Stress-induced sodium retention and hypertension: a review and hypothesis

Blood chemistry and biliverdin differ according to reproduction and tourism in a free-living lizard

Changes in the physiological health of species are an essential indicator of changing conditions and environmental challenges. Reponses to environmental challenges can often induce stress, influence physiology, and change metabolism in organisms. Here we tested blood chemistry parameters indicative of stress and metabolic activity using an i-STAT point-of-care blood analyzer in seven populations of free-ranging rock iguanas exposed to varying levels of tourism and supplemental feeding. We found significant differences in blood chemistry (glucose, oxygen, carbon dioxide, hematocrit, hemoglobin, calcium, potassium, and biliverdin levels) among populations exposed to varying levels of tourism, and some variation between sexes and reproductive states. However, different variables are not directly related to one another, suggesting that the causal physiological pathways driving tourism-induced differences are influenced by mechanisms that are not detected by common analyses of blood chemistry. Future work should investigate upstream regulators of these factors affected by tourism. Regardless, these blood metrics are known to be both stress sensitive and related to metabolic activity, suggesting that exposure to tourism and associated supplemental feeding by tourists are generally driven by stress-related changes in blood chemistry, biliverdin, and metabolism.

The stress, salt excretion, and nighttime blood pressure (SABRE) study: Rationale and study design

Background

Abnormal diurnal patterns of blood pressure (BP) on ambulatory BP monitoring (ABPM), defined by reduced BP dipping or elevated nighttime BP, are associated with increased risk for adverse cardiovascular events. Psychological stress is associated with abnormal diurnal patterns of BP. Exposure to an acute stressor (e.g., mental stress task) normally increases urinary sodium excretion. However, some individuals have sodium retention after stress provocation, revealing substantial between-person variability in the degree of stress-induced sodium excretion. Prior research suggests urinary sodium excretion that does not occur during the daytime may shift toward the nighttime, accompanied by an increase in nighttime BP. Associations between psychological stress and the diurnal patterns of sodium excretion and BP are not yet fully understood.

Design

The study is conducted in both the laboratory and naturalistic environment with a multi-racial/ethnic sample of 211 healthy adults. In the laboratory, change in urinary sodium excretion in response to mental stress tasks is examined with pre-/post-stress assessments of sodium excretion. Changes in angiotensin-II, catecholamines, BP, heart rate, endothelin-1, and cortisol are also assessed. In the 24-hour naturalistic environment, the diurnal patterns of sodium excretion and systolic BP are assessed as daytime-to-nighttime ratio of sodium excretion and ABPM, respectively. Ecological momentary assessments of perceived stress are also collected.

Summary

The SABRE study investigates previously unexplored associations between stress-induced urinary excretion in the laboratory, diurnal patterns of sodium excretion and BP in the naturalistic environment, and ecological stress. It has high potential to advance our understanding of the role of psychological stress in hypertension.

Changes of Plasma Analytes Reflecting Metabolic Adaptation to the Different Stages of the Lactation Cycle in Healthy Multiparous Holstein Dairy Cows Raised in High-Welfare Conditions

Simple Summary

This study investigates the changes occurring in plasma analytes of healthy multiparous Holstein dairy cows during the dry, the postpartum, the early and the late lactation phases. A welfare assessment at the herd level and a retrospective subclinical diseases screening were used as blocking factors for the selection of reference individuals. Thus, this study provides measurements of the physiological variations affecting plasma analytes concentrations during the pivotal stages of the lactation cycle in a healthy, high welfare-raised subset of reference individuals and suggest an explanation for the underlying processes involved. Finally, we propose reference intervals for plasma analytes in the stages investigated.

