Relationships of BMI with Body Composition, Blood Lipoproteins and Pressure in African American Teenagers

Abstract

PURPOSE: The metabolic syndrome is occurring more frequently and this is especially true in African Americans. The co-morbid relationships between the different metabolic disease conditions are not clear. Therefore, the purpose of this study was to evaluate the relationships of BMI with body composition, blood lipoproteins and pressure in African American teenagers. METHODS: One hundred ten teenagers (55 boys and 55 girls) with a mean age of 14.2 ± 1.2 years were evaluated for total cholesterol, HDL- cholesterol, glucose, systolic (SBP), diastolic (DBP) and mean (MBP) blood pressure, waist circumference, waist/hip ratio and percent body fat (%fat). They were divided by gender into three groups based on Body Mass Index (BMI) classifications (average weight BMI 18–24.9 kg/m2; overweight BMI 25–29.9 kg/m2; and extremely overweight – BMI >30 kg/m2) and evaluated for the differences and relationships using ANOVA and correlations, respectively. RESULTS: Although %fat values were different (p<0.05) for each of the BMI classifications, blood lipoproteins and glucose were not (p>0.05) and this was true for both genders. The overweight girls DBP was lower than the DBP of the other two groups and SBP, DBP, MAP of the extremely overweight boys was larger (p<0.05) than that of the average weight boys. When the subjects were evaluated for relationships by gender, all BP values were related to BMI for both genders, but total cholesterol was the only lipoprotein related to BMI and that was for the teenage girls. CONCLUSIONS: These results suggest that obesity as estimated by BMI appears to have a stronger relationship with blood pressure for teenage African American boys and lipoproteins for African American girls. However, all values for both blood pressure and lipoproteins were within acceptable ranges. These data indicate that higher BMI values tend to be associated with higher values for other metabolic syndrome conditions in African American teenagers.