Decreased erythrocyte NA+,K+-ATPase activity and increased plasma TBARS in prehypertensive patients.

The essential hypertension has been associated with membrane cell damage. The aim of the present study is investigate the relationship between erythrocyte Na(+),K(+)-ATPase and lipoperoxidation in prehypertensive patients compared to normotensive status. The present study involved the prehypertensive patients (systolic: 136 ± 7 mmHg; diastolic: 86.8 ± 6.3 mmHg; n = 8) and healthy men with normal blood pressure (systolic: 110 ± 6.4 mmHg; diastolic: 76.1 ± 4.2 mmHg; n = 8) who were matched for age (35 ± 4 years old). The venous blood samples of antecubital vein (5 mL) were collected into a tube containing sodium heparin as anticoagulant (1000 UI), and erythrocyte ghosts were prepared for quantifying Na(+),K(+)-ATPase activity. The extent of the thiobarbituric acid reactive substances (TBARS) was determined in plasma. The statistical analysis was carried out by Student's t-test and Pearson's correlation coefficient. A P < 0.05 was considered significant. The Na(+),K(+)-ATPase activity was lower in prehypertensive patients compared with normotensive subjects (4.9 versus 8.0 nmol Pi/mg protein/min; P < 0.05). The Na(+),K(+)-ATPase activity correlated negatively with TBARS content (r = -0.6; P < 0.05) and diastolic blood pressure (r = -0.84; P < 0.05). The present study suggests that Na(+),K(+)-ATPase activity reduction and elevation of the TBARS content may underlie the pathophysiological aspects linked to the prehypertensive status.

ASSOCIATION BETWEEN THE SCREEN TIME AND THE CARDIORESPIRATORY FITNESS WITH THE PRESENCE OF METABOLIC RISK IN SCHOOLCHILDREN.

OBJECTIVE: To verify the association between screen time and cardiorespiratory fitness with the presence of metabolic risk in schoolchildren in an isolated and clustered manner. METHODS: Cross-sectional study with 1.200 schoolchildren from Santa Cruz do Sul-RS. Screen time and cardiorespiratory fitness were evaluated. The continuous metabolic risk score was calculated by summing the Z score of the waist circumference, systolic blood pressure, glucose, triglycerides, total cholesterol, low-density lipoprotein (LDL-C) and high-density lipoprotein (HDL-C). RESULTS: Children (34.3%) and adolescents (48.2%) had high screen time, while 44.3% of the children and 53.3% of the adolescents were unfit in relation to cardiorespiratory fitness. Regarding the relation of screen time/cardiorespiratory fitness, 14.7% of the children and 26.9% of the adolescents presented high screen time and low levels of cardiorespiratory fitness. The presence of metabolic risk was shown in children (17.1%) and adolescents (14.7%). The presence of metabolic risk was directly associated with low levels of cardiorespiratory fitness in children and adolescents. When analyzed in clusters, the metabolic risk in children was 11% more prevalent in subjects with low screen time/unfit and 12% in subjects with high screen time/unfit, whereas in adolescents, the prevalence of metabolic risk was also higher in those with low screen time/unfit (8%) and high screen time/unfit (7%). CONCLUSIONS: The presence of metabolic risk in children and adolescents was associated with low levels of cardiorespiratory fitness, independent of screen time, in an isolated or clustered manner.

High blood pressure in schoolchildren: Associated sociodemographic and biochemical factors. / Pressão arterial elevada em escolares: fatores sociodemográficos e bioquímicos associados.

INTRODUCTION AND OBJECTIVE: Pediatric hypertension has increased in the last decade, and it is thus crucial to identify the factors associated with the development of high blood pressure (BP) and other cardiovascular disorders. The aim of this study was to determine whether there is an association between high BP and sociodemographic and biochemical factors in schoolchildren. METHODS: This cross-sectional study included 1201 children and adolescents, between seven and 17 years old, of both sexes. The sociodemographic data analyzed were gender, age, school system and socioeconomic status. Among biochemical indicators, blood glucose, triglycerides, total cholesterol, HDL-cholesterol (HDL-C) and LDL-cholesterol (LDL-C) were assessed. In the analysis of BP, schoolchildren were classified as normal, borderline or hypertensive. Associations were tested using Poisson regression through prevalence ratios (PR). RESULTS: High BP was identified in 16.2% of the students. In females, the prevalence of high BP was 7% lower than in males (p=0.001), but was higher among adolescents (PR: 1.11, p<0.001) and schoolchildren in the state school system (PR: 1.05; p=0.013). Concerning biochemical indicators, BP change was associated with pre-diabetes (PR: 1.09; p=0.001) and borderline HDL-C (PR: 1.09; p=0.007). CONCLUSION: Among the sociodemographic factors associated with high BP are male gender, adolescence and attending the state education system. This condition was also associated with pre-diabetes and borderline HDL-C.

Relationship between Dyslipidemia, Cultural Factors, and Cardiorespiratory Fitness in Schoolchildren.

BACKGROUND: The presence of dyslipidemia and behavioral aspects are determinants of cardiovascular risk, especially in childhood and adolescence. OBJECTIVE: To verify possible relationships between dyslipidemia, cultural factors, and cardiorespiratory fitness (CRF) in schoolchildren. METHODS: This cross-sectional study evaluated a sample of 1,254 children and adolescents between the ages of 7 and 17 from the South of Brazil, 686 of whom were female. Dyslipidemia was defined as increased levels of at least one of the following lipid profile parameters: triglycerides (TG), total cholesterol (TC) and fractions of high (HDL-c) and low-density lipoprotein (LDL-c). Cultural aspects were evaluated by a self-reported questionnaire. Data were analyzed by logistic regression, considering the odds ratios (OR) and confidence intervals (CI) at 95%. RESULTS: The results revealed a high prevalence of dyslipidemia (41.9%), which was associated with female sex (OR: 1.56; IC: 1.24-1.96) and overweight/obese status (OR: 1.55; IC: 1.20-2.00). When lipid profile parameters were evaluated separately, high levels of LDL-c were observed to be associated with sedentary school transport (OR: 1.59; IC: 1.20-2.09). Schoolchildren who were overweight/obese had higher chances of elevated levels of TC (OR: 1.40; IC: 1.07-1.84) and TG (OR: 3.21; IC: 1.96-5.26). HDL-c was shown to be related to high television time (OR: 1.59; IC: 1.00-2.54). CONCLUSION: Alterations in lipid parameters are associated with cultural factors, especially those related to sedentary lifestyle and low levels of CRF.