Abstract

Here, we tested the changes occurring in several plasma analytes during different stages of the lactation cycle of high welfare raised multiparous Holstein cows, and provided reference intervals (RI) for plasma analytes concentrations. Eleven high-welfare farms (HWF) located in Northern Italy were selected and their herds used to recruit 361 clinically healthy cows undergoing the dry (from −30 to −10 days from real calving; DFC), the postpartum (from 3 to 7 DFC), the early lactation (from 28 to 45 DFC) and the late lactation phases (from 160 to 305 DFC). Cows affected by subclinical diseases (SCD) were retrospectively excluded, and a subset of 285 cows was selected. Data of plasma analytes underwent ANOVA testing using physiological phases as predictors. The individual effect of each phase was assessed using a pairwise t-test assuming p ≤ 0.05 as a significance limit. A bootstrap approach was used to define the reference interval (RI) for each blood analyte within physiological phases having a pairwise t-test p ≤ 0.05. The concentration of nonesterified fatty acids, albumin, cholesterol, retinol, paraoxonase and tocopherol changed throughout all the physiological phases, whereas the concentration of K, alkaline phosphatase and thiol groups remained stable. Triglycerides, Zn, and ferric ion reducing antioxidant power in the dry phase and BHB, Ca, myeloperoxidase, haptoglobin, reactive oxygen metabolites and advanced oxidation of protein product in postpartum differed compared with other physiological phases. During the dry phase, Packed cell volume, Cl, and urea concentrations were similar to during the postpartum phase. Similarly, Na, γ-glutamyl transferase and β-carotene concentrations were similar to during the early lactation phase; fructosamine and bilirubin concentrations were similar to during the late lactation phase. During the postpartum phase, fructosamine and P concentrations were similar to during the early lactation phase, and the aspartate transaminase concentration was similar to during the late lactation phase. During the early lactation phase, Mg, creatinine, total protein, globulin and ceruloplasmin concentrations were similar to during the postpartum phase, while the urea concentration was similar to during the late lactation phase. All these plasma analytes differed among the other phases. This study identifies physiological trends affecting plasma analytes concentrations during the different stages of the lactation cycle and provides a guideline for the duration and magnitude of their changes when animals are healthy and raised in optimal welfare conditions.

The renin-angiotensin aldosterone system and osteoporosis: findings from the Women's Health Initiative

New users of RAAS inhibitors, including ACE inhibitors and ARBs, have a small increased risk for fracture in the first 3 years of use, with a reduced risk of fracture with longer duration of use.

INTRODUCTION

Pharmacological inhibitors of the renin-angiotensin aldosterone system (RAAS) are used to treat hypertension. However, the relationship of these medications to osteoporosis is inconsistent, and no study has included simultaneous measurements of both incident fractures and bone mineral density (BMD).

METHODS

The association of RAAS inhibitor use (n = 131,793) with incident fractures in new users of these medications in women in the Women's Health Initiative over a minimum median follow-up of 6.5 years was assessed by Cox proportional hazard models. The association of incident fractures by a cumulative duration of use of these medications (< 3 years.) and (> 3 years.) was also estimated. Subgroup analysis of fracture risk by RAAS inhibitor use confined to women with hypertension was also performed (n = 33,820). The association of RAAS inhibitor use with changes in BMD of the hip was estimated by linear regression in 8940 women with dual energy X-ray absorptiometry measurements.

RESULTS

There was no significant association between RAAS inhibitor use and all fractures in the final adjusted multivariable models including hip BMD (HR 0.86 (0.59, 1.24)). However, among users of RAAS inhibitors, including ACE inhibitors and angiotensin receptor blockers (ARBs), hazard ratios for all incident fracture sites in final multivariable models including hip BMD showed dramatic differences by duration of use, with short duration of use (3 years or less) associated with a marked increased risk for fracture (HR 3.28 (1.66, 6.48)) to (HR 6.23 (3.11, 12.46)) and use for more than 3 years associated with a reduced fracture risk (HR 0.40 (0.24, 0.68) to (HR 0.44 (0.20, 0.97)) . Findings were similar in the subgroup of women with a history of hypertension. There was no significant change in BMD of the hip by RAAS inhibitor use.

