Hypertension in the US Black population: risk factors, complications, and potential impact of central aortic pressure on effective treatment

Optimization of respiratory-gated auricular vagus afferent nerve stimulation for the modulation of blood pressure in hypertension

Background

The objective of this pilot study was to identify frequency-dependent effects of respiratory-gated auricular vagus afferent nerve stimulation (RAVANS) on the regulation of blood pressure and heart rate variability in hypertensive subjects and examine potential differential effects by sex/gender or race.

Methods

Twenty hypertensive subjects (54.55 ± 6.23 years of age; 12 females and 8 males) were included in a within-person experimental design and underwent five stimulation sessions where they received RAVANS at different frequencies (i.e., 2 Hz, 10 Hz, 25 Hz, 100 Hz, or sham stimulation) in a randomized order. EKG and continuous blood pressure signals were collected during a 10-min baseline, 30-min stimulation, and 10-min post-stimulation periods. Generalized estimating equations (GEE) adjusted for baseline measures were used to evaluate frequency-dependent effects of RAVANS on heart rate, high frequency power, and blood pressure measures, including analyses stratified by sex and race.

Results

Administration of RAVANS at 100 Hz had significant overall effects on the reduction of heart rate (β = -2.03, p = 0.002). It was also associated with a significant reduction of diastolic (β = -1.90, p = 0.01) and mean arterial blood pressure (β = -2.23, p = 0.002) in Black hypertensive participants and heart rate in female subjects (β = -2.83, p = 0.01) during the post-stimulation period when compared to sham.

Conclusion

Respiratory-gated auricular vagus afferent nerve stimulation exhibits frequency-dependent rapid effects on the modulation of heart rate and blood pressure in hypertensive patients that may further differ by race and sex. Our findings highlight the need for the development of optimized stimulation protocols that achieve the greatest effects on the modulation of physiological and clinical outcomes in this population.

Emerging roles of ferroptosis in cardiovascular diseases

The mechanism of cardiovascular diseases (CVDs) is complex and threatens human health. Cardiomyocyte death is an important participant in the pathophysiological basis of CVDs. Ferroptosis is a new type of iron-dependent programmed cell death caused by excessive accumulation of iron-dependent lipid peroxides and reactive oxygen species (ROS) and abnormal iron metabolism. Ferroptosis differs from other known cell death pathways, such as apoptosis, necrosis, necroptosis, autophagy and pyroptosis. Several compounds have been shown to induce or inhibit ferroptosis by regulating related key factors or signalling pathways. Recent studies have confirmed that ferroptosis is associated with the development of diverse CVDs and may be a potential therapeutic drug target for CVDs. In this review, we summarize the characteristics and related mechanisms of ferroptosis and focus on its role in CVDs, with the goal of inspiring novel treatment strategies.

Metabolic Syndrome Components in a Nondiabetic Afro-Caribbean Population: Influence of Gender and Age

Background: Our aim was to describe the prevalence of metabolic syndrome (MetS) and its components among Afro-Caribbean adults without diabetes and cardiovascular complications. Methods: Participants were recruited from a Health Center in Guadeloupe, French West Indies. MetS was defined according to the NCEP ATP III. Prevalence of MetS and MetS components were compared across age groups and sex. The odds ratios (ORs) and 95% confidence intervals were obtained using logistic regression. Results: There were 1011 participants (68.8% women, mean age 47.8 ± 11.8 years). Prevalence of MetS was 17.9% (21.1% women, 10.8% men) and increased by age in women. High blood pressure had the highest prevalence among men and among women ≥60 years. Prevalence of abdominal obesity (AbO) was higher in women than in men. High triglyceride levels were uncommon at all ages and, men and women <40 years, compared with the other groups had higher prevalence of low high-density lipoprotein cholesterol (HDL-C) levels. With multiple logistic regression, compared with adults <40 years, those ≥60 years had the highest OR for prevalent hypertension 7.8 (4.8-12.8); P < 0.001, AbO 2.1 (1.3-3.3); P = 0.002 and high fasting blood glucose levels 5.5 (3.1-9.8); P < 0.001. They also had lower odds for having low HDL-C than the younger ones (G1: age <40 years). Among persons ≥60 years, OR for MetS was 1.9 (1.1-3.6); P = 0.013 compared with the referent group. Compared with men, women had higher odds of MetS 2.2 (1.5-3.3); P < 0.001. Conclusion: Women were more likely to have MetS than men and persons ≥60 years were significantly more likely to have MetS than persons <40 years. Preventive measures are required to reduce the prevalence of MetS.

