Homeostasis model assessment is more reliable than the fasting glucose/insulin ratio and quantitative insulin sensitivity check index for assessing insulin resistance among obese children and adolescents

Objective. Simple fasting methods to measure insulin resistance, such as the homeostasis model assessment (HOMA), fasting glucose/insulin ratio (FGIR), and quantitative insulin sensitivity check index (QUICKI) methods, have been widely promoted for adult studies but have not been evaluated formally among children and adolescents. The aim of this study was to compare the HOMA, FGIR, and QUICKI methods for measuring insulin resistance, expressed by oral glucose tolerance test (OGTT) results, among obese children and adolescents. Methods. Fifty-seven pubertal obese children and adolescents ( 30 girls and 27 boys; mean age, 12.04 +/- 2.90 years; mean BMI: 29.57 +/- 5.53) participated in the study. All participants underwent an OGTT. Blood samples were obtained 0, 30, 60, 90, and 120 minutes after oral glucose administration for glucose and insulin measurements, and 2 separate groups were studied, according to the presence or absence of insulin resistance. HOMA, FGIR, and QUICKI methods were studied for validation of insulin resistance determined with the OGTT for these groups. Results. The groups consisted of 25 obese children and adolescents with insulin resistance ( 14 girls and 11 boys; mean age: 12.88 +/- 2.88 years; mean BMI: 31.29 +/- 5.86) and 32 subjects without insulin resistance ( 16 girls and 16 boys; mean age: 11.38 +/- 2.79 years; mean BMI: 28.23 +/- 4.94). There were significant differences in the mean HOMA ( 6.06 +/- 4.98 and 3.42 +/- 3.14, respectively) and QUICKI ( 0.313 +/- 0.004 and 0.339 +/- 0.004, respectively) values between the 2 groups. Sensitivity and specificity calculations based on insulin resistance with receiver operating characteristic curve analysis indicated that HOMA had high sensitivity and specificity for measuring insulin resistance. Conclusions. As a measure of insulin resistance among children and adolescents, HOMA is more reliable than FGIR and QUICKI. The present HOMA cutoff point for diagnosis of insulin resistance is 3.16. The HOMA cutoff point of > 2.5 is valid for adults but not for adolescents.