Sex Differences in Hypertension: Recent Advances

Salt-sensitive hypertension in chronic kidney disease: distal tubular mechanisms

Chronic kidney disease (CKD) causes salt-sensitive hypertension that is often resistant to treatment and contributes to the progression of kidney injury and cardiovascular disease. A better understanding of the mechanisms contributing to salt-sensitive hypertension in CKD is essential to improve these outcomes. This review critically explores these mechanisms by focusing on how CKD affects distal nephron Na+ reabsorption. CKD causes glomerulotubular imbalance with reduced proximal Na+ reabsorption and increased distal Na+ delivery and reabsorption. Aldosterone secretion further contributes to distal Na+ reabsorption in CKD and is not only mediated by renin and K+ but also by metabolic acidosis, endothelin-1, and vasopressin. CKD also activates the intrarenal renin-angiotensin system, generating intratubular angiotensin II to promote distal Na+ reabsorption. High dietary Na+ intake in CKD contributes to Na+ retention by aldosterone-independent activation of the mineralocorticoid receptor mediated through Rac1. High dietary Na+ also produces an inflammatory response mediated by T helper 17 cells and cytokines increasing distal Na+ transport. CKD is often accompanied by proteinuria, which contains plasmin capable of activating the epithelial Na+ channel. Thus, CKD causes both local and systemic changes that together promote distal nephron Na+ reabsorption and salt-sensitive hypertension. Future studies should address remaining knowledge gaps, including the relative contribution of each mechanism, the influence of sex, differences between stages and etiologies of CKD, and the clinical relevance of experimentally identified mechanisms. Several pathways offer opportunities for intervention, including with dietary Na+ reduction, distal diuretics, renin-angiotensin system inhibitors, mineralocorticoid receptor antagonists, and K+ or H+ binders.

The association between menstrual symptoms and hypertension among young women: A prospective longitudinal study

OBJECTIVES

To investigate whether menstrual symptoms are associated with increased risk of hypertension among young women, and whether the relationship is bi-directional.

STUDY DESIGN

We included 7729 women participating in the Australian Longitudinal Study on Women's Health, aged 22-27 years in 2000 and who were followed up every 3 years until 2015. Premenstrual syndrome, painful (dysmenorrhoea), heavy (menorrhagia), and irregular menstrual periods over the previous 12 months were self-reported and recorded as 'never', 'rarely', 'sometimes', or 'often'. Questions regarding physician-diagnosed hypertension were asked, specifically for other than during pregnancy (defined as chronic hypertension) and during pregnancy (hypertensive disorder in pregnancy, HDP). Longitudinal data were analysed with generalised estimating equation time-lagged models to estimate relative risks (RRs) and 95 % confidence intervals (CI), adjusted for time-varying covariates.

MIAN OUTCOME MEASURES

Chronic hypertension, HDP, and menstrual disorders.

RESULTS

Over 15 years of follow-up, 757 women (9.8 %) reported having been diagnosed with chronic hypertension. Among 4473 parous women, 483 (10.8 %) reported a diagnosis of HDP. Women who often experienced heavy periods had an increased risk of incident chronic hypertension (RR 1.53, 1.13-2.09), compared with those who had not experienced heavy periods. We also found that women with chronic hypertension had an increased risk of incident heavy (RR 1.23, 1.02-1.50) and irregular periods (RR 1.42, 1.17-1.72). However, there was no apparent association between any menstrual symptoms and subsequent risk of HDP.

CONCLUSIONS

The association between heavy periods (menorrhagia) and chronic hypertension may be bi-directional in young women. Chronic hypertension may also be associated with subsequent risk of irregular periods.

Prevalence of Comorbidities and Risks Associated with COVID-19 Among Black and Hispanic Populations in New York City: an Examination of the 2018 New York City Community Health Survey

Background

The coronavirus disease (COVID-19) pandemic has affected Blacks and Hispanics in New York City (NYC) disproportionately. This study aims to assess the relationship of race/ethnicity with COVID-19 associated factors such as hypertension, diabetes, neighborhood poverty, and frontline work, in NYC.

Methods

The 2018 New York City Community Health Survey was used to examine the association of hypertension, diabetes, and neighborhood poverty level with race/ethnicity in log-binomial regression models. Number of intensive care unit (ICU) beds and the distribution of frontline workers were acquired from the US Census, the State of New York Department of Labor, and Centers for Medicare and Medicaid Services.

Results

Neighborhoods with high poverty level had a greater risk of hypertension among Blacks (relative risk (RR), 95% confidence interval (CI): 3.4, 1.9–6.4) and diabetes among Hispanics (RR, 95% CI: 5.5, 2.2–14.0), compared with Whites in the lowest poverty neighborhoods. Disproportionately greater percentages of frontline workers were comprised of Blacks (29.4%, 95% CI: 29.3–29.5%) and Hispanics (35.5%, 95% CI: 35.3–35.6%). Predominantly Black and Hispanic boroughs with greater level of poverty had one ICU bed per 900 adults of 60 years of age or older, compared with one ICU bed per 452 in predominantly White boroughs with less poverty.

Conclusion

The greater prevalence of the factors associated with COVID-19 infection and adverse outcomes puts Black and Hispanic populations in NYC at a greater risk. These factors are also related to poverty and should be mitigated together with reducing racial/ethnic inequities.

Velocity Pulsatility and Arterial Distensibility Along the Internal Carotid Artery

Background Attenuation of velocity pulsatility along the internal carotid artery (ICA) is deemed necessary to protect the microvasculature of the brain. The role of the carotid siphon within the whole ICA trajectory in pulsatility attenuation is still poorly understood. This study aims to assess arterial variances in velocity pulsatility and distensibility over the whole ICA trajectory, including effects of age and sex. Methods and Results We assessed arterial velocity pulsatility and distensibility using flow-sensitized 2-dimensional phase-contrast 3.0 Tesla magnetic resonance imaging in 118 healthy participants. Velocity pulsatility index (vPI=(V_max-V_min)/V_mean) and arterial distensibility defined as area pulsatility index (A_max-A_min)/A_mean) were calculated at C1, C3, and C7 segments of the ICA. vPI increased between C1 and C3 (0.85±0.13 versus 0.93±0.13, P<0.001 for averaged right+left ICA) and decreased between C3 and C7 (0.93±0.13 versus 0.84±0.13, P<0.001) with overall no effect (C1-C7). Conversely, the area pulsatility index decreased between C1 and C3 (0.18±0.06 versus 0.14±0.04, P<0.001) and increased between C3 and C7 (0.14±0.04 versus 0.31±0.09, P<0.001). vPI in men is higher than in women and increases with age (P<0.015). vPI over the carotid siphon declined with age but remained stable over the whole ICA trajectory. Conclusions Along the whole ICA trajectory, vPI increased from extracranial C1 up to the carotid siphon C3 with overall no effect on vPI between extracranial C1 and intracranial C7 segments. This suggests that the bony carotid canal locally limits the arterial distensibility of the ICA, increasing the vPI at C3 which is consequently decreased again over the carotid siphon. In addition, vPI in men is higher and increases with age.

Location-specific risk factors for intracerebral hemorrhage: Systematic review and meta-analysis

OBJECTIVE

To conduct a systematic review and meta-analysis of studies reporting on risk factors according to location of the intracerebral hemorrhage.

METHODS

We searched PubMed and Embase for cohort and case-control studies reporting ≥100 patients with spontaneous intracerebral hemorrhage that specified the location of the hematoma and reported associations with risk factors published until June 27, 2019. Two authors independently extracted data on risk factors. Estimates were pooled with the generic variance-based random-effects method.

RESULTS

After screening 10,013 articles, we included 42 studies totaling 26,174 patients with intracerebral hemorrhage (9,141 lobar and 17,033 nonlobar). Risk factors for nonlobar intracerebral hemorrhage were hypertension (risk ratio [RR] 4.25, 95% confidence interval [CI] 3.05-5.91, I ² = 92%), diabetes mellitus (RR 1.35, 95% CI 1.11-1.64, I ² = 37%), male sex (RR 1.63, 95% CI 1.25-2.14, I ² = 61%), alcohol overuse (RR 1.48, 95% CI 1.21-1.81, I ² = 19%), underweight (RR 2.12, 95% CI 1.12-4.01, I ² = 31%), and being a Black (RR 2.83, 95% CI 1.02-7.84, I ² = 96%) or Hispanic (RR 2.95, 95% CI 1.69-5.14, I ² = 71%) participant compared with being a White participant. Hypertension, but not any of the other risk factors, was also a risk factor for lobar intracerebral hemorrhage (RR 1.83, 95% CI 1.39-2.42, I ² = 76%). Smoking, hypercholesterolemia, and obesity were associated with neither nonlobar nor lobar intracerebral hemorrhage.

