[Hypercholesterolemia and its risk factors among schoolchildren]

[Conicity index as a predictor of changes in the lipid profile of adolescents in a city in Northeast Brazil]

The objective was to evaluate the conicity index (C Index) as a predictor of changes in the lipid profile of adolescents and to establish its cutoff points. This was a cross-sectional study in 774 adolescents of both sexes (55% girls), 10 to 14 years of age. C Index was calculated according to the formula proposed by Valdez, considering body mass, height, and waist circumference (WC). Changes in the adolescents' lipid profile were defined according to one of the following conditions: elevated levels of total cholesterol, low-density lipoprotein (LDL), and triglycerides and low levels of high-density lipoprotein (HDL). The predictive power of the conicity index for altered lipid profile and its cutoff points were determined by Receiver Operating Characteristic (ROC) curves. The C Index was a good predictor of lipid alterations in adolescents, emphasizing triglycerides in boys 10 to 11 years of age (ROC = 0.67; 95%CI: 0.50-0.85) and 12 to 14 (ROC = 0.69; 95%CI: 0.59-0.80), and in girls 10 to 11 years (ROC = 0.65; 95%CI: 0.50-0.79); and LDL in girls 10 to 11 years (ROC = 0.70; 95%CI: 0.59-0.80) and boys (ROC = 0.65; 95%CI: 0.55-0.75) and girls (ROC = 0.62; 95%CI: 0.50-0.75) 12 to 14 years. The cutoff points for the C Index varied from 1.12 to 1.16 between boys and girls. The C Index can be used to predict lipid alterations, and its cutoff points can be used to screen adolescents for risk of alterations in lipid profile.

Body Mass Index Is Better than Other Anthropometric Indices for Identifying Dyslipidemia in Chinese Children with Obesity

BACKGROUND

Body mass index (BMI), waist circumference (WC), and waist-to-hip ratio (WHR) are used in screening and predicting obesity in adults. However, the best identifier of metabolic complications in children with obesity remains unclear. This study evaluated lipid profile distribution and investigated the best anthropometric parameter in association with lipid disorders in children with obesity.

METHODS

A total of 2243 school children aged 7-17 years were enrolled in Guangzhou, China, in 2014. The anthropometric indices and lipid profiles were measured. Dyslipidemia was defined according to the US Guidelines for Cardiovascular Health and Risk Reduction in Children and Adolescents. The association between anthropometry (BMI, WC, and WHR) and lipid profile values was examined using chi-square analysis and discriminant function analysis. Information about demography, physical activity, and dietary intake was provided by the participant children and their parents.

RESULTS

Children aged 10-14 and 15-17 years old generally had higher triglyceride values but lower median concentration of total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol compared with children aged 7-9 years old (all P < 0.001). These lipid parameters fluctuated in children aged 10-14 years old. The combination of age groups, BMI, WC and WHR achieved 65.1% accuracy in determining dyslipidemic disorders. BMI correctly identified 77% of the total dyslipidemic disorders in obese children, which was higher than that by WHR (70.8%) (P< 0.05).

CONCLUSION

The distribution of lipid profiles in Chinese children differed between younger and older age groups, and the tendency of these lipid levels remarkably fluctuated during 10 to 14 years old. BMI had better practical utility in identifying dyslipidemia among school-aged children with obesity compared with other anthropometric measures.

Frequency of obesity and related risk factors among school children and adolescents in a low-income community. A cross-sectional study

CONTEXT AND OBJECTIVE

The frequency of obesity at an early age may contribute to atherosclerosis and cardiovascular disease (CVD) in adults. This study measured the frequency of obesity and cardiovascular risk factors in children and adolescents aged 6 to 17 years.

DESIGN AND SETTING

Cross-sectional study in a school located in a region of low income and socioeconomic status in Santa Rita do Sapucai, Minas Gerais, Brazil.

METHODS

A total of 175 students were classified using body mass index (BMI) and their waist circumference, blood pressure, number of hours of sedentary behavior and school meals were evaluated. Serum concentrations of fasting blood glucose, total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL-C) and high-density lipoprotein (HDL-C) were analyzed.

