Hypertension in blacks: insights from Africa

Genetic Appraisal of RAAS-Associated SNPs: REN (rs16853055), AGT (rs3789678) and ACE (rs4305) in Preeclamptic Women Living with HIV Infection

PURPOSE OF REVIEW

The primary goal of this review article was to determine whether the three RAAS-associated SNPs, Renin-rs16853055, AGT-rs3789678 and ACE-rs4305 are genetically linked to the development of hypertension in preeclampsia. The secondary goal was to establish if there was a link between these SNPs and HIV infection.

RECENT FINDINGS

There is a paucity of findings related to the aforementioned SNPs and preeclampsia. There are no recent findings on the rs16853055 renin polymorphism. The rs3789678 angiotensinogen polymorphism correlated significantly with gestational hypertension. The rs4305 ACE polymorphism showed no significant association with the development of pregnancy-induced hypertension. There are conflicting findings when determining the relationship between ethnicity and the predisposition of preeclampsia and hypertension in relation to the discussed RAAS-associated SNPs. To date, the association between RAAS-associated SNPs and preeclamptic women co-morbid with HIV in South Africa has revealed that certain alleles of the AGT gene are more prominent in HIV-infected PE compared to normotensive pregnant HIV-infected women.

A Systematic Review and Meta-analysis of Renin-angiotensin System Inhibitors and Angiotensin Receptor Neprilysin Inhibitors in Preventing Recurrence After Atrial Fibrillation Ablation

ABSTRACT

To systematically evaluate the efficacy and safety of renin-angiotensin system inhibitors (RASIs) and angiotensin receptor neprilysin inhibitors in preventing the recurrence of atrial fibrillation after atrial fibrillation ablation, we have written this meta-analysis. We systematically searched randomized controlled trials or cohort studies on RASIs and angiotensin receptor neprilysin inhibitor-sacubitril/valsartan (SV) in preventing the recurrence of atrial fibrillation. Two researchers independently screened the literature, extracted the data, and assessed the risk of bias in the included studies. Afterward, the meta-analysis was performed using RevMan 5.3 software. This meta-analysis results showed that the recurrence rate of atrial fibrillation after ablation in subjects using RASIs was lower than that in subjects not using them [relative risk = 0.85, 95% confidence interval (CI) (0.72-0.99), P = 0.03]; the recurrence rate in subjects using SV was lower than that in subjects using RASIs [RR= 0.50, 95% CI (0.37-0.68), P < 0.00001]. These results show that both the use of RASIs and SV can prevent the recurrence of after atrial fibrillation ablation, among which the use of SV is more effective.

Salt Sensitivity of Blood Pressure in Black People: The Need to Sort Out Ancestry Versus Epigenetic Versus Social Determinants of Its Causation

Race is a social construct, but self-identified Black people are known to have higher prevalence and worse outcomes of hypertension than White people. This may be partly due to the disproportionate incidence of salt sensitivity of blood pressure in Black people, a cardiovascular risk factor that is independent of blood pressure and has no proven therapy. We review the multiple physiological systems involved in regulation of blood pressure, discuss what, if anything is known about the differences between Black and White people in these systems and how they affect salt sensitivity of blood pressure. The contributions of genetics, epigenetics, environment, and social determinants of health are briefly touched on, with the hope of stimulating further work in the field.

Associated factors with hypertension, known poorly controlled hypertension, and newly diagnosed hypertension among people aged 18-70 in Senegal

Introduction

In this study, we aimed to determine the factors associated with hypertension, known poorly controlled hypertension, and newly diagnosed hypertension in 2015 to improve the prevention of this pathology in our country.

Methods

This was a secondary analysis of the national WHO STEPwise survey database. It had a quantitative, descriptive, and analytical aim. The sampling was done in stratification in three stages of sampling. Statistical analysis was performed using Rstudio 4.0.2 software. It was a descriptive, bivariate, and multivariate analysis using binomial logistic regression for explanatory purposes.

Results

The risk factors for being hypertensive among 18-70- year-olds in Senegal in 2015 were: having taken their blood pressure at least once in their life; having taken their cholesterol levels at least once in their life; having received advice to reduce salt consumption; having received advice on how to reduce the amount of sugar; having a lean body mass index; being overweight; being obese III; and being between 35-39 and 65-70 years old. The protective factors are: checking the salt content indicated on the labels; and consuming salt-rich dishes "often" compared to "never". The risk factors for being newly diagnosed with hypertension among 18-70-year-olds in Senegal in 2015 were: having a history of stroke; having a resting heart rate greater than 80 beats per minute; consuming palm oil; and having high fasting blood sugar. The protective factors are: having a high average number of meals eaten per week not prepared at home; checking the salt content indicated on the label; and being of female sex. The risk factors for being known to have poorly controlled hypertension among 18-70- year-olds in Senegal in 2015 were: judging their reduction in salt consumption as "very important"; and having received advice to reduce their salt consumption. The protective factors are: performing physical activity only when traveling; and limiting the consumption of salty meals.

Conclusion

Senegalese family cooking exposes to hypertension, small actions limiting salt consumption strongly protect against hypertension, and simple physical activity during travel strongly protects against hypertension, but the health system is very little proactive in the primordial and primary prevention of hypertension.