High urate concentration is associated with elevated blood pressure in schoolchildren.

Background Studies in adults have shown a relationship between high blood pressure and hyperuricemia, but few studies have investigated this association in children and adolescents. The aim of the present study was to associate urate concentration with systolic blood pressure (SBP) and diastolic blood pressure (DBP) in schoolchildren. Methods This cross-sectional study used a sample of 2335 schoolchildren in basic education between 7 and 17 years old. Blood pressure was classified by percentile according to Brazilian parameters for sex and age, reclassified into two categories: normal and borderline/hypertension. Blood collection to obtain serum for urate concentration analysis was performed after a 12-h fast. Values above 5.5 mg/dL were considered hyperuricemia. Descriptive data were presented in frequency and percentage. Linear regression and Poisson regression (prevalence ratio [PR]) was used to test the association between urate concentration and blood pressure. Results Urate concentration was weakly associated with SBP (ß: 0.05; 95% CI: 0.02-0.08) and DBP (ß: 0.03; 95% CI: 0.01-0.05) z-scores. Schoolchildren with hyperuricemia had a higher prevalence of high SBP (PR: 1.12; p<0.001) and DBP (PR: 1.08; p<0.001). Conclusions Elevated urate concentration is associated with altered blood pressure in schoolchildren.

Relationship between Cardiometabolic Parameters and Elevated Resting and Effort Heart Rate in Schoolchildren.

Background: Little has been studied on heart rate and its relationship with metabolic disorders. Objective: To identify possible association between heart rate (HR) and metabolic disorders in children and adolescents. Methods: This cross-sectional study evaluated 2.098 subjects, aged between 7 and 17 years. The variables evaluated were: HR, systolic (SBP) and diastolic blood pressure (DBP), pulse pressure (PP), double-product (DP), myocardial oxygen consumption (mVO2), lipids, glucose and uric acid levels, body mass index (BMI) and waist circumference (WC). The values of HR at rest and effort were divided into quartiles. The association between continuous values of HR and cardiometabolic indicators was tested by linear regression. Results: LDL cholesterol presented a significantly higher mean (p = 0.003) in schoolchildren with resting HR greater or equal to 91 bpm, compared to students with less than 75 bpm. Compared with the quartiles of effort HR, SBP, DBP, glucose and uric acid presented high values when HR was greater or equal than 185 bpm. SBP, glucose and HDL cholesterol demonstrated a significant association with resting HR. Uric acid was observed as a predictor of increased effort HR. Conclusion: Schoolchildren with a higher resting HR have higher mean of LDL cholesterol. For effort HR, there was an increase in blood pressure, glucose and uric acid levels. Uric acid has been shown to be a predictor of elevated effort HR.

Fundamento: Pouco se tem estudado sobre frequência cardíaca e suas relações com alterações metabólicas. Objetivo: Verificar se existe associação entre frequência cardíaca e disfunções metabólicas em crianças e adolescentes. Método: Estudo transversal com 2.098 escolares, com idade entre 7 e 17 anos. As variáveis avaliadas foram: frequência cardíaca (FC), pressão arterial sistólica (PAS), diastólica (PAD) e de pulso (PP), duplo-produto (DP), consumo de oxigênio pelo miocárdio (mVO2), perfil lipídico e glicêmico, níveis de ácido úrico, índice de massa corporal (IMC) e circunferência da cintura (CC). Os valores de FC de repouso e esforço foram divididos em quartis. A associação entre os valores contínuos de FC com indicadores cardiometabólicos foi testada por meio da regressão linear. Resultdos: O colesterol LDL apresentou média significativamente superior (p = 0,003) nos escolares com FC de repouso maior ou igual a 91 bpm, em comparação aos escolares que apresentaram menos de 75 bpm. Comparados com os quartis da FC de esforço, a PAS, PAD, glicose e ácido úrico apresentaram valores elevados quando a FC foi igual ou superior a 185 bpm. A PAS, a glicose e o colesterol HDL demonstraram associação significativa com a FC de repouso. Observou-se o ácido úrico como um preditor do aumento da FC de esforço. Conclusão: Escolares com FC de repouso mais elevada apresentam médias superiores de colesterol LDL. Para FC de esforço, observou-se elevação na pressão arterial, nos níveis de glicose e de ácido úrico. O ácido úrico demonstrou ser preditor da elevação da FC de esforço.

Hypertension and Different Levels of Body Mass Index and Cardiorespiratory Fitness Amongst Adolescents

Abstract Background Hypertension is an increasingly common problem in adolescents; amongst the associated factors, physical inactivity and obesity are increasing the risk of developing cardiovascular diseases. Objective To verify whether there is an association between higher blood pressure levels amongst adolescents with the relationship between different levels of body mass index (BMI) and cardiorespiratory fitness (CRF). Method Cross-sectional study consisting of 860 adolescents. Higher blood pressure (BP) was considered as borderline and hypertension as the classification. BMI was categorized as low-normal weight and overweight-obesity. The CRF was assessed by a nine-minute run/walk test and classified into low or appropriate levels (less and more favorable to health, respectively). Later, BMI and CRF were grouped into one categorical variable: (I) low/normal weight and appropriate CRF levels; (II) low/normal weight and low CRF levels; (III) overweight/obesity and appropriate CRF levels; and (IV) overweight/obesity and low CRF levels. Data were analyzed using Poisson regression, through the prevalence ratio (PR) and 95% confidence intervals (CI). The p-values of p <0.05 were considered significant. Results Adolescents with overweight/obesity and low CRF levels had a 22% higher BP prevalence. Moreover, children with overweight/obesity, but with appropriate CRF levels, have a 15% higher BP prevalence. Conclusion Adolescents with overweight/obesity had a higher prevalence of BP, regardless of CRF levels. It is suggested that maintaining normal BMI is a protective factor for less favorable BP.

