Blood Pressure In African Americans Research Articles

Mediating effects of BMI on the association between DNA methylation regions and 24-h blood pressure in African Americans.

DNA methylation is an important epigenetic mechanism that may influence blood pressure (BP) regulation and hypertension risk. Obesity, a major lifestyle factor associated with hypertension, may interact with DNA methylation to affect BP. However, the indirect effect of DNA methylation on 24-hBP measurements mediated by obesity-related phenotypes such as BMI has not been investigated. Causal mediation analysis was applied to examine the mediating role of BMI in the relation between DNA methylation and 24-h BP phenotypes, including SBP, DBP and mean arterial blood pressure (MAP), in 281 African American participants. Analysis of 38 215 DNA methylation regions, derived from 1,549,368 CpG sites across the genome, identified up to 138 methylation regions that were significantly associated with 24-h BP measurements through BMI mediation. Among them, 38 (19.2%) methylation regions were concurrently associated with SBP, DBP and MAP. Genes associated with BMI-mediated methylation regions are potentially involved in various chronic diseases such as coronary artery disease and renal disease, which are often caused or exacerbated by hypertension. Notably, three genes (CDH4, NOTCH1 and COLGALT1) showed both direct associations with 24-h BP measurements and indirect associations through BMI after adjusting for age and sex covariates. Our findings suggest that DNA methylation may contribute to the regulation of 24-h BP in African Americans both directly and indirectly through BMI mediation.

Heart 2 Heart: Pilot Study of a Church-Based Community Health Worker Intervention for African Americans with Hypertension.

African Americans (AAs) have higher prevalence of uncontrolled hypertension than Whites, which leads to reduced life expectancy. Barriers to achieving blood pressure control in AAs include mistrust of healthcare and poor adherence to medication and dietary recommendations. We conducted a pilot study of a church-based community health worker (CHW) intervention to reduce blood pressure among AAs by providing support and strategies to improve diet and medication adherence. To increase trust and cultural concordance, we hired and trained church members to serve as CHWs. AA adults (n = 79) with poorly controlled blood pressure were recruited from churches in a low-income, segregated neighborhood of Chicago. Participants had an average of 7.5 visits with CHWs over 6months. Mean change in systolic blood pressure across participants was - 5mm/Hg (p = 0.029). Change was greater among participants (n = 45) with higher baseline blood pressure (- 9.2, p = 0.009). Medication adherence increased at follow-up, largely due to improved timeliness of medication refills, but adherence to the DASH diet decreased slightly. Intervention fidelity was poor. Recordings of CHW visits revealed that CHWs did not adhere closely to the intervention protocol, especially with regard to assisting participants with action plans for behavior change. Participants gave the intervention high ratings for acceptability and appropriateness, and slightly lower ratings for feasibility of achieving intervention behavioral targets. Participants valued having the intervention delivered at their church and preferred a church-based intervention to an intervention conducted in a clinical setting. A church-based CHW intervention may be effective at reducing blood pressure in AAs.

Using Complementary and Integrative Medicine to Treat High Blood Pressure in African Americans in the United States: Impact of Knowledge, Beliefs, Attitudes, and Behaviors

Background: African Americans have the highest prevalence of high blood pressure (HBP) in the United States, but the lowest blood pressure control rates among all major racial/ethnic groups. This study examined the extent to which African Americans use home remedies to treat HBP and assessed their knowledge, beliefs, attitudes, and behaviors regarding such use. Materials and Methods: This study utilized a descriptive, exploratory, cross-sectional, and correlational research design. We determined the association between knowledge, beliefs, attitudes, and behaviors and use of home remedies among participants using a principal investigator-developed online questionnaire entitled the Beliefs about Hypertension Survey (BHS). Results: Reliability for the BHS representing all four dependent variables was good (Cronbach's α = 0.848). The study sample was 254 African Americans with and without HBP (79.9% females; 83% aged 30–59). Participants were more willing to use home remedies to treat rather than to prevent HBP, with 58% of participants with HBP reporting current use of home remedies as treatment. Results of the Multivariate Analysis of Variance test indicated statistical significance (P = 0.000) only for the behavior variable (α = 0.05), with no significant differences found between participants with and without HBP with respect to knowledge, beliefs, and attitudes. Conclusion: The results suggest that diagnosis of HBP increases African Americans' willingness to use home remedies, but this group needs more education about the effects and risk factors of HBP. Further evidence-based studies will help to increase knowledge and acceptance of home remedies as a viable treatment option for HBP.