Promise of Physiological Profiling to Prevent Stroke in People of African Ancestry: Prototyping Ghana

PURPOSE OF REVIEW

Worldwide, compared to other racial/ethnic groups, individuals of African ancestry have an excessively higher burden of hypertension-related morbidities, especially stroke. Identifying modifiable biological targets that contribute to these disparities could improve global stroke outcomes. In this scoping review, we discuss how pathological perturbations in the renin-angiotensin-aldosterone pathways could be harnessed via physiological profiling for the purposes of improving blood pressure control for stroke prevention among people of African ancestry.

RECENT FINDINGS

Transcontinental comparative data from the USA and Ghana show that the prevalence of treatment-resistant hypertension among stroke survivors is 42.7% among indigenous Africans, 16.1% among African Americans, and 6.9% among non-Hispanic Whites, p < 0.0001. A multicenter clinical trial of patients without stroke in 3 African countries (Nigeria, Kenya, and South Africa) demonstrated that physiological profiling using plasma renin activity and aldosterone to individualize selection of antihypertensive medications compared with usual care resulted in better blood pressure control with fewer medications over 12 months. Among Ghanaian ischemic stroke survivors treated without renin-aldosterone profiling data, an analysis revealed that those with low renin phenotypes did not achieve any meaningful reduction in blood pressure over 12 months on 3-4 antihypertensive medications despite excellent adherence. For a polygenic condition such as hypertension, individualized therapy based on plasma renin-aldosterone-guided selection of therapy for uncontrolled BP following precision medicine principles may be a viable strategy for primary and secondary stroke prevention with the potential to reduce disparities in the poor outcomes of stroke disproportionately shared by individuals of African ancestry. A dedicated clinical trial to test this hypothesis is warranted.

Aldosterone and angiotensin II profiles in young black and white women using different hormonal contraceptives: the African-PREDICT study

Exogenous estrogens and progestins may affect the components of the renin-angiotensin-aldosterone system (RAAS). Changes in ventricular blood volume are associated with increased secretion of N-terminal pro-hormone B-type natriuretic peptide (NT-proBNP), which may also be affected by hormonal contraceptives. In this study, we aimed to compare components of the RAAS and NT-proBNP between groups using different hormonal contraceptives, including the combination pill, the injection or implant, and controls (no contraception) in black and white women of fertile age (20 - 30 years). Secondly, we determined whether blood pressure and NT-proBNP are associated with the RAAS components. We included 397 black and white women not using contraceptives, 120 using the combination pill, and 103 receiving an injection/implant. RAAS Triple-A analysis was carried out with LC-MS/MS quantification, and blood pressure measurements (ABPM) taken over 24 h. We found that serum aldosterone was higher (475.7 vs. 249.2 pmol/L; p < 0.001) in the combination pill group than in the no contraception group of white women. The aldosterone-angiotensin II ratio (AA2) was higher (5.4 vs. 2.5; p < 0.001) in the combination pill group than in the no contraception group. In the black women using the combination pill, we found a borderline-positive and borderline-negative association between 24-h systolic blood pressure and NT-proBNP with equilibrium (eq) Ang II, respectively. In white women using the combination pill, only CRP contributed positively and independently to NT-proBNP. To conclude, activation of RAAS by different hormonal contraceptives may increase future risk for the development of hypertension in young black and white women.

Racial Differences in XO (Xanthine Oxidase) and Mitochondrial DNA Damage-Associated Molecular Patterns in Resistant Hypertension

BACKGROUND

We previously reported increased plasma XO (xanthine oxidase) activity in patients with resistant hypertension. Increased XO can cause mitochondrial DNA damage and promote release of fragments called mitochondrial DNA damage-associated molecular patterns (mtDNA DAMPs). Here, we report racial differences in XO activity and mtDNA DAMPs in Black and White adults with resistant hypertension.

METHODS

This retrospective study includes 91 resistant hypertension patients (44% Black, 47% female) with blood pressure >140/90 mm Hg on ≥4 medications and 37 normotensive controls (30% Black, 54% female) with plasma XO activity, mtDNA DAMPs, and magnetic resonance imaging of left ventricular morphology and function.

RESULTS

Black-resistant hypertension patients were younger (mean age 52±10 versus 59±10 years; P=0.001), with higher XO activity and left ventricular wall thickness, and worse diastolic dysfunction than White resistant hypertension patients. Urinary sodium excretion (mg/24 hour per kg) was positively related to left ventricular end-diastolic volume (r=0.527, P=0.001) and left ventricular mass (r=0.394, P=0.02) among Black but not White resistant hypertension patients. Patients with resistant hypertension had increased mtDNA DAMPs versus controls (P<0.001), with Black mtDNA DAMPS greater than Whites (P<0.001). Transmission electron microscopy of skeletal muscle biopsies in resistant hypertension patients demonstrates mitochondria cristae lysis, myofibrillar loss, large lipid droplets, and glycogen accumulation.

CONCLUSIONS

These data warrant a large study to examine the role of XO and mitochondrial mtDNA DAMPs in cardiac remodeling and heart failure in Black adults with resistant hypertension.

Characterization of the Renin-Angiotensin-Aldosterone System in Young Healthy Black Adults: The African Prospective Study on the Early Detection and Identification of Hypertension and Cardiovascular Disease (African-PREDICT Study)

[Figure: see text].

