Obesidade e síndrome metabólica na infância e adolescência

Body fat, cardiovascular risk factors and polymorphism in the FTO gene: randomized clinical trial and different physical exercise for adolescents

OBJECTIVE

To investigate the effects of different physical exercise programs and polymorphisms of the FTO (fat mass and obesity-associated gene) on body composition and cardiovascular risk factors in adolescents with overweight and obesity.

METHODS

A randomized, parallel, double-blind clinical trial consisting of the adolescent overweight from the state public network, in a simple representative random sample, who participated in an aerobic exercise or weight training intervention for 10 weeks. Anthropometry, body composition, biochemical markers, sexual maturation, and rs9939609 polymorphism in the FTO gene were assessed. 347 adolescents had their characterization of nutritional status. 72 individuals with overweight and obesity were invited to participate. 39 remained for the start of the program and were randomly allocated to both types of intervention. In the end, 26 subjects participated in the intervention programs, with 12 and 14 in the aerobic and weight training programs, respectively.

RESULTS

Heterozygous and homozygous bearers of risk allele A participating in the aerobic program showed improvements in glycemia (p = 0.002) and total cholesterol (p = 0.023) and a reduction in body fat mass (p = 0.041). The weight training program reduced glycemia in patients with the risk allele A (p = 0.027). Cameron's stage four sexual maturation participants were 2.1 times more likely to improve their body fat (CI = 1.31-3.39).

CONCLUSION

Aerobic exercises produced exclusively a significant decrease in fat mass and total cholesterol in patients with risk allele A. Distinct physical exercise programs may cause diverse changes in risk variables related to the health of adolescents.

Anthropometric status and lipid profile among children and adolescents: Changes after 18-month follow-up

BACKGROUND & AIMS

Overweight children and adolescents are more likely to evolve with high cholesterol, be obese adults and develop cardiovascular disease. The objective of this study was to identify the influence of anthropometric status on the changes in the lipid profile of children and adolescents during an 18-month follow-up period.

METHODS

A cohort study involving 540 boys and girls from 7 to 15 years of age was conducted over 18 months' follow-up. The outcome variables were the lipid indicators and the principal exposure variable was anthropometric status, measured by different indicators. A generalized estimating equation (GEE) approach was used to identify the associations of interest.

RESULTS

Irrespective of age, sex, socio-economic status, physical activity and diet, for each gain of 1 cm in the waist circumference (WC) mean in the adjusted model, triglyceride levels increased by a mean of 0.5 mg/dl (p < 0.000) and there was an increase of 0.21 mg/dL in the total cholesterol after the 18-month period. The increase of 0.1 in the mean body mass index (BMI) Z-score promoted a gain of 2.7 mg/dL in the triglycerides mean levels (p < 0.000) and an increase of 1.5 mg/dL in the total cholesterol mean levels (p = 0.014) after the follow-up period. Regarding the waist-to-height ratio (WHtR) and conicity index (CI), an increment of 40.6 mg/dL (p = 0.02) and of 30.1 mg/dL (p = 0.01) was observed in the triglycerides' mean when the participants increased 0.1 in the WHtR mean and CI mean, and the same was observed in the total cholesterol mean, with an increase of 45.4,g/dL (p = 0.02) and 19.3 mg/dL (p = 0.03), for each indicator, respectively. Changes of the traditional anthropometric indicators (WC and BMI) did not promote variations in the mean levels of LDL-cholesterol. HDL-cholesterol was not influenced by the changes in the anthropometric indicators.

CONCLUSIONS

At the baseline, a higher triglyceride mean and lower levels of HDL-c were observed in children and adolescents with altered anthropometric status for all measures. Mean triglyceride and total cholesterol levels are influenced by changes in the anthropometric status, regardless of the measure, after 18 months of follow-up. However, for LDL-cholesterol, it was observed that changes in the traditional anthropometric indicators (WC and BMI) did not promote variations in the mean levels of this biochemical variable, while HDL-c was not influenced by changes in any of the anthropometric indicators.