CONCLUSIONS

In postmenopausal women, use of RAAS inhibitors, including ACE inhibitors and ARBs, is associated with an increased risk for fracture among new users of these medications in the first 3 years of use. However, long-term use (> 3 years) is associated with a reduced risk. Consideration for fracture risk may be part of the decision-making process for initiation of these medications for other disease states.

Board examination stress effect on diastolic function

BACKGROUND

To this date, effects of mental stress on cardiac function have not been clearly investigated. Although hemodynamic and neuroendocrine adverse effects of daily mental stress on cardiovascular morbidity and mortality have been reported, its direct impact on diastolic function of the heart has not been previously studied. In this study, we aimed to assess the role of Board Exam anxiety on right and left ventricular diastolic function in medical residents.

METHODS

Forty medical residents prior to participation in the medical board exam were enrolled in our study. Right prior to as well as 2 month after the exam, all residents underwent trans-thoracic Doppler echocardiography. Right ventricular systolic and diastolic functions and echocardiography indices were measured. Levels of anxiety were measured using Beck Anxiety Inventory Questionnaire before and after the exam. Pre exam and post exam results of study population as well as low and high anxiety groups were evaluated.

RESULTS

Early to late mitral inflow velocity (E/A ratio) in LV inflow increased after board exam (P-value <.001). E/A ratio in RV inflow increased after board exam (P-value: .002). Early mitral inflow to its annular velocity (E/E' ratio) in septal wall decreased after board exam (P-value<.001). The change in E/E' RV free wall did not reach statistical significance (P = .57). Mitral annuls velocities measured by TDI in septal and lateral wall and also tricuspid annulus velocity increased after board exam (P-value<.05). The comparison of these changes between the high-stress and low-stress groups of residents revealed significant differences. Comparison of changes of E/A ratio in the mitral and tricuspid inflow as well as the E/E' in the septum and free wall of the right ventricle before and after the Board Exam between high-stress and low-stress groups was not statistically significant, although there was a trend of more changes in high- stress group residents.

CONCLUSION

This is the first report of comprehensive sequential assessment of left and right ventricular diastolic functions during and after a real subacute stress occasion. The finding of a decreased E/A and E' in response to mental stress suggests that repetitive mental stress may induce diastolic dysfunction which is a mechanism of diastolic heart failure in individuals at risk.

Relation of urinary endothelin-1 to stress-induced pressure natriuresis in healthy adolescents

We hypothesize that delayed natriuresis during mental stress increases the risk of hypertension and other diseases. Our preclinical studies demonstrate an important role for renal endothelin-1 (ET-1) in regulating sodium excretion. Thus, we predict ET-1 may be linked to the delayed stress response in at-risk individuals. We hypothesize that reduced renal ET-1 accounts for derangements in sodium handling under stress, a link never explored in a large human cohort. We determined urinary ET-1 excretion in three observational studies of changes in sodium excretion during mental stress, in which 776 healthy youth (15-19 years) enrolled in a 5-hour protocol (2 hours of rest before and after 1 hour of mental stress). In all studies, 60-minute urine samples were obtained throughout the protocol. Subjects were grouped as retainers (reduced sodium excretion during stress relative to baseline) or excreters (increased sodium excretion during stress relative to baseline). In excreters, ET-1 excretion was significantly increased from baseline to stress (+0.02 pg/min; P < .001). In contrast, ET-1 excretion was significantly higher (P = .028) in retainers than excreters at baseline but significantly reduced in retainers under stress (-0.02 pg/min; P < .001). ET-1 excretion declined further in retainers during recovery but returned to prestress levels in excreters. Albumin excretion and albumin-to-creatinine ratio were significantly higher in retainers (P = .022, P < .001, respectively). Thus, loss of ET-1-dependent natriuresis may account for sodium retention during stress and may predispose retainers to renal diseases such as hypertension and kidney disease.