CONCLUSIONS

Hypertension is a risk factor for both nonlobar and lobar intracerebral hemorrhage, although with double the effect for nonlobar intracerebral hemorrhage. Diabetes mellitus, male sex, alcohol overuse, underweight, and being a Black or Hispanic person are risk factors for nonlobar intracerebral hemorrhage only. Hence, the term hypertensive intracerebral hemorrhage for nonlobar intracerebral hemorrhage is not appropriate.

Distribution of Medical Conditions among Dental Patients

Aims

The aim of the study was to determine the distribution of medical conditions among dental patients in our local environment.

Settings and Design

This is a descriptive cross-sectional study conducted at the Oral Diagnosis (OD) Clinic of Obafemi Awolowo University Teaching Hospital Complex (OAUTHC), Ile-Ife, Osun State.

Materials and Methods

Participants were selected using a simple random method from the pool of dental patients who presented at the OD Clinic of OAUTHC during the study period. Information was obtained from each participant using a structured questionnaire organized into sections. Section 1 collected information on participants' biodata such as age, sex, and weight. Section 2 recorded data on the history of the presence of relevant oral and systemic symptoms, while section 3 collected information on findings from intraoral and extraoral examination.

Statistical Analysis Used

The results were analyzed using STATA 13 statistical software.

Results

Of the 1503 patients who visited dental hospital during the study period, 176 (11.7%) had medical problems. The mean age of patients with medical problems was 48.5 ± 21.0 years. The mean age was higher in men compared to women (P = 0.013). More than one-fifth (21.6%) of the patients were first diagnosed in the dental clinic. Hypertension was the most frequently seen medical condition, closely followed by peptic ulcer and diabetes mellitus. Patients whose medical problems were first diagnosed following dental consultation were significantly older than those with known medical conditions.

Conclusions

Prevalence of medical conditions in dental patients is high. Hypertension is the most frequently associated systemic conditions among dental patients. Medical conditions were common among older age group (>50 years), males, and those with gum problems.

Determinants of hypertension in Nepal using odds ratios and prevalence ratios: an analysis of the Demographic and Health Survey 2016

This cross-sectional study investigated the factors associated with hypertension among Nepalese adults aged 18 years or above using data from the Nepal Demographic and Health Survey 2016. Prevalence ratios (PRs) and odds ratios (ORs) were obtained using log-binomial regression and logistic regression, respectively. Initially, unadjusted PRs and ORs were obtained. The variables that yielded a significance level below 0.2 in unadjusted analyses were included in the multivariable analysis. The overall prevalence of hypertension among the 13,393 participants (58% male and 61.2% urban) was 21.1% (n = 2827). In the adjusted analysis, those aged 30-49 years (adjusted PR [APR]: 3.1, 95% Confidence Interval (CI): 2.6, 3.7; adjusted OR [AOR]: 3.6, 95% CI: 2.9, 4.5), 50-69 years (APR: 5.3, 95% CI: 4.4, 6.6; AOR: 8.2, 95% CI: 6.4, 10.4) and ≥70 years (APR: 7.3, 95% CI: 5.8, 9.2; AOR: 13.6, 95% CI: 10.1, 18.3) were more likely to be hypertensive than younger participants aged 18-29 years. Males (APR: 1.3, 95% CI: 1.2, 1.4; AOR: 1.5, 95% CI: 1.3, 1.7), overweight/obese participants (APR: 1.8, 95% CI: 1.7, 2.0; AOR: 2.4, 95% CI: 2.2, 2.8) and those in the richest wealth quintile (APR: 1.3, 95% CI: 1.1, 1.5; AOR: 1.5, 95% CI: 1.1, 1.9) had higher prevalences and odds of hypertension than their female, normal weight/underweight and poorest wealth quintile counterparts, respectively. Those residing in Province 4 (APR: 1.2, 95% CI: 1.0, 1.5; AOR: 1.4, 95% CI: 1.1, 1.8) and Province 5 (APR: 1.2, 95% CI: 1.0, 1.4; AOR: 1.3, 95% CI: 1.1, 1.7) were more likely to be hypertensive than those residing in Province 1. The point estimate was inflated more in magnitude by ORs than by PRs, but the direction of association remained the same. Public health programmes in Nepal aimed at preventing hypertension should raise awareness among the elderly, males, individuals in the richest wealth quintile and the residents of Provinces 4 and 5.

Nitric oxide and oxidative stress pathways do not contribute to sex differences in renal injury and function in Dahl SS/Jr rats

The burden of hypertension in the United States is increasing and yields significant morbidity and mortality, and sex differences in hypertension are widely recognized. Reduced nitric oxide (NO) bioavailability and increased oxidative stress are known to contribute to the pathogenesis of hypertensive renal injury, and but their contributions to sex differences in injury progression of are undefined. Our purpose was to test the hypothesis that male hypertensive rats have accelerated renal injury compared to females and to determine the contributions of the nitric oxide pathway and oxidative stress in these differences. Male and female Dahl SS/Jr rats, a model that spontaneously develops hypertension with age, were allowed to age on a 0.3% NaCl diet until 3 or 6 months of age, at which points blood pressure was measured and plasma, tissue, and urine were collected. While no significant sex differences in blood pressure were present at either time point, renal injury measured by urine protein excretion was more severe (male = 44.9 ± 6; female = 15±3 mg/day/100 g bw, p = .0001), and renal function was reduced (male = 0.48 ± 0.02; female = 0.7 ± 0.03 ml min-1  g-1 kw, p = .001) in males compared to females with age. Both male and female rats exhibited reduced nitric oxide metabolites (3 months: male = 0.65 ± 0.1; female = 0.74 ± 0.3; 6 months: male = 0.16 ± 0.1; female = 0.41 ± 0.1 ml min-1  g-1 kw, p, age = 0.02, p, sex = 0.3). Levels of urinary TBARS were similar (3 months: male = 20±1.5; female = 23±1.8; 6 months: male = 26±4.8; female = 23±4.7µM day g-1 kw, p, age = 0.4, p, sex = 0.9), extracellular superoxide dismutase (EC SOD) mRNA was greater in females (3 months: male = 0.35 ± 0.03; female = 1.4 ± 0.2; 6 months: male = 0.4 ± 0.05; female = 1.3 ± 0.1 normalized counts, p, age = 0.7, p, sex < 0.0001), but EC SOD protein expression was not different (3 months: male = 0.01 ± 0.002; female = 0.01 ± 0.002; 6 months: male = 0.02 ± 0.004; female = 0.01 ± 0.002 relative density, p, age = 0.2, p, sex = 0.8). These data support the presence of significant sex differences in renal injury and function in the Dahl S rat and identify a need for further study into the mechanisms involved.

Androgens' effects on cerebrovascular function in health and disease

Androgens affect the cerebral vasculature and may contribute to sex differences in cerebrovascular diseases. Men are at a greater risk for stroke and vascular contributions to cognitive impairment and dementia (VCID) compared to women throughout much of the lifespan. The cerebral vasculature is a target for direct androgen actions, as it expresses several sex steroid receptors and metabolizing enzymes. Androgens’ actions on the cerebral vasculature are complex, as they have been shown to have both protective and detrimental effects, depending on factors such as age, dose, and disease state. When administered chronically, androgens are shown to be pro-angiogenic, promote vasoconstriction, and influence blood-brain barrier permeability. In addition to these direct effects of androgens on the cerebral vasculature, androgens also influence other vascular risk factors that may contribute to sex differences in cerebrovascular diseases. In men, low androgen levels have been linked to metabolic and cardiovascular diseases including hypertension, diabetes, hyperlipidemia, and obesity, which greatly increase the risk of stroke and VCID. Thus, a better understanding of androgens’ interactions with the cerebral vasculature under physiological and pathological conditions is of key importance.

