Liver steatosis in obese prepubertal children: a possible role of insulin resistance.
OBJECTIVE
To determine whether in obese prepubertal children insulin resistance (IR) is associated with the development of liver steatosis.


METHODS
Cross-sectional study evaluating the prevalence of liver steatosis in 100 severely obese prepubertal children and comparing IR indexes between children with (group 1) and without steatosis (group 2). Furthermore, IR indexes were compared to values of 50 normal weight children. Fasting blood samples were collected for the evaluation of liver function tests, lipid profile, plasma glucose, and insulin levels. All children underwent an oral glucose tolerance test and anthropometric measurements. Hepatic ultrasound was performed according to international criteria and by one single operator. Analysis was performed by Mann-Whitney U-test, Pearson correlation, and logistic regression.


RESULTS
Liver steatosis was found in 52% obese children and was equally distributed between the two sexes. Obese children were more insulin resistant when compared to controls (homeostasis model assessment of IR (HOMA-IR): P = 0.0001; whole body insulin sensitivity index (WBISI): P = 0.0005; fasting glucose/fasting insulin ratio (G/I): P = 0.0001), and group 1 presented an even higher degree of IR when compared to group 2 (HOMA-IR P = 0.0001; WBISI P = 0.0004; G/I P = 0.0001). The area under the curve (AUC) for insulin was significantly higher in group 1 when compared to group 2, while no difference was found in the AUC for glucose. There was no association between IR and adiposity indexes (P >0.05). The role of IR as a predictor for the development of steatosis was analyzed by multiple logistic regression, which documented that IR indexes were significantly related to steatosis independently of BMI-SDS.


CONCLUSIONS
Liver steatosis is an emerging problem in prepubertal severely obese children, and it appears to be an association between liver steatosis and IR in these subjects.
D'Adamo
Ebe
E
Department of Pediatrics, University of Chieti, Chieti, Italy.
Impicciatore
Mario
M
Capanna
Rita
R
Loredana Marcovecchio
M
M
Masuccio
Fabio G
FG
Chiarelli
Francesco
F
Mohn
Angelika A
AA
D001786:Blood Glucose / Q000032:analysis; D016022:Case-Control Studies; D002648:Child; D003430:Cross-Sectional Studies; D005234:Fatty Liver / Q000097:blood / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D007558:Italy / Q000453:epidemiology; D008055:Lipids / Q000097:blood; D008111:Liver Function Tests; D016015:Logistic Models; D008297:Male; D009765:Obesity / Q000097:blood / Q000150:complications / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000503:physiopathology*; D015995:Prevalence; D012307:Risk Factors; D012720:Severity of Illness Index; D014463:Ultrasonography
D001786:Blood Glucose; D007328:Insulin; D008055:Lipids