Association between the screen time and the cardiorespiratory fitness with the presence of metabolic risk in schoolchildren / Associação entre o tempo de tela e a aptidão cardiorrespiratória e a presença de risco metabólico em escolares

ABSTRACT Objective: To verify the association between screen time and cardiorespiratory fitness with the presence of metabolic risk in schoolchildren in an isolated and clustered manner. Methods: Cross-sectional study with 1.200 schoolchildren from Santa Cruz do Sul-RS. Screen time and cardiorespiratory fitness were evaluated. The continuous metabolic risk score was calculated by summing the Z score of the waist circumference, systolic blood pressure, glucose, triglycerides, total cholesterol, low-density lipoprotein (LDL-C) and high-density lipoprotein (HDL-C). Results: Children (34.3%) and adolescents (48.2%) had high screen time, while 44.3% of the children and 53.3% of the adolescents were unfit in relation to cardiorespiratory fitness. Regarding the relation of screen time/cardiorespiratory fitness, 14.7% of the children and 26.9% of the adolescents presented high screen time and low levels of cardiorespiratory fitness. The presence of metabolic risk was shown in children (17.1%) and adolescents (14.7%). The presence of metabolic risk was directly associated with low levels of cardiorespiratory fitness in children and adolescents. When analyzed in clusters, the metabolic risk in children was 11% more prevalent in subjects with low screen time/unfit and 12% in subjects with high screen time/unfit, whereas in adolescents, the prevalence of metabolic risk was also higher in those with low screen time/unfit (8%) and high screen time/unfit (7%). Conclusions: The presence of metabolic risk in children and adolescents was associated with low levels of cardiorespiratory fitness, independent of screen time, in an isolated or clustered manner.

RESUMO Objetivo: Verificar a associação entre tempo de tela e aptidão cardiorrespiratória, de forma isolada e agrupada, e a presença de risco metabólico em escolares. Métodos: Estudo transversal com 1.200 escolares de Santa Cruz do Sul (RS). Foram avaliados o tempo de tela e a aptidão cardiorrespiratória. Foi calculado o escore de risco metabólico por meio da soma do escore Z, da circunferência da cintura, da pressão arterial sistólica, da glicose, dos triglicerídeos, do colesterol total, do colesterol da lipoproteína de baixa densidade (LDL) e do colesterol da lipoproteína de alta densidade (HDL). Resultados: Crianças (34,3%) e adolescentes (48,2%) apresentaram elevado tempo de tela, enquanto 44,3% das crianças e 53,3% dos adolescentes foram inaptos no tocante à aptidão cardiorrespiratória. Na relação tempo de tela/aptidão cardiorrespiratória, 14,7% das crianças e 26,9% dos adolescentes exibiram elevado tempo de tela e baixos níveis de aptidão cardiorrespiratória. A presença de risco metabólico foi evidenciada em crianças (17,1%) e em adolescentes (14,7%). A presença de risco metabólico esteve associada diretamente com baixos níveis de aptidão cardiorrespiratória nas crianças e nos adolescentes no que se refere às variáveis de forma isolada. Quando analisado de modo agrupado, o risco metabólico em crianças foi 11% mais prevalente em sujeitos com baixo tempo de tela/inaptos e 12% em sujeitos com elevado tempo de tela/inaptos, enquanto em adolescentes a prevalência de risco metabólico também foi superior nos escolares com baixo tempo de tela/inaptos (8%) e elevado tempo de tela/inaptos (7%). Conclusões: A presença de risco metabólico em crianças e adolescentes esteve associada com baixos níveis de aptidão cardiorrespiratória, independentemente do tempo de tela, tanto de modo isolado quanto agrupado.

Relação tempo de tela e aptidão cardiorrespiratória: associação com pressão arterial alterada em escolares / Relation between screen time and cardiorespiratory fitness: association with altered blood pressure in schoolchildren

Objetiva-se verificar se a relação tempo de tela (TT) e aptidão cardiorrespiratória (APCR) está associada com as alterações na pressão arterial (PA) em crianças e adolescentes. Trata-se de um estudo transversal com 2166 escolares, de ambos os sexos, com idades entre 6 e 17 anos. Foi aplicado um questionário com questões referentes ao estilo de vida, para verificação do TT (computador, vídeo game e TV), que foi computado em horas e classificado como elevado TT (≥ 2 horas diárias) e baixo TT (< 2 horas diárias). Para avaliação da PA, foi considerada alterada nos casos limítrofes e hipertensão, para pressão arterial sistólica (PAS) e diastólica (PAD). A APCR foi avaliada por meio do teste de corrida/caminhada de 6 minutos. Para a análise dos dados foi utilizada a estatística descritiva, por meio da frequência e percentual, para caracterizar os sujeitos, sendo aplicada a regressão de Poisson para obtenção dos valores de razão de prevalência (RP) e intervalos de confiança (IC), na relação da variável preditora (relação TT/APCR) com o desfecho (PA alterada). Como resultados encontrados, observou-se que 24,8% dos escolares apresentam elevado TT e baixos níveis de APCR. Em relação à PA, 18,7% dos indivíduos estiveram com a PAS alterada e 15,4% com PAD alterada. A associação entre PA alterada e a relação TT/APCR somente foi evidenciada para PAS entre as meninas. Nesse sentido, observou-se que a alteração na PAS é mais prevalente entre os escolares com baixo TT/inapto (RP: 1,07; p=0,008) e com elevado TT/inapto (RP: 1,06; p=0,029). Conclui-se que as meninas com baixos níveis de APCR, independente do TT, apresentam maior prevalência de PAS alterada....(AU)