Reducing effect of aerobic exercise on blood pressure of essential hypertensive patients: A meta-analysis

BACKGROUND

The comprehensive meta-analysis aimed to explore the reductive effect of aerobic exercise on blood pressure of hypertensive patients.

METHODS

The related researches were selected from PubMed and Embase databases up to June 2016. Based on specific inclusive criteria, the eligible studies were selected, and the heterogeneities in their results were estimated by χ-based Q-test and I statistics. Quantitative meta-analysis was assessed by R 3.12 software, and results were presented by standardized mean difference (SMD) and their 95% confidence intervals (CIs). Outcome indicators were systolic blood pressure (SBP) and diastolic blood pressure (DBP). The publication biases were estimated by Egger test. Besides, the "leave one out" method was used for sensitivity evaluations.

RESULTS

As a result, a total of 13 papers with 802 samples were included. Based on the meta-analysis results, there were no significant differences in SBP and DBP between aerobic and control groups before exercise (SMD = 0.15, 95%CI: -0.16-0.46; SMD = 0.16, 95% CI: -0.23-0.55). However, significant reductions were obviously in aerobic group after aerobics, compared with control (SMD = -0.79, 95% CI: -1.29 to -0.28; SMD = -0.63, 95% CI: -1.14 to -0.12). A significant publication bias was detected in SBP (t = -2.2314, P = 0.04549) but not in DBP (t = -1.4962, P = 0.1604). Additionally, the DBP result would be altered after the exclusion of 2 individual papers.

CONCLUSION

Aerobic exercise may be a potential nonpharmacological treatment for blood pressure improvement in essential hypertensive patients.

Gender differences in the relationships between psychosocial factors and hypertension

Gender differences in the epidemiology, pathophysiology, clinical manifestations and outcomes of cardiovascular disease are well established but there is still a lack of awareness of this both in the general population and among healthcare providers. In addition to the traditionally recognized cardiovascular risk factors, more recently psychosocial risk factors such as stress, mood disorders, low socioeconomic status and sleep disorders have been linked to cardiovascular diseases and hypertension. Psychosocial factors may have different cardiovascular consequences in men and women; thus further efforts are required to explore pathophysiological mechanisms, to obtain gender-specific data from clinical trials and to translate this knowledge into everyday clinical practice.

Stress and salt sensitivity in primary hypertension

As the development of hypertension and target organ damage becomes more prevalent, it becomes exceedingly important to determine the underlying mechanisms through which this detrimental development occurs. Specifically, our studies and others have explored mechanisms through which stress elicits a salt-sensitive response in approximately 20-30 % of the population, resulting in the early development of hypertension and target organ damage. Data associated with this stress-induced cardiovascular response pattern have recently demonstrated additional effects across the body systems including factors contributing to the development of osteoporosis, obesity, autoimmune disease, and chronic inflammation. As each of these diseases become more prevalent in conjunction with hypertension, further research may discover stress and salt sensitivity to be at the "heart" of the matter for the development of many of today's most deadly conditions.

Interaction of stress and dietary NaCl intake in hypertension: renal neural mechanisms

A synthesizing concept of the development of primary hypertension is that it arises from an interaction of genetic and environmental factors. Of the environmental factors, dietary NaCl intake and mental stress are among the most thoroughly investigated. This review will focus on the interaction between genetic predisposition and the environmental influences of dietary NaCl intake and mental stress in the development of primary hypertension.

Association of quality of life, anxiety, and depression with left atrial ablation outcomes

BACKGROUND

Atrial fibrillation (AF) is associated with significant impairment of quality of life (QoL). Anxiety and depression are common in AF patients and might predispose to AF. We sought to investigate associations of preablative QoL and stress parameters with AF ablation outcomes, as well as possible changes in QoL, anxiety, and depression parameters after ablation.

