Human gut microbiome viewed across age and geography.

Gut microbial communities represent one source of human genetic and metabolic diversity. To examine how gut microbiomes differ among human populations, here we characterize bacterial species in fecal samples from 531 individuals, plus the gene content of 110 of them. The cohort encompassed healthy children and adults from the Amazonas of Venezuela, rural Malawi and US metropolitan areas and included mono- and dizygotic twins. Shared features of the functional maturation of the gut microbiome were identified during the first three years of life in all three populations, including age-associated changes in the genes involved in vitamin biosynthesis and metabolism. Pronounced differences in bacterial assemblages and functional gene repertoires were noted between US residents and those in the other two countries. These distinctive features are evident in early infancy as well as adulthood. Our findings underscore the need to consider the microbiome when evaluating human development, nutritional needs, physiological variations and the impact of westernization.

Tetracycline resistance genes acquired at birth.

Newborns acquire their first microbiota at birth. Maternal vaginal or skin bacteria colonize newborns delivered vaginally or by C-section, respectively (Dominguez-Bello et al. 2010 #884). We aimed to determine differences in the presence of four tetracycline (tet) resistance genes, in the microbes of ten newborns and in the mouth and vagina of their mothers, at the time of birth. DNA was amplified by PCR with primers specific for [tet(M), tet(O), tet(Q), and tet(W)]. Maternal vaginas harbored all four tet resistance genes, but most commonly tet(M) and tet(O) (63 and 38 %, respectively). Genes coding for tet resistance differed by birth mode, with 50 % of vaginally delivered babies had tet(M) and tet(O) and 16 and 13 % of infants born by C-section had tet(O) and tet(W), respectively. Newborns acquire antibiotic resistance genes at birth, and the resistance gene profile varies by mode of delivery.

Delivery mode shapes the acquisition and structure of the initial microbiota across multiple body habitats in newborns.

Upon delivery, the neonate is exposed for the first time to a wide array of microbes from a variety of sources, including maternal bacteria. Although prior studies have suggested that delivery mode shapes the microbiota's establishment and, subsequently, its role in child health, most researchers have focused on specific bacterial taxa or on a single body habitat, the gut. Thus, the initiation stage of human microbiome development remains obscure. The goal of the present study was to obtain a community-wide perspective on the influence of delivery mode and body habitat on the neonate's first microbiota. We used multiplexed 16S rRNA gene pyrosequencing to characterize bacterial communities from mothers and their newborn babies, four born vaginally and six born via Cesarean section. Mothers' skin, oral mucosa, and vagina were sampled 1 h before delivery, and neonates' skin, oral mucosa, and nasopharyngeal aspirate were sampled <5 min, and meconium <24 h, after delivery. We found that in direct contrast to the highly differentiated communities of their mothers, neonates harbored bacterial communities that were undifferentiated across multiple body habitats, regardless of delivery mode. Our results also show that vaginally delivered infants acquired bacterial communities resembling their own mother's vaginal microbiota, dominated by Lactobacillus, Prevotella, or Sneathia spp., and C-section infants harbored bacterial communities similar to those found on the skin surface, dominated by Staphylococcus, Corynebacterium, and Propionibacterium spp. These findings establish an important baseline for studies tracking the human microbiome's successional development in different body habitats following different delivery modes, and their associated effects on infant health.

The bacterial microbiota in the oral mucosa of rural Amerindians.

The oral microbiota plays an important role in buccal health and in diseases such as periodontitis and meningitis. The study of the human oral bacteria has so far focused on subjects from Western societies, while little is known about subjects from isolated communities. This work determined the composition of the oral mucosa microbiota from six Amazon Amerindians, and tested a sample preservation alternative to freezing. Paired oral swabs were taken from six adults of Guahibo ethnicity living in the community of Platanillal, Amazonas State, Venezuela. Replicate swabs were preserved in liquid nitrogen and in Aware Messenger fluid (Calypte). Buccal DNA was extracted, and the V2 region of the 16S rRNA gene was amplified and pyrosequenced. A total of 17 214 oral bacterial sequences were obtained from the six subjects; these were binned into 1034 OTUs from 10 phyla, 30 families and 51 genera. The oral mucosa was highly dominated by four phyla: Firmicutes (mostly the genera Streptococcus and Veillonella), Proteobacteria (mostly Neisseria), Bacterioidetes (Prevotella) and Actinobacteria (Micrococcineae). Although the microbiota were similar at the phylum level, the Amerindians shared only 62 % of the families and 23 % of the genera with non-Amerindians from previous studies, and had a lower richness of genera (51 vs 177 reported in non-Amerindians). The Amerindians carried unidentified members of the phyla Bacteroidetes, Firmicutes and Proteobacteria and their microbiota included soil bacteria Gp1 (Acidobacteriaceae) and Xylanibacter (Prevotellaceae), and the rare genus Phocoenobacter (Pasteurellaceae). Preserving buccal swabs in the Aware Messenger oral fluid collection device substantially altered the bacterial composition in comparison to freezing, and therefore this method cannot be used to preserve samples for the study of microbial communities.

