Body trunk fat and insulin resistance in post-pubertal obese adolescents.
OBJECTIVE
Insulin resistance is a metabolic disorder commonly associated with excess body fat accumulation that may increase chronic disease risk. The present study was undertaken to evaluate the relationship between body composition and insulin resistance among obese adolescents.


METHODS
Cross-sectional study, at the Adolescence Center, Pediatric Department, Universidade Federal de São Paulo.


METHODS
Body composition was assessed using dual-energy X-ray absorptiometry. Dietary intake was evaluated using a three-day dietary record. The biochemical evaluation comprised glucose, insulin, serum lipid, leptin and ghrelin measurements. Insulin resistance was calculated by means of the homeostasis model assessment of insulin resistance (HOMA-IR).


RESULTS
Forty-nine post-pubertal obese adolescents participated in the study: 12 boys and 37 girls of mean age 16.6 (1.4) years and mean body mass index (BMI) of 35.0 (3.9) kg/m(2). The mean glucose, insulin and HOMA values were 90.3 (6.4) mg/dl, 16.6 (8.1) microIU/ml and 3.7 (1.9), respectively. Hyperinsulinemia and insulin resistance were observed in 40.2% and 57.1% of the subjects, respectively. Adolescents with insulin resistance had higher BMI and body trunk fat. There was a trend towards higher leptin concentration in obese individuals with insulin resistance. Insulin resistance was positively correlated with body trunk fat, BMI, body fat mass (kg), leptin and body fat percentage. Furthermore, there was a negative correlation between HOMA-IR and lean body mass. The body composition predicted 30% of the HOMA-IR levels, according to linear regression models.


CONCLUSIONS
Body trunk fat was significantly associated with insulin resistance, demonstrating the clinical importance of abdominal obesity during adolescence.
Outpatient Clinics for Adolescents (CSCA), Universidade Federal de São Paulo (Unifesp), and Nutrition Department, Faculdade de Saúde Pública (FSP), Universidade de São Paulo (USP), São Paulo, Brazil.
Luana Caroline dos
LC
Santos
Isa de Pádua
Ide P
Cintra
Mauro
M
Fisberg
Lígia Araújo
LA
Martini
D000273:Adipose Tissue / Q000378:metabolism; D000293:Adolescent; D001823:Body Composition / Q000502:physiology*; D050218:Body Fat Distribution; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism / Q000503:physiopathology; D004032:Diet; D005260:Female; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance / Q000502:physiology*; D016014:Linear Models; D008297:Male; D009765:Obesity / Q000378:metabolism*
D007328:Insulin