Relationships of BMI with Body Composition, Blood Lipoproteins and Pressure in Pre-Teenage African Americans

Abstract

PURPOSE: Childhood obesity is occurring in epidemic proportions, but the co-morbid effects of obesity are unclear. Therefore, the purpose of this study was to evaluate the relationships of obesity with blood pressure, lipoproteins and body composition in pre-teenage African American children. METHODS: A comparative research design was employed as 134 children (65 boys and 69 girls) between 10 and 12 (X= 11.1) years of age volunteered as subjects. They were divided by gender into three groups based on 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 in and relationships with body composition, lipoproteins and blood pressure using ANOVA and correlations. RESULTS: No differences (p>0.05) were observed for the blood lipoproteins and glucose across the three BMI groups for the boys or the girls and values for all three BMI groups for both genders fell within the desirable ranges for children. Systolic (SBP), diastolic (DBP) and mean (MAP) blood pressures were higher (p<0.05) for the extremely overweight girls, but the values were <the 90%. No differences were observed for blood pressure for the boys across the BMI groups and all values were <the 90%. When the subjects were grouped by gender and evaluated for relationships between BMI and the other variables, %fat, waist circumference, SBP, DBP, MAP and heart rate at the end of a three minute step test were related (p<0.05) for the girls. Only %fat, waist circumference and SBP were related (p<0.05) for the boys. CONCLUSIONS: These data suggest that different BMI classifications provide similar information about blood lipoproteins in African American boys and girls, but provide different co-morbid BP information for girls than it does for boys.