This study aims to verify if the relation of screen time (ST) and cardiorespiratory fitness (CRF) is associated with the presence of alteration in blood pressure (BP) in children and adolescents. This is a cross-sectional study with 2166 students, aged 6 to 17 years. A questionnaire with questions related to lifestyle was used to verify the ST (computer, video game and TV), which was computed in hours and classified as high ST (≥ 2 hours daily) and low ST (<2 hours daily). For BP evaluation, borderline cases and hypertension were considered as altered BP, for systolic (SBP) and diastolic (DBP) pressure. CRF was assessed by the 6-minute walk/run test. For data analysis, descriptive statistics were used, by means of frequency and percentage, to characterize the subjects, and Poisson regression was used to obtain the prevalence ratio (PR) and confidence intervals (CI) values, in relation to the predictor variable ST/CRF) with the outcome (PA altered). As results, we observed that 24.8% of the students present high ST and low levels of CRF. In relation to BP, 18.7% and 15.4% of subjects had altered SBP and DBP, respectively. The association between altered BP and the ST/CRF ratio was only evidenced for SBP among girls. In this sense, it was observed that the change in SBP is more prevalent among schoolchildren with low ST/inapt (PR: 1.07, p = 0.008) and with high ST/inapt (PR: 1.06, p = 0.029). It is concluded that girls with low CRF levels, regardless of ST, present a higher prevalence of altered SBP....(AU)

Relationship between Dyslipidemia, Cultural Factors, and Cardiorespiratory Fitness in Schoolchildren / Relação entre Dislipidemia, Fatores Culturais e Aptidão Cardiorrespiratória em Escolares

Abstract Background: The presence of dyslipidemia and behavioral aspects are determinants of cardiovascular risk, especially in childhood and adolescence. Objective: To verify possible relationships between dyslipidemia, cultural factors, and cardiorespiratory fitness (CRF) in schoolchildren. Methods: This cross-sectional study evaluated a sample of 1,254 children and adolescents between the ages of 7 and 17 from the South of Brazil, 686 of whom were female. Dyslipidemia was defined as increased levels of at least one of the following lipid profile parameters: triglycerides (TG), total cholesterol (TC) and fractions of high (HDL-c) and low-density lipoprotein (LDL-c). Cultural aspects were evaluated by a self-reported questionnaire. Data were analyzed by logistic regression, considering the odds ratios (OR) and confidence intervals (CI) at 95%. Results: The results revealed a high prevalence of dyslipidemia (41.9%), which was associated with female sex (OR: 1.56; IC: 1.24-1.96) and overweight/obese status (OR: 1.55; IC: 1.20-2.00). When lipid profile parameters were evaluated separately, high levels of LDL-c were observed to be associated with sedentary school transport (OR: 1.59; IC: 1.20-2.09). Schoolchildren who were overweight/obese had higher chances of elevated levels of TC (OR: 1.40; IC: 1.07-1.84) and TG (OR: 3.21; IC: 1.96-5.26). HDL-c was shown to be related to high television time (OR: 1.59; IC: 1.00-2.54). Conclusion: Alterations in lipid parameters are associated with cultural factors, especially those related to sedentary lifestyle and low levels of CRF.

Resumo Fundamento: A presença de dislipidemia e os aspectos comportamentais são fatores determinantes do risco cardiovascular, sobretudo na infância e adolescência. Objetivos: Verificar possíveis relações entre dislipidemia, fatores culturais e aptidão cardiorrespiratória (APCR) em escolares. Métodos: São sujeitos deste estudo transversal 1.254 crianças e adolescentes do Sul do Brasil, sendo 686 do sexo feminino, com idade entre 7 e 17 anos. Foi considerada dislipidemia a presença de níveis aumentados em pelo menos um dos parâmetros do perfil lipídico: triglicerídeos (TG), colesterol total (CT) e frações de alta (HDL-c) e baixa densidade (LDL-c). Os aspectos culturais foram avaliados por meio de questionário autorreferido pelo escolar. Os dados foram analisados pela regressão logística, considerando os valores de razão de chances (odds ratio; OR) e intervalos de confiança (IC) para 95%. Resultados: Foi encontrada elevada prevalência de dislipidemia (41,9%), a qual esteve associada com o sexo feminino (OR: 1,56; IC: 1,24-1,96) e com a presença de sobrepeso/obesidade (OR: 1,55; IC: 1,20-2,00). Quando os componentes do perfil lipídico foram avaliados de forma separada, observou-se que altos níveis de LDL-c se associaram ao deslocamento sedentário para a escola (OR: 1,59; IC: 1,20-2,09). Escolares com sobrepeso/obesidade apresentam maiores chances de elevação nos níveis de CT (OR: 1,40; IC: 1,07-1,84) e TG (OR: 3,21; IC: 1,96-5,26). O HDL-c apresentou associação com o elevado tempo em frente à televisão (OR: 1,59; IC: 1,00-2,54). Conclusão: A presença de alteração nos parâmetros lipídicos associa-se com fatores culturais, especialmente voltados ao sedentarismo e baixos níveis de APCR.