Ultrasonographic evaluation of the common carotid intima-media complex in healthy and overweight/obese children

BACKGROUND

Obesity is a global epidemic, including among children. It is therefore necessary to identify cardiovascular changes in overweight/obese children as early as possible. Mode B ultrasonography of the common carotids can be used to precisely evaluate in real time early changes in the thickness of the intima-media complex (IMC), which can detect onset of the atherosclerosis process.

OBJECTIVES

This study compared IMC thickness between schoolchildren with and without overweight/obesity.

METHODS

A sample of 59 children of both sexes, aged 7 to 10 years, were recruited from health centers in São Paulo, Brazil. Children were classified by z scores for body mass index (BMI) into two groups, with or without overweight/obesity. These groups were then compared in terms of IMC thickness.

RESULTS

The groups were homogenous for age and sex. The mean IMC measurement in the group with overweight/obesity was 0.49 (± 0.07) mm, whereas in the group free from overweight/obesity it was 0.41 (± 0.05) mm (p < 0.01). These differences were maintained when groups with and without overweight/obesity were compared separately by sex and for right and left sides. The coefficient for the correlation between IMC measurement and BMI z score was 0.61 (95% confidence interval = 0.42-0.75). Within the same nutritional status group, there were no differences between sexes or between right and left sides.

CONCLUSIONS

Intima-media thickness was greater among children with overweight/obesity and was directly proportional to BMI z score, denoting increased cardiovascular risk in this group.

Intra-abdominal fat measurement by ultrasonography: association with anthropometry and metabolic syndrome in adolescents

OBJECTIVE

To associate intra-abdominal fat thickness measured by ultrasonography to the factors related to metabolic syndrome and to determine cutoff points of intra-abdominal fat measurement associated with a greater chance of metabolic syndrome in adolescents.

METHODS

This was a cross-sectional study, with 423 adolescents from public schools. Intra-abdominal fat was measured by ultrasonography. Anthropometric data were collected, and biochemical analyses were performed.

RESULTS

Intra-abdominal fat was measured by ultrasonography, showing a statistically significant association with the diagnosis of metabolic syndrome (p=0.037), body mass index (p<0.001), elevated triglyceride levels (p=0.012), decreased plasma HDL levels (p=0.034), and increased systemic blood pressure values (p=0.023). Cutoff values of intra-abdominal fat thickness measurements were calculated by ultrasound to estimate the individuals most likely to develop metabolic syndrome. In the logistic regression models, the cutoff values that showed the highest association with metabolic syndrome in males were 4.50, 5.35, 5.46, 6.24, and 6.50cm for the ages of 14, 15, 16, 17, and 18/19 years, respectively. In the female gender, the cutoff values defined for the same age groups were 4.46, 4.55, 4.45, 4.90, and 6.46cm. In an overall analysis using the ROC curve, without gender and age stratification, the cut-off of 3.67cm showed good sensitivity, but low specificity.

CONCLUSION

Ultrasonography is a useful method to estimate intra-abdominal adipose tissue in adolescents, which is associated with the main factors related to obesity and metabolic syndrome.

