Blood pressure among overweight adolescents from urban school children in Pune, India

OBJECTIVES: To examine the magnitude of overweight and its association with blood pressure (BP) among adolescents. DESIGN: Cross-sectional study with all children in age range 9-16 years (n=1146 boys and 1077 girls) from two schools catering to urban affluent high socio-economic class (HSE), for anthropometric measurements by trained investigators and BP measurement by a pediatrician using sphygmomanometer. RESULTS: The prevalence of overweight based on conventional body mass index (BMI) cutoff was 27.5% for boys and 20.9% for girls but varied for different indicators. Prevalence of high systolic blood pressure (HSBP) was 12.0% in boys and 9.7% in girls and increased with increasing levels of BMI, weight, triceps skin fold thickness (TSFT) and percent body fat. Mean level of SBP among overweight children was significantly (P<0.001) higher by about 12 mm Hg, whereas that for diastolic blood pressure was higher by 8 mm Hg (P<0.001) as compared to their non-overweight (age, sex-matched) counterparts. This was true in both sexes and for all indicators used for assessing overweight. Prevalence of HSBP increased suddenly beyond BMI value of 20 kg/m2 in boys and 21.5 kg/m2 in girls, beyond TSFT value of 12 mm for boys and 14 mm for girls whereas such cutoffs for body fat were above 25% in both sexes. These cutoffs appear much lower than the conventional ones and therefore indicate the need for validation of conventional cutoffs in different populations. CONCLUSIONS: Our findings highlight that BP measurement needs to be a routine part of physical examination in school children, and the use of cutoffs anchored to metabolic risks may be essential for assessment of obesity.