High prevalence of non-dipping patterns among Black Africans with uncontrolled hypertension: a secondary analysis of the CREOLE trial

BACKGROUND

Dipping of blood pressure (BP) at night is a normal physiological phenomenon. However, a non-dipping pattern is associated with hypertension mediated organ damage, secondary forms of hypertension and poorer long-term outcome. Identifying a non-dipping pattern may be useful in assessing risk, aiding the decision to investigate for secondary causes, initiating treatment, assisting decisions on choice and timing of antihypertensive therapy, and intensifying salt restriction.

OBJECTIVES

To estimate the prevalence and factors associated with non-dipping pattern and determine the effect of 6 months of three antihypertensive regimens on the dipping pattern among Black African hypertensive patients.

METHODS

This was a secondary analysis of the CREOLE Study which was a randomized, single blind, three-group trial conducted in 10 sites in 6 Sub-Saharan African countries. The participants were 721 Black African patients, aged between 30 and 79 years, with uncontrolled hypertension and a baseline 24-h ambulatory blood pressure monitoring (ABPM). Dipping was calculated from the average day and average night systolic blood pressure measures.

RESULTS

The prevalence of non-dipping pattern was 78% (564 of 721). Factors that were independently associated with non-dipping were: serum sodium > 140 mmol/l (OR = 1.72, 95% CI 1.17-2.51, p-value 0.005), a higher office systolic BP (OR = 1.03, 95% CI 1.01-1.05, p-value 0.003) and a lower office diastolic BP (OR = 0.97, 95% CI 0.95-0.99, p-value 0.03). Treatment allocation did not change dipping status at 6 months (McNemar's Chi2 0.71, p-value 0.40).

CONCLUSION

There was a high prevalence of non-dipping among Black Africans with uncontrolled hypertension. ABPM should be considered more routinely in Black Africans with uncontrolled hypertension, if resources permit, to help personalise therapy. Further research is needed to understand the mechanisms and causes of non-dipping pattern and if targeting night-time BP improves clinical outcomes. Trial registration ClinicalTrials.gov (NCT02742467).

[Evaluation of a woman's care program after pre-eclampsia]

INTRODUCTION

The medical treatment of preeclampsia is well structured in its acute phase but the required follow-up with patients in post-partum is discussed. However, preeclampsia is associated with an increased risk of cardiovascular morbi-mortality in the long term. In order to optimize the post-partum treatment, a care program has been developed for these patients in the city of Nantes, France. This includes a check-up of the cardiovascular risks at a day hospital. Our study presents the first results of this program.

METHODS

The study included 134 patients who were diagnosed with preeclampsia between October 2016 and January 2019 in the Nantes area, France, and took part in the program within the year following their childbirth. A descriptive analysis was first carried out and then a multivariate logistic regression model was used to investigate the risk factors for persistent high blood pressure after preeclampsia.

RESULTS

The study detected 28 cases of persistent hypertension (20.9%), 34 cases of obesity (25.3%) and 1 case of diabetes. Hypertension was predominantly diastolic, mild and sometimes masked (35.7%). In a third of the cases (32.1%), the hypertension was secondary. High blood pressure was found to be more frequent in older patients (OR: 2.26; 95% CI: 1.25-4.11, p=0.072), patients from sub-Saharan Africa (OR: 11.52; 95% CI: 2.67-49.86, p=0.01) and multiparous patients (OR: 7.82; 95% CI: 1.15-53.21, p=0.035).

CONCLUSION

The study confirmed that this care program enables an earlier detection and therefore treatment of the cardiovascular risk factors of these young women.

[Refractory and resistant hypertension in patients with type 2 diabetes mellitus: differences in metabolic profile and endothelial function]

AIM

To determine the prevalence of refractory hypertension (RfH) in patients with and without type 2 diabetes mellitus (DM), as well as to evaluate whether diabetic patients with RfH significant differ from those with uncontrolled resistant hypertension (RH) in clinical phenotype, metabolic profile and endothelial function.

MATERIALS AND METHODS

The study included 193 patients with RH: RH 74 patients with diabetes and 119 patients without DM. Uncontrolled RH and RfH were defined by the presence of uncontrolled blood pressure BP (140 and/or 90 mm Hg) despite the use of 3 but 5 antihypertensive drugs (for RH) and 5 antihypertensive drugs, including a mineralocorticoid receptor antagonist (for RfH). Clinical examination, lab tests were performed. Flow-mediated dilation (FMD) and vasoreactivity of middle cerebral artery (MCA) using both breath-holding and hyperventilation test were measured by high-resolution ultrasound.

RESULTS

The prevalence of refractory hypertension in patients with and without DM was similar (30% vs 28%, respectively). No differences in BP levels, data of echocardiography and clinical phenotype were found between the diabetic groups, but value of HOMA index, plasma resistin level and postprandial glycaemia were higher in patients with RfH. FMD and MCA reactivity to the breath-holding test were worse in patients with RfH, and they had a more pronounced vasoconstrictor response of MCA to the hyperventilation test compared to patients with RH.

