Profiles of blood pressure among children and adolescents with different body mass index categories in Shandong, China

Background: The International Obesity Task Force recently developed an extended body mass index (BMI) cut-offs for screening thinness, overweight and obesity among children and adolescents. The present study examined the profiles of blood pressure (BP) among children and adolescents with different BMI categories in Shandong, China. Methods: Data for this study were obtained from a large cross-sectional survey of schoolchildren. A total of 44,630 students (22,404 boys and 22,226 girls) aged 7-18 years participated in this study. The grades of body weight (thinness grade 1-3, normal weight, overweight and obesity grade 1-3) was defined by the international BMI cut-offs. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured on one occasion. High BP was defined as SBP and/or DBP >= 95th percentile for age and gender. Results: The overall prevalence of thinness (grade 1-3), overweight and obesity (grade 1-3) were 7.80, 18.74 and 8.56% for boys and 11.16, 13.53 and 3.70% for girls, respectively, boys had a lower prevalence of thinness and higher prevalence of overweight and obesity than girls (p < .01). Urban boys and girls had a lower prevalence of thinness and higher prevalence of overweight and obesity than their rural counterparts (p < .01). Children and adolescents with high BMI had a higher BP levels than their counterparts with normal and low BMI. Conclusion: High BMI is strongly related to elevated BP. Our findings emphasize the importance of the prevention of overweight/obesity to prevent future-related problems such as hypertension in children and adolescents.