Impaired vascular function in obese adolescents with insulin resistance.
OBJECTIVE
To evaluate endothelial function (EF) in a cohort of obese adolescents with impaired insulin sensitivity.


METHODS
Cardiovascular risk factors and adipocytokines, along with digital hyperemia, were evaluated by peripheral arterial tonometry (PAT) in adolescents with obesity and insulin resistance (IR) in relation to healthy, nonobese controls.


RESULTS
The obese and control subjects were of similar age (13.4+/-1.7 years vs 14.0+/-1.4 years) and sex. The obese subjects had IR (mean homeostasis model of assessment [HOMA] score=5.4; 95% confidence interval=3.3-7.5) and significantly greater body mass index (BMI) (BMI z-score 2.4+/-0.2 kg/m(2) vs 0.0+/-0.8 kg/m(2)) and waist circumference (WC) measures (109.6+/-11.1cm vs 70.5+/-9.4 cm) with elevated low-density lipoprotein cholesterol (LDL-C), triglyceride, and high-sensitivity C-reactive protein levels. The mean PAT ratio was significantly lower in obese adolescents compared with controls (1.51+/-0.4 vs 2.06+/-0.4; P=.002), indicative of impaired EF. Linear regression demonstrated associations between PAT ratio and BMI, WC, age, and LDL-C but not between PAT and leptin, resistin, or adiponectin levels or IR.


CONCLUSIONS
Obese adolescents with IR exhibited significantly worse EF as assessed by PAT compared with healthy, nonobese controls, and EF showed a significant association with measures of adiposity and other cardiovascular risk factors.
Mahmud
Farid H
FH
Paediatric Endocrinology, Department of Paediatrics, University of Western Ontario, London, Ontario, Canada. farid.mahmud@sickkids.ca
Hill
David J
DJ
Cuerden
Meaghan S
MS
Clarson
Cheril L
CL
D000293:Adolescent; D000704:Analysis of Variance; D015415:Biomarkers / Q000032:analysis*; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000032:analysis; D016022:Case-Control Studies; D008078:Cholesterol, LDL / Q000032:analysis; D015331:Cohort Studies; D016001:Confidence Intervals; D004730:Endothelium, Vascular / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D016014:Linear Models; D008297:Male; D008365:Manometry; D009765:Obesity / Q000150:complications* / Q000175:diagnosis; D011336:Probability; D011379:Prognosis; D012016:Reference Values; D018570:Risk Assessment; D014280:Triglycerides / Q000032:analysis; D014652:Vascular Diseases / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D055105:Waist Circumference
D015415:Biomarkers; D008078:Cholesterol, LDL; D014280:Triglycerides; D002097:C-Reactive Protein