Replication of European hypertension associations in a case-control study of 9,534 African Americans

Objective

Hypertension is more prevalent in African Americans (AA) than other ethnic groups. Genome-wide association studies (GWAS) have identified loci associated with hypertension and other cardio-metabolic traits like type 2 diabetes, coronary artery disease, and body mass index (BMI), however the AA population is underrepresented in these studies. In this study, we examined a large AA cohort for the generalizability of 14 Metabochip array SNPs with previously reported European hypertension associations.

Methods

To evaluate associations, we analyzed genotype data of 14 SNPs for their associations with a diagnosis of hypertension, systolic blood pressure (SBP), and diastolic blood pressure (DBP) in a case-control study of an AA population (N = 9,534). We also performed an age-stratified analysis (>30, 30≥59 and ≥60 years) following the hypertension definition described by the 8th Joint National Committee (JNC). Associations were adjusted for BMI, age, age², sex, clinical confounders, and genetic ancestry using multivariable regression models to estimate odds ratios (ORs) and beta-coefficients. Analyses stratified by sex were also conducted. Meta-analyses (including both BioVU and COGENT-BP cohorts) were performed using a random-effects model.

Results

We found rs880315 to be associated with systolic hypertension (SBP≥140 mmHg) in the entire cohort (OR = 1.14, p = 0.003) and within women only (OR = 1.16, p = 0.012). Variant rs17080093 associated with lower SBP and DBP (β = -2.99, p = 0.0352 and - β = 1.69, p = 0.0184) among younger individuals, particularly in younger women (β = -3.92, p = 0.0025 and β = -1.87, p = 0.0241 for SBP and DBP respectively). SNP rs1530440 associated with higher SBP and DBP measurements (younger individuals β = 4.1, p = 0.039 and β = 2.5, p = 0.043 for SBP and DBP; (younger women β = 4.5, p = 0.025 and β = 2.9, p = 0.028 for SBP and DBP), and hypertension risk in older women (OR = 1.4, p = 0.050). rs16948048 increases hypertension risk in younger individuals (OR = 1.31, p = 0.011). Among mid-age women rs880315 associated with higher risk of hypertension (OR = 1.20, p = 0.027). rs1361831 associated with DBP (β = -1.96, p = 0.02) among individuals older than 60 years. rs3096277 increases hypertension risk among older individuals (OR = 1.26 p = 0.0015), however, this variant also reduces SBP among younger women (β = -2.63, p = 0.0102).

Conclusion

These findings suggest that European-descent and AA populations share genetic loci that contribute to blood pressure traits and hypertension. However, the OR and beta-coefficient estimates differ, and some are age-dependent. Additional genetic studies of hypertension in AA are warranted to identify new loci associated with hypertension and blood pressure traits in this population.

Differences in Baseline Characteristics and Outcomes in Young Caucasians and African Americans with Acute Myocardial Infarction

BACKGROUND

The incidence of acute myocardial infarction (AMI) in young patients is increasing. While race-related differences in clinical characteristics and outcomes for older AMI patients have been well-studied, such differences in young patients are unknown.

METHODS

We performed a retrospective review of charts of Caucasian and African American (AA) patients <50 years of age, presenting with AMI between 2010 and 2017 in an urban, community hospital in Detroit, Michigan.

RESULTS

A total of 271 patients were identified with 156 being AAs (57.5%). Mean age was 43 years which was similar in both groups. AAs with AMI were 2.2 times more likely to be women and to have a history of diabetes and 1.2 times more likely to have BMI >30 kg/m². History of coronary artery disease (1.8-fold) and hypertension (1.5-fold) were also more common in AAs. Overall presenting features were similar, other than that AAs presented more often with non-ST-elevation MI and tended to present less often with cardiac arrest. No differences were observed in the angiographic findings or in-hospital outcomes in the two groups, with the exception of lower need of mechanical support in AAs.

