Nanci Maria de França

Metabolic syndrome and risk factors for cardiovascular disease in obese children: the relationship with insulin resistance (HOMA-IR)

OBJECTIVE To identify the prevalence of metabolic syndrome and risk factors for the development of cardiovascular diseases and to investigate their relationship with insulin resistance. METHODS This was a cross-sectional study of 52 obese children. The sample was chosen at random after the body mass index [weight (kg)/stature (m)(2)] of 1,550 schoolchildren had been calculated. Children were defined as obese when their BMI was above the 95th percentile of the Centers for Disease Control and Prevention classification. Blood samples were taken after fasting and glycemia, high-density lipoproteins, triglycerides and insulin were all assayed. Body fat was evaluated using dual energy X-ray absorptiometry. Arterial blood pressure and insulin resistance were also measured. Metabolic syndrome was defined according to National Cholesterol Education Program criteria, with cutoff points adjusted for the age of the sample. RESULTS Metabolic syndrome was detected in 17.3% of the children investigated. Insulin resistance was significantly different for females (3.8-/+2.2; 95%CI 2.9-4.8) and males (2.6-/+1.3; 95%CI 2.1-3.1); p = 0.016. Around 44.2% of the sample exhibited at least two risk factors, and 15% exhibited arterial hypertension. Hypertriglyceridemia was observed in 50 and 70.8% of boys and girls, respectively. Lower than desirable high-density lipoprotein levels were only observed among the girls. CONCLUSIONS Obese children exhibited a high prevalence of metabolic syndrome. The children with greater insulin resistance exhibited more risk factors. In the light of these findings intervention measures are necessary in order to prevent excessive weight gain during childhood.OBJECTIVE: To identify the prevalence of metabolic syndrome and risk factors for the development of cardiovascular diseases and to investigate their relationship with insulin resistance. METHODS: This was a cross-sectional study of 52 obese children. The sample was chosen at random after the body mass index [weight (kg)/stature (m)2] of 1,550 schoolchildren had been calculated. Children were defined as obese when their BMI was above the 95th percentile of the Centers for Disease Control and Prevention classification. Blood samples were taken after fasting and glycemia, high-density lipoproteins, triglycerides and insulin were all assayed. Body fat was evaluated using dual energy X-ray absorptiometry. Arterial blood pressure and insulin resistance were also measured. Metabolic syndrome was defined according to National Cholesterol Education Program criteria, with cutoff points adjusted for the age of the sample. RESULTS: Metabolic syndrome was detected in 17.3% of the children investigated. Insulin resistance was significantly different for females (3.8±2.2; 95%CI 2.9-4.8) and males (2.6±1.3; 95%CI 2.1-3.1); p = 0.016. Around 44.2% of the sample exhibited at least two risk factors, and 15% exhibited arterial hypertension. Hypertriglyceridemia was observed in 50 and 70.8% of boys and girls, respectively. Lower than desirable high-density lipoprotein levels were only observed among the girls. CONCLUSIONS: Obese children exhibited a high prevalence of metabolic syndrome. The children with greater insulin resistance exhibited more risk factors. In the light of these findings intervention measures are necessary in order to prevent excessive weight gain during childhood.

Predicting insulin resistance in children: anthropometric and metabolic indicators

OBJECTIVE To predict insulin resistance in children based on anthropometric and metabolic indicators by analyzing the sensitivity and specificity of different cutoff points. METHODS A cross-sectional study was carried out of 109 children aged 7 to 11 years, 55 of whom were obese, 23 overweight and 31 well-nourished, classified by body mass index (BMI) for age. Measurements were taken to determine BMI, waist and hips circumferences, waist circumference/hip circumference ratio, conicity index and body fat percentage (dual emission X-ray absorptiometry). Fasting blood samples were taken to measure triglyceridemia, glycemia and insulinemia. Insulin resistance was evaluated by the glycemic homeostasis method, taking the 90th percentile as the cutoff point. Receiver operating characteristic curves were analyzed to a 95% confidence interval in order to identify predictors of glycemic homeostasis, and sensitivity and specificity were then calculated. RESULTS After analysis of the area under the receiver operating characteristic curve (confidence interval), indicators that demonstrated the power to predict insulin resistance were, in the following order: insulinemia = 0.99 (0.99-1.00), 18.7 microU mL(-1); body fat percentage = 0.88 (0.81-0.95), 41.3%; BMI = 0.90 (0.83-0.97), 23.69 kg m(2-(1)); waist circumference= 0.88 (0.79-0.96), 78.0 cm; glycemia = 0.71 (0.54-0.88), 88.0 mg dL(-1); triglyceridemia = 0.78 (0.66-0.90), 116.0 mg dL(-1) and conicity index = 0.69 (0.50-0.87), 1.23 for the whole sample; and were: insulinemia = 0.99 (0.98-1.00), 19.54 microU mL(-1); body fat percentage = 0.76 (0.64-0.89), 42.2%; BMI = 0.78 (0.64-0.92), 24.53 kg m(2-(1)); waist circumference = 0.77 (0.61-0.92), 79.0 cm and triglyceridemia = 0.72 (0.56-0.87), 127.0 mg dL(-1), for the obese subgroup. CONCLUSIONS Anthropometric and metabolic indicators appear to offer good predictive power for insulin resistance in children between 7 and 11 years old, employing the cutoff points with the best balance between sensitivity and specificity of the predictive technique.