Helicobacter pylori and intestinal parasites are not detrimental to the nutritional status of Amerindians.

Gastrointestinal parasites have evolved with humans and colonize many asymptomatic subjects. We investigated the influence of microbial gastrointestinal colonization on the nutritional status of rural Amerindians (40 males and 61 females). Helicobacter pylori was detected by 13C-breath test, and intestinal parasites were detected in fecal specimens. Body morphometry and bioelectrical impedance measurements were measured. Although Amerindians showed low height and weight for age, they had an adequate body mass index, morphometric parameters, and cell mass. Intestinal parasites were detected in 99% of the subjects, with no detrimental effect on nutritional parameters. Helicobacter pylori was present in 82% of adults and half the children, and was positively correlated with improved nutritional status. Despite the high prevalence of gastrointestinal microbes often associated with disease, the studied population of Amerindians had a body morphometry and composition indicative of good nutritional status, and improved in children positive for gastric H. pylori.

[Manaca, sweet potato and yam: possible substitutes of wheat in foods for two ethnic population in Venezuelan Amazon]. / Manaca, batata y ñame: posibles sustitutos del trigo en alimentos para dos etnias del Amazonas venezolano.

In this study, flours from manaca or acai (Euterpe oleracea Mart), sweet potato (Ipomea batatas), and yam (Dioscorea spp.), species grown in the Venezuelan Amazon, were obtained. The proximal composition, water activity (a(w)), Fe, Ca, Zn, Mg, Cu, Na and K content were determined for the flours of manaca, sweet potato and yam. These flours were used as ingredients of products for the inhabitants of the indigenous populations of the Venezuelan Amazon (Piaroa and Hiwi). Two types of products that traditionally contain wheat flour in their formulation (ingredient they know by transculturation) were formulated; an attempt to substitute it totally or partially by the manaca, sweet potato and/or yam flours was made. For the selection of the products to be formulated, the preferences and eating habits of the indigenous communities and ease and simplicity of the preparations to be developed, were considered. The two products formulated were cookies and "small cakes". To decide on the formulation(s) of the final product(s), sensorial evaluations were made in the laboratory and in the indigenous communities Piaroa and Hiwi. High fat content (16%), dietetic fiber (59.7%) and iron (25 mg / 100 g) in manaca or acai flour were remarkable. Two types of cookies and two of "small cakes" were equally accepted by the indigenous communities. Cookies supply a high iron amount (about 24%). The feasibility of substituting the wheat flour by manaca, sweet potato and yam flour in products accepted by two ethnic populations of the Venezuelan Amazon was demonstrated.

Effect of influenza-induced fever on human bioimpedance values.

BACKGROUND AND AIMS: Bioelectrical impedance analysis (BIA) is a widely used technique to assess body composition and nutritional status. While bioelectrical values are affected by diverse variables, there has been little research on validation of BIA in acute illness, especially to understand prognostic significance. Here we report the use of BIA in acute febrile states induced by influenza. METHODS: Bioimpedance studies were conducted during an H1N1 influenza A outbreak in Venezuelan Amerindian villages from the Amazonas. Measurements were performed on 52 subjects between 1 and 40 years of age, and 7 children were re-examined after starting Oseltamivir treatment. Bioelectrical Impedance Vector Analysis (BIVA) and permutation tests were applied. RESULTS: For the entire sample, febrile individuals showed a tendency toward greater reactance (p=0.058) and phase angle (p=0.037) than afebrile individuals, while resistance and impedance were similar in the two groups. Individuals with repeated measurements showed significant differences in bioimpedance values associated with fever, including increased reactance (p<0.001) and phase angle (p=0.007), and decreased resistance (p=0.007) and impedance (p<0.001). CONCLUSIONS: There are bioelectrical variations induced by influenza that can be related to dehydration, with lower extracellular to intracellular water ratio in febrile individuals, or a direct thermal effect. Caution is recommended when interpreting bioimpedance results in febrile states.