LOCALIZED FAT-FREE MASS DOES NOT INFLUENCE MUSCLE STRENGTH IN OBESE AND NON-OBESE BOYS

ABSTRACT Introduction: Obesity in adolescents has increased worldwide, and is generally associated with poor eating habits and physical inactivity. Objective: To compare absolute and relative muscle strength with body mass (BM), fat-free mass (FFM) and localized FFM of upper and lower limbs among obese and non-obese adolescents. Methods: BM, height and body mass index (BMI) were verified in 39 male adolescents (aged 13-17 years). Body composition was measured by dual-energy X-ray absorptiometry (DXA) and maximal strength of upper and lower limbs was estimated by a one-repetition maximum (1RM) test. Participants were divided into three groups: eutrophic (normal weight) (n=11), overweight (n=14), and obese (n=14). One-way ANOVA was used to compare the variables, followed by a Bonferroni post-hoc test for multiple comparisons. Pearson's correlation coefficient was used for relevant correlations and multiple linear regression to verify the influence of anthropometric variables, body composition and muscle strength of upper and lower limbs. Results: Obese and overweight adolescents had absolute muscle strength values similar to those of the eutrophic adolescents, which were lower when corrected by BM (p<0.001). However, muscle strength related to FFM and localized FFM were similar between groups in both upper and lower limbs. Linear regression showed that BMI explained 59% of the variation in absolute muscle strength of the lower limbs (β=0.59, p<0.05), FFM explained 84% of the variation in absolute muscle strength of the upper limbs (β=0.84, p<0.01) and 68% of the lower limbs (β=0.68; p<0.01), while localized FM was inversely associated in the lower limbs (β=−0.53, p<0.05). Conclusion: Muscle strength of lower and upper limbs, when corrected by localized FFM, does not distinguish between overweight and normal weight adolescents, indicating that obesity does not have a negative effect on generation of muscle strength in obese boys. Level of Evidence III; Case-control study.

TRUNK BODY MASS INDEX: A NEW REFERENCE FOR THE ASSESSMENT OF BODY MASS DISTRIBUTION

BACKGROUND

Body mass index (BMI) has some limitations for nutritional diagnosis since it does not represent an accurate measure of body fat and it is unable to identify predominant fat distribution.

AIM

To develop a BMI based on the ratio of trunk mass and height.

METHODS

Fifty-seven patients in preoperative evaluation to bariatric surgery were evaluated. The preoperative anthropometric evaluation assessed weight, height and BMI. The body composition was evaluated by bioimpedance, obtaining the trunk fat free mass and fat mass, and trunk height. Trunk BMI (tBMI) was calculated by the sum of the measurements of the trunk fat free mass (tFFM) and trunk fat mass (tFM) in kg, divided by the trunk height squared (m2)). The calculation of the trunk fat BMI (tfBMI) was calculated by tFM, in kg, divided by the trunk height squared (m2)). For the correction and adjustment of the tBMI and tfBMI, it was calculated the relation between trunk extension and height, multiplying by the obtained indexes.

RESULTS

The mean data was: weight 125.3±19.5 kg, height 1.63±0.1 m, BMI was 47±5 kg/m2) and trunk height was 0.52±0,1 m, tFFM was 29.05±4,8 kg, tFM was 27.2±3.7 kg, trunk mass index was 66.6±10.3 kg/m², and trunk fat was 32.3±5.8 kg/m². In 93% of the patients there was an increase in obesity class using the tBMI. In patients with grade III obesity the tBMI reclassified to super obesity in 72% of patients and to super-super obesity in 24% of the patients.

CONCLUSION

The trunk BMI is simple and allows a new reference for the evaluation of the body mass distribution, and therefore a new reclassification of the obesity class, evidencing the severity of obesity in a more objectively way.

EFFECT OF PHYSICAL ACTIVITY ON CARDIOMETABOLIC MARKERS IN ADOLESCENTS: SYSTEMATIC REVIEW

ABSTRACT The accumulation of body fat is a major risk factor for cardiometabolic diseases. Obesity can be considered a chronic systemic inflammatory disease in adults and younger people. The control of subclinical inflammation process through the practice of physical activity (PA) can mitigate the effects of risk factors that trigger atherosclerosis that worsens with advancing age. The objective of this study was to conduct a systematic review of the influence of physical activity and/or exercise on cardiometabolic markers and othrer risk factors of cardiovascular disease in adolescents. A systematic review was conducted in electronic databases Scopus, Pubmed, Conchrane Collection and SciELO. The terms used in the search were "cardiovascular diseases AND inflammation AND adolescents AND physical activity OR exercise". A total of 24 original articles were evaluated, being 14 longitudinal and 10 cross-sectional studies. Overall, 16 articles (66.66%) showed that PA, exercise and/or sedentary behavior may have influenced or have been related to the concentration of cardiometabolic markers. All studies that examined lifestyle changes showed reduction of cardiometabolic markers. Some limitations were observed: reduced samples, lack of dietary prescription, evaluation and control of volume and intensity of exercise. Most of the studies analyzed showed that the physical activity could influence and decrease the concentrations of cardiometabolic markers in adolescents. However, studies with representative sample size and precise control in assessing the level of physical activity and/or exercise are required to determine accurately the changes that the more active lifestyle can bring on inflammatory process, as well as other risk factors for cardiometabolic diseases in adolescents.

