37% of normal-weight adolescents had at least one risk factor for cardiovascular disease (CVD)
as did 49% of those who were overweight and 61% of those who were obese, according to a recent study published online 21st May 2012 in Pediatrics.
Ashleigh L. May, PhD, an epidemic intelligence service officer in the Division of Heart Disease and Stroke Prevention at the US Centers for Disease Control and Prevention, and colleagues analysed data on 3383 adolescents between the ages of 12 and 19 years who participated in the National Health and Nutrition Examination Survey, a cross-sectional, stratified, multistage probability sample survey of the US population done between 1999 and 2008.
Among all the adolescents in the study, the overall prevalence of risk factors was 14% for prehypertension or hypertension, 22% for borderline or high LDL cholesterol, 6% for low HDL cholesterol and 15% for prediabetes or diabetes.
The prevalence of prediabetes and diabetes increased from 9% to 21% between 1999 and 2008. Obesity did not increase during the span of the study, possibly because of increased awareness of the problem in the general population, the authors note.
When the researchers stratified the sample population by body mass index (BMI), they found that a "....consistent dose-response increase in the prevalence of each of these CVD risk factors was observed by weight categories..."
Overweight and obese adolescents were more likely to have two risk factors than normal-weight youths. Obese adolescents were more likely to have three or more risk factors than their normal-weight peers. The most common combination of risk factors in obese and overweight adolescents was prehypertension or hypertension and borderline or high LDL cholesterol.
Adolescents were categorised as obese if they were in the 95th percentile or higher for BMI and overweight if they fell between the 85th and 95th percentiles. Normal weight adolescents fell between the 5th and 85th percentiles. Those below the 5th percentile were not included in the study.
The authors note that CVD risk factors are often present during childhood and adolescence, but the overt manifestations of these risk factors, such as heart attack and stroke, do not usually emerge until adulthood ."
"Adolescence represents a window of opportunity for assessment of CVD risk factors and the promotion of lifestyles that will affect the development and progression of CVD" the authors write.
Information on family history, exercise, diet, and smoking behaviors was not included in the analysis because it was not available in the data used for the study. Other limitations included the fact that measures other than BMI, such as waist circumference or waist-to-height ratio, may be better predictors of CVD risk factors than BMI in children and adolescents.
Finally, the scarcity of studies similar to the National Health and Nutrition Examination Survey makes it difficult to compare the results of this study with previous research. "This highlights the need for initiating surveillance of CVD risk factors among adolescents" the authors conclude.
“...Overweight and obese adolescents were more likely to have two risk factors than normal-weight youths and obese adolescents were more likely to have three or more risk factors than their normal-weight peers....”