CONCLUSIONS

In conclusion, our data provide important, not previously described information on race-related differences in history, presentation, clinical and angiographic features and outcomes in AAs compared with Caucasians younger than 50 with AMI. These findings may have implications for tailoring specific preventive strategies to decrease the incidence of AMI and its associated adverse events in both racial groups.

Low birth weight and abnormal pre-pregnancy body mass index were at higher risk for hypertensive disorders of pregnancy

Low birth weight is known to be associated with hypertension, cardiovascular disease and hypertensive disorders of pregnancy (HDP); however, this association might vary by race/ethnicity. This study aimed to clarify the association between women's own birth weight and their subsequent risk for HDP in a Japanese population, in combination with pre-pregnancy body mass index (BMI). We conducted a cohort study as part of the Tohoku Medical Megabank Birth and Three-Generation Cohort Study in Miyagi, Japan. Our study's population included 4810 women. A multivariate logistic regression analysis was performed to calculate the adjusted odds ratio (aOR) and the 95% confidence interval (CI) of the women's own birth weight for HDP, in the combination categories of birth weight and pre-pregnancy BMI. As a result, the group with a low birth weight of <2500 g had a significant association with HDP (the aOR, 1.50; 95% CI, 1.02-2.21). In the subtype analysis, the odds ratio for only preeclampsia was significantly increased in the low birth weight group (aOR, 3.37; 95% CI, 1.84-6.16). In the group with a low birth weight, the prevalence of HDP was higher in both the underweight and overweight groups. In conclusion, there was a significant association between low birth weight and subsequent HDP in Japanese women. Furthermore, a significant association with HDP was found for women born with a low birth weight who were underweight or overweight as adults. Maintaining a normal weight may be effective for preventing HDP even if a woman was born small.

Association between dietary carotenoid intakes and hypertension in adults: National Health and Nutrition Examination Survey 2007-2014

OBJECTIVE

Few epidemiological studies concentrated on dietary carotenoids and hypertension since new hypertension guideline released in 2017. Thus, this study was aimed to evaluate their association.

METHODS

Data from National Health and Nutrition Examination Survey (NHANES) 2007-2014 were used in this cross-sectional study. Dietary carotenoids data were obtained from 24-h dietary recall interviews. Hypertension was defined as SBP at least 130 mmHg or DBP at least 80 mmHg, taking antihypertensive medicine or self-report. Logistic regression models and restricted cubic spline models were applied to explore the associations between α-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein with zeaxanthin, and total carotenoids from diet and supplements and hypertension. Total carotenoids showed significant reductive risk of hypertension at 100 μg/kg per day and over.

RESULTS

A total of 17 398 adults aged 20 years and over were identified. High dose of β-carotene, lycopene, lutein with zeaxanthin, and total carotenoids were significantly associated with decreased risk of hypertension in crude results. After multivariate-adjustment in model 2, the odds ratios (OR) with 95% confidence intervals (CI) of β-cryptoxanthin, lycopene, lutein with zeaxanthin and total carotenoids for hypertension were 0.79 (0.67-0.93), 0.85 (0.73-0.98), 0.69 (0.58-0.83), 0.73 (0.62-0.86) for the highest versus lowest quartile intakes, respectively. Dose-response analyses showed that all of the carotenoids were inversely associated with hypertension in a linear manner. Total carotenoids showed significant effect of lower risk of hypertension at 100 μg/kg per day.

CONCLUSION

Intakes of α-carotene, β-carotene, β-cryptoxanthin, lycopene, lutein with zeaxanthin, and total carotenoids were inversely associated with hypertension in US adults. The intake of total carotenoids was suggested at least 100 μg/kg per day for general adult population.

