Can the insulin sensitivity index (ISI) in association with insulin-like growth factor binding protein-1 identify insulin resistance early in overweight children?
Association between insulin resistance (IR) and non-alcoholic fatty liver disease (NAFLD) has been reported. This prompted us to evaluate the power of the insulin sensitivity index (ISI) in association with IGFBP-1 to identify IR early in obese children/adolescents. OGTT was performed in 34 obese/overweight children/adolescents. Glucose, insulin and IGFBP-1 were measured in serum samples and ISI was calculated. Considering the presence of three or more risk factors for IR as a criterion for IR, ISI < 4.6 showed 87.5% sensitivity and 94.5% specificity in diagnosing IR. IGFBP-1 was lower in the group with ISI < 4.6 (p < 0.01). In this group, three patients had higher than expected IGFBP-1, suggesting hepatic IR, while three patients with ISI > 4.6 showed very low IGFBP-1 levels.


CONCLUSIONS
ISI < 4.6 is a good indicator of early peripheral IR and, associated with IGFBP-1, can identify increased risk of hepatic IR. Low IGFBP-1 levels among non-IR children may indicate increased portal insulin levels.
Malaquias
Alexsandra C
AC
Department of Pediatricse, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
Bezzan
Paula C
PC
Montenegro
Renan
R
Daneluzzi
Júlio C
JC
Ricco
Rubens G
RG
Del Ciampo
Luis A
LA
Ferraz
Ivan S
IS
Elias
Jorge
J
Martinelli
Ana L C
AL
Martinelli
Carlos E
CE
D002648:Child; D015331:Cohort Studies; D005951:Glucose Tolerance Test; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000097:blood*; D008055:Lipids / Q000097:blood; D009765:Obesity / Q000097:blood*; D050177:Overweight / Q000097:blood*
D018970:Insulin-Like Growth Factor Binding Protein 1; D008055:Lipids