Genomic Ancestry, Self-Reported “Color” and Quantitative Measures of Skin Pigmentation in Brazilian Admixed Siblings

A current concern in genetic epidemiology studies in admixed populations is that population stratification can lead to spurious results. The Brazilian census classifies individuals according to self-reported “color”, but several studies have demonstrated that stratifying according to “color” is not a useful strategy to control for population structure, due to the dissociation between self-reported “color” and genomic ancestry. We report the results of a study in a group of Brazilian siblings in which we measured skin pigmentation using a reflectometer, and estimated genomic ancestry using 21 Ancestry Informative Markers (AIMs). Self-reported “color”, according to the Brazilian census, was also available for each participant. This made it possible to evaluate the relationship between self-reported “color” and skin pigmentation, self-reported “color” and genomic ancestry, and skin pigmentation and genomic ancestry. We observed that, although there were significant differences between the three “color” groups in genomic ancestry and skin pigmentation, there was considerable dispersion within each group and substantial overlap between groups. We also saw that there was no good agreement between the “color” categories reported by each member of the sibling pair: 30 out of 86 sibling pairs reported different “color”, and in some cases, the sibling reporting the darker “color” category had lighter skin pigmentation. Socioeconomic status was significantly associated with self-reported “color” and genomic ancestry in this sample. This and other studies show that subjective classifications based on self-reported “color”, such as the one that is used in the Brazilian census, are inadequate to describe the population structure present in recently admixed populations. Finally, we observed that one of the AIMs included in the panel (rs1426654), which is located in the known pigmentation gene SLC24A5, was strongly associated with skin pigmentation in this sample.

The influence of intense intermittent versus moderate continuous exercise on postprandial lipemia

INTRODUCTION: Postprandial lipemia is characterized by an increased concentration of circulating lipids after fat intake and is an independent risk factor for cardiovascular disease. Exercise is known to reduce postprandial lipemia and its negative clinical outcomes. OBJECTIVE: This study investigated the effect of intense intermittent versus moderate continuous exercise using the same energy expenditure in postprandial lipemia. MATERIALS AND METHODS: Twenty healthy men (aged 21.5±3.5 years) performed a random sequence of either rest or 500 Kcal tests separated by a minimum 48 h interval as follows: (a) no exercise (control), (b) intense intermittent exercise, or (c) moderate continuous exercise. Each test series was completed 30 min before ingestion of a high-fat meal (1 g fat/kg). Venous blood was collected before and at 1, 2, 3 and 4 hours after the high-fat meal. Postprandial lipemia was assessed using the area under the curve approach as well as a kinetic profile of mean lipid variables. Statistical significance was tested at the p≤0.05 level. RESULTS: With both statistical approaches, intense intermittent and moderate continuous exercises were both effective in reducing postprandial triglycerides; however, only intense intermittent exercise reduced the levels of postprandial very low density lipoprotein. Intense intermittent and continuous exercise produced lower levels of insulinemia using the area under the curve analysis only. CONCLUSION: Intense intermittent or continuous exercise with an energy expenditure of 500 kcal completed 30 min before ingestion of high-fat meal reduced postprandial lipid levels to different levels in physically active men. Understanding these relevant differences will enable clinicians to provide the best exercise prescription for patients.