Racial Differences in Left Ventricular Mass and Wave Reflection Intensity in Children

The burden of heart failure is disproportionately higher in African Americans, with a higher prevalence seen at an early age. Examination of racial differences in left ventricular mass (LVM) in childhood may offer insight into risk for cardiac target organ damage (cTOD) in adulthood. Central hemodynamic load, a harbinger of cTOD in adults, is higher in African Americans. The purpose of this study was to examine racial differences in central hemodynamic load and LVM in African American and non-Hispanic white (NHW) children. Two hundred sixty-nine children participated in this study (age, 10 ± 1 years; n = 149 female, n = 154 African American). Carotid pulse wave velocity (PWV), forward wave intensity (W1) and reflected wave intensity (negative area, NA) was assessed from simultaneously acquired distension and flow velocity waveforms using wave intensity analysis (WIA). Wave reflection magnitude was calculated as NA/W1. LVM was assessed using standard 2D echocardiography and indexed to height as LVM/[height (2.16) + 0.09]. A cutoff of 45 g/m (2.16) was used to define left ventricular hypertrophy (LVH). LVM was higher in African American vs. NHW children (39.2 ± 8.0 vs. 37.2 ± 6.7 g/m (2.16), adjusted for age, sex, carotid systolic pressure and socioeconomic status; p < 0.05). The proportion of LVH was higher in African American vs. NHW children (25 vs. 12 %, p < 0.05). African American and NHW children did not differ in carotid PWV (3.5 ± 4.9 vs. 3.3 ± 1.3 m/s; p > 0.05). NA/W1 was higher in African American vs. NHW children (8.5 ± 5.3 vs. 6.7 ± 2.9; p < 0.05). Adjusting for NA/W1 attenuated racial differences in LVM (38.8 ± 8.0 vs. 37.6 ± 7.0 g/m (2.16); p = 0.19). In conclusion, racial differences in central hemodynamic load and cTOD are present in childhood. African American children have greater wave intensity from reflected waves and higher LVMI compared to NHW children. WIA offers novel insight into early life origins of racial differences in central hemodynamic load and cTOD.

The association of serum zinc and copper with hypertension: A meta-analysis

OBJECTIVE

The association of serum zinc (Zn), copper (Cu) with the risk of hypertension (HT) remains controversial. Therefore, we conducted a meta-analysis to explore the relationships.

METHODS

We searched relevant literatures on PubMed and Web of Science up to September 2018. Pooled standard mean difference (SMD) with corresponding 95% confidence interval (CI) was calculated by random effects model.I² was used to evaluate heterogeneity among studies.

RESULTS

25 articles of serum Zn and 22 articles of serum Cu were included in meta-analysis. HT patients had lower serum Zn [SMD (95%CI): -0.612(-0.951, -0.274), z = 3.54, P_{for z} <0.001; I² = 97.0%, P_forI² <0.001], whereas no significant difference of serum Cu was shown between HT patients and controls [SMD (95%CI): 0.153(-0.101, 0.407)]. Also, male HT patients had lower serum Zn [SMD (95%CI): -1.443(-2.868, -0.017), z = 1.98, P_{for z} = 0.047; I² = 98.8%, P_forI² <0.001]. In subgroup analysis, a lower serum Zn was observed in HT patients in studies conducted in Europe [-1.066(-1.759, -0.374)], in case-control studies [-0.718(-1.294, -0.142)], in matched case-control studies [-0.939(-1.646, -0.233)] and studies involving treated patients [-1.416(-2.195, -0.638)]. Meanwhile, a higher serum Cu was found in HT patients in studies conducted in Africa [1.96(1.402, 2.518)], and in matched case-control studies [0.655(0.204, 1.107)].

CONCLUSION

The present meta-analysis indicates that serum Zn level in HT patients was significantly lower than that in controls, while no significantly different serum Cu level was found between HT patients and controls. Future studies are needed to confirm these results in future research.

Cognitive Function and Vascular Risk Factors Among Older African American Adults

To evaluate the association between vascular risk factors and cognitive impairment among older African American (AA) adults in a primary care clinic. Participants included 96 AA adults aged 60 years or older who were evaluated for global and domain-specific cognition. Participants were interviewed using the Computerized Assessment of Memory and Cognitive Impairment (CAMCI). The relationship between CAMCI cognitive domain scores and vascular risk factors were examined using hierarchical regression models. Patients who smoked, those with higher SBP/DBP values had lower accuracy rates on CAMCI cognitive domains (attention, executive, memory).Those with higher BMI had better attention scores. Patients with higher HbA1C values had worse verbal memory. Patients with higher blood pressure were significantly faster in responding to tasks in the executive domain. Primary care providers working with older AA adults with these VRFs could implement cognitive screening earlier into their practice to reduce barriers of seeking treatment.

