Racial and etiopathologic dichotomies in insulin hypersecretion and resistance in obese children.
OBJECTIVE
To assess insulin dynamics to oral glucose tolerance testing in obese children, denoting individual contributions of insulin hypersecretion versus resistance to racial and etiopathogenetic specificity.


METHODS
We performed 3-hour oral glucose tolerance testing in 113 nondiabetic obese children (age 13.6 +/- 3.1 years; 41 male, 78 female; 37 black, 41 white; 35 with central nervous system [CNS] insult). The corrected insulin response (CIRgp; measuring beta-cell secretion) and the composite insulin sensitivity index (CISI) were computed and log-transformed, and each was modeled in terms of the other, plus race/etiology, age, sex, body mass index z score, glucose tolerance, pubertal status, and geographic location.


RESULTS
A scatterplot of logCIRgp versus logCISI showed that racial and etiopathogenetic groups plotted in different areas. CISI (controlled for CIRgp and other variables) was only 13% lower in blacks than in whites ( P = .32). Conversely, CIRgp (controlled for CISI and other variables) was 49% higher in blacks ( P = .028). CNS insult exhibited a 40% higher CIRgp ( P = .054) and 11% higher CISI ( P = .42) than intact white subjects.


CONCLUSIONS
Insulin hypersecretion and resistance are distinct phenomena in childhood obesity. Insulin hypersecretion appears to be the more relevant insulin abnormality both in obese blacks and in CNS insult.
Preeyasombat
Chaluntorn
C
Department of Pediatrics, University of California-San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143-0434, USA.
Bacchetti
Peter
P
Lazar
Ann A
AA
Lustig
Robert H
RH
D000293:Adolescent; D044383:Black People; D001927:Brain Diseases / Q000150:complications* / Q000378:metabolism*; D005260:Female; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance / Q000208:ethnology*; D000078790:Insulin Secretion; D008297:Male; D009765:Obesity / Q000208:ethnology / Q000209:etiology* / Q000378:metabolism; D044465:White People
D007328:Insulin