The microbiome of uncontacted Amerindians.

Most studies of the human microbiome have focused on westernized people with life-style practices that decrease microbial survival and transmission, or on traditional societies that are currently in transition to westernization. We characterize the fecal, oral, and skin bacterial microbiome and resistome of members of an isolated Yanomami Amerindian village with no documented previous contact with Western people. These Yanomami harbor a microbiome with the highest diversity of bacteria and genetic functions ever reported in a human group. Despite their isolation, presumably for >11,000 years since their ancestors arrived in South America, and no known exposure to antibiotics, they harbor bacteria that carry functional antibiotic resistance (AR) genes, including those that confer resistance to synthetic antibiotics and are syntenic with mobilization elements. These results suggest that westernization significantly affects human microbiome diversity and that functional AR genes appear to be a feature of the human microbiome even in the absence of exposure to commercial antibiotics. AR genes are likely poised for mobilization and enrichment upon exposure to pharmacological levels of antibiotics. Our findings emphasize the need for extensive characterization of the function of the microbiome and resistome in remote nonwesternized populations before globalization of modern practices affects potentially beneficial bacteria harbored in the human body.

Distinct cutaneous bacterial assemblages in a sampling of South American Amerindians and US residents.

The human skin harbors complex bacterial communities. Prior studies showing high inter-individual variation focused on subjects from developed countries. We therefore compared cutaneous bacterial communities of Amerindians in the Venezuelan Amazon with subjects in the United States. Forearm skin specimens were studied from healthy Amerindians in Platanillal village in Amazonas State, and from healthy persons in New York and Colorado. All skin sampling used similar swab/buffer techniques. Multiplexed V2-targeted 16S rRNA gene pyrosequencing yielded high quality sequences from 112 samples. The results show 20 phyla, with three (Proteobacteria, Firmicutes, Actinobacteria) predominating. US residents and Venezuelan Amerindians had significantly different forearm skin bacterial community compositions, with United States dominated by Propionibacterium. Among the Amerindians, there was a deep split based on bacterial community membership, with 30 and 42 samples, respectively, falling into each of the two groups, not associated with age, gender, or body mass index. One Amerindian group had diversity similar to the United States, but was dominated by Staphylococcus rather than Propionibacterium. The other Amerindian group was significantly more diverse and even than the US or the other Amerindian group, and featured a broad range of Proteobacteria. The results provide evidence that ethnicity, lifestyle and/or geography are associated with the structure of human cutaneous bacterial communities.

Household social determinants of ascariasis and trichuriasis in North Central Venezuela.

Ascariasis and trichuriasis are highly prevalent parasitoses in tropical countries caused by Ascaris lumbricoides and Trichuris trichiura, respectively. Their prevalence is associated with poor sanitation and hygiene, among other biological and social factors. In this study, the associations of household social determinants with these soil-transmitted helminthiases in North Central Venezuela was assessed in the context of a National Study on Human Growth and Development (SENACREDH). This was a probabilistic, stratified, cross-sectional survey with a sample of 3388 individuals that weighted represents 4 675 433 inhabitants from the region. The prevalence of ascariasis and trichuriasis was 3.73% and 1.13%, respectively. In the univariate and multivariate analyses, these prevalences were significantly higher in those living in vulnerable houses [adjusted OR (AOR) = 1.479, 95% CI 1.428-1.532; and AOR = 10.519, 95% CI 9.971-11.097, respectively], houses located in rural areas (AOR = 2.067, 95% CI 2.035-2.101; and AOR = 1.918, 95% CI 1.868-1.970, respectively) and houses with a soil floor (AOR = 5.027, 95% CI 4.895-5.162; and AOR = 5.190, 95% CI 4.944-5.448, respectively), among other factors. People living in rural households with inappropriate building materials, insufficient basic public services such as water and waste disposal, and surrounding disease-prone environments are at higher risk of acquiring A. lumbricoides and T. trichiura infections.

