Resting Heart Rate is Associated with Blood Pressure in Male Children and Adolescents

Objectives To analyze the association between resting heart rate and blood pressure in male children and adolescents and to identify if this association is mediated by important confounders.Study design Cross-sectional study carried out with 356 male children and adolescents from 8 to 18 years old. Resting heart rate was measured by a portable heart rate monitor according to recommendations and stratified into quartiles. Blood pressure was measured with an electronic device previously validated for pediatric populations. Body fatness was estimated by a dual-energy x-ray absorptiometry.Results Obese subjects had values of resting heart rate 7.8% higher than nonobese (P = .001). Hypertensive children and adolescents also had elevated values of resting heart rate (P = .001). When the sample was stratified in nonobese and obese, the higher quartile of resting heart rate was associated with hypertension in both groups of children and adolescents.Conclusions This study confirms the existence of a relationship between elevated resting heart rate and increased blood pressure in a pediatric population, independent of adiposity, ethnicity and age. (J Pediatr 2011; 158:634-7).

Ambulatory blood pressure monitoring in children with obstructive sleep apnea and primary snoring

Objective: To evaluate the systemic blood pressure (BP) during daytime and nighttime in children with sleep breathing disorders (SBD) and compare parameters of BP in children with diagnosis of obstructive sleep apnea syndrome (OSA) to those one with primary snoring (PS).Methods: Children, both genders, aged from 8 to 12 years, with symptoms of SBD realized an overnight polysomnography followed by a 24 h recording of ambulatory BP.Results: All subjects presented with a history of snoring 7 nights per week. Children who have apnea/hipoapnea index >= four or a apnea index >= one presented a mean BP of 93 +/- 7 mmHg and 85 +/- 9 mmHg diurnal and nocturnal respectively whereas children who have a apnea/hipoapnea < four or a apnea index < one presented 90 +/- 7 mmHg and 77 +/- 2 mmHg. Eight children out of fourteen, from OSA group, lost the physiologic nocturnal dipping of the blood pressure. Among OSA children 57% were considered non-dippers. Two (16%) have presented absence of nocturnal dipping among children with primary snoring. The possibility of OSA children loosing physiologic blood pressure dipping was 6.66 higher than the possibilities of patients from PS group.Discussion: Our results indicate that children with sleep apnea syndrome exhibit a higher 24 h blood pressure when compared with those of primary snoring in form of decreased degree of nocturnal dipping and increased levels of diastolic and mean blood pressure, according to previous studies in literature. OSA in children seems to be associated to the development of hypertension or other cardiovascular disease. (C) 2012 Elsevier B.V. All rights reserved.

Women with TT genotype for eNOS gene are more responsive in lowering blood pressure in response to exercise

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

End-systolic pressure-diameter relation of the left ventricle during transient and sustained elevations of blood pressure

OBJECTIVE: To assess the effect of transient and sustained variations in cardiac load on the values of the end-systolic pressure-diameter relation (ESPDR) of the left ventricle. METHODS: We studied 13 dogs under general anesthesia and autonomic blockade. Variations of cardiac loads were done by elevation of blood pressure by mechanical constriction of the aorta. Two protocols were used in each animal: gradual peaking and decreasing pressure variation, the transient arterial hypertension protocol (TAH), and a quick and 10 min sustained elevation, the sustained arterial hypertension protocol(SAH). Then, we compared the ESDR in these two situations. RESULTS: Acute elevation of arterial pressure, being it transitory or sustained, did not alter the heart frequency and increased similarly the preload and after load. However, they acted differently in end systolic pressure-diameter relation. It was greater in the SAH than TAH protocol, 21.0±7.3mmHg/mm vs. 9.2±1.2mmHg/mm (p<0.05). CONCLUSION: The left ventricular ESPDR values determined during sustained pressure elevations were higher than those found during transient pressure elevations. The time-dependent activation of myocardial contractility associated with the Frank-Starling mechanism is the major factor in inotropic stimulation during sustained elevations of blood pressure, determining an increase in the ESPDR values.

Independent impact of glycemia ad blood pressure in albuminuria on high-risk subjects for metabolic syndrome