Racial Differences in Aortic Stiffness in Children

OBJECTIVE

To investigate racial differences in central blood pressure and vascular structure/function as subclinical markers of atherosclerotic cardiovascular disease in children.

STUDY DESIGN

This cross-sectional study recruited 54 African American children (18 female, 36 male; age 10.5 ± 0.9 years) and 54 white children (27 female, 26 male; age 10.8 ± 0.9 years) from the Syracuse City community as part of the Environmental Exposures and Child Health Outcomes study. Participants underwent blood lipid and vascular testing on 2 separate days. Carotid artery intima-media thickness and aortic stiffness were measured by ultrasonography and carotid-femoral pulse wave velocity, respectively. Blood pressure was assessed at the brachial artery and estimated in the carotid artery using applanation tonometry.

RESULTS

African American children had significantly higher pulse wave velocity (4.8 ± 0.8 m/s) compared with white children (4.2 ± 0.7 m/s; P < .05), which remained significant after adjustment for confounding variables including socioeconomic status. African American children had significantly higher intima-media thickness (African American 0.41 ± 0.06, white 0.39 ± 0.05 mm), and carotid systolic blood pressure (African American 106 ± 11, white 102 ± 8 mm Hg; P < .05) compared with white children, although these racial differences were no longer present after covariate adjustments for height.

CONCLUSIONS

Racial differences in aortic stiffness are present in childhood. Our findings suggest that racial differences in subclinical cardiovascular disease occur earlier than previously recognized.

Noninvasive Central Systolic Blood Pressure Is More Strongly Related to Kidney Function Decline Than Peripheral Systolic Blood Pressure in a Chinese Community-Based Population

This study aimed to investigate the association of noninvasive central aortic blood pressure with kidney function decline in a Chinese community-based population with normal kidney function at baseline. A total of 3153 Chinese participants from an atherosclerosis cohort were included in our analysis. The primary outcome was renal function decline defined as a drop in estimated glomerular filtration rate (eGFR) category accompanied by a ≥25% drop in eGFR from baseline; or a sustained decline in eGFR of >5 mL/min per 1.73 m(2)/y. The secondary outcomes were rapid eGFR decline (a decline in eGFR of >3 mL/min per 1.73 m(2)/y) and new incidence of chronic kidney disease. Participants were 56.6±8.5 years old, 36.0% were males, and 48.8% had hypertension. Mean (SD) baseline eGFR was 101.2±10.6 mL/min per 1.73 m(2) After a mean 2.35-year follow-up, the incidence of renal function decline, rapid eGFR decline and chronic kidney disease were 7.3%, 19.7%, and 0.7%, respectively. In multivariate logistic-regression analyses, central and peripheral systolic blood pressure (SBP) were both independently associated with all outcomes after adjustment for various confounders. When peripheral SBP was forced into the model with central SBP simultaneously, its significant association with the 3 outcomes all disappeared; however, central SBP was still significantly related with all outcomes even after further adjusting peripheral SBP. In conclusion, central SBP is a stronger predictor compared with peripheral SBP for early kidney function decline in a Chinese community-based population with normal kidney function at baseline.

The Prevalence of Atherosclerosis in Those with Inflammatory Connective Tissue Disease by Race, Age, and Traditional Risk Factors