[Differences between observed and estimated by hematocrit hemoglobin and its relevance in the diagnosis of anemia among coastal population in Venezuela: analysis of the second national study of human growth and development (SENACREDH)]. / Diferencias entre la hemoglobina observada y estimada por hematocrito y su importancia en el diagnóstico de anemia en población costera venezolana: análisis del segundo estudio nacional de crecimiento y desarrollo humano (SENACREDH).

OBJECTIVES: To evaluate the differences between the observed hemoglobin levels and those estimated based on hematocrit in the context of the 2nd National Study of Human Growth and Development of the Venezuelan Population (SENACREDH). MATERIALS AND METHODS: 6,004 individuals were chosen by a probabilistic multistage cluster sampling representing 7,286,781 inhabitants from North Central Coastal area (Vargas, Carabobo, Capital District, Aragua and Miranda). Means of observed and estimated hemoglobin (hematocrit/3) were compared, using t test for related samples and linear regression. RESULTS: Mean difference between the values of observed and estimated hemoglobin was -0.3446 ±0.0002 (p<0.001); significantly overestimating the hemoglobin values. Regression models of hemoglobin on hematocrit showed an r2=0,87. In order to correct the estimation, we propose a new formula for calculating hemoglobin based on haematocrit values: estimated hemoglobin=(Haematocrit/3.135)+ 0.257. CONCLUSIONS: There is an overestimation of hemoglobin levels from hematocrit levels and therefore an underestimation of the prevalence of anemia; however, a high positive correlation between them was found, allowing modeling for achieving a better estimation of the hemoglobin from the hematocrit value.

Diferencias entre la hemoglobina observada y estimada por hematocrito y su importancia en el diagnóstico de anemia en población costera venezolana: análisis del segundo estudio nacional de crecimiento y desarrollo humano (SENACREDH) / Differences between observed and estimated by hematocrit hemoglobin and its relevance in the diagnosis of anemia among coastal population in Venezuela: analysis of the second national study of human growth and development (SENACREDH)

Objetivos. Evaluar las diferencias entre el valor de hemoglobina observada y el valor estimado a partir del hematocrito en el marco del Segundo Estudio Nacional de Crecimiento y Desarrollo Humano de la Población Venezolana (SENACREDH) en el eje centro norte costero del país. Materiales y métodos. Por medio de un muestreo probabilístico multietápico por conglomerados se seleccionó un total de 6004 sujetos que representan 7 286 781 habitantes del eje Centro Norte Costero (Vargas, Carabobo, Distrito Capital, Aragua y Miranda). Se compararon medias de la hemoglobina observada y hemoglobina estimada (hematocrito/3), usando la prueba t para muestras relacionadas. Se realizaron regresiones lineales entre hemoglobina observada y hematocrito. Resultados. Se observó que el promedio de las diferencias entre la asignadas a la hemoglobina observada y la estimada por el hematocrito fue de -0,3446 ± 0,0002 (p<0,001); sobreestimando significativamente los valores de hemoglobina. Modelos de regresión del hematocrito para la hemoglobina arrojan un valor de r2=0,87. Al corregir la estimación, se propone una nueva forma de calcularla, con la siguiente fórmula: hemoglobina estimada = (hematocrito/3,135) + 0,257. Conclusiones. Existe una sobreestimación de hemoglobina y, por tanto, subestimación de la prevalencia de anemia a partir del hematocrito; sin embargo, se encuentra una alta correlación entre ambos componentes que permite modelar una mejor estimación de la hemoglobina a partir del hematocrito.

Objectives. To evaluate the differences between the observed hemoglobin levels and those estimated based on hematocrit in the context of the 2nd National Study of Human Growth and Development of the Venezuelan Population (SENACREDH). Materials and methods. 6,004 individuals were chosen by a probabilistic multistage cluster sampling representing 7,286,781 inhabitants from North Central Coastal area (Vargas, Carabobo, Capital District, Aragua and Miranda). Means of observed and estimated hemoglobin (hematocrit/3) were compared, using t test for related samples and linear regression. Results. Mean difference between the values of observed and estimated hemoglobin was -0.3446 ±0.0002 (p<0.001); significantly overestimating the hemoglobin values. Regression models of hemoglobin on hematocrit showed an r2=0,87. In order to correct the estimation, we propose a new formula for calculating hemoglobin based on haematocrit values: estimated hemoglobin=(Haematocrit/3.135)+ 0.257. Conclusions: There is an overestimation of hemoglobin levels from hematocrit levels and therefore an underestimation of the prevalence of anemia; however, a high positive correlation between them was found, allowing modeling for achieving a better estimation of the hemoglobin from the hematocrit value.