RESULTS

37.2% of the students had BMI above the 85th percentile and had significantly lower age, higher prevalence of hypertension, higher serum TC, LDL-C and TG, and greater waist circumference than those with BMI below the 85th percentile. Hypertension was observed in 2.9% of the students; 5.1% presented impaired glucose tolerance, 40% had two risk factors for atherosclerosis and 26.9% had three risk factors. A sedentary lifestyle was significantly less prevalent among subjects with BMI above the 85th percentile and was significantly correlated with serum TC and LDL-C. The school meals were hypoglycemic, hyperproteic and hyperlipidemic.

CONCLUSION

One third of the children and adolescents had weights greater than or equal to the age-adjusted weight, and this was associated with greater waist circumference, hypertension and prevalence of dyslipidemia.

Fatores associados à dislipidemia em crianças de 4 a 7 anos de idade

Objetivo: Avaliar o perfil lipídico e fatores associados à dislipidemia em crianças. Métodos: Estudo transversal que avaliou crianças de 4 a 7 anos acompanhadas nos primeiros meses de vida por um Programa de Extensão da Universidade Federal de Viçosa, Minas Gerais. Foram consideradas as dosagens de colesterol total, lipoproteína de alta densidade, lipoproteína de baixa densidade e triglicerídeos. Foram estudadas variáveis possivelmente associadas ao perfil lipídico, sendo elas variáveis maternas, sociodemográficas e aquelas associadas à criança. Foram realizadas análises bivariada e multivariadas, sendo as últimas por meio de regressão logística múltipla. Resultados: A amostra foi constituída por 185 crianças, de ambos os sexos. Observou-se que 46,5% (n=86) apresentaram valores aumentados de colesterol total, 9,2% (n=17) de lipoproteína de baixa densidade e 4,9% (n=9) de triglicerídeos. Com relação à lipoproteína de alta densidade, 35,1% (n=65) apresentaram valores abaixo do desejável. Demonstrou associação independente com o perfil lipídico das crianças a renda per capita, escolaridade materna e idade materna (associando-se à lipoproteína de baixa densidade) e o excesso de peso, que se associou a maiores prevalências de alterações em triglicerídeos. Conclusão: Foram observadas altas prevalências de dislipidemias. Condições sociodemográficas e estado nutricional demonstraram influenciar, também em crianças, a ocorrência de dislipidemias, as quais são citadas como fatores de risco para as doenças cardiovasculares. Revela-se a importância de se estudar esses fatores desde a infância, realizando-se estudos com outras faixas etárias que verifiquem a prevalência e fatores associados, de forma a promover o cuidado com a saúde desse grupo populacional.

[Cardiovascular risk and associated factors in schoolchildren in Belém, Pará State, Brazil]

This cross-sectional study aimed to identify risk factors for cardiovascular disease in a stratified cluster sample of 557 schoolchildren (6-19 years) in Belém, Pará State, Brazil. Potential risk factors were obesity, hypertension, dyslipidemia, diabetes, smoking, physical inactivity, and atherogenic diet. Socio-demographic and lifestyle variables were tested in a binary logistic regression model. The most prevalent risk factors were overweight (20.4%), dyslipidemia (48.1%), and physical inactivity (66.2%). Children below ten years of age and those from higher-income families and with higher maternal schooling showed greater odds of developing overweight; meanwhile, those with overweight were more prone to developing hypercholesterolemia and hypertriglyceridemia. The findings point to the need to implement strategies to prevent overweight in early childhood, through balanced nutrition and regular physical activity, in order to effectively reduce the prevalence of risk factors in schoolchildren.

Sociodemographic, anthropometric and dietary determinants of dyslipidemia in preschoolers

OBJECTIVE

To investigate the determinants of dyslipidemia in preschoolers.

METHODS

A total of 227 preschoolers residing in an urban area of the city of Diamantina, Minas Gerais, Brazil were evaluated at age 5 years, using a cross-sectional design. Dietary intake from a food frequency questionnaire, anthropometric/biochemical parameters, and socioeconomic/behavioral information from a questionnaire were evaluated. 'Mixed diet', 'snack', and 'unhealthy' dietary patterns were identified using principal component analysis. The determinants of dyslipidemia were examined using Poisson regression analysis.