CONCLUSION

The prevalence of RfH is the same in patients with and without diabetes. Diabetic patients with refractory hypertension have a more unfavorable metabolic profile and greater impairment of endothelial function than patients with uncontrolled resistant hypertension.

Associations of central and peripheral blood pressure with the renin-angiotensin-aldosterone system in healthy young adults: the African-PREDICT study

This study investigated associations of brachial and central blood pressure (BP) with detailed renin-angiotensin-aldosterone system (RAAS) components in a healthy young population stratified according to ethnicity and sex. We included healthy black men (n = 285) and women (n = 304) and white men (n = 278) and women (n = 305) aged 20-30 years old. We derived central systolic BP (cSBP), measured clinic and 24-h systolic and diastolic BP. Aldosterone and equilibrium angiotensin levels were assessed and used for calculating angiotensin-derived markers for plasma renin activity (PRA-S, Angiotensin I + Angiotensin II), angiotensin-converting enzyme (ACE-S, Angiotensin II/Angiotensin I), and two markers for adrenal effects of angiotensin II, the aldosterone-to-renin ratio (ARR-S, Aldosterone/PRA-S) and the aldosterone-to-angiotensin II-ratio (AA2-R, Aldosterone/Angiotensin II)_. Young black men and women presented with lower RAAS components and higher cSBP compared to their white counterparts (all p ≤ 0.001). In multivariable-adjusted regression analyses, positive associations of cSBP with ARR-S and AA2-R and negative associations with PRA-S and angiotensin II were found for black women (all p ≤ 0.001); this pattern was also observed for 24-h and clinic BP (p ≤ 0.045). A similar trend of RAAS associations was present in black men but only for clinic BP (all p ≤ 0.047). In white men, negative associations between clinic SBP and PRA-S, angiotensin II and aldosterone were detected (all p ≤ 0.048). No associations were observed in white women. Positive associations of central and peripheral BP with the ratio of aldosterone to PRA-S and angiotensin II only in healthy, young black adults suggest that relative aldosterone excess may contribute to early hypertension development in this group.

Renin-Angiotensin System Inhibitors for the Prevention of Atrial Fibrillation Recurrence After Ablation - A Meta-Analysis

BACKGROUND

Atrial fibrillation (AF) recurrence remains a tricky problem in patients undergoing ablation. This meta-analysis aimed to summarize the current literature to clarify whether renin-angiotensin system inhibitors (RASIs) prevent AF recurrence after ablation.Methods and Results:Relevant studies were searched on Pubmed and EMBASE through December 2019. Pooled relative risk (RR) of AF recurrence was calculated. Subgroup analyses according to study design, race, and follow-up duration were further performed. A total of 15 studies examining 4,300 patients were included, with 3 randomized controlled trials and 12 cohort studies. Overall analysis showed that RASIs significantly reduced AF recurrence after ablation (RR=0.83; 95% confidence interval (CI) 0.70-0.98, P=0.028; I²=68.9%). Subgroup analysis further indicated that positive results were found in randomized controlled trials (RR=0.51, 95% CI 0.37-0.70, P<0.001; I²=4%), studies conducted in Asia (RR=0.59, 95% CI 0.46-0.76, P<0.001; I²=30.7%), and studies with follow-up duration ≥1 year (RR=0.82, 95% CI 0.70-0.95, P=0.01; I²=59.1%); negative results were found in cohort studies, studies conducted in Europe or the USA, and studies with follow-up duration <1 year.

CONCLUSIONS

RASIs can potentially prevent AF recurrence after ablation under selected conditions. However, more studies are required to confirm this finding due to the variation in current evidence.

The Effects of Salt and Glucose Intake on Angiotensin II and Aldosterone in Obese and Nonobese Patients with Essential Hypertension

Background

The exact mechanisms for the development of essential hypertension are not known. Activation of the renin-angiotensin-aldosterone system (RAAS) in adipose tissue may represent an important link between obesity and hypertension. This study investigates the effects of oral intake of glucose with and without NaCl on angiotensin II (AngII) and aldosterone in obese and nonobese patients with essential hypertension.

Methods

Twenty newly diagnosed untreated essential hypertensive patients and 15 normotensive control subjects matched for age, gender, and BMI were studied. Participants fasted overnight (8–10 hrs), and then each subject took 75 gm glucose alone and with 3 gm NaCl, each dissolved in 250 ml. Subjects were monitored for 2 hours. Half hourly BP, plasma glucose (PG), serum Na⁺, K⁺, insulin, AngII, and aldosterone were measured. Subjects were classified into obese (BMI >30 Kg/m²) (11 patients and 8 control) and nonobese (BMI <30 Kg/m²) (9 patients and 7 control).

Results

After intake of glucose with NaCl serum, AngII was significantly higher in obese hypertensive patients compared with nonobese patients (P = 0.016). Intake of glucose with NaCl resulted in a significantly higher serum Na in obese hypertensive patients compared with nonobese patients Na (P = 0.009). Serum aldosterone was significantly higher in obese patients (P = 0.03, after glucose; P = 0.003, after glucose with NaCl) and in nonobese patients (P = 0.000 and P = 0.000, respectively) compared with their respective normotensive control subjects. In obese and nonobese patients, intake of glucose and glucose with NaCl showed no significant change in the levels of serum AngII and aldosterone which was associated a significant increase in serum Na in obese patients (P = 0.03) and a highly significant reduction in serum K in nonobese patients (P = 0.001).