Background: Microalbuminuria may reflect diffuse endothelial damage. Considering that diabetes and hypertension cause vasculopathy, we investigated associations of albumin-to-creatinine ratio (ACR) with plasma glucose and blood pressure levels in high-risk subjects for metabolic syndrome. Methods: A sample of 519 (246 men) Japanese-Brazilians (aged 60 ± 11 years), who participated in a population-based study, had their ACR determined in a morning urine specimen. Backward models of multiple linear regression were created for each gender including log-transformed values of ACR as dependent variable; an interaction term between diabetes and hypertension was included. Results: Macroalbuminuria was found in 18 subjects. ACR mean values for subjects with normal glucose tolerance, impaired fasting glycemia, impaired glucose tolerance and diabetes were 9.9 ± 6.0, 19.0 ± 35.4, 20.7 ± 35.4, and 33.9 ± 55.0 mg/g, respectively. Diabetic subjects showed higher ACR than the others (p < 0.05). An increase in the proportion of albuminuric subjects was observed as glucose metabolism deteriorated (4.9, 17.0, 23.0 and 36.0%). Stratifying into 4 groups according to postchallenge glycemia (< 7.8 mmol/l, n = 9 1; ≥ 7.8 mmol/l, n = 4 10) and hypertension, hypertensive and glucose-intolerant subgroups showed higher ACR values. ACR was associated with gender, waist circumference, blood pressure, plasma glucose and triglyceride (p < 0.05); albuminuric subjects had significantly higher levels of such variables than the normoalbuminuric ones. In the final models of linear regression, systolic blood pressure and 2-hour glycemia were shown to be independent predictors of ACR for both genders (p < 0.05). In men, also waist was independently associated with ACR. No interaction was detected between diabetes and hypertension. Conclusions: These findings suggest that both glucose intolerance and hypertension could have independent but not synergistic effects on endothelial function - reflected by albumin loss in urine. Such hypothesis needs to be confirmed in prospective studies. © 2004 Dustri-Verlag Dr. K. Feistle.

Is 44-hour better than 24-hour ambulatory blood pressure monitoring in hemodialysis?

The aim of this study is to evaluate if hemodialysis (HD) patients with similar blood pressure (BP) in the whole inter-HD period could have different target organ lesions and survival if the behavior of BP differs from the first to the second day of the inter-HD period. The present study compares 44-hour ambulatory BP monitoring (ABPM) patterns in 45 HD patients. Three BP patterns emerged: group A (n = 15) had similar BPs throughout (138 ± 11/88 ± 12 in the first 22 h vs. 140 ± 11/87 ± 12 mm Hg in the second 22-hour period); group B (n = 15) had a significant systolic BP rise from the first to the second period (132 ± 15/80 ± 12 vs. 147 ± 12/86 ± 13 mm Hg, p < 0.05); group C (n = 15) had significantly higher BPs (p < 0.05) than the other 2 groups throughout the whole inter-HD period, with no significant change between the 2 halves (172 ± 14/108 ± 12 vs. 173 ± 18/109 ± 14 mm Hg). Ventricular mass and survival during the 30-month follow-up period were statistically significantly better in group A, intermediate in group B and worse in group C. The data suggest that a 44-hour ABPM is more accurate than a 24-hour one in evaluating organ lesion and prognosis in HD patients. Copyright © 2006 S. Karger AG.

Determinants of blood pressure in type 2 diabetic subjects with high occurrence of inadequate glycemic control

Study design: Association study Objective: To analyze the association between different biological/behavioral risk factors and blood pressure in a sample of type 2 diabetes mellitus patients with poor glycemic control. Methods: A sample of 121 type 2 diabetic patients was selected in the Public Healthcare System in a middle size Brazilian city. Blood pressure was measured using an aneroid device, previously calibrated. Six determinants of blood pressure were taken into count: age, hypoglycemic agents, general obesity, abdominal obesity, eating behaviors and physical activity level. Results: The type 2 diabetic patients presented mean age of 60.1±8.9 years-old and, at least, one risk factor. Eating behaviors (OR adj= 0.31 [0.12-0.75]) and sports practice (OR adj= 0.12 [0.02-0.75]) constituted protective factors associated with lower systolic blood pressure. On the other hand, age was positively associated with high systolic blood pressure (OR adj= 3.81 [1.39-10.38]). Patients with 5-6 risk factors, presented higher values of systolic and (F= 3.857; p= 0.011 [post hoc with p= 0.039]), diastolic blood pressure (F= 4.158; p= 0.008 [post hoc with p= 0.036]) and increased occurrence of hypertension (p= 0.010). Conclusion: Our findings indicate that, behavioral variables were important determinants of blood pressure in type 2 diabetic patients with poor glycemic control and clustering of behavioral and biological risk factors increase the hypertension occurrence.

The relationship between training status, blood pressure and uric acid in adults and elderly