Rationale and design of the Heart-to-Heart study: A church-based intervention to reduce blood pressure in African Americans

Heart-to-Heart (H2H) is a church-based behavioral cluster randomized trial to measure the effectiveness of a lifestyle education program for reducing blood pressure (BP) in African American adults with uncontrolled BP. Design and implementation of this study were informed by our ALIVE pilot study conducted with church pastors and leaders using a community-based participatory research methodology. The current study employs a cross-over design in which all participants receive two 6-month programs in different orders: the intervention arm receives the H2H program first, followed by a financial education program, and the comparator arm receives the programs in the reverse order. Approximately 34 churches will be randomized with the aim of including at least 272 participants across churches. The H2H program consists of 24 weekly dietitian-led diet and lifestyle virtual education sessions, 12 Bible studies taught by the church pastor reinforcing positive dietary behaviors from a biblical perspective, daily self-monitoring of BP, and, as needed, one-on-one support from a community health worker to assist with medication adherence. The Money Smart program consists of 14 financial education sessions and 12 Bible studies teaching the biblical basis of good financial management over a 6-month period. The primary outcome measure is systolic BP at 6 months with a follow-up at 12 months. Secondary outcome measures include medication adherence, Dietary Approaches to Stop Hypertension (DASH) diet adherence, self-efficacy for hypertension self-care, social support for eating a healthy diet, hypertension and nutrition knowledge, beliefs about medicines, barriers to medication use, depression, and financial knowledge and behaviors.

Identification of a SGCD × Discrimination Interaction Effect on Systolic Blood Pressure in African American Adults in the Jackson Heart Study.

In the United States, hypertension disproportionately afflicts over half of African American adults, many of whom also experience racial discrimination. Understanding gene × discrimination effects may help explain racial disparities in hypertension. We tested for the main effects and interactive effects of 5 candidate single nucleotide polymorphisms (SNPs: rs2116737, rs11190458, rs2445762, rs2597955, and rs2416545) and experiences of discrimination on blood pressure (BP) in African Americans not taking antihypertensive medications in the Jackson Heart Study from Mississippi (n = 2,933). Multiple linear regression models assumed an additive genetic model and adjusted for ancestry, age, sex, body mass index, education, and relatedness. We additionally tested recessive and dominant genetic models. Discrimination was significantly associated with higher diastolic BP (P = 0.003). In contrast, there were no main effects of any SNP on BP. When analyzing SNPs and discrimination together, SGCD (Sarcoglycan Delta; rs2116737) demonstrated a gene × environment interaction. Specifically, an SGCD × Discrimination interaction was associated with systolic BP (β =1.95, P = 0.00028) in a recessive model. Participants carrying a T allele, regardless of discrimination experiences, and participants with a GG genotype and high experiences of discrimination had higher systolic BP than participants with a GG genotype and low experiences of discrimination. This finding suggests the SGCD GG genotype may have a protective effect on systolic BP, but only in a setting of low discrimination. The inclusion of culturally relevant stressors, like discrimination, may be important to understand the gene-environment interplay likely underlying complex diseases with racial health inequities.

The Interactive Effects of Education and Social Support on Blood Pressure in African Americans

This study examined whether the effects of received and provided social support on blood pressure (BP) would differ by education. Data from 602 African American adults (48-95 years) enrolled in the Baltimore Study of Black Aging—Patterns of Cognitive Aging were analyzed using multiple linear regression. We found no main effects of received and provided social support on BP. However, a significant moderation effect was observed for systolic BP, such that greater received social support was positively associated with higher systolic BP among individuals with low levels of education, adjusting for age, sex, chronic health conditions, and depressive symptoms. The findings demonstrate that social support and education have joint effects on blood pressure, which highlights the importance of considering psychosocial determinants of adverse cardiovascular health outcomes that disproportionately affect African Americans.

Abstract 11070: Antihypertensive Medication Challenges, Adherence, and Blood Pressure in African Americans with a History of Uncontrolled Hypertension

Introduction: African American adults with uncontrolled hypertension may have structural inequities in access to, intensity of, as well as greater challenges using antihypertensive medications, all of which may contribute to inadequate blood pressure (BP) control. Traditional self-reported measures of adherence suffer from social desirability bias and are not consistently correlated with BP control. Hypothesis: African Americans with higher systolic BP (SBP) experience more medication challenges (access, med taking) that are correlated with BP. Methods: Data at baseline are from a cluster randomized trial of patient-level coaching vs. practice level facilitation and the combination of the two interventions in 1596 adult African American patients (39% male; mean age 57 ± 12 yrs.) seen in rural primary care practices with a history of uncontrolled hypertension (average over the last year ≥ 140/90 mmHg). In bivariate and correlation analyses, we examined the cross-sectional association of self-reported medication adherence vs. self-reported medication challenges with SBP level at baseline. These relationships were further examined in a linear regression model with SBP as the outcome while controlling for age, gender, and annual income. Results: Patients were taking a mean of 2.4 antihypertensive medications. SBP level was significantly correlated with the number of antihypertensive medication challenges reported (p < 0.01). While those reporting lower medication adherence also reported significantly more medication challenges, mean SBP was not significantly different by self-reported medication adherence level. However, mean SBP was significantly higher in patients reporting 4 or more medication challenges (158 vs. 155mmHg, p=0.004). In linear regression analysis, age, income, and self-reported medication challenges (β = 0.3; .95% CI: 0.03 - 0.6; p = 0.028) were independently associated with SBP level while gender and self-reported medication adherence were not. Conclusion: African Americans with uncontrolled BP often require more intensive antihypertensive regimens. However, such regimens may be associated with more medication challenges that may adversely impact adherence and BP control.

