Results of blood pressure screening in a population of school-aged children in the province of Milan: role of overweight

OBJECTIVES: To study the prevalence of high blood pressure (BP) in an Italian paediatric population, and to verify whether in this population elevated BP values are associated with overweight (OW). STUDY DESIGN: Children (1206 males, 1210 females) from the lower-grade public schools (ages 6-11 years) were studied. Body weight, height and BP were measured in each child. Elevated BP was defined if resting systolic and/or diastolic BP values equalled or exceeded the 95th percentile according to gender, age and height, based on the US normative BP tables. Overweight children were identified using four different methods: (1) the classification based on the relative body weight; (2) the French references by Rolland-Cachera et al. (Am J Clin Nutr 1982; 36:178-184); (3) the International Obesity Task Force charts; and (4) the Italian charts defined by Cacciari et al. (Eur J Clin Nutr 2002; 56:171-180). RESULTS: The prevalence of high BP in our population was 4.2% and was significantly higher in females (65/1210 = 5.4%) than in males (37/1206 = 3.1%), P = 0.005. The different methods used to define OW provide different estimates of OW prevalence (from 17.0 to 38.6%). The percentage of high BP subjects was significantly higher in OW than in normal-weight children regardless of the method used for the definition of the weight class (P < 0.0001), in both genders. In addition, for each age range, absolute systolic and diastolic BP values were higher in OW as compared to normal-weight children both in males and in females (P < 0.0001). CONCLUSIONS: Our study indicates the importance of performing BP screenings in the paediatric population, and to promote interventions that may reduce the prevalence of OW in children.