METHODS

A total of 57 consecutive patients with paroxysmal AF underwent pulmonary vein (PV) antral isolation. The Short-Form Life Survey-36 items (SF-36), the State-Trait Anxiety Inventory (STAI), and the Beck Depression Inventory (BDI) were assessed before and at 6 months after ablation.

RESULTS

After a mean follow-up of 8.0 ± 2.5 months, 41 patients (71.9%) remained free from arrhythmia. Baseline mental health summary QoL SF-36 score was significantly lower in patients with AF recurrence (53.2 ± 10.3 vs 69.7 ± 17.9; P = 0.001), while the physical health summary score did not differ significantly between patients with and without recurrence. Patients with recurrence had higher baseline STAI-trait (41.9 ± 1.5 vs 34.7 ± 4.9) and BDI (17.3 ± 9.7 vs 5.4 ± 3.0) scores (P < 0.001 for both). In multivariable analysis, SF-36 mental health summary, STAI-trait, and BDI scores remained significant predictors of recurrence after adjustment for age, gender, body mass index, diabetes, and hypertension. Mental and physical domain SF-36 summary scores were significantly improved 6 months after ablation (P = 0.001) and a significant reduction in symptoms of depression (P = 0.001) and anxiety (P = 0.001) was observed.

CONCLUSIONS

Baseline QoL, anxiety, and depression metrics were associated with AF recurrence following PV antral isolation. Furthermore, there was a significant improvement in QoL, anxiety, and depression after left atrial ablation.

Function of cGMP-dependent protein kinase II in volume load-induced diuresis

Atrial natriuretic peptide (ANP)/cGMPs cause diuresis and natriuresis. Their downstream effectors beyond cGMP remain unclear. To elucidate a probable function of cGMP-dependent protein kinase II (cGKII), we investigated renal parameters in different conditions (basal, salt diets, starving, water load) using a genetically modified mouse model (cGKII-KO), but did not detect any striking differences between WT and cGKII-KO. Thus, cGKII is proposed to play only a marginal role in the adjustment of renal concentration ability to varying salt loads without water restriction or starving conditions. When WT mice were subjected to a volume load (performed by application of a 10-mM glucose solution (3% of BW) via feeding needle), they exhibited a potent diuresis. In contrast, urine volume was decreased significantly in cGKII-KO. We showed that AQP2 plasma membrane (PM) abundance was reduced for about 50% in WT upon volume load, therefore, this might be a main cause for the enhanced diuresis. In contrast, cGKII-KO mice almost completely failed to decrease AQP2-PM distribution. This significant difference between both genotypes is not induced by an altered p-Ser256-AQP2 phosphorylation, as phosphorylation at this site decreases similarly in WT and KO. Furthermore, sodium excretion was lowered in cGKII-KO mice during volume load. In summary, cGKII is only involved to a minor extent in the regulation of basal renal concentration ability. By contrast, cGKII-KO mice are not able to handle an acute volume load. Our results suggest that membrane insertion of AQP2 is inhibited by cGMP/cGKII.

Essential hypertension: an approach to its etiology and neurogenic pathophysiology

Essential hypertension, a rise in blood pressure of undetermined cause, includes 90% of all hypertensive cases and is a highly important public health challenge that remains, however, a major modifiable cause of morbidity and mortality. This review emphasizes that, from an evolutionary point of view, we are adapted to ingest and excrete <1 g of sodium (2.5 g of salt) per day and that essential hypertension develops when the kidneys become unable to excrete the amount of sodium ingested, unless blood pressure is increased. The renal-mean arterial pressure set-point model is briefly described to explain that a shift of the pressure natriuresis relationship toward abnormally high pressure levels is a pathophysiological characteristic of essential hypertension. Evidence indicating that this anomaly in the pressure natriuresis relationship arises from a sympathetic nervous system dysfunction is briefly formulated, and the most widely accepted pathophysiologic proposal to explain the development of this sympathetic dysfunction is described, with commentaries about novel action mechanisms of some drugs currently used in essential hypertension treatment.