RESULTS

The prevalence of dyslipidemia in this study was 65.19%. Preschoolers who less frequently consumed foods in the 'mixed diet' dietary pattern had a higher risk of high concentrations of low-density lipoprotein cholesterol (PR=2.30; p=0.004) when compared with those with more frequent consumption of the 'mixed diet' dietary pattern. Preschoolers whose mothers had lower levels of education presented a lower risk of high concentrations of low-density lipoprotein cholesterol (PR=0.43; p=0.003), and preschoolers who were overweight/obese presented with greater risk of high concentrations of low-density lipoprotein cholesterol (PR=2.23; p=0.003).

CONCLUSION

The determinants of dyslipidemia identified in this study were less frequent consumption of foods in the 'mixed diet' dietary pattern, higher body mass index, and lower level of maternal education. This study shows that despite the young age of the group under study, they already present a high prevalence of dyslipidemia, which is an important risk factor for cardiovascular disease.

Cardiovascular risk factor investigation: a pediatric issue

OBJECTIVES

To correlate cardiovascular risk factors (e.g., hypertension, obesity, hypercholesterolemia, hypertriglyceridemia, hyperglycemia, sedentariness) in childhood and adolescence with the occurrence of cardiovascular disease.

SOURCES

A systematic review of books and selected articles from PubMed, SciELO and Cochrane from 1992 to 2012.

SUMMARY OF FINDINGS

Risk factors for atherosclerosis are present in childhood, although cardiovascular disease arises during adulthood. This article presents the main studies that describe the importance of investigating the risk factors for cardiovascular diseases in childhood and their associations. Significant rates of hypertension, obesity, dyslipidemia, and sedentariness occur in children and adolescents. Blood pressure needs to be measured in childhood. An increase in arterial blood pressure in young people predicts hypertension in adulthood. The death rate from cardiovascular disease is lowest in children with lower cholesterol levels and in individuals who exercise regularly. In addition, there is a high prevalence of sedentariness in children and adolescents.

CONCLUSIONS

Studies involving the analysis of cardiovascular risk factors should always report the prevalence of these factors and their correlations during childhood because these factors are indispensable for identifying an at-risk population. The identification of risk factors in asymptomatic children could contribute to a decrease in cardiovascular disease, preventing such diseases as hypertension, obesity, and dyslipidemia from becoming the epidemics of this century.

Genetic and environmental influences on blood pressure and physical activity: a study of nuclear families from Muzambinho, Brazil

Blood pressure (BP) and physical activity (PA) levels are inversely associated. Since genetic factors account for the observed variation in each of these traits, it is possible that part of their association may be related to common genetic and/or environmental influences. Thus, this study was designed to estimate the genetic and environmental correlations of BP and PA phenotypes in nuclear families from Muzambinho, Brazil. Families including 236 offspring (6 to 24 years) and their 82 fathers and 122 mothers (24 to 65 years) were evaluated. BP was measured, and total PA (TPA) was assessed by an interview (commuting, occupational, leisure time, and school time PA). Quantitative genetic modeling was used to estimate maximal heritability (h²), and genetic and environmental correlations. Heritability was significant for all phenotypes (systolic BP: h² = 0.37 ± 0.10, P < 0.05; diastolic BP: h² = 0.39 ± 0.09, P < 0.05; TPA: h² = 0.24 ± 0.09, P < 0.05). Significant genetic (r g) and environmental (r e) correlations were detected between systolic and diastolic BP (r g = 0.67 ± 0.12 and r e = 0.48 ± 0.08, P < 0.05). Genetic correlations between BP and TPA were not significant, while a tendency to an environmental cross-trait correlation was found between diastolic BP and TPA (r e = -0.18 ± 0.09, P = 0.057). In conclusion, BP and PA are under genetic influences. Systolic and diastolic BP share common genes and environmental influences. Diastolic BP and TPA are probably under similar environmental influences.