Background: Hypertension can be generated by a great number of mechanisms including elevated uric acid (UA) that contribute to the anion superoxide production. However, physical exercise is recommended to prevent and/or control high blood pressure (BP). The purpose of this study was to investigate the relationship between BP and UA and whether this relationship may be mediated by the functional fitness index.Methods: All participants (n = 123) performed the following tests: indirect maximal oxygen uptake (VO2max), AAHPERD Functional Fitness Battery Test to determine the general fitness functional index (GFFI), systolic and diastolic blood pressure (SBP and DBP), body mass index (BMI) and blood sample collection to evaluate the total-cholesterol (CHOL), LDL-cholesterol (LDL-c), HDL-cholesterol (HDL-c), triglycerides (TG), uric acid (UA), nitrite (NO2) and thiobarbituric acid reactive substances (T-BARS). After the physical, hemodynamic and metabolic evaluations, all participants were allocated into three groups according to their GFFI: G1 (regular), G2 (good) and G3 (very good).Results: Baseline blood pressure was higher in G1 when compared to G3 (+12% and +11%, for SBP and DBP, respectively, p<0.05) and the subjects who had higher values of BP also presented higher values of UA. Although UA was not different among GFFI groups, it presented a significant correlation with GFFI and VO2max. Also, nitrite concentration was elevated in G3 compared to G1 (140±29 μM vs 111± 29 μM, for G3 and G1, respectively, p<0.0001). As far as the lipid profile, participants in G3 presented better values of CHOL and TG when compared to those in G1.Conclusions: Taking together the findings that subjects with higher BP had elevated values of UA and lower values of nitrite, it can be suggested that the relationship between blood pressure and the oxidative stress produced by acid uric may be mediated by training status. © 2013 Trapé et al.; licensee BioMed Central Ltd.

Involvement of the median preoptic nucleus in blood pressure control

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The Association Between Cardiovascular Risk Factors and High Blood Pressure in Adolescents: A School-Based Study

Objective: Although previous studies have analyzed the association between cardiovascular risk factors and blood pressure in adolescents, few studies conducted in developing countries analyzed whether the aggregation of risk factors contributes to an increased risk of high blood pressure in adolescents. The objective of this study was to assess the association between cardiovascular risk factors (including general overweight, abdominal obesity, high consumption of foods rich in fats, and insufficient physical activity levels) and high blood pressure in adolescents.Methods: This study was carried out from 2007 to 2008 with 1021 adolescents (528 girls) from primary schools located in the city of Londrina- Brazil. Blood pressure was assessed using an oscillometric device. General overweight was obtained through body mass index, abdominal obesity was assessed using waist circumference, and the consumption of foods rich in fat and physical activity were assessed using a questionnaire. The sum of these risk factors was determined.Results: Adolescents with three or four aggregated risk factors were more likely to have higher values of systolic and diastolic blood pressure when compared with adolescents who did not have any cardiovascular risk factors (P = 0.001 for both). Logistic regression indicated that groups of adolescents with 2 (OR = 2.46 [1.11-5.42]; P = 0.026), 3 (OR = 4.97 [2.07-11.92]; P = 0.001) or 4 risk factors (OR = 6.79 [2.24-19.9]; P = 0.001) presented an increased likelihood of high blood pressure.Conclusions: The number of cardiovascular risk factors was found to be related to high blood pressure in adolescents. (C) 2014 Wiley Periodicals, Inc.

Cultural consonance and arterial blood pressure in urban Brazil

In previous research in Brazil, we tested the hypothesis that cultural consonance is associated with arterial blood pressure. Cultural consonance is the degree to which individuals are able to approximate in their own behaviors the prototypes for behavior encoded in shared cultural models. Individuals who had higher cultural consonance in the domains of lifestyle and social support had lower blood pressures. The aim of the current research was to replicate and extend these findings. First, a more extensive cultural domain analysis was carried out, improving the description of cultural models. Second, more sensitive measures of cultural consonance were developed. Third, data were collected in the same community studied previously. The following findings emerged: (a) cultural domain analysis (using a mix of quantitative and qualitative techniques) indicated that cultural models for these domains are widely shared within the community; (b) the associations of cultural consonance in these domains with arterial blood pressure were replicated; and, (c) the pattern of the associations differed slightly from that observed in earlier research. This pattern of associations can be understood in terms of macrosocial influences over the past ten years. The results support the importance of long-term fieldwork in anthropology. (c) 2005 Elsevier Ltd. All rights reserved.

High sodium intake during postnatal phases induces an increase in arterial blood pressure in adult rats

Coordenadoria de Aperfeiçoamento em Pesquisa (CAPES)

Impact of obesity on autonomic modulation, heart rate and blood pressure in obese young people

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Long-term facial artery catheter implantation for serial arterial blood sampling and invasive arterial blood pressure measurement in horses

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of the Omron MX3 Plus monitor for blood pressure measurement in adolescents

This study analyzed the accuracy/agreement of the Omron MX3 monitor on 165 adolescents. Blood pressure was measured by the automatic monitor connected in Y with the mercury column (three consecutive and simultaneous measures). The independent measures were analyzed, and the mean differences between systolic and diastolic measures for both methods were calculated and compared with British Hypertension Society (BHS) and Association for the Advancement of Medical Instrumentation (AAMI) criteria. The automatic monitor received the highest degree of BHS recommendations for systolic and diastolic blood pressures according to the BHS. The median (25th and 75th) difference between the observer and the monitor measurements was -2 (-6 and 1) mmHg for systolic and 0 (-3 and1) mmHg for diastolic pressures. The monitor also satisfies the AAMI standard for the studied population. In conclusion, the Omron MX3 Plus monitor can be considered reliable and valid for clinical practice and is in accordance with BHS and AAMI criteria.