Conclusion

Failure of suppression or inappropriate maintenance of secretion of AngII and aldosterone in both hypertensive groups by intake of glucose with NaCl may indicate a possible mechanism of essential hypertension.

Racial/Ethnic Disparities in Dietary Intake of U.S. Children Participating in WIC

Recent studies have assessed diet quality of low-income U.S. children participating in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC), but differences by race/ethnicity remain unknown. We assessed racial/ethnic disparities in nutrient intake from dietary sources (not supplements) among children participating in WIC, with a focus on priority nutrients and food groups for future WIC food package revisions, as described in a recent report by the National Academies of Sciences, Engineering, and Medicine (NASEM). We used data from the 2011-2014 National Health and Nutrition Examination Surveys (NHANES) and multivariable linear regression analysis to evaluate relationships between race/ethnicity and nutrient/food group intake of children participating in WIC. All data were analyzed using SAS 9.4 survey procedures, accounting for the complex survey design of the NHANES. Compared to non-Hispanic White children, Hispanic children had diets with better nutrient distribution and lower dietary energy density, while non-Hispanic Black children had diets with poorer nutrient intake. Hispanic children had higher potassium and fiber intake, and consumed more legumes, while non-Hispanic Black children had lower calcium and vitamin D intake, higher sodium intake, and lower total dairy intake, compared to non-Hispanic White children. These findings can inform WIC nutrition education messages and future food package revisions.

Distinct inflammatory mediator patterns in young black and white adults: The African-predict study

OBJECTIVE

Inflammatory mediators have been implicated in the early stages of cardiovascular disease development, including hypertension. Since global reports reflect a higher hypertension prevalence in black than white populations, we hypothesise the involvement of specific inflammatory mediators. We therefore compared a detailed range of 22 inflammatory mediators between young black and white adults, and determined the relationship with blood pressure.

APPROACH AND RESULTS

We included 1197 adults (20-30 years; 50% black; 52% female) with detailed ambulatory blood pressures. Blood samples were analysed for 22 inflammatory mediators. For pro-inflammatory mediators, the black adults had higher C-reactive protein, interferon-inducible T-cell alpha chemoattractant, macrophage inflammatory protein 3 alpha (all p ≤ 0.008), but lower interferon-gamma, interleukin (IL)-1β, IL-8, IL-12, IL-17A, and tumour necrosis factor alpha (all p ≤ 0.048). For anti-inflammatory mediators the black group consistently had lower levels (IL-5, IL-10 and IL-13 (all p ≤ 0.012)), resulting in generally higher pro-to-anti-inflammatory ratios in black than white adults (p ≤ 0.001). In mediators with pro- and anti-inflammatory functions, the black group had lower granulocyte-macrophage colony-stimulating factor and IL-6 (both p ≤ 0.010). These patterns were confirmed after adjustment for age, sex and waist circumference, or when stratifying by hypertensive status, sex and socio-economic status. Multi-variable adjusted regression analyses and factor analysis yielded no relationship between inflammatory mediators and blood pressure in this young healthy population.

CONCLUSIONS

Black and white ethnic groups each consistently presented with unique inflammatory mediator patterns regardless of blood pressure, sex or social class. No association with blood pressure was seen in either of the groups.

ARMC 5 Variants and Risk of Hypertension in Blacks: MH- GRID Study

Background We recently found that ARMC 5 variants may be associated with primary aldosteronism in blacks. We investigated a cohort from the MH - GRID (Minority Health Genomics and Translational Research Bio-Repository Database) and tested the association between ARMC 5 variants and blood pressure in black s. Methods and Results Whole exome sequencing data of 1377 black s were analyzed. Target single-variant and gene-based association analyses of hypertension were performed for ARMC 5, and replicated in a subset of 3015 individuals of African descent from the UK Biobank cohort. Sixteen rare variants were significantly associated with hypertension ( P=0.0402) in the gene-based (optimized sequenced kernel association test) analysis; the 16 and one other, rs116201073, together, showed a strong association ( P=0.0003) with blood pressure in this data set. The presence of the rs116201073 variant was associated with lower blood pressure. We then used human embryonic kidney 293 and adrenocortical H295R cells transfected with an ARMC 5 construct containing rs116201073 (c.*920T>C). The latter was common in both the discovery ( MH - GRID ) and replication ( UK Biobank) data and reached statistical significance ( P=0.044 [odds ratio, 0.7] and P=0.007 [odds ratio, 0.76], respectively). The allele carrying rs116201073 increased levels of ARMC5 mRNA , consistent with its protective effect in the epidemiological data. Conclusions ARMC 5 shows an association with hypertension in black s when rare variants within the gene are considered. We also identified a protective variant of the ARMC 5 gene with an effect on ARMC 5 expression confirmed in vitro. These results extend our previous report of ARMC 5's possible involvement in the determination of blood pressure in blacks.

