Deterioration of insulin sensitivity and beta-cell function in overweight Hispanic children during pubertal transition: a longitudinal assessment.
OBJECTIVE
To examine 1-year changes in insulin dynamics in overweight Hispanic children at high-risk of type 2 diabetes as a function of body composition and pubertal transition.


METHODS
Longitudinal changes in insulin dynamics, body composition and maturation were determined in 132 Hispanic children (70 boys/62 girls; aged 10.9 +/- 1.8 years).


METHODS
Body composition was determined by dual energy x-ray absorptiometry and Tanner stage by physical examination. Insulin sensitivity (SI), the acute insulin response to glucose (AIR) and the disposition index (DI; an index of beta-cell function) were determined using an insulin modified intravenous glucose tolerance test. These measures were conducted at baseline and 1-year later.


RESULTS
Fat mass increased by 13% (3.0 kg) and SI declined by 24%. In repeated measures analysis of variance, the fall in insulin sensitivity over 1 year remained highly significant even after adjusting for baseline fat mass, age, gender and change in fat mass. The fall in SI was not significantly influenced by Tanner stage. However, subjects in earlier maturation showed a compensatory increase in AIR (i.e. appropriate beta-cell compensation), whereas subjects in the latter stages of maturation did not (i.e. poor compensation).


CONCLUSIONS
These results indicate that failure to increase AIR in response to the fall in SI may be one factor in the pathogenesis of the progression of pediatric type 2 diabetes in this at risk population.
Goran
Michael I
MI
Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles 90033, USA. goran@usc.edu
Shaibi
Gabriel Q
GQ
Weigensberg
Marc J
MJ
Davis
Jamie N
JN
Cruz
Martha L
ML
D015502:Absorptiometry, Photon; D000273:Adipose Tissue; D000293:Adolescent; D000704:Analysis of Variance; D001823:Body Composition; D015992:Body Mass Index; D002648:Child; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000208:ethnology / Q000378:metabolism*; D005260:Female; D018149:Glucose Intolerance / Q000378:metabolism; D005951:Glucose Tolerance Test; D006630:Hispanic or Latino; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance / Q000208:ethnology*; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D008137:Longitudinal Studies; D008297:Male; D050177:Overweight / Q000208:ethnology*; D011627:Puberty / Q000208:ethnology / Q000378:metabolism*; D012307:Risk Factors
D007328:Insulin