Hypertensive female Sprague-Dawley rats require an intact nitric oxide synthase system for compensatory increases in renal regulatory T cells

We have previously shown that hypertensive female rats have more regulatory T cells (Tregs), which contribute more to blood pressure (BP) control in female versus male rats. Based on known protective properties of Tregs, the goal of the present study was to investigate the mechanisms by which female rats maintain Tregs. The present study was designed to 1) compare the impact of three hypertension models on the percentage of renal Tregs and 2) test the hypothesis that nitric oxide synthase (NOS) inhibition prevents increases in renal Tregs and exacerbates renal damage in female Sprague-Dawley rats. Rats (11-14 wk old) were randomized to one of the following four groups: control, norepinephrine (NE) infusion, angiotensin II infusion, or the NOS inhibitor N^ω-nitro-l-arginine methyl ester (l-NAME) in drinking water. BP was measured via tail cuff. After 2 wk of treatment, kidneys were isolated and processed to measure Tregs via flow cytometric analysis and renal injury via urinary albumin excretion, plasma creatinine, and histological analyses. Hypertensive treatments increased BP in all experimental animals. Increases in BP in norepinephrine-and angiotensin II-treated rats were associated with increases in renal Tregs versus control. In contrast, l-NAME treatment decreased Tregs compared with all groups. l-NAME treatment modestly increased albumin excretion. However, plasma creatinine was comparable among the groups, and there was no histological evidence of glomerular or tubular injury. This study provides insights into the mechanisms regulating renal Tregs and supports that an intact NOS system is crucial for female rats to have BP-related increases in renal Tregs.

Self-reported hypertension as a predictor of chronic health conditions among older adults in Ghana: analysis of the WHO Study on global Ageing and adult health (SAGE) Wave 2

Introduction

Hypertension has been identified as a significant predictor of many chronic health conditions. Body Mass Index (BMI) and Quality of Life (QoL) are key determinants of hypertension especially among elderly populations. In this study, we examined the effect of self-reported hypertension (SRH) on chronic health conditions and quality of life among older adults in Ghana.

Methods

The WHO Study on Global Ageing and Adult Health Wave 2 data for Ghana, collected from 2014 to 2015 was applied in this study. Data for older adults aged 50 years and above were analyzed. Weighted descriptive and inferential analyses were performed using Stata 14. We predicted any potential associations between SRH and chronic health conditions using a corrected chi-square and Coarsened Exact Matching with adjusted odds ratios.

Results

The prevalence of SRH among older adults in Ghana was 15.8%. This was significantly associated with sex, marital status, religion, place of residence, working status, location/region, health status BMI, and QoL. In all, older adults with poor health status, obese state and high QoL had 3.15, 2.17 and 2.76 odds of SRH respectively [AOR(95%CI)p-value=3.15(1.65-6.02)0.001, 2.17(1.31-3.59)0.003 and 2.76(1.04-7.31)0.041)]. In addition, older adults with SRH were at increased risk of reporting chronic conditions such as stroke, angina, diabetes and cataract.

Conclusion

Overall, a key observation from this analysis is that SRH (and not only clinically diagnosed hypertension) is significantly associated with co-morbidities. In Ghana, older adults with SRH have increased risk of co-morbidities including diabetes, stroke, angina, and cataract. Interventions to improve the awareness and early detection of hypertension at the population level is key. Controlling hypertension at the population level will reduce prevalence of chronic conditions and increased protection.

Improving translational research in sex-specific effects of comorbidities and risk factors in ischaemic heart disease and cardioprotection: position paper and recommendations of the ESC Working Group on Cellular Biology of the Heart

Ischaemic heart disease (IHD) is a complex disorder and a leading cause of death and morbidity in both men and women. Sex, however, affects several aspects of IHD, including pathophysiology, incidence, clinical presentation, diagnosis as well as treatment and outcome. Several diseases or risk factors frequently associated with IHD can modify cellular signalling cascades, thus affecting ischaemia/reperfusion injury as well as responses to cardioprotective interventions. Importantly, the prevalence and impact of risk factors and several comorbidities differ between males and females, and their effects on IHD development and prognosis might differ according to sex. The cellular and molecular mechanisms underlying these differences are still poorly understood, and their identification might have important translational implications in the prediction or prevention of risk of IHD in men and women. Despite this, most experimental studies on IHD are still undertaken in animal models in the absence of risk factors and comorbidities, and assessment of potential sex-specific differences are largely missing. This ESC WG Position Paper will discuss: (i) the importance of sex as a biological variable in cardiovascular research, (ii) major biological mechanisms underlying sex-related differences relevant to IHD risk factors and comorbidities, (iii) prospects and pitfalls of preclinical models to investigate these associations, and finally (iv) will provide recommendations to guide future research. Although gender differences also affect IHD risk in the clinical setting, they will not be discussed in detail here.

Differences in renal BMAL1 contribution to Na+ homeostasis and blood pressure control in male and female mice

The renal circadian clock has a major influence on the function of the kidney. Aryl hydrocarbon receptor nuclear translocator-like protein 1 [ARNTL; also known as brain and muscle ARNT-like 1 (BMAL1)] is a core clock protein and transcription factor that regulates the expression of nearly half of all genes. Using male and female kidney-specific cadherin BMAL1 knockout (KS-BMAL1 KO) mice, we examined the role of renal distal segment BMAL1 in blood pressure control and solute handling. We confirmed that this mouse model does not express BMAL1 in thick ascending limb, distal convoluted tubule, and collecting duct cells, which are the final locations for solute and fluid regulation. Male KS-BMAL1 KO mice displayed a substantially lower basal systolic blood pressure compared with littermate control mice, yet their circadian rhythm in pressure remained unchanged [male control mice: 127 ± 0.7 mmHg (n = 4) vs. male KS-BMAL KO mice: 119 ± 2.3 mmHg (n = 5), P < 0.05]. Female mice, however, did not display a genotype difference in basal systolic blood pressure [female control mice: 120 ± 1.6 mmHg (n = 5) vs. female KS-BMAL1 KO mice: 119 ± 1.5 mmHg (n = 7), P = 0.4]. In addition, male KS-BMAL1 KO mice had less Na+ retention compared with control mice in response to a K+-restricted diet (15% less following 5 days of treatment). However, there was no genotype difference in Na+ handling after a K+-restricted diet in female mice. Furthermore, there was evidence indicating a sex-specific response to K+ restriction where female mice reabsorbed less Na+ in response to this dietary challenge compared with male mice. We propose that BMAL1 in the distal nephron and collecting duct contributes to blood pressure regulation and Na+ handling in a sex-specific manner.

Modest Sodium Reduction Increases Circulating Short-Chain Fatty Acids in Untreated Hypertensives: A Randomized, Double-Blind, Placebo-Controlled Trial

High-sodium diet may modulate the gut microbiome. Given the circulating short-chain fatty acids (SCFAs) are microbial in origin, we tested the hypothesis that the modest sodium reduction would alter circulating SCFA concentrations among untreated hypertensives, and the changes would be associated with reduced blood pressure and improved cardiovascular phenotypes. A total of 145 participants (42% blacks, 19% Asian, and 34% females) were included from a randomized, double-blind, placebo-controlled cross-over trial of sodium reduction with slow sodium or placebo tablets, each for 6 weeks. Targeted circulating SCFA profiling was performed in paired serum samples, which were collected at the end of each period, so as all outcome measures. Sodium reduction increased all 8 SCFAs, among which the increases in 2-methylbutyrate, butyrate, hexanoate, isobutyrate, and valerate were statistically significant (Ps<0.05). Also, increased SCFAs were associated with decreased blood pressure and improved arterial compliance. There were significant sex differences of SCFAs in response to sodium reduction (Ps<0.05). When stratified by sex, the increases in butyrate, hexanoate, isobutyrate, isovalerate, and valerate were significant in females only (Ps<0.05), not in males (Ps>0.05). In females, changes in isobutyrate, isovalerate, and 2-methylbutyrate were inversely associated with reduced blood pressures (Ps<0.05). Increased valerate was associated with decreased carotid-femoral pulse wave velocity (P=0.040). Our results show that dietary sodium reduction increases circulating SCFAs, supporting that dietary sodium may influence the gut microbiome in humans. There is a sex difference in SCFA response to sodium reduction. Moreover, increased SCFAs are associated with decreased blood pressures and improved arterial compliance. Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT00152074.