Obesidade e aptidão física relacionada à saúde: um estudo com escolares de 10 a 13 anos de Santa Cruz do Sul - Brasil / Obesity and health related physical fitness: a study with schoolchildren aged 10 to 13 years from Santa Cruz do Sul ­ Brazil

Introdução: O sobrepeso e a obesidade são considerados problemas de saúde pública e têm sido ligados a baixos níveis de atividade física, tornando-se fatores de risco à saúde e contribuindo para o aparecimento de doenças crônicas.Bons níveis de aptidão física também são fatores que reduzemdoenças crônicas. Objetivo: Avaliar a associação entre obesidade e aptidão física relacionada àsaúde em escolares de 10 a 13 anos de idade. Casuística e métodos: Estudo transversal compostopor 785 escolares, de ambos os sexos, entre 10 e 13 anos de idade, pertencentes a escolas municipais e estaduais de Santa Cruz do Sul, RS ­ Brasil. Foram avaliados o Índice de Massa Corporal (IMC) de acordo com os parâmetros da Organização Mundial da Saúde, e as características de aptidão físicade flexibilidade, resistência muscular e aptidão cardiorrespiratória (APCR) segundo os protocolosdo Projeto Esporte Brasil. Resultados: Em ambos os sexos, os valores médios de Índice de MassaCorporal são superiores entre os adolescentes classificados na faixa de risco à saúde para resistênciaabdominal e aptidão cardiorrespiratória, em relação aos adolescentes na faixa saudável (p<0,05).Além disso, adolescentes com sobrepeso/obesidade apresentam maior prevalência de baixos níveisde resistência abdominal (10% para meninos e 20% para meninas) e de aptidão cardiorrespiratória(21% para meninos e 22% para meninas). Conclusão: A presença de sobrepeso e obesidade estáassociada com baixos níveis de resistência abdominal e de aptidão cardiorrespiratória, em escolarescom 10 a 13 anos de idade.

Introduction: Overweight and obesity are considered public health problems and have been linked to low levels of physical activity. Both diseases became risk factors for health and contribute to the development of chronic diseases. Good levels of physical fitness are risk-reducing factors for chronic diseases. Objective: Evaluate the association between obesity and health-related physical fitness in schoolchildren aged 10 to 13 years. Patients and Methods: We carried out a cross-sectional study with 785 schoolchildren of both sexes age ranging from 10 to 13 years-old, who attend public schools in Santa Cruz do Sul, RS ­ Brazil. We evaluated the Body Mass Index (BMI), according to parameters of World Health Organization, and health-related physical fitness characteristics of flexibility, muscular endurance and cardiorespiratory fitness (CRF) according to the protocols of the Projeto Esporte Brasil. Results: In both sexes, the mean values ofBody MassIndex were higher among adolescents classified in the health-risk zone for abdominal resistance and cardiorespiratory fitness, in relation to adolescents in the healthy zone (p<0.05). In addition, overweight/obese adolescents showeda higher prevalence of low levels of abdominal resistance (10% for boys and 20% for girls) and cardiorespiratory fitness (21% for boys and 22% for girls). Conclusion: The presence of overweight and obesity is associated with low levels of abdominal resistance and cardiorespiratory fitness in schoolchildren aged 10 to 13 years-old.

Prevalence of obesity and cardiovascular risk among children and adolescents in the municipality of Santa Cruz do Sul, Rio Grande do Sul.

CONTEXT AND OBJECTIVE: Studies have demonstrated that metabolic complications from child obesity, although silent, increase the risk of development of cardiovascular diseases in adulthood. The present paper sought to describe the prevalence of overweight/obesity and analyze the possible relationship between obesity and other cardiovascular risk factors among children and adolescents. DESIGN AND SETTING: Cross-sectional study, conducted in a university. METHODS: The study included 564 children and adolescents, aged 8 to 17 years. Body mass index and waist circumference were used to evaluate obesity. Other cardiovascular risk factors were evaluated, like systolic and diastolic blood pressure, glycemia, triglycerides and total cholesterol. Descriptive analysis was used for sample characterization, the chi-square test for categorical variables and Pearson's linear correlation for evaluating the relationship between obesity indicators and other cardiovascular risk factors. RESULTS: High prevalence of overweight/obesity was found among the schoolchildren (25.3% among the boys and 25.6% among the girls), along with abdominal obesity (19.0%). The overweight/obese schoolchildren presented higher percentages for the pressure and biochemical indicators, compared with underweight and normal-weight schoolchildren. Body mass index and waist circumference showed a weak correlation with the variables of age and systolic and diastolic blood pressure (P < 0.001), but there was no correlation between these obesity indices and biochemical variables. CONCLUSION: The high prevalence of overweight/obesity and its relationship with other cardiovascular risk factors demonstrate that it is necessary to develop intervention and prevention strategies from childhood onwards, in order to avoid development of chronic-degenerative diseases in adulthood.

Relationship between anthropometric measures and cardiovascular risk factors in children and adolescents.

BACKGROUND: Obesity has been identified as an important risk factor in the development of cardiovascular diseases; however, other factors, combined or not with obesity, can influence cardiovascular risk and should be considered in cardiovascular risk stratification in pediatrics. OBJECTIVE: To analyze the association between anthropometry measures and cardiovascular risk factors, to investigate the determinants to changes in blood pressure (BP), and to propose a prediction equation to waist circumference (WC) in children and adolescents. METHODS: We evaluated 1,950 children and adolescents, aged 7 to 18 years. Visceral fat was assessed by WC and waist-hip relationship, BP and body mass index (BMI). In a randomly selected subsample of these volunteers (n = 578), total cholesterol, glucose and triglycerides levels were evaluated. RESULTS: WC was positively correlated with BMI (r = 0.85; p < 0.001) and BP (SBP r = 0.45 and DBP = 0.37; p < 0.001). Glycaemia and triglycerides showed a weak correlation with WC (r = 0.110; p = 0.008 e r = 0.201; p < 0.001, respectively). Total cholesterol did not correlate with any of the variables. Age, BMI and WC were significant predictors on the regression models for BP (p < 0.001). We propose a WC prediction equation for children and adolescents: boys: y = 17.243 + 0.316 (height in cm); girls: y = 25.197 + 0.256 (height in cm). CONCLUSION: WC is associated with cardiovascular risk factors and presents itself as a risk factor predictor of hypertension in children and adolescents. The WC prediction equation proposed by us should be tested in future studies.

