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White coat hypertension (WCH) is a very well documented situation, where the casual blood pressure (BP) is elevated and the ambulatory blood pressure (ABP) means are normal. But, there is one another situation called white coat normotension (WCN), where the casual BP is elevated with normal ABP means. Few studies have examined this situation, particularly in overweight and obese children and adolescents. Our objective was to evaluate the existence and prevalence of WCN in overweight and obese children and adolescents. Twenty-eight normotensive patients (17 M/11 F) from 10 to 17 years old, were evaluated from January 1999 to June 2000 and all of them were submitted to ambulatory blood pressure monitoring (ABPM). BP were measured 3 times/hr from 8 am to 10 pm and 2 times/hr from 10 pm to 8 am. Wake and sleep period were defined by patient self-report. WCN was defined by mean BP criteria as wake systolic (SBP) or diastolic (DBP) > 95th percentile ( Task Force for Hypertension Control in Children and Adolescent) or by BP load criteria as 24 hr SBP or DBP load > 30 % ( using 24 hr 95th percentile normative pediatric ABPM data) with normal casual BP. The criteria used for overweight and obesity were defined by body mass index (BMI), according to Expert Committee on Clinical Guidelines for Overweight in Adolescent Preventive Service. In relation to mean BP, the prevalence of WCN was 28.5% for SBP (8/28, being 7 M) and no patients had elevated DBP. As BP loads, 50 % (14/28, being 12 M) had systolic BP loads > 30% and only one patient (3.5 %) had diastolic BP loads > 30%. Eight patients ( 28.5 %) had elevated mean SBP and systolic BP loads, being 7 boys (87.5 %) and 7 were obese (87.5 %). From the total of the 17 boys, 12 (70.5 %) had any degree of alteration in respect to BP load or mean BP and from the 11 girls, only 2 (18.1%) had them. As obesity and overweight, 12 of the 14 altered patients (85.7%) were obese and only 2 overweight. In relation to the 14 normotensive patients with normal BP loads and normal mean BP, 9 were girls(64.3%) and 9 were obese (64.2%). We conclude that WCN is common in obese and overweight children, and it occurs principally in obese, boys, and in relation to the systolic BP. Maybe this elevated prevalence in boys, be due the lesser tolerability in relation to the ABPM and probably they are more active than the girls during the wake period. Further studies should be done to confirm these findings.

Ambulatory blood pressure monitoring (ABPM) has demonstrated a high prevalence of white coat hypertension (WCH) in adults, but few studies exist in obese and overweight children and adolescents. We can define WCH as elevated casual blood pressure (BP) with normal 24-hr mean BP, but ABPM in adults has shown that BP load( % of BP readings > 95th percentile) is better to predict hypertensive end-organ injury than mean BP. Our objective was to evaluate the prevalence of hypertension (HTN) and WCH in overweight and obese children and adolescents by both mean BP criteria and BP load criteria. From January 1999 to June 2000, 39 patients ( 22M/17F) from 10 to 17 years old were evaluated and in all, ABPM were performed. They were evaluated by two cardiologists and the BP was measured two times by each one, with 5 minutes interval. HTN were considered when the average of these 4 measures (systolic or diastolic) > 95th percentile. In relation to ABPM, BP was measured 3 times/hr from 8 am to 10 pm and 2 times/hr from 10 pm to 8 am. Wake and sleep period were defined by patient self-report. WCH was defined by mean BP criteria as wake systolic BP (SBP) and diastolic BP (DBP) < 95th percentile (Task Force for HTN Control in Children and Adolescent) and by BP load criteria as 24-hr SBP and DBP load < 30% (using 24-hr 95th percentile normative pediatric ABPM data). The criteria used for overweight and obesity were defined by body mass index (BMI) according to Expert Committee on Clinical Guidelines for Overweight in Adolescent Preventive Service. The prevalence of HTN was 28.2% (11/39), being 54.6% females (6/11) and 90.9% (10/11) were obese. The prevalence of WCH defined by mean BP criteria was 45.4% (5/11) and 80% were girls (4/5) and 80% (4/5) were obese. BP load was normal (< 30%) in 27.2% (3/11) for SBP and 81.8% (9/11) for DBP. The prevalence of WCH by BP load criteria (SBP and DBP < 30%) was 27.2% (3/11), being 66.6% girls (2/3) and 66.6% obese (2/3); 27.2 % (3/11) of patients had WCH by both criteria (mean BP and BP load). The HTN and WCH in obese and overweight children and adolescents are common and they occur more often in girls and obese. ABPM should be used in hypertensive obese and overweight children to avoid mistaken for casual HTN that may lead to unnecessary use of medication and expensive diagnostic approaches.

Hypertension prevalence in adolescents is a controversial issue with rates that ranging from 4 to 28%. There is also lack of information about its prevalence in a population living in a tropical area like the Amazonic region with high temperatures and humidity all year round. The objective was evaluate the hypertension prevalence in a young urban population of the Amazonic region. From the list of local schooling system and considering rates extracted from Brazilian census data, we selected a random probabilistic sampling of 649 teenagers, stratified by age, gender, race and socioeconomic class in Belem, capital of Para state, Amazonic region of Brazil. All teenagers had their arterial blood pressure (BP), weight, height, body mass index (BMI) and stage of sexual maturity evaluated. Ages ranged between 10 and 18 years old. The hypertension prevalence (greater than 95 th percentile according to ACC/AHA-Task Force Report) was 3.8% (3.5 % for girls and 4.4% for boys). There was no significant difference of BP and BMI with races (white, black and mulato). The correlation of age, weight and height against systolic and diastolic BP showed an increase in its levels directly related to those variables. BP was increased only for boys whose ages were above 12 years old. Hypertension prevalence in adolescents of the Brazilian Amazonic region was much less than expected from data of the medical literature for a population with similar demographic patterns. Regional food intake as well as geographical aspects, besides cultural and anthropologic variables, need to be investigated.