Deuterium oxide dilution and body composition in overweight and obese schoolchildren aged 6-9 years

OBJECTIVE

To correlate different methods of body composition assessment in overweight or obese schoolchildren, using deuterium oxide (D2O) dilution as a reference.

METHODS

Percentage of total body water (%TBW), fat free mass (%FFM), and body fat (%BF) were assessed by D2O and tetrapolar electrical bioimpedance analysis (BIA) in 54 obese and overweight students aged 6-9 years. Skinfold thickness (ST), body mass index (BMI), conicity index (CI), waist circumference (WC), waist-to-height ratio (WHtR), and waist-to-hip (WHR) ratio were also used.

RESULTS

Mean values for body composition were 38.4%±8.4% BF, 44.9%±6.1% TBW and 61.6%±8.4% FFM. There was no significant difference in body weight, body fat mass (FM), TBW, and FFM between genders. Regarding D2O, ST underestimated %BF, and overestimated %FFM in both genders (p<0.05). BIA overestimated %TBW in the group as a whole and in males (p<0.05). The only positive and strong correlations occurred in females regarding the WC (σ=0.679), CI (r=0.634), and WHtR (r=0.666).

CONCLUSIONS

In this sample of obese and overweight children, there were strong correlations between body composition measured by D2O and some indices and anthropometric indicators in females, but there was no positive and strong correlation of fat tissue with the indices/indicators at all ages and in both genders.

Design, randomization and methodology of the TriAtiva Program to reduce obesity in school children in Southern Brazil

Background

The prevalence of child obesity in Brazil has increased rapidly in recent decades. There is, therefore, an urgent need to develop effective strategies to prevent and control child obesity. In light of these considerations, an intervention program with a focus on nutrition education and physical activity was developed for to prevent and control obesity in schools. The intervention was called the TriAtiva Program: Education, Nutrition and Physical Activity. This article describes the design, randomization and method used to evaluate the TriAtiva program.

Methods/design

This randomized controlled cluster trial was performed in 12 municipal schools in the city of Porto Alegre/RS (six schools in the intervention group and six control schools) which offered first- through fourth grade, during one school year. The TriAtiva Program was implemented through educational activities related to healthy eating and physical activity, creating an environment which promoted student health while involving the school community and student families. The primary outcome of the present study was body mass, while its secondary outcomes were waist circumference, percent body fat, blood pressure and behavioural variables such as eating habits and physical activity levels, as well as the prevalence, incidence and remission rates of obesity.

Discussion

The intervention was developed based on a comprehensive review of controlled trials of similar design. The TriAtiva Program: Education, Nutrition and Physical Activity was the first study in Southern Brazil to use a randomized controlled design to evaluate an intervention involving both nutrition education and physical activity in schools. Our results will contribute to the development of future interventions aimed at preventing and controlling child obesity in schools, especially in Brazil. Brazilian Clinical Trials Registry (REBEC) number RBR2xx2z4.