Predição da resistência à insulina em crianças: indicadores antropométricos e metabólicos

OBJECTIVE: To predict insulin resistance in children based on anthropometric and metabolic indicators by analyzing the sensitivity and specificity of different cutoff points. METHODS: A cross-sectional study was carried out of 109 children aged 7 to 11 years, 55 of whom were obese, 23 overweight and 31 well-nourished, classified by body mass index (BMI) for age. Measurements were taken to determine BMI, waist and hips circumferences, waist circumference/hip circumference ratio, conicity index and body fat percentage (dual emission X-ray absorptiometry). Fasting blood samples were taken to measure triglyceridemia, glycemia and insulinemia. Insulin resistance was evaluated by the glycemic homeostasis method, taking the 90th percentile as the cutoff point. Receiver operating characteristic curves were analyzed to a 95% confidence interval in order to identify predictors of glycemic homeostasis, and sensitivity and specificity were then calculated. RESULTS: After analysis of the area under the receiver operating characteristic curve (confidence interval), indicators that demonstrated the power to predict insulin resistance were, in the following order: insulinemia = 0.99 (0.99-1.00), 18.7 µU×mL-1; body fat percentage = 0.88 (0.81-0.95), 41.3%; BMI = 0.90 (0.83-0.97), 23.69 kg×m2-¹; waist circumference= 0.88 (0.79-0.96), 78.0 cm; glycemia = 0.71 (0.54-0.88), 88.0 mg×dL-1; triglyceridemia = 0.78 (0.66-0.90), 116.0 mg×dL-1 and conicity index = 0.69 (0.50-0.87), 1.23 for the whole sample; and were: insulinemia = 0.99 (0.98-1.00), 19.54 µU×mL-1; body fat percentage = 0.76 (0.64-0.89), 42.2%; BMI = 0.78 (0.64-0.92), 24.53 kg×m2-¹; waist circumference = 0.77 (0.61-0.92), 79.0 cm and triglyceridemia = 0.72 (0.56-0.87), 127.0 mg×dL-1, for the obese subgroup. CONCLUSIONS: Anthropometric and metabolic indicators appear to offer good predictive power for insulin resistance in children between 7 and 11 years old, employing the cutoff points with the best balance between sensitivity and specificity of the predictive technique.

Association of body mass index and insulin resistance with metabolic syndrome in Brazilian children

La obesidad en asociacion con la hipertension, dislipidemia e hiperglicemia compone el sindrome metabolico (SM), un conjunto bien reconocido de factores de riesgo para el desarrollo de la diabetes tipo 2 y enfermedad cardiovascular (DCV)1. Diversos estudios han sugerido que el SM tiene inicio en edad precoz2-7. Aunque la definicion del SM en ninos y adolescentes es controvertida8, el agrupamiento de multiples factores de riesgo cardiovasculares similares a los observados en adultos9 ha sido observado en la ninez, persistiendo hasta la edad adulta10.BACKGROUND The clustering of cardiovascular risk factors called metabolic syndrome occurs in both children and adults. Insulin resistance and obesity are usual parts of the picture, but their joint effects on the onset of the syndrome remains somewhat debatable. OBJECTIVE The purpose of the current study was to examine the relationship of the body mass index (BMI) and insulin resistance with the metabolic syndrome (MS) in children. METHODS We studied 109 children, 55 boys and 54 girls, between 7 and 11 years of age (55 obese, 23 overweight and 31 controls). The weight status of each child was defined based on BMI/age ratio. Blood glucose, HDL, triglycerides and insulin were measured using fasting samples. Blood pressure was measured twice. The metabolic syndrome was defined according to the NCEP ATP III criteria. RESULTS The diagnosis of the MS was only found in obese children. The greater frequency of MS and of many of its components have been found in the children classified above the third quartile of the HOMA index, which is consistent with an association between insulin resistance and cardiovascular risk factors among the Brazilian children. CONCLUSION The present study shows that obesity and insulin resistance are likely to play a role in the development of cardiovascular risk factors in children since the prevalence of classic risk factors was higher in the upper BMI and HOMA percentiles.

