Comparison of body shape and physical activity among adolescents with normotensive and elevated blood pressure in Shandong, China.

BACKGROUND: Several studies have provided ample evidence that hypertension in adults has its onset in childhood; children and adolescents with elevated blood pressure (BP) are more likely to become hypertensive adults. Shandong province is one of the areas of China with higher prevalence of hypertension. However, no studies on the relationship between physique and BP have been reported in Shandong Province, China.

AIM: The present study examined the difference in body shape and physical activity (PA) between adolescents with normotensive and elevated BP in Shandong, China.

SUBJECTS AND METHODS: Data for this study were obtained from a large cross-sectional survey of schoolchildren carried out in 2010.A total of 28 039 students (14 084 boys and 13 955 girls) aged 10-17 years participated in this study. Height, weight, waist circumference (WC), BP, triceps and subscapular skinfolds of all subjects were measured and the sum of triceps and subscapular skinfold thickness was applied. Body mass index (BMI) of adolescents was calculated from their height and weight and the prevalence of overweight and obesity were obtained according to the International Obesity Task Force (IOTF) cut-offs. Elevated BP was defined as systolic blood pressure (SBP) and/or diastolic blood pressure (DBP) ≥ 95th percentile for age and gender. PA attitudes and behaviours were assessed by a standardized questionnaire.

RESULTS: The mean values of BMI, WC and SFT for both boys and girls were all significantly higher in the elevated BP group than in the normal BP group in all age categories (p < 0.01). More adolescents with elevated BP were overweight or obese compared with normal BP subjects. Significant differences in PA were observed between the elevated and normal BP group, adolescents with elevated BP had poor PA attitudes and behaviours compared with normal BP subjects.

CONCLUSION: Adolescents with elevated BP had high levels of BMI, WC, SFT and poor PA attitudes and behaviours. These findings reinforce the importance of preventing overweight and obesity and improving their attitudes towards physical activity.