Birth weight, current anthropometric markers, and high sensitivity C-reactive protein in Brazilian school children

Studies have shown associations of birth weight with increased concentrations of high sensitivity C-reactive protein. This study assessed the relationship between birth weight, anthropometric and metabolic parameters during childhood, and high sensitivity C-reactive protein. A total of 612 Brazilian school children aged 5-13 years were included in the study. High sensitivity C-reactive protein was measured by particle-enhanced immunonephelometry. Nutritional status was assessed by body mass index, waist circumference, and skinfolds. Total cholesterol and fractions, triglycerides, and glucose were measured by enzymatic methods. Insulin sensitivity was determined by the homeostasis model assessment method. Statistical analysis included chi-square test, General Linear Model, and General Linear Model for Gamma Distribution. Body mass index, waist circumference, and skinfolds were directly associated with birth weight (P < 0.001, P = 0.001, and P = 0.015, resp.). Large for gestational age children showed higher high sensitivity C-reactive protein levels (P < 0.001) than small for gestational age. High birth weight is associated with higher levels of high sensitivity C-reactive protein, body mass index, waist circumference, and skinfolds. Large for gestational age altered high sensitivity C-reactive protein and promoted additional risk factor for atherosclerosis in these school children, independent of current nutritional status.

Prevalence of arterial hypertension among Brazilian adolescents: systematic review and meta-analysis

Background

Cardiovascular diseases are the leading cause of death in the world and are responsible for a high number of disability-adjusted life years. Elevated blood pressure is an independent, linear and continuous risk factor for cardiovascular disease and has also been reported in the young population. Brazil is a country of continental dimensions, and is very heterogeneous with respect to socioeconomic and cultural aspects. Brazilian studies on the subject of hypertension in adolescence are not nationally representative, and this provides a rationale for the conduction of a meta-analysis to assess the magnitude of the problem in the country.

Methods

Hypertension studies in adolescents published from 1990 to September 2010 were searched in six electronic databases. Forest plots of the prevalence of hypertension were built for the overall population and by gender. Heterogeneity was assessed using I² statistics. Meta-regression models were adjusted in order to identify possible sources of heterogeneity.

Results

Of 3,631 articles initially identified, 17 were considered eligible for systematic review. The pooled prevalence of hypertension, estimated through random effects models, was 8.12% (95% CI 6.24 - 10.52) for the total population. Overall, prevalence was higher in males, 8.75% (95% CI 5.81 - 12.96) than females, 6.31%, (95% CI 4.41 - 8.96). Several variables were investigated in the heterogeneity analysis: region of the study, sample size, age and method of blood pressure measurement. The only variables that partially and inconsistently explained the observed heterogeneity (I² = 95.3%) were the region of the country where the study was conducted and sample.

Conclusions

There was a large variation in hypertension prevalence and in the methods used for its evaluation throughout studies with Brazilian adolescents, indicating the need for standardized procedures and validated methods for hypertension measurement. Despite the large observed heterogeneity, and the small number of studies in some regions of Brazil, the pooled prevalence found in both males and females shows that systemic arterial hypertension should be monitored in the population aged 10–20 years and that specific measures are required to prevent and control the disease, as well as its risk factors. Studies that compare regional heterogeneities may contribute to the knowledge of factors associated with increased blood pressure among adolescents.

Hypertriglyceridemic waist phenotype: association with metabolic abnormalities in adolescents

OBJECTIVE

This study aimed to identify the prevalence of hypertriglyceridemic waist (HTW) phenotype, and to evaluate its association with metabolic abnormalities in adolescents of low socioeconomic status.

METHOD

This was a cross-sectional study with a random sample of 1,076 adolescents between 11 and 17 years, of both genders, from public schools. The participants underwent anthropometric measurements (weight, height, and waist circumference), and levels of total cholesterol, low-density-lipoprotein cholesterol (LDL-C), high-density-lipoprotein cholesterol (HDL-C), non-HDL cholesterol, triglyceride (TG), and fasting glucose were measured. Information regarding the socioeconomic status of the participants' families was obtained. The HTW phenotype was defined by the simultaneous presence of increased waist circumference (≥ 90(th) percentile for age and gender) and serum triglyceride levels (≥ 100mg/dL). A logistic regression analysis was used to evaluate the associations of interest.