Prediction of metabolic syndrome in children through anthropometric indicators

FUNDAMENTO: Debido a la necesidad de medir las variables antropometricas, bioquimicas y hemodinamicas para el diagnostico del sindrome metabolico, se percibe la dificultad de la evaluacion de grandes poblaciones, principalmente en ninos, provocada por el dificil acceso y por el caracter invasivo. Es urgente la necesidad de desarrollar formas diagnosticas de facil aplicacion, buena precision y bajo costo, con la finalidad de predecir el sindrome metabolico ya en las edades iniciales. OBJETIVO: Verificar la prevalencia del sindrome metabolico en ninos y probar los indicadores antropometricos con capacidad predictiva. METODOS: Estudio transversal realizado con 109 ninos, de 7 a 11 anos. Se utilizo el criterio National Cholesterol Education Program para el diagnostico del sindrome metabolico, adaptado a la edad. Como posibles predictores, fueron probados: indice de masa corporal (IMC), circunferencia de la cintura (CC), relacion cintura/cadera (RCC), indice de conicidad (indice C) y el porcentual de grasa corporal. RESULTADOS: La prevalencia del sindrome metabolico fue de 13,3% y 36% para ninos y ninas, respectivamente. Los principales indicadores antropometricos fueron: IMC = 0,81 (0,69 - 0,94), CC = 0,79 (0,64 - 0,94), grasa corporal = 0,79 (0,66 - 0,92) y RCC = 0,37 (0,21 - 0,54). CONCLUSION: Fueron considerados factores predictores del sindrome metabolico la CC superior a 78 cm, la grasa corporal superior a 41% y el IMC superior a 24,5 kg/m2. El indice C y la RCC no fueron considerados predictores.BACKGROUND Because of the need to measure anthropometric, biochemical and hemodynamic variables for the diagnosis of metabolic syndrome, we realize how difficult it is to analyze large populations, especially children, due to the poor accessibility and the invasive character. There is an urgent need to develop easy-to-use, accurate and low-cost diagnostic tools in order to predict metabolic syndrome at early ages. OBJECTIVE To verify the prevalence of metabolic syndrome in children and to test predictive anthropometric indicators. METHODS Cross-sectional study conducted among 109 children aged 7 to 11 years. The age-adjusted National Cholesterol Education Program definition was used for the diagnosis of metabolic syndrome. The following parameters were tested as possible predictors: body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), conicity index (C index), and body fat percentage. RESULTS The prevalence of metabolic syndrome was 13.3% and 36% for boys and girls, respectively. The main anthropometric indicators were: BMI = 0.81 (0.69 - 0.94), WC = 0.79 (0.64 - 0.94), body fat = 0.79 (0.66 - 0.92) and WHR = 0.37 (0.21 - 0.54). CONCLUSION WC higher than 78 cm, body fat higher than 41%, and BMI higher than 24.5 kg/m² were considered predictors of metabolic syndrome. The C index and WHR were not considered predictors.

Predição da síndrome metabólica em crianças por indicadores antropométricos

FUNDAMENTO: Debido a la necesidad de medir las variables antropometricas, bioquimicas y hemodinamicas para el diagnostico del sindrome metabolico, se percibe la dificultad de la evaluacion de grandes poblaciones, principalmente en ninos, provocada por el dificil acceso y por el caracter invasivo. Es urgente la necesidad de desarrollar formas diagnosticas de facil aplicacion, buena precision y bajo costo, con la finalidad de predecir el sindrome metabolico ya en las edades iniciales. OBJETIVO: Verificar la prevalencia del sindrome metabolico en ninos y probar los indicadores antropometricos con capacidad predictiva. METODOS: Estudio transversal realizado con 109 ninos, de 7 a 11 anos. Se utilizo el criterio National Cholesterol Education Program para el diagnostico del sindrome metabolico, adaptado a la edad. Como posibles predictores, fueron probados: indice de masa corporal (IMC), circunferencia de la cintura (CC), relacion cintura/cadera (RCC), indice de conicidad (indice C) y el porcentual de grasa corporal. RESULTADOS: La prevalencia del sindrome metabolico fue de 13,3% y 36% para ninos y ninas, respectivamente. Los principales indicadores antropometricos fueron: IMC = 0,81 (0,69 - 0,94), CC = 0,79 (0,64 - 0,94), grasa corporal = 0,79 (0,66 - 0,92) y RCC = 0,37 (0,21 - 0,54). CONCLUSION: Fueron considerados factores predictores del sindrome metabolico la CC superior a 78 cm, la grasa corporal superior a 41% y el IMC superior a 24,5 kg/m2. El indice C y la RCC no fueron considerados predictores.BACKGROUND Because of the need to measure anthropometric, biochemical and hemodynamic variables for the diagnosis of metabolic syndrome, we realize how difficult it is to analyze large populations, especially children, due to the poor accessibility and the invasive character. There is an urgent need to develop easy-to-use, accurate and low-cost diagnostic tools in order to predict metabolic syndrome at early ages. OBJECTIVE To verify the prevalence of metabolic syndrome in children and to test predictive anthropometric indicators. METHODS Cross-sectional study conducted among 109 children aged 7 to 11 years. The age-adjusted National Cholesterol Education Program definition was used for the diagnosis of metabolic syndrome. The following parameters were tested as possible predictors: body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), conicity index (C index), and body fat percentage. RESULTS The prevalence of metabolic syndrome was 13.3% and 36% for boys and girls, respectively. The main anthropometric indicators were: BMI = 0.81 (0.69 - 0.94), WC = 0.79 (0.64 - 0.94), body fat = 0.79 (0.66 - 0.92) and WHR = 0.37 (0.21 - 0.54). CONCLUSION WC higher than 78 cm, body fat higher than 41%, and BMI higher than 24.5 kg/m² were considered predictors of metabolic syndrome. The C index and WHR were not considered predictors.

