Abstract:Increasing prevalence of hypertension in children and adolescents has become a significant public health issue driving a considerable amount of research. Aspects

The relationship between obesity and hypertension is well established both in children and adults. The mechanisms through which obesity directly causes hypertension are still an area of research. Activation of the sympathetic nervous system has been considered to have an important function in the pathogenesis of obesity-related hypertension. The arterial-pressure control mechanism of diuresis and natriuresis, according to the principle of infinite feedback gain, seems to be shifted toward higher blood-pressure levels in obese individuals. During the early phases of obesity, primary sodium retention exists as a result of increase in renal tubular reabsorption. Extracellular-fluid volume is expanded and the kidney-fluid apparatus is resetted to a hypertensive level, consistent with a model of hypertension because of volume overload. Plasma renin activity, angiotensinogen, angiotensin II and aldosterone values display significant increase during obesity. Insulin resistance and inflammation may promote an altered profile of vascular function and consequently hypertension. Leptin and other neuropeptides are possible links between obesity and the development of hypertension. Obesity should be considered as a chronic medical condition, which is likely to require long-term treatment. Understanding of the mechanisms associated with obesity-related hypertension is essential for successful treatment strategies. Hypertension Research (2010) 33, 386-393; doi:10.1038/hr.2010.9Keywords: leptin; obesity; pressure natriuresis; rennin-angiotensin-aldosterone system; sympathetic nervous system INTRODUCTION Obesity is a common disorder that develops from the interaction between the genotype and the environment and involves social, behavioral, cultural, physiological, metabolic and genetic factors. A large number of studies have shown that obesity has an important negative impact on health in a population, leading to the recommendation for general practitioners to have an important function in the management of this condition and of its associated comorbidities such as hypertension, hyperlipidemia and hyperinsulinemia/insulin resistance. The relationship between obesity and hypertension is well established both in adults and children. 1,2 Obese individuals exhibit higher levels of office as well as ambulatory blood pressure (BP) from childhood to old age. Obese subjects display higher BP levels than non-obese individuals even in the normotensive range. The combination of obesity, hypertension and other cardiovascular risk factors significantly increases the probability of adverse cardiovascular outcomes, and raises considerations for aggressive treatment strategies. 3 The mechanisms through which obesity directly causes hypertension are still an area of research. Human and animal studies have elucidated the function of adipose tissue derivatives (adipokines and cytokines), neurohumoral pathways, metabolic functions and modulation of pressor/depressor mechanisms. Although obesity-related hypertension may be the result of a combinatio...

Document Reviewers: Luis Alcocer (Mexico), Christina Antza (Greece), Mustafa Arici (Turkey), Eduardo Barbosa (Brazil), Adel Berbari (Lebanon), Luís Bronze (Portugal), John Chalmers (Australia), Tine De Backer (Belgium), Alejandro de la Sierra (Spain), Kyriakos Dimitriadis (Greece), Dorota Drozdz (Poland), Béatrice Duly-Bouhanick (France), Brent M. Egan (USA), Serap Erdine (Turkey), Claudio Ferri (Italy), Slavomira Filipova (Slovak Republic), Anthony Heagerty (UK), Michael Hecht Olsen (Denmark), Dagmara Hering (Poland), Sang Hyun Ihm (South Korea), Uday Jadhav (India), Manolis Kallistratos (Greece), Kazuomi Kario (Japan), Vasilios Kotsis (Greece), Adi Leiba (Israel), Patricio López-Jaramillo (Colombia), Hans-Peter Marti (Norway), Terry McCormack (UK), Paolo Mulatero (Italy), Dike B. Ojji (Nigeria), Sungha Park (South Korea), Priit Pauklin (Estonia), Sabine Perl (Austria), Arman Postadzhian (Bulgaria), Aleksander Prejbisz (Poland), Venkata Ram (India), Ramiro Sanchez (Argentina), Markus Schlaich (Australia), Alta Schutte (Australia), Cristina Sierra (Spain), Sekib Sokolovic (Bosnia and Herzegovina), Jonas Spaak (Sweden), Dimitrios Terentes-Printzios (Greece), Bruno Trimarco (Italy), Thomas Unger (The Netherlands), Bert-Jan van den Born (The Netherlands), Anna Vachulova (Slovak Republic), Agostino Virdis (Italy), Jiguang Wang (China), Ulrich Wenzel (Germany), Paul Whelton (USA), Jiri Widimsky (Czech Republic), Jacek Wolf (Poland), Grégoire Wuerzner (Switzerland), Eugene Yang (USA), Yuqing Zhang (China).

White-coat hypertension (WCH) and masked hypertension have been associated with increased cardiovascular risk in adults. In the current study, we investigated: (a) the prevalence of WCH and masked hypertension in pediatric patients and (b) the association of these conditions with target organ damage. A total of 85 children underwent office blood pressure measurements, 24-h ambulatory blood pressure monitoring, echocardiography and ultrasonography of the carotid arteries. Subjects with both office and ambulatory normotension or hypertension were characterized as confirmed normotensives or hypertensives, respectively; WCH was defined as office hypertension with ambulatory normotension and masked hypertension as office normotension and ambulatory hypertension. WCH was found in 12.9% and masked hypertension in 9.4% of the subjects. WCH was significantly more prevalent in obese subjects, while masked hypertension was only present in non-obese ones. Confirmed and masked hypertensives had significantly higher left ventricular mass index than confirmed normotensives (34.0+/-5.8 g/m(2.7), 31.9+/-2.9 g/m(2.7) and 25.3+/-5.6 g/m(2.7), respectively, P<0.05). White-coat hypertensives tended to have higher left ventricular mass index than confirmed normotensives, but the difference was not statistically significant (27.8+/-5.1 g/m(2.7) versus 25.3+/-5.6 g/m(2.7)). No significant differences were found in the intima-media thickness of the carotid arteries between confirmed normotensives, white-coat hypertensives, masked hypertensives and confirmed hypertensives. WCH and masked hypertension are common conditions in children. Confirmed and masked hypertension in pediatric patients are accompanied by increased left ventricular mass index.