There is a strongest response in LW and NW subjects during the first phase of insulin response and in OW and OW during the second one. It reveals a necessity to stratify subjects with low variability during OGTT and absent decrease of insulin level after 30 min. as risky even despite of absent diabetes and dysglycemia.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology