Early cardiovascular autonomic dysfunction, beta cell function and insulin resistance in obese adolescents.
OBJECTIVE
The aim of this study was to assess the metabolic and cardiovascular autonomic phenotype in adolescent obesity.


METHODS
Eighteen non diabetic obese individuals and ten lean age-matched control adolescents were included in the study. All subjects underwent Oral Glucose Tolerance Test (OGTT) with insulin and glucose determination for the calculation of AUC, OGIS, QUICKI, and disposition index. Cardiovascular assessments included 24-hour Holter ECG for HRV measurements, ABP monitoring and echocardiography.


RESULTS
Obese adolescents had higher serum lipids, reduced insulin sensitivity and higher insulin resistance. Obese individuals showed indeed a normal beta-cell function, with insulin AUC and disposition index similar to controls. However, obese adolescents presented a progressive reduction ofvagal indexes (RMSSD, HF) and an increase in sympathetic indexes (LF, LF/HF), which correlated with OGIS and beta-cell function parameters.


CONCLUSIONS
Adolescent obesity is characterized by insulin resistance with normal beta-cell function. Metabolic modifications may lead to an early impairment of the autonomic pattern.
Rabbone
Ivana
I
Department of Pediatrics, University of Torino, Torino, Italy. ivana.rabbone@unito.it
Bobbio
Adriana
A
Rabbia
Franco
F
Bertello
Maria Cristina
MC
Ignaccoldo
Maria Giovanna
MG
Saglio
Elisa
E
Morello
Fulvio
F
Veglio
Franco
F
Pacini
Giovanni
G
Cerutti
Franco
F
D000293:Adolescent; D001342:Autonomic Nervous System Diseases / Q000453:epidemiology*; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000502:physiology; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000453:epidemiology*; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology*; D050417:Insulin-Secreting Cells / Q000502:physiology*; D009765:Obesity / Q000097:blood* / Q000150:complications / Q000503:physiopathology*; D012307:Risk Factors
D001786:Blood Glucose; D007328:Insulin