2-Methoxyestradiol Attenuates Angiotensin II-Induced Hypertension, Cardiovascular Remodeling, and Renal Injury

Estradiol may antagonize the adverse cardiovascular effects of angiotensin II (Ang II). We investigated the effects of 2-methoxyestradiol (2-ME), a nonestrogenic estradiol metabolite, on Ang II-induced cardiovascular and renal injury in male rats. First, we determined the effects of 2-ME on Ang II-induced acute changes in blood pressure, renal hemodynamics, and excretory function. Next, we investigated the effects of 2-ME and 2-hydroxyestardiol (2-HE) on hypertension and cardiovascular and renal injury induced by chronic infusion of Ang II. Furthermore, the effects of 2-ME on blood pressure and cardiovascular remodeling in the constricted aorta (CA) rat model and on isoproterenol-induced (ISO) cardiac hypertrophy and fibrosis were examined. 2-ME had no effects on Ang II-induced acute changes in blood pressure, renal hemodynamics, or glomerular filtration rate. Both 2-ME and 2-HE reduced hypertension, cardiac hypertrophy, proteinuria, and mesangial expansion induced by chronic Ang II infusions. In CA rats, 2-ME attenuated cardiac hypertrophy and fibrosis and reduced elevated blood pressure above the constriction. Notably, 2-ME reduced both pressure-dependent (above constriction) and pressure-independent (below constriction) vascular remodeling. 2-ME had no effects on ISO-induced renin release yet reduced ISO-induced cardiac hypertrophy and fibrosis. This study shows that 2-ME protects against cardiovascular and renal injury due to chronic activation of the renin-angiotensin system. This study reports for the first time that in vivo 2-ME reduces trophic (pressure-independent) effects of Ang II and related cardiac and vascular remodeling.

Gender differences in the association between mental health status, hypertension, and emergency department visits in the United States

Hypertension has been found to be elevated in people with mental illness, and this comorbidity may lead to differential emergency department use by gender. Gender differences in this association were assessed using the 2016 Medical Expenditure Panel Survey ( n = 20,443). A combined effect variable for mental health and hypertension was created for stratified, multivariable logistic regression analysis. The likelihood of emergency department visits was higher for women compared to men in all categories of the combined effect variable. In particular, regardless of hypertension status, women with poor mental health had 35 percent and 39 percent increased likelihood of emergency department visits compared to men.

Hypertension, Antihypertensive Use and the Delayed-Onset of Huntington's Disease

Background

Hypertension is a modifiable cardiovascular risk factor implicated in neurodegeneration and dementia risk. In Huntington's disease, a monogenic neurodegenerative disease, autonomic and vascular abnormalities have been reported. This study's objective was to examine the relationship between hypertension and disease severity and progression in Huntington's disease.

Methods

Using longitudinal data from the largest worldwide observational study of Huntington's disease (n = 14,534), we assessed the relationship between hypertension, disease severity, and rate of clinical progression in Huntington's disease mutation carriers. Propensity score matching was used to statistically match normotensive and hypertensive participants for age, sex, body mass index, ethnicity, and CAG length.

Results

Huntington's disease patients had a lower prevalence of hypertension compared with age‐matched gene‐negative controls. Huntington's disease patients with hypertension had worse cognitive function, a higher depression score, and more marked motor progression over time compared with Huntington's disease patients without hypertension. However, hypertensive patients taking antihypertensive medication had less motor, cognitive, and functional impairment than Huntington's disease patients with untreated hypertension and a later age of clinical onset compared with untreated hypertensive patients and normotensive individuals with Huntington's disease.

Conclusions

We report the novel finding that hypertension and antihypertensive medication use are associated with altered disease severity, progression, and clinical onset in patients with Huntington's disease. These findings have implications for the management of hypertension in Huntington's disease and suggest that prospective studies of the symptomatic or disease‐modifying potential of antihypertensives in neurodegenerative diseases are warranted. © 2020 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Cardiovascular Effects of Pharmacological Targeting of Sphingosine Kinase 1

High blood pressure is a risk factor for cardiovascular diseases. Ang II (angiotensin II), a key pro-hypertensive hormone, mediates target organ consequences such as endothelial dysfunction and cardiac hypertrophy. S1P (sphingosine-1-phosphate), produced by Sphk1 (sphingosine kinase 1), plays a pivotal role in the pathogenesis of hypertension and downstream organ damage, as it controls vascular tone and regulates cardiac remodeling. Accordingly, we aimed to examine if pharmacological inhibition of Sphk1 using selective inhibitor PF543 can represent a useful vasoprotective and cardioprotective anti-hypertensive strategy in vivo. PF543 was administered intraperitoneally throughout a 14-day Ang II-infusion in C57BL6/J male mice. Pharmacological inhibition of Sphk1 improved endothelial function of arteries of hypertensive mice that could be mediated via decrease in eNOS (endothelial nitric oxide synthase) phosphorylation at T495. This effect was independent of blood pressure. Importantly, PF543 also reduced cardiac hypertrophy (heart to body weight ratio, 5.6±0.2 versus 6.4±0.1 versus 5.9±0.2 mg/g; P<0.05 for Sham, Ang II+placebo, and Ang II+PF543-treated mice, respectively). Mass spectrometry revealed that PF543 elevated cardiac sphingosine, that is, Sphk1 substrate, content in vivo. Mechanistically, RNA-Seq indicated a decreased expression of cardiac genes involved in actin/integrin organization, S1pr1 signaling, and tissue remodeling. Indeed, downregulation of Rock1 (Rho-associated coiled-coil containing protein kinase 1), Stat3 (signal transducer and activator of transcription 3), PKC (protein kinase C), and ERK1/2 (extracellular signal-regulated kinases 1/2) level/phosphorylation by PF543 was observed. In summary, pharmacological inhibition of Sphk1 partially protects against Ang II-induced cardiac hypertrophy and endothelial dysfunction. Therefore, it may represent a promising target for harnessing residual cardiovascular risk in hypertension.

Sex-Specific Association of Blood Pressure Categories With All-Cause Mortality: The Rural Chinese Cohort Study

Introduction

The relationship between blood pressure categories and all-cause mortality has not been fully addressed in cohort studies, especially in the general Chinese population. Our study aimed to assess the sex-specific association of systolic blood pressure (SBP), diastolic blood pressure (DBP), and 2017 United States hypertension guidelines with all-cause mortality in China.

Methods

We conducted a prospective study of 13,760 rural Chinese adults aged 18 or older (41.1% men). Mean age overall was 49.4, 51.0 for men, and 48.3 for women. We analyzed the blood pressure–mortality relationship by using restricted cubic splines and Cox proportional-hazards regression analysis, estimating hazard ratios (HRs) and 95% confidence intervals (CIs).

Results

During a mean follow-up of 5.95 years, 710 people died (60.3% men) from any cause. We found a U-shaped SBP–mortality or DBP–mortality relationship for both sexes. Mortality risk was increased for men with SBP 120–139 mm Hg (adjusted HR [aHR], 1.42; 95% CI, 1.10–1.82) or ≥140 mm Hg (aHR, 2.05; 95% CI, 1.54–2.72), and for DBP ≥90 mm Hg (aHR, 1.53; 95% CI, 1.10–2.13) as compared with SBP 100–119 mm Hg or DBP 70–79 mm Hg. Mortality risk also was increased for men with blood pressure status defined according to 2017 US hypertension guidelines as elevated, SBP 120–129 and DBP >80 mm Hg (aHR 1.48; 95% CI,1.11–1.98); stage 1 hypertension, SBP/DBP 130–139/80–89 mm Hg (aHR 1.53; CI, 1.19–1.97); and stage 2 hypertension, SBP/DBP ≥140/90 mm Hg (aHR 1.83; CI, 1.33–2.51). No significant relationship was observed for women.

Conclusion

Elevated blood pressure and stages 1 and 2 hypertension were positively associated with all-cause mortality for men but not women in rural China.

Does Gender Influence the Relationship Between High Blood Pressure and Dementia? Highlighting Areas for Further Investigation

BACKGROUND

Gender differences have been noted in studies linking blood pressure to all-cause dementia, and the two most common forms of dementia: Alzheimer's disease (AD) and vascular dementia (VaD). However, how gender modifies the relationship between blood pressure and dementia remains unclear.

OBJECTIVE

To review evidence for a gender modifying effect on the link between blood pressure and all-cause dementia.

METHODS

A systematic review was conducted according to PRISMA guidelines. Sixteen out of 256 reviewed articles met inclusion criteria.