Pressão arterial alterada em adolescentes: associação com fatores de risco às doenças cardiovasculares de seus pais / Altered arterial blood pressure in adolescents: association with risk factors to their parents´ cardiovascular diseases

Este estudo teve como objetivo verificar se existe associação entre pressão arterial (PA) alterada em adolescentes com fatores de risco às doenças cardiovasculares de seus pais. Estudo transversal com 859 adolescentes, sendo 479 (55,8%) do sexo feminino, entre dez a 17 anos, estudantes de escolas da rede pública e privada, do município de Santa Cruz do Sul-RS. Considerou-se alteração na PA sistólica e diastólica os casos limítrofes e hipertensão. Foram utilizados os valores de razão de prevalência (RP), por meio da regressão de Poisson. Constatou-se elevado percentual de adolescentes com alteração na PA (19,4%), sendo esta superior entre os adolescentes, cujas mães apresentam hipertensão (RP: 1,09) e histórico de infarto (RP: 1,25). Entre os pais, somente colesterol elevado associou-se com a alteração da PA, nos adolescentes (RP: 1,08). Conclui-se que é elevada a prevalência de PA alterada em escolares, estando esta associada com fatores de risco às doenças cardiovasculares dos pais.

Current analysis verified whether there was any association between altered arterial blood pressure (BP) in adolescents and risk factors for their parents´ cardiovascular diseases. Current transversal analysis involved 859 adolescents, 479 (55.8%) females, aged 10 - 17 years, in government-run and private schools in Santa Cruz do Sul RS Brazil. Borderline and hypertension cases were considered alterations in systolic and diastolic AP. Prevalence ratio (PR) rates were employed by Poisson regression. Results showed high percentage of adolescents with changes in BP (19.4%), which was higher among adolescents with hypertensive mothers (PR: 1.09) and stroke history (PR: 1.25). Only high cholesterol among parents was associated with AP alterations in adolescents (PR: 1.08). High AP in school children is associated with risk factors for parents´ cardiovascular diseases.

Obesity and arterial hypertension in schoolchildren from Santa Cruz do Sul--RS, Brazil.

OBJECTIVE: To verify the prevalence of obesity and hypertension in schoolchildren from Santa Cruz do Sul - RS, Brazil, in 2005 and 2008. METHOD: The study was performed with two consecutive cross-sectional measurements, consisting of a stratified cluster sample, totaling 414 students, aged between 7 and 17 years, of which 215 (51.9%) were males and 199 (48.1%) were females. Obesity was assessed by body mass index (BMI) and percentage of body fat (%BF). Hypertension was measured by blood pressure values, both systolic (SBP) and diastolic (DBP). RESULTS: BMI assessment showed 18.6% and 22.3% of excess weight in males and 22.6% and 14.6% in females (in 2005 and 2008, respectively). Regarding obesity, the prevalence was 4.7% in both years for males and a reduction from 12.6% to 9.0% was observed in females. When analyzing the difference between assessments, there was significance in the BMI classification (p = 0.022) and %BF (p = 0.017) only in females. Statistically significant changes in SBP were found only in males (p < 0.001). CONCLUSION: The levels of excess weight, obesity, and %BF in females, as well as the increased levels of systolic blood pressure in males, demonstrate the need for early intervention through more effective public health campaigns.

Relationship between Cardiometabolic Parameters and Elevated Resting and Effort Heart Rate in Schoolchildren / Associação entre Indicadores Cardiometabólicos e Elevação da Frequência Cardíaca de Repouso e Esforço em Escolares

Abstract Background: Little has been studied on heart rate and its relationship with metabolic disorders. Objective: To identify possible association between heart rate (HR) and metabolic disorders in children and adolescents. Methods: This cross-sectional study evaluated 2.098 subjects, aged between 7 and 17 years. The variables evaluated were: HR, systolic (SBP) and diastolic blood pressure (DBP), pulse pressure (PP), double-product (DP), myocardial oxygen consumption (mVO2), lipids, glucose and uric acid levels, body mass index (BMI) and waist circumference (WC). The values of HR at rest and effort were divided into quartiles. The association between continuous values of HR and cardiometabolic indicators was tested by linear regression. Results: LDL cholesterol presented a significantly higher mean (p = 0.003) in schoolchildren with resting HR greater or equal to 91 bpm, compared to students with less than 75 bpm. Compared with the quartiles of effort HR, SBP, DBP, glucose and uric acid presented high values when HR was greater or equal than 185 bpm. SBP, glucose and HDL cholesterol demonstrated a significant association with resting HR. Uric acid was observed as a predictor of increased effort HR. Conclusion: Schoolchildren with a higher resting HR have higher mean of LDL cholesterol. For effort HR, there was an increase in blood pressure, glucose and uric acid levels. Uric acid has been shown to be a predictor of elevated effort HR.

Resumo Fundamento: Pouco se tem estudado sobre frequência cardíaca e suas relações com alterações metabólicas. Objetivo: Verificar se existe associação entre frequência cardíaca e disfunções metabólicas em crianças e adolescentes. Método: Estudo transversal com 2.098 escolares, com idade entre 7 e 17 anos. As variáveis avaliadas foram: frequência cardíaca (FC), pressão arterial sistólica (PAS), diastólica (PAD) e de pulso (PP), duplo-produto (DP), consumo de oxigênio pelo miocárdio (mVO2), perfil lipídico e glicêmico, níveis de ácido úrico, índice de massa corporal (IMC) e circunferência da cintura (CC). Os valores de FC de repouso e esforço foram divididos em quartis. A associação entre os valores contínuos de FC com indicadores cardiometabólicos foi testada por meio da regressão linear. Resultados: O colesterol LDL apresentou média significativamente superior (p = 0,003) nos escolares com FC de repouso maior ou igual a 91 bpm, em comparação aos escolares que apresentaram menos de 75 bpm. Comparados com os quartis da FC de esforço, a PAS, PAD, glicose e ácido úrico apresentaram valores elevados quando a FC foi igual ou superior a 185 bpm. A PAS, a glicose e o colesterol HDL demonstraram associação significativa com a FC de repouso. Observou-se o ácido úrico como um preditor do aumento da FC de esforço. Conclusão: Escolares com FC de repouso mais elevada apresentam médias superiores de colesterol LDL. Para FC de esforço, observou-se elevação na pressão arterial, nos níveis de glicose e de ácido úrico. O ácido úrico demonstrou ser preditor da elevação da FC de esforço.