Urinary prostasin excretion is associated with adiposity in nonhypertensive African-American adolescents

BACKGROUND

Metabolic abnormalities in obesity can overstimulate the renal epithelial sodium channel (ENaC) and subsequently lead to blood pressure (BP) elevation. Prostasin, a membrane-bound/secretive serine protease, is thought to activate ENaC via the proteolytic cleavage of the channel. Our specific aim was to explore whether there is a relationship between adiposity and urinary prostasin excretion at the population level.

METHODS

In 271 African-American adolescents, urinary prostasin concentrations were determined by enzyme-linked immunosorbent assay and normalized by urinary creatinine.

RESULTS

Urinary prostasin excretion increased in the overweight/obese group (n = 110, 38.2 ± 4.0 ng/mg) vs. the normal-weight group (n = 161, 20.7 ± 1.2 ng/mg, P = 0.03). Urinary prostasin excretion was significantly correlated with BMI percentiles (r = 0.14, P = 0.02), waist circumference (r = 0.13, P = 0.05), total body fat mass (r = 0.20, P < 0.01), and percentage body fat (r = 0.23, P < 0.01). Urinary prostasin excretion was also correlated with plasma aldosterone (r = 0.11, P = 0.05) and systolic BP (SBP; r = 0.15, P = 0.02), but the significances disappeared after adjustment of any of the adiposity variables.

CONCLUSION

Our data for the first time suggest that adiposity plays a role in urinary prostasin excretion, and its associations with aldosterone and BP appear to be modulated by adiposity. Whether urinary prostasin excretion is a biomarker/mechanism underlying obesity-related hypertension deserves further investigations.

Improvement of diabetic or obese patients' erythrocyte deformability by the program of the brain-oriented obesity control system (BOOCS)

Diabetes is characterized by absolute or relative insulin deficiency complicated with microangiopathy, whereas obesity stems from insulin resistance. A psychosomatic approach to obesity and diabetes has been highlighted, including the brain-oriented obesity control system (BOOCS). Impaired deformability of erythrocytes in obese or diabetic patients is closely linked to disturbed microcirculation, and improvement of abnormal erythrocyte rheology is a prerequisite for the prevention and treatment of microangiopathy. Therefore, erythrocyte filterability, whole cell deformability defined as flow rate of erythrocyte suspension relative to that of saline, was assessed by the nickel-mesh-filtration technique. Subjects included healthy controls (group A, n = 14), diabetic, non-obese participants (group B, n = 29), and non-diabetic, obese participants (group C, n = 32) in the 6-month BOOCS program, and most patients in groups B and C (86.9 %) completed this program. Baseline mean erythrocyte filterabilities were 89.4 ± 1.7 % in group A, 82.8 ± 5.2 % in group B, and 84.1 ± 5.6 % in group C, showing significant intergroup differences (p < 0.001). This program significantly improved (p < 0.001) the impaired erythrocyte filterability in groups B (87.9 ± 4.4 %) and C (88.5 ± 3.7 %). Declines in HbA1c (p = 0.387) and body mass index (p = 0.479) were not correlated to this improvement. These findings indicate that the mechanisms of BOOCS-induced improvement of diabetic or obese patients' erythrocyte deformability are multifactorial, and that the BOOCS program for these patients is a holistic, cost-effective, and highly compliant approach possibly ameliorating microcirculation.