RESULTS

For women, higher midlife systolic blood pressure (SBP) and hypertension were both associated with greater risk of all-cause dementia, AD, and VaD, in six out of seven studies. Two of these studies reported higher midlife SBP/hypertension were associated with greater risk for all-cause dementia in women, but not men. One study reported higher midlife SBP associated with greater AD risk in women, but not men. However, another study reported that midlife hypertension associated with AD risk in men, but not women. No clear gender differences were reported in the relationship between late-life high blood pressure/hypertension with all-cause dementia or AD.

CONCLUSION

Studies rarely, and inconsistently, analyzed or reported gender effects. Therefore, interpretation of available evidence regarding the role of gender in blood pressure associated dementia was difficult. Several studies indicated higher midlife SBP was associated with greater risk of all-cause dementia for women, compared to men. Future studies should evaluate women-specific aging processes that occur in midlife when considering the association between blood pressure and dementia risk.

UTCI as a bio-meteorological tool in the assessment of cold-induced stress as a risk factor for hypertension

BACKGROUND

Hypertension (HT) affects >1/3 of adult populations in developed countries. Several studies reported periodic changes in blood pressure (BP) values depending on atmospheric conditions, and analyzed the impact of outdoor temperature, atmospheric pressure, relative humidity and other meteorological parameters. The Universal Thermal Climate Index (UTCI) is a bio-meteorological index derived from an analysis of human thermal balance that comprehensively describes the impact of meteorological factors, including both cold stress and heat stress and their physiological consequences.

AIM

Our aim was to assess the relationship between UTCI values and the number of consultations for HT within the framework of the healthcare system.

METHODS

This work presents a retrospective epidemiological study of data collected in Olsztyn (Poland), characterized by cold climate type. The analytical material comprised 5578 consultations in emergency departments (EDs) due to HT.

RESULTS

Seasonal differences in the numbers of HT consultations with a significant increase in winter months were noticed, especially as regards women. Under cold stress conditions, the relative risk (RR) related to consultations for HT was 2-fold higher for women as compared to thermoneutral conditions (p < 0.001). For men these differences were also statistically significant, though at a much smaller level (p = 0.03). The increased RR of HT due to cold stress was found among younger and older women contrary to the women at the perimenopausal age.

CONCLUSIONS

Cold stress should be considered as a significant risk factor among patients, particularly women, diagnosed with cardiovascular diseases. The UTCI is an adequate bio-meteorological tool for the assessment of relationships between atmospheric conditions and occurrence of cardiac symptoms.

Enhanced Renal Vascular Responsiveness to Angiotensin II and Norepinephrine: A Unique Feature of Female Rats with Congestive Heart Failure

Background/Aims: We found recently that the aortocaval fistula (ACF)-induced heart failure (HF) results in higher mortality in female than in male rats. Possibly, the development of renal dysfunction in the females, unlike in males, is associated with altered renal vascular responsiveness to angiotensin II (ANG II). Methods: Five or 20 weeks after ACF creation (compensated and decompensated HF, respectively), we assessed renal blood flow (RBF) responses to intrarenal administration of ANG II, norepinephrine (NE), and acetylcholine (Ach) in female ACF and sham-operated rats. Results: In ACF females, ANG II decreased RBF more than in healthy animals, unlike with earlier published data in male ACF rats that responded similarly. Also, NE decreased RBF more in female ACF rats, whereas Ach increased RBF to the same extent in female ACF and sham-operated rats. RBF responses to intravenous administration of NE and Ach were almost identical in female and male ACF rats. Conclusion: Female ACF rats studied at the onset of HF decompensation reveal, in contrast to male rats, enhanced renal vascular responsiveness to both NE and ANG II. When associated with the demonstrated increased intrarenal ANG II and NE concentrations, such hyperresponsiveness might promote the development of renal dysfunction and accelerate HF decompensation.

Prescribing pattern of antihypertensive medication and adherence to Joint National Commission-8 guidelines in a rural tertiary care Indian teaching hospital

Background Antihypertensive medications are one among the most highly used drugs across the globe as well as in India, and their prescribing pattern will be erratic despite the various clinical guidelines. Few studies address the pattern and adherence to the standard treatment guidelines in India. This study aimed to review the prescribing pattern of antihypertensive medications in a rural tertiary care teaching Indian hospital and to investigate the adherence to the Joint National Commission-8 (JNC-8) guidelines on prevention, detection, evaluation, and treatment of hypertension in adults. Methods A prospective observational study was conducted among the participants from four different inpatient wards who are aged >18 years, without gender restriction. The prescription pattern was reviewed and adherence to the JNC-8 guidelines was also assessed. A purposive sampling technique was adopted and descriptive statistics were used in Statistical Package for the Social Sciences v16. Results Of the 101 participants included in the study, 62 (61.39%) were female, 23.76% were aged <30 and >60 years, and the other 52.48% belong to the range of 30-60 years. As per JNC-8 guidelines, 4.95%, 17.82%, 44.55%, and 32.67% of patients were classified as normal, pre-hypertensive, stage I, and stage II, respectively. Most of them (31.68%) were free from comorbidities. The most (23.76%) prescribed drug was calcium channel blocker (CCB), and 15.84% of the patients received combination therapy. Treatment was effective in 70.30% of the patients through analyzing their blood pressure even though the adherence to the JNC-8 guidelines was only in 54.46%. Conclusions Our study revealed that CCB was the most prescribed drug, and in spite of the only 50% adherence rate, treatment was effective in the majority of the population. The treatment outcome can be improved if the adherence rate is increased further.

Association between Advanced Glycation End Products, Soluble RAGE Receptor, and Endothelium Dysfunction, Evaluated by Circulating Endothelial Cells and Endothelial Progenitor Cells in Patients with Mild and Resistant Hypertension

The aim of the present study was to evaluate advanced glycation end products (AGEs) and soluble form of receptor RAGE (sRAGE) concentrations as well as the AGEs/sRAGE ratio in mild (MH) and resistant (RH) hypertensive patients in comparison with normotensive individuals. We also evaluated the association between AGEs, sRAGE as well as AGEs/sRAGE ratio and circulating endothelial cells (CECs) and circulating endothelial progenitor cells (CEPCs). The MH group consisted of 30 patients, whereas 30 patients were classified for the RH group. The control group (C) included 25 normotensive volunteers. AGEs and sRAGE were measured using enzyme-linked-immunosorbent assay (ELISA). The multicolor flow cytometry was used for analysis of CECs and CEPCs. Significantly higher levels of AGEs in RH cohort were observed as compared to C cohort. Furthermore, significantly lower sRAGE levels as well as a higher AGEs/sRAGE ratio were observed between MH and RH cohorts. Significant correlations were found in the MH cohort for sRAGE and CECs, and CEPCs. The elevation of AGEs levels suggests that oxidative modification of proteins occurs in hypertension pathogenesis. The decrease in sRAGE levels and elevation of the AGEs/sRAGE ratio in MH and RH groups may suggest that hypertensive patients are less protected against the side effects of AGEs as a consequence of an insufficient competitive role of sRAGE against the AGEs-RAGE axis. Finally, it may be concluded that the level of AGEs may be an independent predictor of the condition and function of the endothelium. Furthermore, sRAGE may be classified as a potential biomarker of inflammation and endothelium dysfunction.

Factors associated with hypertension among adults in Nepal as per the Joint National Committee 7 and 2017 American College of Cardiology/American Heart Association hypertension guidelines: a cross-sectional analysis of the demographic and health survey 2016

OBJECTIVES

This study investigated the determinants of hypertension in Nepal according to both the Joint National Committee 7 (JNC7) and the American College of Cardiology/American Heart Association (2017 ACC/AHA) guidelines.

DESIGN

Cross-sectional study.

SETTING

This study used data collected from the 2016 Nepal Demographic and Health Survey data.

PARTICIPANTS

13 393 weighted adults aged ≥18 years enrolled by a stratified cluster sampling strategy were included in our analysis.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was hypertension, which was defined according to JNC7 (systolic blood pressure (SBP) ≥140 mm Hg and/or diastolic blood pressure (DBP) ≥90 mm Hg) and 2017 ACC/AHA guidelines (SBP ≥130 mm Hg and/or DBP ≥80 mm Hg). Antihypertensive medication users were also classified as hypertensive. After descriptive analysis, multilevel logistic regression was applied to obtain ORs.

