Development of a prediction equation for insulin sensitivity from anthropometry and fasting insulin in prepubertal and early pubertal children.
OBJECTIVE
To test the utility of homeostasis model assessment (HOMA) in predicting insulin sensitivity [x10(- 4) min(-1)/(microIU/ml)] in children and to develop and compare two new prediction equations for insulin sensitivity in children using demographic and anthropometric measures in the presence or absence of fasting insulin.


METHODS
We studied 156 white and African-American children with complete data (mean age 9.7 +/- 1.8 years, 87.8% Tanner Stage 1 or 2). For development of new equations, two-thirds of the children were randomly assigned to a development group, whereas the remaining children were assigned to a cross-validation group.


RESULTS
A modified HOMA equation accurately predicted insulin sensitivity, but its utility is similar to fasting insulin alone. Demographic and anthropometric measures alone did not predict insulin sensitivity accurately, even when precise measures of body composition were included in the prediction model. Ethnicity, calf skinfold, and fasting insulin together explained 73% of the variance in insulin sensitivity and accurately predicted insulin sensitivity. The regression of measured versus predicted insulin sensitivity in the cross-validation group was not significantly different from the line of identity (P > 0.05). Mean difference between measured and predicted insulin sensitivity was also not significant (P > 0.05). Some bias was apparent, particularly in white boys.


CONCLUSIONS
Ethnicity, calf skinfold, and fasting insulin can accurately predict insulin sensitivity with greater precision than HOMA or fasting insulin alone (R(2) = 0.73). Future studies, however, are needed to examine whether a universal equation is possible. A cross-validated prediction equation may be useful in population-based studies when complex measures of insulin sensitivity are not available.
Huang
Terry T-K
TT
Institute for Health Promotion and Disease Prevention Research, Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California 90089, USA.
Johnson
Maria S
MS
Goran
Michael I
MI
D000886:Anthropometry; D044383:Black People; D001786:Blood Glucose / Q000378:metabolism; D001824:Body Constitution; D001827:Body Height; D001835:Body Weight; D002140:California; D002648:Child; D005215:Fasting / Q000502:physiology*; D006706:Homeostasis; D006801:Humans; D007328:Insulin / Q000097:blood* / Q000502:physiology*; D011237:Predictive Value of Tests; D011627:Puberty / Q000097:blood / Q000502:physiology*; D012044:Regression Analysis; D012680:Sensitivity and Specificity; D012885:Skinfold Thickness; D044465:White People; D001741:Black or African American
D001786:Blood Glucose; D007328:Insulin