Oral disposition index in obese youth from normal to prediabetes to diabetes: relationship to clamp disposition index.
OBJECTIVE
We sought to assess the glucose disposition index using an oral glucose tolerance test (OGTT; oDI) compared with the glucose disposition index measured from the combination of the euglycemic-hyperinsulinemic and hyperglycemic clamps (cDI) in obese pediatric subjects spanning the range of glucose tolerance.


METHODS
Overweight/obese adolescents (n = 185) with varying glucose tolerance (87 normal, 54 impaired, 31 with type 2 diabetes, and 13 with type 1 diabetes) completed an OGTT and both a hyperinsulinemic-euglycemic and a hyperglycemic clamp study. Indices of insulin sensitivity and β-cell function were calculated, and 4 different oDI estimates were calculated as the products of insulin and C-peptide-based sensitivity and secretion indices.


RESULTS
Mirroring the differences across groups by cDI, the oDI estimates were greatest in normal glucose tolerance adolescents and lowest in type 2 diabetes mellitus and obese with type 1 diabetes mellitus adolescents. The insulin-based oDI estimates correlated with cDI overall (r ≥ 0.74, P < .001) and within each glucose tolerance group (r ≥ 0.40, P < .001). Also, oDI and cDI predicted 2-hour OGTT glucose similarly.


CONCLUSIONS
The oDI is a simple surrogate estimate of β-cell function relative to insulin sensitivity that can be applied to obese adolescents with varying glucose tolerance in large-scale epidemiological studies where the applicability of clamp studies is limited due to feasibility, cost, and labor intensiveness.
Division of Weight Management and Wellness, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA 15224, USA.
Lindsey George
LG
Sjaarda
Fida
F
Bacha
Sojung
S
Lee
Hala
H
Tfayli
Elisa
E
Andreatta
Silva
S
Arslanian
D000293:Adolescent; D003920:Diabetes Mellitus / Q000378:metabolism*; D005260:Female; D015309:Glucose Clamp Technique; D006801:Humans; D008297:Male; D009765:Obesity / Q000378:metabolism*; D011236:Prediabetic State / Q000378:metabolism*