Excesso de peso e pressão arterial elevada em escolares: prevalência e fatores associados / Excess weight and high blood pressure in schoolchildren: prevalence and associated factors

INTRODUCTION: Recent studies have indicated that increases in overweight and obesity rates as well as cardiovascular risk factors, such as hypertension, are occurring at younger ages. However, the causes and factors associated with these increases are still difficult to determine OBJECTIVE: To identify the associated factors and the prevalence of overweight and high blood pressure among schoolchildren METHODS: One thousand eight hundred sixty-eight students comprised the sample. The data were obtained through anthropometric measurements, blood pressure measurements, cardiopulmonary evaluations and questionnaires. Descriptive statistics, chi-square tests and Poisson regressions (p ≤ 0.05) were used. RESULTS: In this sample, 28.6% and 15.9% of the students were overweight and had high blood pressure, respectively. The males were found to be more susceptible to both of the studied risk factors. The prevalence of high blood pressure among the adolescents was 1.173 - fold greater than that among the children. In contrast, adolescence itself was a protective factor in terms of overweight (RP = 0754). The prevalence of overweight in the children with increased waist circumferences and poor cardiopulmonary aptitudes were increased by 5.5 - and 1.3 - fold, respectively CONCLUSION: The prevalence of overweight and high blood pressure in the school population was high in the investigated city. Cardiorespiratory aptitude, increased waist circumference and family history exhibited influences on overweight and high blood pressure.

INTRODUÇÃO: Estudos atuais vêm apontando para o aumento das taxas de sobrepeso e obesidade e de fatores de risco cardiovasculares, como a hipertensão, em idades cada vez menores. No entanto, as causas e os fatores associados a este aumento ainda são de difícil de determinação OBJETIVO: Identificar os fatores associados e a prevalência de excesso de peso e níveis pressóricos entre os escolares MÉTODO: A amostra envolveu 1867 escolares. Os dados foram obtidos por meio de avaliações antropométricas, medidas da pressão arterial, avaliação cardiorrespiratória e aplicação de questionários. Utilizou-se estatística descritiva, qui-quadrado e regressão de Poisson (p d" 0,05) RESULTADOS: 28,6% e 15,9% dos escolares apresentaram excesso de peso e pressão elevada, respectivamente. O sexo masculino mostrou-se mais suscetível a ambos os fatores de risco estudados. Adolescentes apresentaram prevalência 1,173 vezes maior de pressão elevada que as crianças. Já, para o excesso de peso, a adolescência apresentou-se como fator de proteção (RP = 0,754). Escolares com circunferência da cintura elevada e aptidão cardiorrespiratória insatisfatória apresentaram prevalência de 5,5 e 1,3 vezes maior de excesso de peso, respectivamente CONCLUSÃO: A prevalência de excesso de peso e pressão elevada na população escolar se mostrou alta no município investigado. Aptidão cardiorrespiratória, circunferência da cintura elevada e o histórico familiar mostraram influenciar no excesso de peso e nos níveis pressóricos elevados.

Excess weight and high blood pressure in schoolchildren: prevalence and associated factors / Excesso de peso e pressão arterial elevada em escolares: prevalência e fatores associados

INTRODUCTION: Recent studies have indicated that increases in overweight and obesity rates as well as cardiovascular risk factors, such as hypertension, are occurring at younger ages. However, the causes and factors associated with these increases are still difficult to determine OBJECTIVE: To identify the associated factors and the prevalence of overweight and high blood pressure among schoolchildren METHODS: One thousand eight hundred sixty-eight students comprised the sample. The data were obtained through anthropometric measurements, blood pressure measurements, cardiopulmonary evaluations and questionnaires. Descriptive statistics, chi-square tests and Poisson regressions (p ≤ 0.05) were used. RESULTS: In this sample, 28.6% and 15.9% of the students were overweight and had high blood pressure, respectively. The males were found to be more susceptible to both of the studied risk factors. The prevalence of high blood pressure among the adolescents was 1.173 - fold greater than that among the children. In contrast, adolescence itself was a protective factor in terms of overweight (RP = 0754). The prevalence of overweight in the children with increased waist circumferences and poor cardiopulmonary aptitudes were increased by 5.5 - and 1.3 - fold, respectively CONCLUSION: The prevalence of overweight and high blood pressure in the school population was high in the investigated city. Cardiorespiratory aptitude, increased waist circumference and family history exhibited influences on overweight and high blood pressure.(AU)

INTRODUÇÃO: Estudos atuais vêm apontando para o aumento das taxas de sobrepeso e obesidade e de fatores de risco cardiovasculares, como a hipertensão, em idades cada vez menores. No entanto, as causas e os fatores associados a este aumento ainda são de difícil de determinação OBJETIVO: Identificar os fatores associados e a prevalência de excesso de peso e níveis pressóricos entre os escolares MÉTODO: A amostra envolveu 1867 escolares. Os dados foram obtidos por meio de avaliações antropométricas, medidas da pressão arterial, avaliação cardiorrespiratória e aplicação de questionários. Utilizou-se estatística descritiva, qui-quadrado e regressão de Poisson (p d" 0,05) RESULTADOS: 28,6% e 15,9% dos escolares apresentaram excesso de peso e pressão elevada, respectivamente. O sexo masculino mostrou-se mais suscetível a ambos os fatores de risco estudados. Adolescentes apresentaram prevalência 1,173 vezes maior de pressão elevada que as crianças. Já, para o excesso de peso, a adolescência apresentou-se como fator de proteção (RP = 0,754). Escolares com circunferência da cintura elevada e aptidão cardiorrespiratória insatisfatória apresentaram prevalência de 5,5 e 1,3 vezes maior de excesso de peso, respectivamente CONCLUSÃO: A prevalência de excesso de peso e pressão elevada na população escolar se mostrou alta no município investigado. Aptidão cardiorrespiratória, circunferência da cintura elevada e o histórico familiar mostraram influenciar no excesso de peso e nos níveis pressóricos elevados.(AU)

[Comparison analysis of blood pressure, obesity, and cardio-respiratory fitness in schoolchildren].