The aldosterone to renin ratio in the diagnosis of primary aldosteronism: Promises and challenges

The complexity of evaluating patients for secondary treatable causes of hypertension is underappreciated. Primary aldosteronism (PA) is the most prevalent cause of secondary hypertension (3%-32% of hypertensive patients). The recent endocrine society clinical practice guideline (ESCPG), "The Management of Primary Aldosteronism: Case Detection, Diagnosis, and Treatment", differs from the previous version in the explicit recognition of PA as a major public health issue. Despite this, PA is underdiagnosed. The guidelines call on physicians to substantially ramp up the screening of hypertensive patients at risk of PA. Further, it recommends the plasma aldosterone to renin ratio (ARR), as the test of choice for screening for PA. However, the ARR is a highly variable test with reported diagnostic sensitivities and specificities ranging from 66% to 100% and 61% to 100%, respectively. Variability of the ARR can be attributed to the high degree of within-subject variation, differences in sampling protocols, laboratory assays, reporting units, the effect of medications and the population characteristics used to establish the decision thresholds. These factors render the possibility of false positive and false negative results-which have the potential to adversely impact patients. The limitations and caveats to the use of the ARR necessitate an effective clinic-laboratory interface, with specialist physician and clinical scientist collaboration for ARR result interpretation. Improvement in the diagnostic sensitivity and specificity of the ARR is predicated on harmonisation of pretesting patient preparation criteria, knowledge of the analytical methods used to derive the ratio and the method-specific threshold for PA.

Short-term effects of perindopril-amlodipine vs perindopril-indapamide on blood pressure control in sub-Saharan type 2 diabetic individuals newly diagnosed for hypertension: A double-blinded randomized controlled trial

Poor blood pressure (BP) control contributes to complications in sub-Saharan African (SSA) type 2 diabetic individuals. Experts have advocated the use of combination therapies for effective BP control in these patients. The suggested combinations should include a RAAS antagonist and either a CCB or a thiazide diuretic; however, their efficacy is yet to be established in SSA. We investigated the short-term effects of two combination therapies on BP control in SSA type 2 diabetic individuals. This was a double-blinded randomized controlled trial conducted at the Yaoundé Central Hospital (Cameroon) from October 2016 to May 2017. We included type 2 diabetic patients, newly diagnosed for hypertension. After baseline assessment and 24-hour ABPM, participants were allocated to receive either a fixed combination of perindopril + amlodipine or perindopril + indapamide for 42 days. Data analyses followed the intention-to-treat principle. We included fifteen participants (8 being females) in each group. Both combinations provided good circadian BP control after 6 weeks with similar efficacy. Twenty-four-hour SBP dropped from 144 to 145 mm Hg vs 128 to 126 mm Hg with perindopril-amlodipine and perindopril-indapamide, respectively (P = 0.003 for both groups). Twenty-four-hour DBP dropped from 85 to 78 mm Hg (P = 0.013) vs 89 to 79 mm Hg (P = 0.006) in the same respective groups. No significant adverse effect was reported. A fixed initial combination of perindopril-amlodipine or perindopril-indapamide achieved similar effective BP control after 6 weeks in SSA type 2 diabetic individuals with newly diagnosed hypertension. Therefore, these combinations can be used interchangeably in this indication.

Science-based Ethnic Bridging in Drug Development; Review of Recent Precedence and Suggested Steps Forward

BACKGROUND

Exposure, safety and/or efficacy of drugs are subject to potential differences between human races or ethnicities, as acknowledged by regulatory guidance and by label texts of various, but not all approved drugs.

OBJECTIVE

The objective of the present review was to assess recent regulatory precedence on drug use and race or ethnicity, with the goal of identifying opportunities for increasing the informative value of clinical ethnic or racial bridging in drug development.

METHODS

Recently, (January 2014-July 2018) FDA approved drug product label texts and approval packages were reviewed for claims, comments and underlying data on use of the product in specific ethnic or racial groups.

RESULTS

Among the 266 FDA-approved products, no product with unambiguous race- or ethnicity specific dosing instructions was retrieved. A small majority (55%) was approved with a claim or comment on race or ethnicity, and of these, a large majority (87%) was based on population pharmacokinetic data analysis. Statements were often related to incidence of a genotype for drug metabolizing enzyme or for other risk factors, or were related to body weight. Absence of clinically relevant exposure differences were often justified in terms of exposure ratios that notably exceeded the typical 0.80-1.25 no-effect boundary.

CONCLUSIONS

Recent precedence reflected a pragmatic, descriptive approach of racial or ethnic bridging, apparently meeting current regulatory expectations, whilst not resulting in strict guidance to prescribers. We recommend further work on defining the objectives of bridging studies, as well as criteria for their design and data analysis. Regarding the latter, we recommend investigating the value of prospectively defined tests for similarity with appropriate follow-up analysis in the case where the test has failed.