Systemic inflammation promotes cardiovascular disease. Inflammatory connective tissue diseases (CTD) like lupus and rheumatoid arthritis associate with cardiovascular risk, but it is unknown whether particular groups of patients have enhanced propensity for atherosclerotic cardiovascular disease (ASCVD) associated with their CTD. Analysis of aggregate health record data at a large U.S. academic center identified CTD and ASCVD status for 287,467 African American and white adults. ASCVD prevalence in those with CTD was 29.7% for African Americans and 14.7% for white patients with prevalence ratios, compared to those without CTD, of 3.1 and 1.8, respectively. When different types of CTD were analyzed individually (rheumatoid arthritis; lupus; scleroderma; Sjögren Syndrome; dermatomyositis/polymyositis; unspecified/mixed CTD; other inflammatory arthropathy), increased ASCVD rates were found in nearly all subsets, always with higher prevalence ratios in African Americans. The prevalence ratio of ASCVD was particularly high in young African Americans. Furthermore, individuals lacking traditional cardiovascular risk factors had more ASCVD if they had CTD (prevalence ratio 2.9). Multivariate analysis confirmed a positive interaction between CTD and African-American race and a negative interaction between CTD and age. The factors driving the observed disproportionate CTD-associated ASCVD in African Americans, young adults, and those without traditional risk factors warrant further study.

Association of Race With Mortality and Cardiovascular Events in a Large Cohort of US Veterans

BACKGROUND

In the general population, blacks experience higher mortality than their white peers, attributed in part to their lower socioeconomic status, reduced access to care, and possibly intrinsic biological factors. Patients with kidney disease are a notable exception, among whom blacks experience lower mortality. It is unclear if similar differences affecting outcomes exist in patients with no kidney disease but with equal or similar access to health care.

METHODS AND RESULTS

We compared all-cause mortality, incident coronary heart disease, and incident ischemic stroke using multivariable-adjusted Cox models in a nationwide cohort of 547 441 black and 2 525 525 white patients with baseline estimated glomerular filtration rate ≥ 60 mL·min⁻¹·1.73 m⁻² receiving care from the US Veterans Health Administration. In parallel analyses, we compared outcomes in black versus white individuals in the National Health and Nutrition Examination Survey (NHANES) 1999 to 2004. After multivariable adjustments in veterans, black race was associated with 24% lower all-cause mortality (adjusted hazard ratio, 0.76; 95% confidence interval, 0.75-0.77; P<0.001) and 37% lower incidence of coronary heart disease (adjusted hazard ratio, 0.63; 95% confidence interval, 0.62-0.65; P<0.001) but a similar incidence of ischemic stroke (adjusted hazard ratio, 0.99; 95% confidence interval, 0.97-1.01; P=0.3). Black race was associated with a 42% higher adjusted mortality among individuals with estimated glomerular filtration rate ≥ 60 mL·min⁻¹·1.73 m⁻² in NHANES (adjusted hazard ratio, 1.42; 95% confidence interval, 1.09-1.87).

CONCLUSIONS

Black veterans with normal estimated glomerular filtration rate and equal access to healthcare have lower all-cause mortality and incidence of coronary heart disease and a similar incidence of ischemic stroke. These associations are in contrast to the higher mortality experienced by black individuals in the general US population.

Hypertension in the African American population: A succinct look at its epidemiology, pathogenesis, and therapy

Arterial hypertension is prevalent in the black population in the United States. It is directly related to cardiovascular and kidney damage. Its pathogenesis is complex and includes the high incidence of obesity, salt sensitivity and the activation of the renin-angiotensin-aldosterone system. This complexity requires a therapeutic combination that includes changes in dietary habits and appropriate antihypertensive regimes. The International Society of Hypertension in Blacks recommends initiating dietary intervention for values of systolic/diastolic arterial blood pressure above 115/75 mmHg and maintaining arterial blood pressure below 135/85 mmHg using appropiate antihypertensive medication. The most adequate antihypertensive drug for this population has yet to be determined.

Hypertension in minority populations: new guidelines and emerging concepts

Persistent disparities in hypertension, CKD, and associated cardiovascular disease have been noted in the United States among racial/ethnic minority groups. Overall, these disparities are largely mediated by social determinants of health. Yet, emerging data suggest additional biologic factors in racial/ethnic disparities in hypertension prevalence, complications, particularly CKD, and responses to treatment. Nevertheless, race is a social construct and not a physiologic concept, and ethnicity, federally defined as the binary "Hispanic/Latino" or "not Hispanic/Latino," is also imprecise. However, race/ethnicity categories may help interpret health-related data, including surveillance and research, and are important in ensuring that clinical trials remain generalizable to diverse populations. There is significant heterogeneity among prespecified groups and, perhaps, greater genetic differences within than between certain racial/ethnic groups. This review will explore hypertension epidemiology, pathophysiology, and management among the diverse and growing US minority groups, specifically African Americans and Hispanics because much less data are available across the wide spectrum of diverse populations. We will highlight the intersection of hypertension and increasingly prevalent CKD, particularly in African Americans. Finally, we propose multidimensional treatment approaches to hypertension among diverse populations, encompassing population, community, health system, and individual-based approaches.