BACKGROUND: During childhood and adolescence, physical inactivity, excess weight, and poor nutrition are risk factors for chronic diseases, especially obesity, hypertension, and diabetes mellitus. Early intervention can prevent the development of these complications. OBJECTIVE: To determine the presence of cardiovascular risk (obesity and hypertension) in schoolchildren and its potential interactions with cardio-respiratory fitness. METHODS: This was a cross-sectional study conducted in a stratified cluster sample of 1,666 schoolchildren, aged between 7 and 17 years, 873 (52.4%) of them male and 793 (47.6%) of them female. The following variables were evaluated: systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index (BMI), body fat percentage (BF %), and cardio-respiratory fitness. SBP and DBP were correlated with waist circumference (WC), waist-hip ratio (WHR), sum of skin folds (SigmaSF), and cardio-respiratory fitness. RESULTS: A BMI assessment of the students showed that 26.7% of them were overweight or obese, and 35.9% had body fat percentage over moderately high. As to blood pressure, we found that 13.9% and 12.1% of the students were borderline or hypertensive, for SBP and DBP, respectively. There was an association among hypertension, obesity, and cardio-respiratory fitness. There was a significant correlation of SBP and DBP with all variables, and also a weak to moderate correlation with age, weight, height, BMI, and waist circumference. CONCLUSION: The presence of hypertension associated with obesity and its effects on cardio-respiratory fitness stress the importance of recommending, since childhood, a more active and healthy lifestyle.

Cumulative incidence of youth obesity is associated with low cardiorespiratory fitness levels and with maternal overweight / Incidência cumulativa de obesidade juvenil está associada com níveis baixos de aptidão cardiorrespiratória e com excesso de peso materno / Incidencia acumulativa de la obesidad juvenil es asociada con niveles de baja aptitud cardiorespiratoria y con sobrepeso materno

This longitudinal study evaluated the association between the incidence of youth overweight/obesity (Ow/Ob) and low levels of cardiorespiratory fitness (CRF) over 4 years and youths' and their parents' demographic and nutritional characteristics. The randomized sample comprised 398 youth, aged 7-17 years at baseline, from a city in southern Brazil. Subjects were classified as being Ow/Ob according to international body mass index (BMI) parameters. Parental weight and height were determined by direct questioning. Youth CRF was measured by a 9-minute walk-and-run test. The cumulative incidences of Ow/Ob and of low CRF levels were 25.1% and 20.5%, respectively. Relative to other youth, youth who were classified as "unhealthy" at baseline (with respect to CRF) and by the fourth year were more likely to be classified as Ow/Ob (relative risks: 1.12 and 1.10, respectively). Youth whose mothers were categorized as Ow/Ob were at higher risk of being classified as Ow/Ob than youth whose mothers had normal BMIs (relative risks: 1.19 at baseline and 1.20 in the fourth year). The incidence of Ow/Ob among the former youth was associated with low CRF levels and with maternal Ob.

O presente estudo longitudinal avaliou a associação entre a incidência de sobrepeso/obesidade e de baixos níveis de aptidão cardiorrespiratória (APCR) em escolares, ao longo de 4 anos, com características demográficas e nutricionais de seus pais. A amostra aleatória foi composta por 398 escolares, com idades entre 7 e 17 anos, de uma cidade do sul do Brasil. Os escolares foram classificados em sobrepeso/obesidade de acordo com os pontos de corte internacionais para o índice de massa corporal (IMC). O peso e a estatura dos pais foram avaliados através de uma pergunta direta. A APCR dos escolares foi avaliada através do teste de corrida/caminhada de 9 minutos. A incidência cumulativa de sobrepeso/obesidade encontrada nos escolares foi de 25,1% e baixos níveis de APCR foi de 20,5%. Escolares classificados com baixos níveis de aptidão cardiorrespiratória (risco relativo: 1,12 no início do estudo e 1,10 após 4 anos) e cujas mães são obesas (risco relativo: 1,19 no início do estudo e 1,20 no quarto ano) apresentaram risco maior de apresentarem sobrepeso/obesidade. Assim, a incidência de sobrepeso/obesidade em escolares está associada com baixos níveis de aptidão cardiorrespiratória e obesidade da mãe.

Este estudio longitudinal examinó la asociación entre la incidencia de sobrepeso/obesidad y de bajos niveles de aptitud cardiorrespiratoria (APCR) en escolares, en un período de cuatro años, con características demográficas y nutricionales de sus padres. La muestra aleatoria estuvo conformada por 398 escolares entre 7 y 17 años, en el sur de Brasil. Los estudiantes fueron clasificados como con sobrepeso/obesidad según los puntos de corte internacionales para el índice de masa corporal (IMC). El peso y la talla de los padres fueron evaluados por una pregunta directa. La APCR en niños se evaluó mediante la prueba de carrera/caminata en nueve minutos. La incidencia acumulada de sobrepeso/obesidad en los niños fue de 25,1% y los bajos niveles de APCR fueron de 20,5%. Los niños clasificados con bajos niveles de aptitud cardiorrespiratoria (riesgo relativo: 1,12 al inicio y 1,10 después de 4 años) y que tienen madre obesa (riesgo relativo: 1,19 al inicio y 1,20 en el cuarto año) tienen un riesgo mayor para el desarrollo de sobrepeso/obesidad. La incidencia de sobrepeso/obesidad en escolares se muestra asociada a los bajos niveles de capacidad cardiorrespiratoria y la obesidad de la madre.