Aspectos clínico-epidemiologícos de la presión arterial en población pediátrica del eje centro norte costero de Venezuela evaluada en el SENACREDH: III: variables antropométricas y bioquímicas asociadas a la presión arterial / Clinical epidemiological aspects of the blood pressure in a paediatric population from the venezuelan central north seaside axis evaluated in the SENACREDEH: III: anthropometrical and biochemical variables associated to the blood pressure

En el contexto del Segundo Estudio Nacional de Crecimiento y desarrollo Humano de la República Bolívariana de Venezuela (SENACREDH), se evaluó la presión arterial en 4017 individuos de 6,00 a 19,99 años en los estados Carabobo, Aragua, Miranda, Vargas y Distrito Capical. Se realizaron modelos de regresión múltiple con variables antropométricas y bioquímicas como predictoras de la presión arterial. La prevalencia de valores de presión arterial mayor igual P90 (Pre-hipertensión arterial e hipertensión arterial) sistólica fue 4,36% y la diastólica aislada fue 4,62%. Aquellos con exceso de índice de masa corporal presentaron prevalencias significativamente mayores de presión arterial sistólica, P90 a <95 (6,3%), P95 a igual P99 (0,9%) en comparación con aquellos con indice de masa corporal normal P90 a <95(1,2%), P95 a <99 (0,7%), > igual P99 (0,3%). Se encontraron resultados similares para la presión arterial diastólica. Aquellos con índice colesterol total/HDL > igual 4,0 presentaron prevalencias significativamente mayores de presión arterial sistólica, P90 a <95 (3,1%), P95 a < P99 (1,7%), > igual P99 (0,6%) en comparación con aquellos con < 4,0 P90 a < P95 (1,7%), P95 a > P99 (1,1%), > igual P99 (0,3%). Se encontraron resultados similares para la presión arterial diastólica. En la regresión múltiple, el índice de masa corporal y la circunferencia de cintura son predictores de la presión arterial sistólica (P<0,001). La circunferencia de cintura lo es también para la presión arterial diastólica (P<0,001). Estas variables se asocian significativamente como predictores de la presión arterial, por lo cual su medición en la evaluación integral cardiovascular debe realizarse no solo para efectos de clasificación sino de potencial estimación del riesgo de hipertensión arterial.

In the context of the Second National Study of Human Growth and Development of the Bolivarian Republic, of Venezuela (SENACREDH), blood pressure was evaluated in 4017 individuals 6.00 to 19.90 years-old from Carabobo, Aragua, Miranda, Vargas state and Capital District. Multiple regression models with anthropometrical and biochemical variables for the blood pressure were done. Prevalence of isolated blood pressure > igual P90 (Prehypertension and hypertension) systolic was 4.36% and diastolic 4.62%. Those with body mass index in excess presented significantly higher prevalences of systolic blood pressure. P90 to igual P99 (0.9%) compared to those with a normal body mass index P90 to igual P99 (0.3%). Similar findings were found for diastolic blood pressure. Those with a total cholesterol/HDL index > igual 4.0 presented significantly higher prevalences of systolic blood pressure, P90 to igual P99 (0.6%) compared to those with <4.0 P90 to igual P99 (0.3%). Similar findings were found for diastolic blood pressure. At multiple regression body mass index and waist circumference are predictor of systolic blood pressure (P<0.001). Waist circunference also for diastolic blood pressure (P<0.001). These variables are significantly associated as predictors of blood pressure, then its assessment in the untegral cardiovascular evaluation should be done not just for classification but also as potential risk estimation for hypertension.

Aspectos clinico-epidemiológicos de la presion arterial en población pediátrica del eje centro norte costero de Venezuela evaluada en el SENACREDH: I. prevalencia de valores en rango de pre-hipertensión e hipertensión arterial / Clinical-epidemiological aspects of the arteial pressure in the paediatric population from the Venezuela northern seaside axis evaluated by the SENACREDH: I. prevalence of the values in the range of prehypertension and hypertension