RESULTS

About 21% (n=2827) and 44% (n=5918) of the individuals aged ≥18 years were classified as hypertensive according to the JNC7 and 2017 ACC/AHA guidelines, respectively. Following factors were found to be significantly associated with hypertension according to the 2017 ACC/AHA guideline: ≥70 years (adjusted OR (AOR) 5.2; 95% CI 4.3 to 6.2), 50-69 years (AOR 3.9; 95% CI 3.4 to 4.4) and 30-49 years (AOR 2.7; 95% CI 2.4 to 3.0) age groups, male gender (AOR 1.7; 95% CI 1.6 to 1.9), being overweight/obese (AOR 3.0; 95% CI 2.7 to 3.3), residence in provinces 4 (AOR 1.5; 95% CI 1.2 to 2.0) and 5 (AOR 1.5; 95% CI 1.2 to 1.9). No significant association was identified with household wealth status and ecological regions of residence using the 2017 ACC/AHA guideline.

CONCLUSIONS

Per both guidelines, multiple factors were associated with hypertension. Public health programme aiming to prevent and control hypertension in Nepal should prioritise these factors and focus on individuals with a higher likelihood of hypertension irrespective of educational level, household wealth status and ecological regions of residence.

Sex, gut microbiome, and cardiovascular disease risk

Key differences exist between men and women in the determinants and manifestations of cardiovascular and cardiometabolic diseases. Recently, gut microbiome-host relations have been implicated in cardiovascular disease and associated metabolic conditions; therefore, gut microbiota may be key mediators or modulators driving the observed sexual dimorphism in disease onset and progression. While current evidence regarding pure physiological sex differences in gut microbiome composition is modest, robust research suggests that gut microbiome-dependent metabolites may interact with important biological pathways under sex hormone control, including toll-like receptor and flavin monooxygenase signaling. Here, we review key sex differences in gut microbiome interactions with four primary determinants of cardiovascular disease, impaired glucose regulation, dyslipidemia, hypertension, and obesity. Through this process, we propose important sex differences in downstream metabolic pathways that may be at the interface of the gut microbiome and cardiovascular disease.

Estrogen negatively regulates the renal epithelial sodium channel (ENaC) by promoting Derlin-1 expression and AMPK activation

The main functions of the epithelial sodium channel (ENaC) in the kidney distal nephron are mediation of sodium and water balance and stabilization of blood pressure. Estrogen has important effects on sodium and water balance and on premenopausal blood pressure, but its role in the regulation of ENaC function is not fully understood. Female Sprague–Dawley rats were treated with 17β-estradiol for 6 weeks following bilateral ovariectomy. Plasma estrogen, aldosterone, creatinine, and electrolytes were analyzed, and α-ENaC and derlin-1 protein expression in the kidney was determined by immunohistochemistry and western blotting. The expression levels of α-ENaC, derlin-1, AMPK, and related molecules were also examined by western blotting and real-time PCR in cultured mouse renal collecting duct (mpkCCDc14) epithelial cells following estrogen treatment. Immunofluorescence and coimmunoprecipitation were performed to detect α-ENaC binding with derlin-1 and α-ENaC ubiquitination. The results demonstrated that the loss of estrogen elevated systolic blood pressure in ovariectomized (OVX) rats. OVX rat kidneys showed increased α-ENaC expression but decreased derlin-1 expression. In contrast, estrogen treatment decreased α-ENaC expression but increased derlin-1 expression in mpkCCDc14 cells. Moreover, estrogen induced α-ENaC ubiquitination by promoting the interaction of α-ENaC with derlin-1 and evoked phosphorylation of AMPK in mpkCCDc14 cells. Our study indicates that estrogen reduces ENaC expression and blood pressure in OVX rats through derlin-1 upregulation and AMPK activation.

Estrogen treatment could prove valuable in tackling high blood pressure (hypertension) in postmenopausal women. Long-term healthy blood pressure is linked to the correct regulation of sodium and water levels in the kidneys. The renal epithelial sodium channel (ENaC) is a cellular membrane channel responsible for mediating sodium reabsorption and fluid balance. Liang and co-workers at Nanjing Medical University in Nanjing, China, conducted experiments on postmenopausal rat models, and found that loss of estrogen elevates systolic blood pressure (the pressure during heart muscle contraction), and that the rats had high levels of ENaC expression. Further investigations showed that estrogen treatment restored blood pressure to normal levels by promoting two key proteins involved in cellular membrane health and energy metabolism. This in turn reinstated normal levels of ENaC breakdown in the kidneys, limiting hypertension.

Comparison of diabetic nephropathy between male and female eNOS-/-db/db mice

Sex is an important biological variable that impacts diverse physiological and pathological processes, including the progression of diabetic nephropathy. Diabetic nephropathy is one of the most common complications of diabetes mellitus and is the leading cause of end-stage renal disease. The endothelial nitric oxide synthase-deficient (eNOS-/-) db/db mouse is an appropriate and valuable model to study mechanisms in the development of diabetic nephropathy because of the similarities of the features of diabetic kidney disease in this model to those in humans. The aim of the present study was to determine whether there was a sex difference in renal injury in eNOS-/-db/db mice. Both male and female eNOS-/-db/db mice showed hyperglycemia, obesity, and renal hypertrophy. However, there was no significant difference in those variables between male and female mice. Furthermore, both male and female diabetic mice showed progressive albuminuria and significantly greater levels of serum creatinine and blood urea nitrogen compared with the same sex of wild-type mice (nondiabetic controls). Although all three variables in female eNOS-/-db/db mice had a tendency to be greater than those in male eNOS-/-db/db mice, those sex differences were not statistically significant. Moreover, both male and female eNOS-/-db/db mice showed significant mesangial expansion, higher glomerular injury scores, profound renal fibrosis, and substantial accumulation of fibronectin and collagen type IV proteins. However, sex differences in those structural changes were not observed. Similarly, survival rates of male and female eNOS-/-db/db mice were comparable. Taken together, the results from the present study suggest no sex difference in renal structural and functional damage in eNOS-/-db/db mice.

Multifactorial correlates of blood pressure in South Asian children in Canada: a cross-sectional study

OBJECTIVE

We sought to explore various correlates of blood pressure (BP) and hypertension, and to identify the most important aggregate combination of correlates for BP in South Asian children.

DESIGN

Cross-sectional study SETTING: Community-based recruitment in two Canadian cities PARTICIPANTS: South Asian children (n=762) provided a range of physiological, lifestyle and social variables. BP was assessed using an automated device. Body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR) and BP were transformed to z-scores using published standards.

OUTCOME MEASURES

Linear and logistic regression analyses were used to explore associations between the range of variables with BP z-scores and hypertension while stepwise regression was used to identify aggregate factors that provided explanatory capacity for systolic BP (SBP) and diastolic BP (DBP) z-scores.

RESULTS

A range of variables were associated with BP z-score and hypertension in unadjusted analysis. On adjustment for confounders, the association between age (β=-0.054, 95% CI=-0.078 to 0.029), female sex (β=-0.208, 95% CI=-0.350 to -0.067), height (β=0.022, 95% CI=0.011 to 0.033), weight (β=0.047, 95% CI=0.040 to 0.055), BMI z-score (β=0.292, 95% CI=0.249 to 0.336), WC z-score (β=0.273, 95% CI=0.219 to 0.326), WHtR z-score (β=0.289, 95% CI=0.236 to 0.342), heart rate (β=0.016, 95% CI=0.010 to 0.022), child's perception of body image (β=0.183, 95% CI=0.128 to 0.239) and grip strength (β=0.025, 95% CI=0.007 to 0.043) with SBP z-score remained. In stepwise regression, age, sex, BMI z-score, heart rate and weight accounted for 30% of the variance of SBP z-score, while age, BMI z-score, heart rate and daily fast food intake accounted for 23% of the DBP z-score variance.

CONCLUSION

Our findings suggest that variables, such as age, sex, height, adiposity and heart rate, provide stronger explanatory capacity to BP variance and hypertension risk than other variables in South Asian children.

