Abstract
Background: BMI cut-offs proposed by the International Obesity Task
Force (IOTF) and the US Centers for Disease Control and Prevention
(CDC) have been widely used to define childhood overweight/obesity.
However, these references have not been thoroughly evaluated in terms
of ability to detect clustering of cardiovascular risk-factors.
Objective: To assess the ability of IOTF and CDC BMI cut-offs to successfully
screen for children and adolescent with clustering of risk-factors.
Methods: 2836 schoolchildren in the 3rd (8–11 years) and 9th (14–17
years) grade were randomly selected from Denmark, Estonia and Portugal.
Risk-factors included in the composite risk-factor score (mean of
Z-scores) were systolic and diastolic blood pressure, triglyceride, total
cholesterol, HDL-cholesterol, insulin resistance and aerobic fitness. Children
with a risk score above 1SD of the composite variable were defined
as being at risk. Logistic regression and ROC analysis were performed.
Results: Independent of the reference used, the likelihood of having
clustering of risk-factors was significantly higher (p-value <0.0001) in
the obese (OR: 17.8 IOTF; 18.1 CDC) and overweight groups (OR: 6.4 IOTF; 5.4 CDC) compared to normal-weight group, regardless of age, gender, puberty and country. However, the screening ability of BMI cutoffs was modest. The area under the ROC curves ranged from 0.52 to 0.70 using IOTF reference and from 0.53 to 0.62 using CDC reference. Obesity cut-offs were highly specific, but less sensitive for identifying children at risk.
Conclusion: Current definitions of childhood obesity tend to be conservative,
whether the IOTF and CDC references are used.
Keywords: cardiovascular risk factors; childhood obesity; classification
systems; screening
Force (IOTF) and the US Centers for Disease Control and Prevention
(CDC) have been widely used to define childhood overweight/obesity.
However, these references have not been thoroughly evaluated in terms
of ability to detect clustering of cardiovascular risk-factors.
Objective: To assess the ability of IOTF and CDC BMI cut-offs to successfully
screen for children and adolescent with clustering of risk-factors.
Methods: 2836 schoolchildren in the 3rd (8–11 years) and 9th (14–17
years) grade were randomly selected from Denmark, Estonia and Portugal.
Risk-factors included in the composite risk-factor score (mean of
Z-scores) were systolic and diastolic blood pressure, triglyceride, total
cholesterol, HDL-cholesterol, insulin resistance and aerobic fitness. Children
with a risk score above 1SD of the composite variable were defined
as being at risk. Logistic regression and ROC analysis were performed.
Results: Independent of the reference used, the likelihood of having
clustering of risk-factors was significantly higher (p-value <0.0001) in
the obese (OR: 17.8 IOTF; 18.1 CDC) and overweight groups (OR: 6.4 IOTF; 5.4 CDC) compared to normal-weight group, regardless of age, gender, puberty and country. However, the screening ability of BMI cutoffs was modest. The area under the ROC curves ranged from 0.52 to 0.70 using IOTF reference and from 0.53 to 0.62 using CDC reference. Obesity cut-offs were highly specific, but less sensitive for identifying children at risk.
Conclusion: Current definitions of childhood obesity tend to be conservative,
whether the IOTF and CDC references are used.
Keywords: cardiovascular risk factors; childhood obesity; classification
systems; screening
| Original language | English |
|---|---|
| Pages | 33 |
| Number of pages | 1 |
| DOIs | |
| Publication status | Published - 14 May 2009 |
| Event | 17th European Congress on Obesity (ECO 2009) - Amsterdam, Netherlands Duration: 6 May 2009 → 9 May 2009 Conference number: 17 |
Conference
| Conference | 17th European Congress on Obesity (ECO 2009) |
|---|---|
| Abbreviated title | ECO2009 |
| Country/Territory | Netherlands |
| City | Amsterdam |
| Period | 6/05/09 → 9/05/09 |