En el contesto del Segundo Estudio Nacional de Crecimiento y Desarrollo Humano de la Republica Bolivariana de Venezuela (SENACREDH). Se evaluó la presión arterial en 4.017 individuos de 6,00 a 19,99 años en los estados Carabobo, Aragua, Miranda, Vargas y Distrito Capital, los cuales representaron para la expansión de los datos 1.340.738 habitantes; 54,89% del sexo masculino. La prevalencia de valores de presión arterial > igual P90 sistólica aislada fue 4,36% siendo significativamente mayor en masculinos (4,89%) que en femenino (3,7%) (p<0,05). Se estimaron alteraciones en los valores de la presión arterial en una proporción cercana a 5% de la población pediátrica de los estados evaluados, lo cual índica una estimación de aproximadamente 67.000, niñas y adolescentes de dicha región geográfica con valores en rango de prehipertensión e hipertensión arterial. Los hallazgos deben conducir a un incremente de estrategias de control y prevención de la hipertensión arterial en dichas poblaciones pediátricas

In the context of the Second National Study of Human Growth and Development of the Bolivarian Republic of Venezuela (SENACREDH), blood pressure was evaluated in 4.017 individuals 6.00 to 19.99 years-old from Carabobo, Aragua, Miranda, Vargas state and Capital District. They represented, for the weighted data. 1.340.738 pop; 54.89 males. Prevalence of isolated systolic BP values < igual P90 was 4.36% being significantly higher in males (4.89%) than in females (3.7%) (P<0.05). Alterations in blood pressure values were estimated in a proportion close to 5% of pediatric population in the states assessed. This indicates an estimation of approximately 67.000 children and adolescents from that geographical region with values in range of prehypertension and hypertension. Those findings should lead to an increase in the control and prevention strategies for high pressure in those pediatric populations

Aspectos clínico-epidemiológicos de la presión arterial en población pediátrica del eje centro norte costero de Venezuela evaluación en el SENACREDH: II. diferencias en la presión arterial de acuerdo a estratos sociales / Clinical-epidemiological aspects of the arterial pressure in the paediatric population from the Venezuela northern seaside axis evaluated by the SENACREDH: II. differences in the arterial pressure according to social strata

En el contexto del segundo estudio Nacional de crecimiento y desarrollo humano de la República Bolivariana de Venezuela (SENACREDH), se evaluó la presión arterial en 4017 individuos de 6,00 a 19,99 años en los estados Carabobo, aragua, Miranda, Vargas y Distrito Capital, los cuales representaron para la expansión de los datos 1340738 habitantes; 54,89% del sexo masculino. La prevalencia de valores de presión arterial > igual P90 (prehipertensión e hipertensión) sistólica aislada 4,36% y 4,62% para la diastólica. Al clasificar por estratos sociales, se encontró que los sujetos de los estratos I + II + III presentaron una prevalencia de presión arterial sistólica > igual P90 significativamente mayor, 5,4%, en comparación con los de estrato IV 4,2% y los del estreto V 3,8% (X²=965,4; P<0,001) (OR=1,35 [IC95% 1,32-1,38] I + II + III vs IV +V). Estos resultados indican que aquellos niños y niñas adolescentes de familias de estratos sociales altos (con condiciones sociales favorables) presentan 1,35 veces más valores de presión arterial sistólica en rangos que corresponden a prehipertensión e hipertensión arterial, en comparación con aquellos de estratos sociales bajos (con condiciones sociales desfavorables). Esto apunta a a la importancia de focalizar las estrategias de control y prevención de la hipertensión arterial en dichas poblaciones pediátricas en mayor riesgo

In the context of the second national study of human growth and development of the Bolivarian Republic of Venezuela (SENACREDH), blood pressure was evaluated in 4017 individuals 6.00 to 19.99 years-old from Carabobo, Aragua, Miranda, Vargas states and Capital District. They represented, for the weighted data, 1.340.738 pop; 54,89% males. Prevalence of isolated blood pressure values ­­> iqual P90 was 4.36% for systolic pressure and 4.62% for diastolic pressure. When those prevalences were adjusted social strata, those from I + II+ III strata presented blood pressure a > iqual P90 prevalence significantly higher, 5,4%, compared to those from IV stratum 4.2% and those fro V stratum 3.8% (X²=965.4; P<0.001) (OR=1.35 [IC 95% 1.32-1.381] I + II + III vs IV + V). These results indicate that those children and teenagers from high social strata families (with better living conditions) present 1.35 times more blood pressure values in ranges corresponding to prehypertension and hypertension, compared to those from low social strata (with less favorable living conditions). This leads to the importance of focus on control and prevention strategies in hypertension in those pediatric populations at higher risk