Neuroendocrine changes and natriuresis in response to social stress in rats

Sympathetic activation is detected by the tachycardic, hypertensive and hyperthermic responses during social conflicts in rodents and primates. Sympathetic nervous system activation promoting sodium retention has long been recognized to play a significant role in the development and maintenance of salt-sensitive hypertension. The objective was to investigate neuroendocrine activation and renal sodium excretion in response to chronic social stress. Male Wistar rats were subjected to social stress in accordance with the resident-intruder paradigm. Intruder rats were subjected to social confrontation once daily for 6 days. After the last confrontation, plasma corticosterone and urinary catecholamines were determined to assess the neuroendocrine activation. Plasma aldosterone, plasma and urinary creatinine, Na(+) , K(+) and urinary volume were also measured. Chronic social stress increased the urinary norepinephrine, dopamine and plasma corticosterone levels, with no changes in epinephrine levels. On the other hand, high plasma aldosterone levels and low urinary sodium excretion without differences in creatinine clearance were observed. In conclusion, social stress had a strong antinatriuretic effect, which is coincident with noradrenergic and corticoadrenal activation and an increase in plasma aldosterone levels. Activation of these factors may promote sodium retention, which has long been recognized to play a significant role in the development and maintenance of hypertension.

From Brain to Behavior: Hypertension's Modulation of Cognition and Affect

Accumulating evidence from animal models and human studies of essential hypertension suggest that brain regulation of the vasculature is impacted by the disease. Human neuroimaging findings suggest that the brain may be an early target of the disease. This observation reinforces earlier research suggesting that psychological factors may be one of the many contributory factors to the initiation of the disease. Alternatively or in addition, initial blood pressure increases may impact cognitive and/or affective function. Evidence for an impact of blood pressure on the perception and experience of affect is reviewed vis-a-vis brain imaging findings suggesting that such involvement in hypertensive individuals is likely.

Stress reduces diastolic function in youth

OBJECTIVE

Research regarding the influence of mental stress (MS) on heart function focused primarily on heart contractility. We hypothesized that MS results in attenuated diastolic function (DF) as early as in adolescence and this effect may differ by race and sex.

METHODS

161 normotensive adolescents (81 blacks and 80 females) performed resting (control) and MS (experimental) conditions on separate visits. Visits lasted for 3 hours (1-hour rest, video game challenge and recovery for experimental visit. Mitral inflow early (E) to late (A) filling velocities (E/A) ratio; mitral valve annular early velocity (E') and E/E' ratio were recorded every 30 minutes to evaluate DF.

RESULTS

BP and HR increased during experimental visit (all p values < .01). E/A ratio progressively increased during control visit (mean [SE], from 1.93 ± 0.42 to 2.01 ± 0.47) but decreased during the stress phase of experimental visit (from 1.91 ± 0.44 to 1.87 ± 0.50, p interaction < .001). In white males, E' increased from rest to stress phase (from 10.3 ± 2.55 to 10.7 ± 2.28 cm/s), whereas E' decreased in white females (from 11.0 ± 2.62 to 10.6 ± 2.53 cm/s), black males (from 10.5 ± 2.31 to 9.9 ± 2.19 cm/s), and black females (from 10.6 ± 2.22 to 10.3 ± 1.86 cm/s, p interaction < .04). During stress, higher A was associated with higher E/E' ratio.

CONCLUSIONS

Recurrent episodes of mental stress may increase the risk of poor DF, and these adverse effects may be stronger in females and black males.

Concepts guiding therapy for hypertension in children

Increasing attention has been focused on identifying children with prehypertension and hypertension (HTN). Obesity and low birthweight are two risk factors that predispose children to develop HTN during their childhood years or later as adults. Early onset of pre-HTN and HTN increases the lifetime risk for cardiovascular sequelae. Lifestyle modification should be part of the initial recommendations for management of all hypertensive children. In those children requiring pharmacologic therapy, the choice of medication should be guided by the etiology of HTN, the needs of the child and the risk and benefit profiles of the various drug classes. The long-term impact of antihypertensive therapy in children is not known. Concerns regarding the effects of HTN and its treatment on cognitive function are of particular importance in the growing child and warrant further study. Ongoing investigations that offer promise for innovative therapeutic approaches in the future are discussed.