A Review of ACE Inhibitors and ARBs in Black Patients With Hypertension

Objective: To review current guidelines and recent data evaluating the efficacy and safety of angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) in black hypertensive patients. Data Sources: Articles evaluating race-specific outcomes in hypertension were gathered using a MEDLINE search with keywords black, African American, ACE inhibitor, angiotensin receptor blocker, angiotensin system, and hypertension. Studies published from 2000 through April 2018 were reviewed. Study Selection and Data Extraction: Six guidelines, 8 monotherapy publications, and 5 combination therapy publications included race-specific results and were included in the review. The authors individually compared and contrasted the results from each publication. Data Synthesis: Numerous monotherapy trials indicate that black patients may have a reduced blood pressure (BP) response with ACE inhibitors or ARBs compared with white patients. Conversely, additional studies propose that race may not be the primary predictor of BP response. Reduced efficacy is not observed in trials involving combination therapy. Some studies suggest increased cardiovascular and cerebrovascular morbidity and mortality with ACE inhibitor or ARB monotherapy in black patients; however, data are conflicting. Relevance to Patient Care and Clinical Practice: This article clarifies vague guideline statements and informs clinicians on the appropriate use of ACE inhibitors or ARBs for hypertension treatment in black patients through an in-depth look into the evidence. Conclusions: Potentially reduced efficacy and limited outcomes data indicate that ACE inhibitors or ARBs should not routinely be initiated as monotherapy in black hypertensive patients. Use in combination with a calcium channel blocker or thiazide diuretic is efficacious in black patients, and there are no data showing that this increases or decreases cardiovascular or cerebrovascular outcomes.

Genetic factors contributing to hypertension in African-based populations: A systematic review and meta-analysis

In a systematic review, the authors explored genetic association studies of essential hypertension in African populations. Studies reporting on the association of polymorphism(s) with hypertension in African populations were included. Appropriate studies were pooled using random effects model meta-analysis, under six potential inheritance models. In all, 46 polymorphisms in 33 genes were investigated for their association with hypertension or blood pressure levels. Meta-analysis was possible for three single nucleotide polymorphisms: rs4340, rs699, and rs5186. An association was found between rs5186, rs699, and hypertension under allele contrast and homozygous codominant models (odds ratio, 1.63 [95% confidence interval, 1.04-2.54] and 4.01 [95% confidence interval, 1.17-13.80] for rs5186, respectively; and 1.80 [95% confidence interval, 1.13-2.87] for rs699). Findings were mostly robust in sensitivity analyses. According to the systematic review, there is currently insufficient evidence on the specific polymorphisms that pose the risk of hypertension in African populations. Large-scale genetic studies are warranted to better understand susceptibility polymorphisms that may be specific to African populations.

Deep-targeted sequencing of endothelial nitric oxide synthase gene exons uncovers exercise intensity and ethnicity-dependent associations with post-exercise hypotension

In previous studies, we found an endothelial nitric oxide synthase gene (NOS3) variant rs2070744 associated with the ambulatory blood pressure (BP) response following bouts of moderate and vigorous intensity acute exercise, termed post-exercise hypotension (PEH). In a validation cohort, we sequenced NOS3 exons for associations with PEH Obese (30.9 ± 3.6 kg.m-2) African American (n = 14) [AF] and Caucasian (n = 9) adults 42.0 ± 9.8 years with hypertension (139.8 ± 10.4/84.6 ± 6.2 mmHg) performed three random experiments: bouts of vigorous and moderate intensity cycling and control. Subjects were attached to an ambulatory BP monitor for 19 h. We performed deep-targeted exon sequencing with the Illumina TruSeq Custom Amplicon kit. Variant genotypes were coded as number of minor alleles (#MA) and selected for additional statistical analysis based upon Bonferonni or Benjamini-Yekutieli multiple testing-corrected P-values under time-adjusted linear models for 19 hourly BP measurements for each subject. After vigorous intensity over 19 h, among NOS3 variants passing multiple testing thresholds, as the #MA increased in rs891512 (P = 6.4E-04), rs867225 (P = 6.5E-04), rs743507 (P = 2.6E-06), and rs41483644 (P = 2.4E-04), systolic (SBP) decreased from 17.5 to 33.7 mmHg; and in rs891512 (P = 9.7E-05), rs867225 (P = 2.6E-05), rs41483644 (P = 1.6E-03), rs3730009 (P = 2.6E-04), and rs77325852 (P = 5.6E-04), diastolic BP decreased from 11.1 mmHg to 20.3 mmHg among AF only. In contrast, after moderate intensity over 19 h in NOS3 rs3918164, as the #MA increased, SBP increased by 16.6 mmHg (P = 2.4E-04) among AF only. NOS3 variants exhibited associations with PEH after vigorous, but not moderate intensity exercise among AF only. NOS3 should be studied further for its effects on PEH in a large, ethnically diverse sample of adults with hypertension to confirm our findings.

Physiological Phenotyping for Personalized Therapy of Uncontrolled Hypertension in Africa

OBJECTIVES

African and African American hypertensives tend to retain salt and water, with lower levels of plasma renin and more resistant hypertension. We tested the hypothesis that physiological phenotyping with plasma renin and aldosterone would improve blood pressure control in uncontrolled hypertensives in Africa.

METHODS

Patients at hypertension clinics in Nigeria, Kenya, and South Africa with a systolic blood pressure >140 mm Hg or diastolic pressure > 90 mm Hg despite treatment were allocated to usual care (UC) vs. physiologically individualized care (PhysRx). Plasma renin activity and aldosterone were measured using ELISA kits. Patients were followed for 1 year; the primary outcome was the percentage of patients achieving blood pressure <140 mm Hg and diastolic <90 mm Hg.