Fatores associados à dislipidemia em crianças e adolescentes de escolas públicas de Salvador, Bahia

OBJETIVO: Este estudo aborda os fatores associados a dislipidemia em crianças e adolescentes matriculados na rede pública de ensino da cidade de Salvador, BA. MÉTODOS: Os participantes foram submetidos a avaliação antropométrica, coleta de sangue para dosagem de colesterol e triglicérides. As informações relacionadas a consumo alimentar, atividade física e condições socioeconômicas e de moradia da família foram fornecidas pelos responsáveis. Regressão logistica mutivariada foi utilizada para as avaliações de interesse. RESULTADOS: A prevalência de dislipidemia encontrada no presente estudo foi de 25,5% (IC:95% 22,7; 28,3). Observou-se associação positiva e estatiticamentre significante entre dislipidemia e excesso de peso (0R = 3,40; IC95%: 2,07-5,58), moderado e alto consumo de alimentos de risco (OR = 1,49; IC95%: 1,01-2,19), baixo e moderado consumo de alimentos protetores (OR = 1,54; IC95%: 1,05-2,26) e menor nível de escolaridade materna (OR = 1,72; IC95%: 1,05-2,26). CONCLUSÃO: O excesso de peso, consumo alimentar inadequado e baixa escolaridade materna constituem fatores associados a dislipidemia.

[Body mass index to the cardiovascular disease risk screening in infancy]

OBJECTIVE

To purpose news body mass index (BMI) cut offs to 7 to 12 years old scholars.

SUBJECTS AND METHODS

1.413 scholars of 7 to 12 years old selected of aleatory way. Were measured the BMI, total cholesterol (TC), and systolic (SBP) and diastolic blood pressure (DBP). To the date analyze were used the receiver operating characteristic curve (ROC curve) and the bivariate analyze.

RESULTS

The BMI cut offs proposed at this study show adequate capacity to identify true positive and negative to the cardiovascular diseases (CVD) risk factors presence. Besides, these cut offs show higher and more balanced sensibility and specificity values than other cut offs proposals.

CONCLUSIONS

The BMI proposed at this study configure with as the more adequate alternative to the screening for the scholars with increased chances to carry DCV risk factors.

[Cardiovascular risk factors in 7-to-10-year-old children in Vitória, Espírito Santo State, Brazil]

The study aimed to identify the simultaneous occurrence of cardiovascular risk factors in children 7 to 10 years of age in Vitória, Espírito Santo State, Brazil, and investigate associated socioeconomic variables. In a sample of 1,282 children, anthropometric data were obtained and blood pressure was measured with an automatic device. Socioeconomic, nutritional, and physical activity data were obtained with a questionnaire. To evaluate the simultaneous occurrence of cardiovascular risk factors, an index was developed including overweight, high blood pressure, poor eating, and sedentary leisure > 4 hours/day. The simultaneous presence of four cardiovascular risk factors was defined as high risk. Socioeconomic status and maternal schooling were included in the logistic regression model. Some 34% of the children presented two cardiovascular risk factors, 20% three factors, and 6.4% four cardiovascular risk factors. Maternal schooling remained associated with high cardiovascular risk (OR: 7.36, 95%CI: 2.09-25.97) and medium risk (OR: 2.57, 95%CI: 1.58-4.20). Low maternal schooling was the most important factor associated with cardiovascular risk.

Pontos de corte para a aptidão cardiorrespiratória e a triagem de fatores de risco para doenças cardiovasculares na infância

O principal objetivo deste estudo foi analisar a validade e propor novos pontos de corte para aptidão cardiorrespiratória de escolares de sete a 12 anos de idade. A amostra foi constituída por 1.413 escolares. A aptidão cardiorrespiratória foi medida através do teste de corrida/caminhada de nove minutos. O colesterol total e as pressões arterial sistólica e diastólica foram medidas e através delas foram criadas referências de fatores de risco para doenças cardiovasculares. Através da curva receiver operating characteristic entre a aptidão cardiorrespiratória e as referências de fatores de risco para doenças cardiovasculares foram identificados os valores dos pontos de corte. Adicionalmente foi utilizada a análise bivariada seguida do cálculo de razão de chances (odds ratio-OR) para identificar quanto os indivíduos que não atenderam os pontos de corte propostos tinham a mais de chance de apresentar fatores de risco para doenças cardiovasculares. Os resultados indicaram que, dentre as propostas analisadas, a que foi sugerida neste estudo apresentou melhores ajustamentos entre sensibilidade e especificidade. Os resultados da análise bivariada mostraram que indivíduos que não atenderam os pontos de corte propostos têm maiores chances de apresentarem fatores de risco para doenças cardiovasculares.

