Validation of insulin sensitivity indices from oral glucose tolerance test parameters in obese children and adolescents.
Given the extreme increase in prediabetes, type 2 diabetes, and the potential for metabolic syndrome in obese youth, identifying simplified indexes for assessing stimulated insulin sensitivity is critical. The purpose of this study was validation of two surrogate indexes of insulin sensitivity determined from the oral glucose tolerance test (OGTT): the composite whole body insulin sensitivity index (WBISI) and the insulin sensitivity index (ISI). An obese population (aged 8-18 yr) of normal and impaired glucose tolerance individuals was studied. One group (n = 38) performed both the euglycemic-hyperinsulinemic clamp and OGTT for comparison of insulin sensitivity measurements as well as (1)H-magnetic resonance spectroscopy estimates of intramyocellular lipid content. Another larger (n = 368) cohort participated only in an OGTT. Both the WBISI and ISI represented good estimates (r = 0.78 and 0.74; P < 0.0005) for clamp-derived insulin sensitivity (glucose disposed, M-value), respectively. In the large cohort, the surrogate indexes demonstrated the shift toward poorer function and increased risk profile as a function of insulin resistance. Additionally, the WBISI and ISI correlated with intramyocellular lipid content (r = -0.74 and -0.71; P < 0.0001), a tissue marker for insulin resistance. Insulin sensitivity can be estimated using plasma glucose and insulin responses derived from the OGTT in obese youth with normal and impaired glucose tolerance.
Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
Catherine W
CW
Yeckel
Ram
R
Weiss
James
J
Dziura
Sara E
SE
Taksali
Sylvie
S
Dufour
Tania S
TS
Burgert
William V
WV
Tamborlane
Sonia
S
Caprio
D000293:Adolescent; D002648:Child; D025461:Feedback, Physiological; D005260:Female; D015309:Glucose Clamp Technique / Q000592:standards; D005951:Glucose Tolerance Test / Q000592:standards*; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance; D007515:Islets of Langerhans / Q000502:physiology; D050356:Lipid Metabolism; D008297:Male; D009765:Obesity / Q000175:diagnosis* / Q000453:epidemiology / Q000378:metabolism*; D012307:Risk Factors; D012720:Severity of Illness Index
D007328:Insulin