RESULTS

The prevalence of HTW phenotype was 7.2% among the adolescents, being higher in the presence of obesity (63.4%) and high levels of non-HDL cholesterol (16.6%) and LDL-C (13.7%). The bivariate analysis indicated that, of the metabolic variables, only blood glucose was not associated with the HTW phenotype. Multivariate analysis adjusted for age and gender indicated that the HTW phenotype was positively associated with high non-HDL cholesterol (odds ratio: 7.0; 95% CI: 3.9-12.6) and low HDL-C levels (odds ratio: 2.7; 95% CI: 1.5-4.8).

CONCLUSIONS

This study demonstrated that the HTW phenotype was associated with an atherogenic lipid profile, and this phenotype is suggested as a screening tool to identify adolescents with metabolic alterations.

Fatores de risco para hipertensão arterial entre estudantes do ensino médio

OBJETIVO: Identificar os valores pressóricos e estimar a frequência de fatores de risco para a hipertensão arterial entre estudantes do ensino médio. MÉTODOS: Estudo descritivo de corte transversal, desenvolvido em escolas da Região Sudeste brasileira. Fizeram parte da amostra 184 adolescentes matriculados na segunda série do ensino médio, em 2009. Além da mensuração das variáveis clínicas, foram aplicados instrumentos para identificação de fatores de risco associados à doença hipertensiva. RESULTADOS: A alteração pressórica foi um parâmetro detectado em 22,3% da amostra. Dentre os fatores de risco investigados, o histórico familiar de doenças cardiovasculares e o consumo de álcool foram os mais prevalentes. CONCLUSÃO: Há necessidade de valorizar as medidas de prevenção primária e detecção precoce da hipertensão arterial entre adolescentes, com especial atenção para a avaliação dos antecedentes familiares e adoção de hábitos de risco.

Importância do contexto sociofamiliar na abordagem de crianças obesas

OBJETIVO: Aprofundar a compreensão das interações interpessoais das crianças obesas no contexto familiar e social. MÉTODOS: Foi utilizada uma metodologia qualitativa de pesquisa, adotando-se uma fundamentação teórico-metodológica apoiada na teoria sistêmica. Empregaram-se os seguintes instrumentos: entrevistas de aprofundamento; técnica do genograma e desenhos da imagem corporal. Os sujeitos da pesquisa foram crianças e seus familiares (pai, mãe e irmãos), atendidos pelo serviço de Nutrologia Pediátrica do Hospital das Clínicas da Universidade Federal de Minas Gerais. RESULTADOS: Evidenciaram-se os seguintes indicadores relevantes: segredos familiares das histórias de origem das figuras parentais; relação emaranhada mãe/filhos que indica certo distanciamento dos pais na relação com as crianças; fenômenos transgeracionais em seus aspectos biológicos e simbólicos da obesidade em três gerações dos grupos familiares estudados; mitos e lealdades familiares, os quais se apresentaram como um suporte da identidade pessoal e familiar no ser gordo. Os sinalizadores auxiliaram a compreender as dificuldades do processo de diferenciação dessas crianças, ou seja, a possibilidade de o emagrecimento ser vivenciado como uma ameaça aos processos de identidade do grupo familiar. CONCLUSÕES: Este estudo possibilitou demonstrar a importância de contextualizar a obesidade na infância, retirando a responsabilidade pelo problema da própria criança e deslocando-a para o contexto sociofamiliar. A prática desta pesquisa indicou outras possibilidades de intervenção, ressaltando a atuação interdisciplinar como postura profissional relevante para o tratamento da obesidade na infância.

