Objective: To determine the association between measures
of adiposity (body mass index and waist circumference)
and risk factors for heart disease, type 2 diabetes,
fatty liver disease, and the clustering of risk factors
in middle adolescence.
Design: Cross-sectional study.
Setting: Secondary schools in Sydney.
Participants: Grade 10 students (N=496; 58.4% boys;
mean [SD] age, 15.4 [0.4] years).
Main Exposures: Height, weight, waist circumference,
blood pressure, and fasting blood samples.
Outcome Measures: Participants were categorized as
overweight or obese using the International Obesity Task
Force cut points and the UK waist circumference cut
points. Blood was analyzed for high- and low-density lipoprotein
cholesterol, triglycerides, insulin, glucose, alanine
aminotransferase, -glutamyltransferase, and highsensitivity
C-reactive protein levels, and the results were
categorized as normal or abnormal according to published
guidelines where possible. Associations between
overweight and obesity and risk factors were explored
using logistic regression. Clustering of risk factors within
individuals was also explored.
Results: Insulin (P.001), alanine aminotransferase
(P.001), -glutamyltransferase (P = .005), highdensity
lipoprotein cholesterol (P.001), highsensitivity
C-reactive protein (P.001), and blood pressure
(P.001) were significantly associated with
overweight and obesity in adolescent boys. In adolescent
girls, insulin, high-density lipoprotein cholesterol
(P.001), and high-sensitivity C-reactive protein
(P.001) were significantly associated with overweight
and obesity. Obese adolescent boys and girls were significantly
more likely to have 2 or more risk factors (boys:
73.5% vs 7.6%; girls: 44.4% vs 5.4%; P.001 for both)
than nonoverweight adolescents.
Conclusions: Overweight and obese adolescents, especially
boys, are at substantial risk for chronic conditions.
Waist circumference is not a better predictor of
metabolic risk factors than is body mass index.