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ARS Home » Plains Area » Houston, Texas » Children's Nutrition Research Center » Research » Publications at this Location » Publication #371546
Title: Evaluating a pragmatic estimate of insulin sensitivity in Latino youth with obesity

Author
item PENA, ARMANDO - Arizona State University
item OLSON, MICAH - Arizona State University
item SOLTERO, ERICA - Children'S Nutrition Research Center (CNRC)
item LEE, CHONG - Arizona State University
item TOLEDO, MEYNARD - Arizona State University
item AYERS, STEPHANIE - Arizona State University
item SHAIBI, GABRIEL - Arizona State University

Submitted to: Clinical Obesity
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/3/2020
Publication Date: 1/21/2020
Citation: Pena, A., Olson, M.L., Soltero, E.G., Lee, C., Toledo, M.J., Ayers, S.L., Shaibi, G.Q. 2020. Evaluating a pragmatic estimate of insulin sensitivity in Latino youth with obesity. Clinical Obesity. https://doi.org/10.1111/cob.12353.
DOI: https://doi.org/10.1111/cob.12353

Interpretive Summary: Decreased insulin sensitivity is a key indicator of the progression towards type 2 diabetes and an important marker to measure in diabetes prevention interventions. There are a number of methods and techniques to measure insulin sensitivity. However, sophisticated clamp techniques can be burdensome to participants, especially children, because they require multiple blood sample collections over long periods of time. These methods can be costly for researchers, making it difficult to include these measures in longitudinal studies. In this study, we used a 2-hour oral glucose tolerance test to examine the validity and cost-differential between a five timepoint verses a two timepoint assessment of insulin sensitivity. In a sample of 65 Latino adolescents (14-16 years old) with obesity, we found that the two timepoint assessment showed good agreement and a similar rate of change over time compared to the five timepoint assessment and the two timepoint assessment cost about 70% less than the five timepoint assessment. This study demonstrated that the two timepoint assessment is a cost-effective surrogate estimate of insulin sensitivity and a useful tool for monitoring changes in insulin sensitivity over time in a high-risk population. This study extends the usability of the two timepoint oral glucose tolerance test for research and clinical settings in pediatrics by reducing the cost and participant burden. This will allow more researchers to include more sophisticated measures of insulin sensitivity in their research, which will contribute to advancing the science on the development and prevention of type 2 diabetes.

Technical Abstract: The whole-body insulin sensitivity index (WBISI) is a widely used surrogate of insulin sensitivity estimated from glucose and insulin concentrations during an oral glucose tolerance test (OGTT). The original WBISI uses five timepoints but reduced sampling models have been proposed. These reduced models have not been applied to the paediatric population. The purpose of this study is to compare cross-sectional agreement and changes in response to lifestyle intervention between the original WBISI and the WBISI120 using fasting and 2-hour glucose and insulin concentrations from OGTT among Latino adolescents with obesity. We also examined the cost-differential between the two measures. Secondary analyses were conducted with data from Latino adolescents (14-16 years) with obesity (BMI>=95th percentile) who were recruited for a randomized controlled lifestyle intervention trial. Baseline data in youth (n=148) who underwent a 2-hour OGTT was used to analyse agreement between WBISI and WBISI120. Data from 65 participants who completed a 12-week lifestyle intervention were used to assess changes and the rate of change between WBISI and WBISI120. Research costs to determine both measures were compared. WBISI120 showed good cross-sectional agreement (ICC agreement=0.88) with the full WBISI. Following intervention, WBISI120 increased 62.5% (M+/-SD, 1.6+/-1.2 to 2.6+/-1.7, P<.001) while WBISI increased by 25.0% (1.6+/-1.0 to 2.0+/-1.0, P<.001) but the rate of change for WBISI and WBISI120 was not significantly different (P=.11). WBISI120 costs ~70% less than WBISI. WBISI120 may offer a cost-effective surrogate estimate of insulin sensitivity in Latino youth with obesity.