Associação entre o índice de massa corporal de pais e de escolares de 7 a 14 anos de Florianópolis, SC, Brasil

OBJETIVOS: verificar a associação entre o Índice de Massa Corporal (IMC) de escolares de 7 a 14 anos e dos respectivos pais. MÉTODOS: estudo transversal com 886 escolares de quatro escolas de Florianópolis, SC. Diagnóstico antropométrico dos escolares e dos pais definido, respectivamente, a partir do IMC para idade de acordo com Centers for Disease Control and Prevention e dos pontos de corte da Organização Mundial da Saúde. A associação entre o IMC dos pais e dos escolares foi estimada por meio da razão de prevalência (RP) com intervalo de confiança (IC) de 95% e teste qui-quadrado com valor de significância de p< 0,05. RESULTADOS: identificou-se prevalência de sobrepeso/obesidade mais elevada em meninos (29,9%) quando comparada a de meninas (17,7%) (p<0,001). Observou-se relação estatisticamente significante entre o IMC de escolares do sexo feminino com o IMC das mães (RP=1,63; IC95%=1,1-3,0; p=0,02) e dos pais (RP=1,78; IC95%= 1,1-3,5; p=0,01). Nos escolares do sexo masculino a associação observada não foi estatisticamente significante. CONCLUSÕES: identificou-se que a prevalência do sobrepeso ou obesidade é 1,63 vezes maior, entre as meninas, quando a mãe também apresenta esse distúrbio e 1,78 vezes maior quando o pai o apresenta, em comparação a mães e pais eutróficos ou de baixo peso.

Perfil lipídico e estado nutricional de adolescentes

OBJETIVOS: Avaliar a associação entre obesidade e dislipidemias em adolescentes do ensino público e privado de Campina Grande-PB, Brasil. MÉTODOS: Estudo transversal com 180 adolescentes de 14 a 17 anos matriculados no ensino público e privado de Campina Grande-PB. O estado nutricional foi classificado segundo os percentis do Índice de Massa Corporal para sexo e idade. Foi realizada coleta sangüínea para avaliação do perfil lipídico (colesterol total, frações HDL-colesterol, LDL-colesterol e triglicerídeos). Considerou-se dislipidemia a existência de alteração em pelo menos um dos exames. As análises estatísticas foram realizadas a partir do Epi Info 3.3 e Stata 7.0. RESULTADOS: A prevalência de sobrepeso foi de 14,4% enquanto que 83,9% dos estudantes eram eutróficos e 1,7% apresentavam baixo peso. Não foram encontradas diferenças estatisticamente significantes para o estado nutricional quando estratificado por sexo e tipo de escola. Todas as taxas bioquímicas investigadas mostraram algum nível de alteração. Chamou à atenção a prevalência de dislipidemia, observada em 66,7% dos estudantes, e a alteração do HDL-colesterol, verificada em 56,7% destes. Registrou-se associação estatisticamente significante (p<0,05) do Índice de Massa Corporal, categorizado em tercis, com o colesterol total e sua fração LDL, inclusive quando estratificados por sexo e tipo de escola. CONCLUSÕES: Considerando-se a faixa etária estudada, foram elevados os achados de sobrepeso e dislipidemia. Recomenda-se a adição de medidas preventivas, a fim de evitar que cada vez mais crianças e adolescentes venham a se tornar adultos portadores de obesidades e outras doenças crônicas.

Prevalência de síndrome metabólica em estudo de base populacional, Vitória, ES - Brasil

Síndrome Metabólica (SM) é um transtorno representado pela agregação de fatores predisponentes para desenvolvimento de doenças cardiovasculares e diabetes. Apesar da importância da SM, há carência de dados sobre as características epidemiológicas desta condição na população brasileira. Determinamos a prevalência da SM por sexo, faixa etária e nível socioeconômico na população da cidade de Vitória, ES, Brasil, utilizando os critérios do NCEP/ATPIII. Foram coletados dados socioeconômicos, bioquímicos, antropométricos e hemodinâmicos em 1.663 indivíduos de amostra randômica da população (25-64 anos) de Vitória. A prevalência foi de 29,8% (IC95 = 28-32%), sem diferença entre sexos. De 25 a 34 anos, a prevalência foi 15,8%, alcançando 48,3% na faixa de 55 a 64 anos. Verificou-se aumento progressivo de prevalência em mulheres do maior para o menor nível socioeconômico. O parâmetro da SM mais freqüente em homens foi hipertensão, seguido de hipertrigliceridemia, baixo HDL-colesterol, hiperglicemia e obesidade abdominal. Nas mulheres, hipertensão em primeiro lugar, seguida do baixo HDL-colesterol, obesidade abdominal, hipertrigliceridemia e hiperglicemia. Conclui-se que a prevalência de SM é elevada, inclusive nos mais jovens, com grande contribuição da hipertensão para o seu diagnóstico. Controle dos fatores de risco deve ser promovido visando reduzir o impacto das doenças cardiovasculares na mortalidade geral.