Colesterolemia, trigliceridemia e excesso de peso em escolares de Santa Maria, RS, Brasil

INTRODUÇÃO: O nível de colesterol na infância é um preditor do nível de colesterol na vida adulta. As consequências do colesterol elevado, somadas a outros fatores de risco constituem problema mundial de saúde pública. OBJETIVO: Estimar a prevalência de hipercolesterolemia, hipertrigliceridemia e excesso de peso em estudantes do município de Santa Maria-RS. Métodos: Estudo transversal com 374 crianças de 10 a 12 anos de idade, de escolas das redes pública e privada, realizado no segundo semestre de 2005 na cidade de Santa Maria-RS. Foram determinados os níveis de colesterol total, triglicerídeos e estado nutricional. RESULTADOS: As prevalências de hipercolesterolemia, hipertrigliceridemia e excesso de peso encontradas foram de 4,7%, 8,9% e 20,7%, respectivamente. Não houve diferença significante entre sexo e rede pública e privada. As crianças com excesso de peso apresentaram maior prevalência de alterações lipídicas. CONCLUSÕES: A prevalência de alterações lipídicas pode ser considerada baixa, mas a prevalência de excesso de peso dos estudantes de Santa Maria mostrou-se relativamente alta, alertando à importância de políticas públicas e à necessidade de assistência pediátrica nessa faixa etária, visando o seu diagnóstico precoce e, principalmente, o aconselhamento nutricional e incentivo à prática esportiva, uma vez que as dislipidemias e o excesso de peso têm sido apontados como fatores de risco para as doenças cardiovasculares.

Prevalência de hipertensão arterialem crianças e adolescentes obesos

Há um incremento na carga de doenças crônicas que afetam a população mundial e, da mesma forma, uma significativa parcela da população brasileira. Figuram nesse contexto a hipertensão arterial e a obesidade, inclusive entre indivíduos de baixa faixa etária. Diante disso, este estudo objetivou investigar a prevalência de hipertensão arterial em crianças e adolescentes obesos, na tentativa de verificar sua manifestação conforme gênero e idade. Para tanto, foram avaliados 129 indivíduos obesos na faixa etária de 7 a 14 anos, de ambos os gêneros. A avaliação consistiu em medidas antropométricas e mensuração da pressão arterial. Posteriormente, as informações foram analisadas estatisticamente com auxílio do programa BioEstat 3.0, que indicou prevalência de hipertensão arterial em ambos os gêneros (masculino = 15,8% e feminino = 26,4%) sem diferirem estatisticamente entre si. Nos diferentes grupos etários, a doença também se manifestou, com destaque para os indivíduos de 13 e 14 anos (52,4%), os quais diferiram estatisticamente dos demais grupos etários. Com isso, concluiu-se que a hipertensão arterial se fez presente de forma marcante na população investigada, indicando que a obesidade pode interferir na elevação da pressão arterial de crianças e adolescentes.

[Fat intake and hypercholesterolemia in a probabilistic sample of adolescents from Niterói, Rio de Janeiro]

OBJECTIVE

To evaluate the relationship between fat intake and serum cholesterol.

METHODS

A survey was conducted in a probabilistic sample of students from public schools in Niterói, state of Rio de Janeiro, Brazil. Anthropometric data were collected on 610 youngsters, 573 of them had blood drown, and 539 answered a simplified questionnaire on fat intake. Multivariate linear regression included as confounders: parents' cholesterolemia, adolescent age and body mass index (BMI).