Effect of Previous Exposure to Malaria on Blood Pressure in Kilifi, Kenya: A Mendelian Randomization Study

Background Malaria exposure in childhood may contribute to high blood pressure ( BP ) in adults. We used sickle cell trait ( SCT ) and α+thalassemia, genetic variants conferring partial protection against malaria, as tools to test this hypothesis. Methods and Results Study sites were Kilifi, Kenya, which has malaria transmission, and Nairobi, Kenya, and Jackson, Mississippi, where there is no malaria transmission. The primary outcome was 24-hour systolic BP. Prevalent hypertension, diagnosed using European Society of Hypertension thresholds was a secondary outcome. We performed regression analyses adjusting for age, sex, and estimated glomerular filtration rate. We studied 1127 participants in Kilifi, 516 in Nairobi, and 651 in Jackson. SCT frequency was 21% in Kilifi, 16% in Nairobi, and 9% in Jackson. SCT was associated with -2.4 (95% CI , -4.7 to -0.2) mm Hg lower 24-hour systolic BP in Kilifi but had no effect in Nairobi/Jackson. The effect of SCT in Kilifi was limited to 30- to 59-year-old participants, among whom it was associated with -6.1 mm Hg ( CI , -10.5 to -1.8) lower 24-hour systolic BP. In pooled analysis allowing interaction by site, the effect of SCT on 24-hour systolic BP in Kilifi was -3.5 mm Hg ( CI , -6.9 to -0.1), increasing to -5.2 mm Hg ( CI , -9.5 to -0.9) when replacing estimated glomerular filtration rate with urine albumin to creatinine ratio as a covariate. In Kilifi, the prevalence ratio for hypertension was 0.86 ( CI , 0.76-0.98) for SCT and 0.89 ( CI , 0.80-0.99) for α+thalassemia. Conclusions Lifelong malaria protection is associated with lower BP in Kilifi. Confirmation of this finding at other sites and elucidating the mechanisms involved may yield new preventive and therapeutic targets.

Understanding sex differences in long-term blood pressure regulation: insights from experimental studies and computational modeling

Sex differences in blood pressure and the prevalence of hypertension are found in humans and animal models. Moreover, there has been a recent explosion of data concerning sex differences in nitric oxide, the renin-angiotensin-aldosterone system, inflammation, and kidney function. These data have the potential to reveal the mechanisms underlying male-female differences in blood pressure control. To elucidate the interactions among the multitude of physiological processes involved, one may apply computational models. In this review, we describe published computational models that represent key players in blood pressure regulation, and highlight sex-specific models and their findings.

Superimposed Preeclampsia Exacerbates Postpartum Renal Injury Despite Lack of Long-Term Blood Pressure Difference in the Dahl Salt-Sensitive Rat

Preeclampsia results in increased susceptibility to hypertension and chronic kidney disease postpartum; however, the mechanisms responsible for disease progression in these women remain unknown. The purpose of this study was to test the hypothesis that 2 mechanisms contribute to the link between the maternal syndrome of preeclampsia and the increased postpartum risk of cardiovascular and renal disease: (1) increased T cells in the kidney and (2) a decreased NO:ET-1 (endothelin-1) ratio. Dahl S rats (a previously characterized model of preeclampsia superimposed on chronic hypertension) who experienced 2 pregnancies and virgin littermate controls were studied at 6 months of age. Mean arterial pressure was measured via telemetry, and renal injury was assessed through both histological analysis and measurement of urinary markers including nephrin, podocalyxin, and KIM-1 (kidney injury marker 1). Contributing mechanisms were assessed through flow cytometric analysis of renal T cells, quantification of plasma TNF-α (tumor necrosis factor-α) and IL-10 (interleukin-10), and quantification of urinary concentrations of NO metabolites and ET-1. Although prior pregnancy did not exacerbate the hypertension at 6 months, this group showed greater renal injury compared with virgin littermates. Flow cytometric analyses revealed an increase in renal T cells after pregnancy, and cytokine analysis revealed a systemic proinflammatory shift. Finally, the NO:ET-1 ratio was reduced. These results demonstrate that the link between the maternal syndrome of superimposed preeclampsia and postpartum risk of chronic kidney disease could involve both immune system activation and dysregulation of the NO:ET-1 balance.

ORAI channels in cellular remodeling of cardiorespiratory disease

Cardiorespiratory disease, which includes systemic arterial hypertension, restenosis, atherosclerosis, pulmonary arterial hypertension, asthma, and chronic obstructive pulmonary disease (COPD) are highly prevalent and devastating diseases with limited therapeutic modalities. A common pathophysiological theme to these diseases is cellular remodeling, which is contributed by changes in expression and activation of ion channels critical for either excitability or growth. Calcium (Ca²⁺) signaling and specifically ORAI Ca²⁺ channels have emerged as significant regulators of smooth muscle, endothelial, epithelial, platelet, and immune cell remodeling. This review details the dysregulation of ORAI in cardiorespiratory diseases, and how this dysregulation of ORAI contributes to cellular remodeling.

Sex differences in risk factors for vascular contributions to cognitive impairment & dementia

Vascular contributions to cognitive impairment and dementia (VCID) is the second most common cause of dementia. While males overall appear to be at a slightly higher risk for VCID throughout most of the lifespan (up to age 85), some risk factors for VCID more adversely affect women. These include female-specific risk factors associated with pregnancy related disorders (e.g. preeclampsia), menopause, and poorly timed hormone replacement. Further, presence of certain co-morbid risk factors, such as diabetes, obesity and hypertension, also may more adversely affect women than men. In contrast, some risk factors more greatly affect men, such as hyperlipidemia, myocardial infarction, and heart disease. Further, stroke, one of the leading risk factors for VCID, has a higher incidence in men than in women throughout much of the lifespan, though this trend is reversed at advanced ages. This review will highlight the need to take biological sex and common co-morbidities for VCID into account in both preclinical and clinical research. Given that there are currently no treatments available for VCID, it is critical that we understand how to mitigate risk factors for this devastating disease in both sexes.

Sex Differences in Hypertension: Where We Have Been and Where We Are Going

While it has been known since the 1940s that men have greater increases in blood pressure (BP) compared with women, there have been intense efforts more recently to increase awareness that women are also at risk for developing hypertension and that cardiovascular diseases (CVDs) are the leading causes of death among both men and women in the United States. With the release of the 2017 Hypertension Clinical Guidelines, 46% of adults in the United States are now classified as hypertensive, and hypertension is the primary modifiable risk factor for the development of CVD. This increase in the prevalence of hypertension is reflected in an increase in prevalence among both men and women across all demographics, although there were greater increases in the prevalence of hypertension among men compared with women. As a result, the well-established gender difference in the prevalence of hypertension is even more pronounced and now extends into the sixth decade of life. The goals of this review are to (i) review the historical clinical trial data and hypertension guidelines from the perspective of both genders and then (ii) review the role of the renin-angiotensin system and T-cell activation in contributing to sex differences in BP control.

Masked hypertension incidence and risk factors in a prospective cohort study

Aims

Masked hypertension may affect up to 30% of the general population and is associated with a high cardiovascular disease risk. No previous study has examined the incidence of masked hypertension and its risk factors. The study aim was to determine the incidence of masked hypertension and to examine its related risk factors.

Methods

This is a cohort study including 1836 initially normotensive participants followed up on average for 2.9 years. Blood pressure was measured using Spacelabs 90207. Manual blood pressure was defined as the mean of the first three readings taken at rest. Ambulatory blood pressure was defined as the mean of the next readings recorded every 15 minutes during daytime working hours. Masked hypertension incidence at follow-up was defined as manual blood pressure less than 140 and less than 90 mmHg and ambulatory blood pressure at least 135 or at least 85 mmHg. Generalised estimating equations were used.

Results

The cumulative incidence of masked hypertension was 10.3% and was associated with male gender (relative risk (RR) 1.51, 95% confidence interval (CI) 1.18–1.94), older age (RR40–49 years 1.56, 95% CI 1.16–2.11, RR≥50 years 1.50, 95% CI 1.06–2.10), higher education (RRcollege 1.31, 95% CI 1.03–1.65), body mass index (RR≥27 1.43, 95% CI 1.11–1.85), smoking (RR 1.51, 95% CI 1.09–2.010) and alcohol intake (RR≥6/week 1.65, 95% CI 1.13–2.03).

Conclusion

The present study is the first to identify risk factors for the incidence of masked hypertension. Current guidelines for hypertension detection recommend ambulatory blood pressure in patients with an elevated blood pressure reading at the clinic. As it is impractical to measure ambulatory blood pressure in all normotensive patients, factors identified in the present study should be considered for the screening of at-risk individuals and for primary prevention of masked hypertension.