Respiratory muscle strength in obese individuals and influence of upper-body fat distribution

CONTEXT AND OBJECTIVE

Pulmonary dysfunction in obese individuals may be associated with respiratory muscle impairment, and may be influenced by predominance of upper-body fat distribution. The objective of this study was to evaluate the strength of respiratory muscles in obese individuals and to analyze the influence of adipose tissue distribution.

DESIGN AND SETTING

Cross-sectional study on the preoperative period prior to bariatric surgery. Research developed within the Postgraduate General Surgery Program, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista (Unesp).

METHOD

Respiratory muscle strength was quantified by measuring maximum inspiratory and expiratory pressures (PImax and PEmax) in obese candidates for bariatric surgery. Adipose tissue distribution was assessed using the waist-hip circumference ratio (WHR). PImax, PEmax and WHR were compared with normal reference values and also in groups with different body mass index (BMI).

RESULTS

We evaluated 23 men and 76 women. All underwent PImax evaluation and 86 underwent PEmax. The mean BMI was 44.42 kg/m2. PImax and PEmax were within normal values; WHR showed that there was predominance of upper-body fat distribution; and there were no correlations among the variables studied. There was no significant variance among the variables PImax, PEmax and WHR when the study population was divided into groups with different BMI.

CONCLUSION

In the obese population studied, the excess weight did not result in impairment of respiratory muscle strength, and their predominant upper-body fat distribution also did not influence respiratory muscle strength.

Metabolic and nutritional profile of obese adolescents with nonalcoholic fatty liver disease

BACKGROUND

The incidence of nonalcoholic fatty liver disease (NAFLD) is increasing due to its prevalence in obesity, diabetes, and insulin-resistance syndrome. The best treatment protocol for NAFLD has not been determined. However, there is evidence that exercise and nutritional intervention can improve and prevent it. The aim of the present study was to evaluate the dietary and metabolic profiles of obese adolescents with NAFLD who participated in a multidisciplinary program.

PATIENTS AND METHODS

We studied 43 adolescents ages 15 to 19 years (17.18 +/- 1.66 years) with a body mass index (BMI) > or = 30, consisting of 30 patients without NAFLD (BMI = 35.80 +/- 3.44 kg/m2) and 13 with NAFLD (BMI = 33.47 +/- 2.34 kg/m2). The NAFLD diagnosis was determined by ultrasonography. Blood samples were collected to analyze glycemia, hepatic aminotransferase levels, and lipid profiles. Insulin resistance was measured by homeostasis model assessment insulin-resistance index (HOMA-IR). The analyses of baseline and postintervention food intake were made by a 3-day inquiry.

RESULTS

At baseline conditions, the patients with NAFLD showed significant differences in body mass, BMI, and visceral and subcutaneous fat. Glucose and visceral and subcutaneous fat presented a significant reduction after treatment in patients with NAFLD. Analyzing the food intake, at baseline we observed a positive correlation between the visceral obesity and lipid consumption only in patients with NAFLD. We also observed significant decrease in energy and cholesterol consumption in patients with NAFLD after the multidisciplinary therapy.

CONCLUSIONS

The intervention promoted a decrease in the prevalence of NAFLD, a significant decrease in visceral obesity, and improved HOMA-IR, glycemia, and serum lipid levels that are risk factors for NAFLD. In summary, the multidisciplinary program is essential in the treatment and prevention of NAFLD.