Associação do índice de massa corporal e da resistência à insulina com síndrome metabólica em crianças brasileiras

La obesidad en asociacion con la hipertension, dislipidemia e hiperglicemia compone el sindrome metabolico (SM), un conjunto bien reconocido de factores de riesgo para el desarrollo de la diabetes tipo 2 y enfermedad cardiovascular (DCV)1. Diversos estudios han sugerido que el SM tiene inicio en edad precoz2-7. Aunque la definicion del SM en ninos y adolescentes es controvertida8, el agrupamiento de multiples factores de riesgo cardiovasculares similares a los observados en adultos9 ha sido observado en la ninez, persistiendo hasta la edad adulta10.BACKGROUND The clustering of cardiovascular risk factors called metabolic syndrome occurs in both children and adults. Insulin resistance and obesity are usual parts of the picture, but their joint effects on the onset of the syndrome remains somewhat debatable. OBJECTIVE The purpose of the current study was to examine the relationship of the body mass index (BMI) and insulin resistance with the metabolic syndrome (MS) in children. METHODS We studied 109 children, 55 boys and 54 girls, between 7 and 11 years of age (55 obese, 23 overweight and 31 controls). The weight status of each child was defined based on BMI/age ratio. Blood glucose, HDL, triglycerides and insulin were measured using fasting samples. Blood pressure was measured twice. The metabolic syndrome was defined according to the NCEP ATP III criteria. RESULTS The diagnosis of the MS was only found in obese children. The greater frequency of MS and of many of its components have been found in the children classified above the third quartile of the HOMA index, which is consistent with an association between insulin resistance and cardiovascular risk factors among the Brazilian children. CONCLUSION The present study shows that obesity and insulin resistance are likely to play a role in the development of cardiovascular risk factors in children since the prevalence of classic risk factors was higher in the upper BMI and HOMA percentiles.

Efeitos da natação e do treinamento resistido na densidade mineral óssea de mulheres idosas

Impact exercises like walking, jumping, running and resistance exercises are largely used to prevent bone loss in older women; however, few studies report the benefits of swimming to bone tissue. Therefore, the purpose of this study was to compare the effects of swimming with resistance training on bone mineral density (BMD) of older women. Twenty-three women with mean age of 63.9 ± 6.49 years were divided in two groups: 1) Swimming group (SWM, n = 13) trained at intensity between 60 and 90% of heart hate reserve; 2) Resistance training group (RT, n = 10) trained the main muscular groups with three sets at 80% of 1RM. Both groups trained 3 days/week, one hour per session, during six months. Femoral neck and lumbar spine (L2 L3 L4) BMD were assessed by DXA before (T0) and after six months (T6) of training. Results showed that mean BMD at lumbar spine at T0 (0.9250 ± 0.1506g/cm2) and T6 (0.9303 ± 0.1269g/cm2) for SWM, and at T0 (0.9739/ ±/ 0.1249g/cm2) and T6 (0.9737 ± 0.1317g/cm2) for RT were not different when inter and intra-compared. Similarly, there were no differences in femoral neck BMD at T0 (0.7784 ± 0.1523g/cm2) and T6 (0.7905±0.1610g/cm2) for SWM, or T0 (0.7546 ± 0.1360g/cm2) and T6 (0.7522 ± 0.1421g/cm2) for RT. The results of this study showed no difference in BMD between RT and SWM after six months of training. Additionally, neither RT nor SWN produced significant increases in BMD of older women.