RESULTS

The prevalence of high concentrations (> 170 mg/dL) of serum cholesterol was 31.2%. Both sexes presented high frequencies (45% approximately) of inadequate intake of fatty foods. Prevalence of overweight was 15.7%, without significant statistical difference between sexes (p= 0.83). Total fat intake as measured by the questionnaire and each one of the nine high fat items was not associated with youngsters' cholesterol. Among girls BMI and parents' hypercholesterolemia were associated with cholesterol levels, but for boys only age showed statistically significant association. Lack of association between fat intake and cholesterol levels was observed.

CONCLUSION

The combined higher prevalence of hypercholesterolemia, overweight and intake of high fat foods suggest that only public health action may curb these epidemics. This may indicate that overall energy intake should be the target of the actions.

Association of serum concentrations of retinol and carotenoids with overweight in children and adolescents

OBJECTIVE

A study was conducted to verify the association between serum concentrations of retinol and carotenoids with overweight in children and adolescents.

METHODS

In total 471 children (7-9.9 y of age) and adolescents (10-17 y of age), living in a poor region of the city of Rio de Janeiro, Brazil, were assessed. Serum concentrations of retinol and carotenoids were assessed by high-performance liquid chromatography, and cutoffs for inadequacy of retinol and carotenoids were <30 and <40 microg/dL, respectively. Overweight was defined by the sex- and age-specific body mass index cutoffs recommended by World Health Organization. The logistic regression model was used to test the association of overweight, gender, and age range with low serum concentrations of retinol and carotenoids.

RESULTS

Prevalences were 10% for low serum concentration of retinol, 55.8% for carotenoids, and 15.3% for overweight. Retinol inadequacy was significantly higher in adolescents (12.6%) than in children (6.8%). The average of carotenoids was significantly lower in overweight subjects (30.40 +/- 16.74 versus 43.06 +/- 25.26 microg/dL, P = 0.001). Overweight children and adolescents presented a greater chance of a decrease in serum concentrations of carotenoids (odds ratio 2.51, 95% confidence interval 1.43-4.39) when compared with non-overweight subjects.

CONCLUSION

An important prevalence of vitamin A deficiency was found. Overweight children, as much as adolescents, may have a greater chance of presenting low concentrations of carotenoids and, hence, a lower antioxidant defense.

Associação entre estado nutricional e atividade física em escolares da Rede Municipal de Ensino em Corumbá - MS

O sedentarismo é fator de risco para o desenvolvimento de sobrepeso e obesidade infantil, condições que se associam à dislipidemia, hipertensão arterial e resistência insulínica, entre outras alterações. O objetivo deste estudo foi avaliar o estado nutricional e a associação com o padrão de atividade física em escolares da Rede Municipal de Ensino de Corumbá (MS). Foi realizado estudo analítico transversal em uma amostra de 403 escolares, com idade entre sete e 10 anos, no qual se consideraram com risco de sobrepeso e sobrepeso as crianças com percentis de IMC < 85 e < 90 e < 90, respectivamente. O índice de atividade física foi determinado por meio de questionário elaborado especificamente para o estudo, obtendo-se dados sobre a duração (minutos), intensidade (equivalente metabólico) e gasto calórico (kcalorias) das atividades físicas ativas e sedentárias. Verificou-se prevalência de 6,2% e 6,5% para risco de sobrepeso e sobrepeso, respectivamente, com prevalência maior nas meninas do que nos meninos. A maioria das atividades físicas realizadas pelas crianças foi leve (< 3 METs) e moderada (3 a 6 METs) e nenhuma atividade física vigorosa (> 6 METs) foi registrada. Quanto maior a idade, menor o tempo despendido nas atividades físicas ativas. Constatou-se que crianças eutróficas são mais ativas, praticam atividades físicas mais intensas e gastam menos tempo assistindo à televisão e jogando videogames do que as crianças com sobrepeso. Os dados evidenciam a importância em promover mudanças no estilo de vida com a adoção de hábitos saudáveis, desde a infância, e a sua manutenção por toda a vida. Crianças ativas favorecem uma população adulta também ativa e saudável contribuindo, conseqüentemente, para a redução da incidência de morbidade e mortalidade na idade adulta.