RESULTS

Results are presented for the 94/105 participants who completed the study (42 UC, 52 PhysRx). Control of both systolic and diastolic pressures was obtained in 11.1% of UC vs. 50.0% of PhysRx (P = 0.0001). Systolic control was achieved in 13.9% of UC vs. 60.3% of PhysRx (P = 0.0001); diastolic control in 36.1% of UC vs. 67.2% of PhysRx, vs. (P = 0.003). Number of visits and total number of medications were not significantly different between treatment groups, but there were differences across the sites. There were important differences in prescription of amiloride as specified in the PhysRx algorithm.

CONCLUSIONS

Physiologically individualized therapy based on renin/aldosterone phenotyping significantly improved blood pressure control in a sample of African patients with uncontrolled hypertension. This approach should be tested in African American and other patients with resistant hypertension. Registered as ISRCTN69440037.

Primary Pediatric Hypertension: Current Understanding and Emerging Concepts

The rising prevalence of primary pediatric hypertension and its tracking into adult hypertension point to the importance of determining its pathogenesis to gain insights into its current and emerging management. Considering that the intricate control of BP is governed by a myriad of anatomical, molecular biological, biochemical, and physiological systems, multiple genes are likely to influence an individual's BP and susceptibility to develop hypertension. The long-term regulation of BP rests on renal and non-renal mechanisms. One renal mechanism relates to sodium transport. The impaired renal sodium handling in primary hypertension and salt sensitivity may be caused by aberrant counter-regulatory natriuretic and anti-natriuretic pathways. The sympathetic nervous and renin-angiotensin-aldosterone systems are examples of antinatriuretic pathways. An important counter-regulatory natriuretic pathway is afforded by the renal autocrine/paracrine dopamine system, aberrations of which are involved in the pathogenesis of hypertension, including that associated with obesity. We present updates on the complex interactions of these two systems with dietary salt intake in relation to obesity, insulin resistance, inflammation, and oxidative stress. We review how insults during pregnancy such as maternal and paternal malnutrition, glucocorticoid exposure, infection, placental insufficiency, and treatments during the neonatal period have long-lasting effects in the regulation of renal function and BP. Moreover, these effects have sex differences. There is a need for early diagnosis, frequent monitoring, and timely management due to increasing evidence of premature target organ damage. Large controlled studies are needed to evaluate the long-term consequences of the treatment of elevated BP during childhood, especially to establish the validity of the current definition and treatment of pediatric hypertension.

Recent advances in preventing stroke recurrence

Recent advances in secondary stroke prevention include new evidence in hypertension, nutrition, anticoagulation, antiplatelet therapy, intracranial stenosis, percutaneous closure of patent foramen ovale, and lipid-lowering therapy. Individualized therapy for hypertension based on phenotyping with plasma renin and aldosterone markedly improves blood pressure control in patients with resistant hypertension. A Mediterranean diet can reduce the risk of stroke by nearly half. The diagnosis and treatment of metabolic vitamin B12 deficiency, and B vitamins to lower homocysteine, can reduce the risk of stroke by approximately 30%. There are problems with clopidogrel that can be overcome by using ticagrelor, and new anticoagulant drugs markedly improve anticoagulation for stroke prevention, particularly in atrial fibrillation. There are pharmacokinetic problems with dabigatran that deserve attention. Intensive medical therapy is better than stenting for intracranial stenosis, and new therapies directed at proprotein convertase subtilisin–kexin type 9 (PCSK9) will revolutionize lipid-lowering therapy. In the past, it was estimated that rational therapy could reduce recurrent stroke by about 80%. With recent advances, we should be able to do even better.

Heterogeneity in Early Responses in ALLHAT (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial)

Randomized trials of hypertension have seldom examined heterogeneity in response to treatments over time and the implications for cardiovascular outcomes. Understanding this heterogeneity, however, is a necessary step toward personalizing antihypertensive therapy. We applied trajectory-based modeling to data on 39 763 study participants of the ALLHAT (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial) to identify distinct patterns of systolic blood pressure (SBP) response to randomized medications during the first 6 months of the trial. Two trajectory patterns were identified: immediate responders (85.5%), on average, had a decreasing SBP, whereas nonimmediate responders (14.5%), on average, had an initially increasing SBP followed by a decrease. Compared with those randomized to chlorthalidone, participants randomized to amlodipine (odds ratio, 1.20; 95% confidence interval [CI], 1.10-1.31), lisinopril (odds ratio, 1.88; 95% CI, 1.73-2.03), and doxazosin (odds ratio, 1.65; 95% CI, 1.52-1.78) had higher adjusted odds ratios associated with being a nonimmediate responder (versus immediate responder). After multivariable adjustment, nonimmediate responders had a higher hazard ratio of stroke (hazard ratio, 1.49; 95% CI, 1.21-1.84), combined cardiovascular disease (hazard ratio, 1.21; 95% CI, 1.11-1.31), and heart failure (hazard ratio, 1.48; 95% CI, 1.24-1.78) during follow-up between 6 months and 2 years. The SBP response trajectories provided superior discrimination for predicting downstream adverse cardiovascular events than classification based on difference in SBP between the first 2 measurements, SBP at 6 months, and average SBP during the first 6 months. Our findings demonstrate heterogeneity in response to antihypertensive therapies and show that chlorthalidone is associated with more favorable initial response than the other medications.