Age and Sex Are Critical Factors in Ischemic Stroke Pathology

Ischemic stroke is a devastating brain injury resulting in high mortality and substantial loss of function. Understanding the pathophysiology of ischemic stroke risk, mortality, and functional loss is critical to the development of new therapies. Age and sex have a complex and interactive effect on ischemic stroke risk and pathophysiology. Aging is the strongest nonmodifiable risk factor for ischemic stroke, and aged stroke patients have higher mortality and morbidity and poorer functional recovery than their young counterparts. Importantly, patient age modifies the influence of patient sex in ischemic stroke. Early in life, the burden of ischemic stroke is higher in men, but stroke becomes more common and debilitating for women in elderly populations. The profound effects of sex and age on clinical ischemic stroke are mirrored in the results of experimental in vivo and in vitro studies. Here, we review current knowledge on the influence of age and sex in the incidence, mortality, and functional outcome of ischemic stroke in clinical populations. We also discuss the experimental evidence for sex and age differences in stroke pathophysiology and how a better understanding of these biological variables can improve clinical care and enhance development of novel therapies.

Vascular type 1 angiotensin receptors control blood pressure by augmenting peripheral vascular resistance in female mice

Angiotensin II (ANG II) is a major mediator of hypertension pathogenesis. In addition, there are well-documented differences in expression of the renin-angiotensin system (RAS) components and ANG II responses between males and females, which may explain sex differences in blood pressure (BP) and hypertension epidemiology. We previously showed that type 1A angiotensin (AT_1A) receptors in vascular smooth muscle cells (VSMCs) play a critical role in BP regulation and hypertension pathogenesis, but these studies were carried out in male mice. Therefore, the major goal of the current studies was to examine the impact of VSMC AT_1A receptors on BP and hypertension pathogenesis in female mice. We found that elimination of VSMC AT_1A receptors in female mice reduced (≈8 mmHg) baseline BP without altering sodium sensitivity. The severity of ANG II-induced hypertension was diminished (≈33% reduction in BP), particularly during the last 2 wk of chronic ANG II infusion, compared with controls, but natriuresis was not altered during the first 5 days of ANG II infusion. Urinary norepinephrine levels were enhanced in female SMKO compared with control mice. There was a virtually complete elimination of ANG II-induced kidney hemodynamic responses with attenuation of acute vasoconstrictor responses in the systemic vasculature. These findings demonstrate that direct vascular actions of AT_1A receptors play a prominent role in BP control and hypertension pathogenesis in female mice.

Compromised regulation of the collecting duct ENaC activity in mice lacking AT1a receptor

ENaC-mediated sodium reabsorption in the collecting duct (CD) is a critical determinant of urinary sodium excretion. Existing evidence suggest direct stimulatory actions of Angiotensin II (Ang II) on ENaC in the CD, independently of the aldosterone-mineralocorticoid receptor (MR) signaling. Deletion of the major renal AT₁ receptor isoform, AT_1a R, decreases blood pressure and reduces ENaC abundance despite elevated aldosterone levels. The mechanism of this insufficient compensation is not known. Here, we used patch clamp electrophysiology in freshly isolated split-opened CDs to investigate how AT_1a R dysfunction compromises functional ENaC activity and its regulation by dietary salt intake. Ang II had no effect on ENaC activity in CDs from AT_1a R -/- mice suggesting no complementary contribution of AT₂ receptors. We next found that AT_1a R deficient mice had lower ENaC activity when fed with low (<0.01% Na⁺ ) and regular (0.32% Na⁺ ) but not with high (∼2% Na⁺ ) salt diet, when compared to the respective values obtained in Wild type (WT) animals. Inhibition of AT₁ R with losartan in wild-type animals reproduces the effects of genetic ablation of AT_1a R on ENaC activity arguing against contribution of developmental factors. Interestingly, manipulation with aldosterone-MR signaling via deoxycosterone acetate (DOCA) and spironolactone had much reduced influence on ENaC activity upon AT_1a R deletion. Consistently, AT_1a R -/- mice have a markedly diminished MR abundance in cytosol. Overall, we conclude that AT_1a R deficiency elicits a complex inhibitory effect on ENaC activity by attenuating ENaC P_o and precluding adequate compensation via aldosterone cascade due to decreased MR availability.

Sexual Dimorphic Pattern of Renal Transporters and Electrolyte Homeostasis

Compared with males, females have lower BP before age 60, blunted hypertensive response to angiotensin II, and a leftward shift in pressure natriuresis. This study tested the concept that this female advantage associates with a distinct sexual dimorphic pattern of transporters along the nephron. We applied quantitative immunoblotting to generate profiles of transporters, channels, claudins, and selected regulators in both sexes and assessed the physiologic consequences of the differences. In rats, females excreted a saline load more rapidly than males did. Compared with the proximal tubule of males, the proximal tubule of females had greater phosphorylation of Na+/H+ exchanger isoform 3 (NHE3), distribution of NHE3 at the base of the microvilli, and less abundant expression of Na+/Pi cotransporter 2, claudin-2, and aquaporin 1. These changes associated with less bicarbonate reabsorption and higher lithium clearance in females. The distal nephrons of females had a higher abundance of total and phosphorylated Na+/Cl- cotransporter (NCC), claudin-7, and cleaved forms of epithelial Na+ channel (ENaC) α and γ subunits, which associated with a lower baseline plasma K+ concentration. A K+-rich meal increased the urinary K+ concentration and decreased the level of renal phosphorylated NCC in females. Notably, we observed similar abundance profiles in female versus male C57BL/6 mice. These results define sexual dimorphic phenotypes along the nephron and suggest that lower proximal reabsorption in female rats expedites excretion of a saline load and enhances NCC and ENaC abundance and activation, which may facilitate K+ secretion and set plasma K+ at a lower level.

Sex and gender differences in hypertensive kidney injury

Hypertension is a complex, multifaceted disorder, affecting ~1 in 3 adults in the United States. Although hypertension occurs in both men and women, there are distinct sex differences in the way in which they develop hypertension, with women having a lower incidence of hypertension until the sixth decade of life. Despite observed sex differences in hypertension, little is known about the molecular mechanisms underlying the development of hypertension in females, primarily because of their underrepresentation in both clinical and experimental animal studies. The first goal of this review is to provide a concise overview of the participation of women in clinical trials, including a discussion of the importance of including females in basic science research, as recently mandated by the National Institutes of Health. The remaining portion of the review is dedicated to identifying clinical and experimental animal studies that concentrate on gender and sex differences in hypertensive kidney disease, ending with a proposed role for T cells in mediating sex differences in blood pressure.

Greater transforming growth factor-β in adult female SHR is dependent on blood pressure, but does not account for sex differences in renal T-regulatory cells

Female spontaneously hypertensive rats (SHR) have more renal regulatory T cells (Tregs) than males, and greater levels of Tregs in female SHR are dependent on blood pressure (BP). However, the molecular mechanism responsible for greater Tregs in female SHR is unknown. Transforming growth factor (TGF)-β is a pleiotropic cytokine critical in the differentiation of naïve T cells into Tregs, and female SHR have higher TGF-β excretion than male SHR. The goals of the current study were to test the hypotheses that 1) female SHR have greater renal TGF-β expression than male SHR, which is dependent on BP and 2) neutralizing TGF-β will decrease renal Tregs in female SHR. Renal cortices were isolated from 5- and 13-wk-old male and female SHR, and TGF-β levels were measured via Western blot and ELISA. Adult female SHR have more free, active TGF-β₁ than 5-wk-old female SHR (46% more) or male SHR (44% more than 5-wk-old males and 56% more than 13-wk-old male SHR). We confirmed greater TGF-β₁ in adult female SHR was due to increases in BP and not sexual maturation by measuring TGF-β₁ levels following treatment with BP-lowering drugs or ovariectomy. Separate female SHR were treated with an antibody to TGF-β_1,2,3; BP was measured, and T cells were assessed in whole blood and the kidney. Neutralizing TGF-β had no effect on BP, although circulating Tregs decreased by 32%, while Th17 cells increased by 64%. Renal Tregs were not altered by antibody treatment, although Th17 cells were decreased by 61%. In conclusion, although TGF-β promotes circulating Tregs in female SHR, it does not account for the sex difference in renal Tregs in SHR.