African Americans, hypertension and the renin angiotensin system

African Americans have exceptionally high rates of hypertension and hypertension related complications. It is commonly reported that the blood pressure lowering efficacy of renin angiotensin system (RAS) inhibitors is attenuated in African Americans due to a greater likelihood of having a low renin profile. Therefore these agents are often not recommended as initial therapy in African Americans with hypertension. However, the high prevalence of comorbid conditions, such as diabetes, cardiovascular and chronic kidney disease makes treatment with RAS inhibitors more compelling. Despite lower circulating renin levels and a less significant fall in blood pressure in response to RAS inhibitors in African Americans, numerous clinical trials support the efficacy of RAS inhibitors to improve clinical outcomes in this population, especially in those with hypertension and risk factors for cardiovascular and related diseases. Here, we discuss the rationale of RAS blockade as part of a comprehensive approach to attenuate the high rates of premature morbidity and mortality associated with hypertension among African Americans.

Hemodynamic and echocardiographic profiles in African American compared with White offspring of hypertensive parents: the HyperGEN study

BACKGROUND

Alterations in cardiovascular structure and function have been shown to precede the finding of elevated blood pressure.

METHODS

This study is part of the Hypertension Genetic Epidemiologic Network (HyperGEN) in which genetic and environmental determinants of hypertension were investigated in 5 geographical field centers. All nonhypertensive offspring (n = 1,035) were included from the entire HyperGEN study population that consists of 2,225 hypertensive patients and 1,380 nonhypertensive patients who had adequate echocardiographic left ventricular (LV) mass measurements. Participants were compared by self-declared race (African American and white).

RESULTS

Nonhypertensive African American offspring were younger (aged 31 years vs. 38 years), more likely to be female, and had a higher body mass index (BMI) and higher systolic blood pressure (SBP) than their white counterparts. After adjusting for age, sex, SBP, pulse pressure (PP), BMI, diabetes status, and family effects, we observed statistically significant and potentially pathophysiological differences (all with P ≤ 0.001) with greater LV mass/height, relative wall thickness, and posterior wall thickness and with lesser midwall shortening, PP/stroke volume, and (PP/stroke volume)/fat-free body mass.

CONCLUSION

This study shows that ethnic differences in hemodynamic and echocardiographic profiles exist in a large, population-based cohort of nonhypertensive offspring of hypertensive parents.

Uric Acid Reduction Rectifies Prehypertension in Obese Adolescents

Epidemiologic studies, animal models, and preliminary clinical trials in children implicate uric acid in the development of essential hypertension. Controversy remains as to whether the observations indicate a general mechanism or a surrogate phenomenon. We sought to determine whether uric acid is a causative mediator of increased blood pressure (BP) and impaired vascular compliance. We report a randomized, double-blinded, placebo-controlled trial comparing 2 mechanisms of urate reduction with placebo in prehypertensive, obese, adolescents, aged 11 to 17 years. Subjects were randomized to the xanthine oxidase inhibitor, allopurinol, uricosuric, probenecid, or placebo. Subjects treated with urate-lowering therapy experienced a highly significant reduction in BP. In clinic systolic BP fell 10.2 mm Hg and diastolic BP fell 9.0 mm Hg in treated patients compared with a rise of 1.7 mm Hg and 1.6 mm Hg systolic and diastolic BP, respectively in patients on placebo. Urate-lowering therapy also resulted in significant reduction in systemic vascular resistance. These data indicate that, at least in adolescents with prehypertension, uric acid causes increased BP that can be mitigated by urate lowering therapy.