The Interactive Effects of Education and Social Support on Blood Pressure in African Americans.

This study examined whether the effects of received and provided social support on blood pressure (BP) would differ by education. Data from 602 African American adults (48-95 years) enrolled in the Baltimore Study of Black Aging-Patterns of Cognitive Aging were analyzed using multiple linear regression. We found no main effects of received and provided social support on BP. However, a significant moderation effect was observed for systolic BP, such that greater received social support was positively associated with higher systolic BP among individuals with low levels of education, adjusting for age, sex, chronic health conditions, and depressive symptoms. The findings demonstrate that social support and education have joint effects on BP, which highlights the importance of considering psychosocial determinants of adverse cardiovascular health outcomes that disproportionately affect African Americans.

Association of Serum Aldosterone and Plasma Renin Activity With Ambulatory Blood Pressure in African Americans: The Jackson Heart Study.

The renin-angiotensin-aldosterone system (RAAS) is an important driver of blood pressure (BP), but the association of the RAAS with ambulatory BP (ABP) and ABP monitoring phenotypes among African Americans has not been assessed. ABP and ABP monitoring phenotypes were assessed in 912 Jackson Heart Study participants with aldosterone and plasma renin activity (PRA). Multivariable linear and logistic regression analyses were used to analyze the association of aldosterone and PRA with clinic, awake, and asleep systolic BP and diastolic BP (DBP) and ABP monitoring phenotypes, adjusting for important confounders. The mean age of participants was 59±11 years and 69% were female. In fully adjusted models, lower log-PRA was associated with higher clinic, awake, and asleep systolic BP and DBP (all P<0.05). A higher log-aldosterone was associated with higher clinic, awake, and asleep DBP (all P<0.05). A 1-unit higher log-PRA was associated with lower odds of daytime hypertension (odds ratio [OR] 0.59 [95% CI, 0.49-0.71]), nocturnal hypertension (OR, 0.68 [95% CI, 0.58-0.79]), daytime and nocturnal hypertension (OR, 0.59 [95% CI, 0.48-0.71]), sustained hypertension (OR, 0.52 [95% CI, 0.39-0.70]), and masked hypertension (OR 0.75 [95% CI, 0.62-0.90]). A 1-unit higher log-aldosterone was associated with higher odds of nocturnal hypertension (OR, 1.38 [95% CI, 1.05-1.81]). Neither PRA nor aldosterone was associated with percent dipping, nondipping BP pattern, or white-coat hypertension. Patterns for aldosterone:renin ratio were similar to patterns for PRA. Suppressed renin activity and higher aldosterone:renin ratios were associated with higher systolic BP and DBP in the office and during the awake and asleep periods as evidenced by ABP monitoring. Higher aldosterone levels were associated with higher DBP, but not systolic BP, in the clinic and during the awake and asleep periods. Further clinical investigation of novel and approved medications that target low renin physiology such as epithelial sodium channel inhibitors and mineralocorticoid receptor antagonists may be paramount in improving hypertension control in African Americans.

The Effect of Nebivolol on Office Blood Pressure of Blacks Residing in Sub-Saharan Africa (A Pilot Study).

Introduction: There is substantial clinical evidence that monotherapy with beta-blockers are less effective in reducing blood pressure among hypertensive Black patients compared to Whites. The highly selective beta-1 agents like nebivolol and bisoprolol have, however, been reported to be effective in reducing blood pressure in African Americans. However, results in African Americans cannot be extrapolated to native Africans because of genetic admixture and gene-environment interaction. There is, therefore, the need for us to generate data that are applicable to Africans residing in sub-Saharan Africa. We therefore decided to evaluate the efficacy and tolerability of highly selective beta-1 agent nebivolol in hypertensive Black patients residing in sub-Saharan Africa.Materials and Methods: The nebivolol study was a multicenter, prospective, observational program among hypertensive patients with 4- and 8-week follow up which was conducted in 5 cities in Nigeria of Abuja, Calabar, Enugu, Oghara, and Port Harcourt. Dosages of nebivolol used in keeping with local prescribing information were 5 and 10 mg once daily each. The effectiveness of treatment was assessed by change from baseline in mean office systolic and diastolic blood pressures, and the proportion of patients achieving the therapeutic goal of <140/90 mmHg. Safety and tolerability of this medication were also assessed.Results: We report the results of the 140 patients studied. The mean age and body mass index were 46.9 ± 7.3 years and 22.3 ± 5.8 kg/m2, respectively, and 57.1% were female. Nebivolol reduced SBP and DBP by 7.6 and 6.6 mmHg, respectively, in 4 weeks, and by 11.1 and 8.0 mm Hg, respectively, in 8 weeks. Blood pressure control was achieved in 54.8% of the patients in 4 weeks and increased to 60.4% in 8 weeks. There was no change in metabolic profile between randomization and at 8 weeks, and erectile dysfunction occurred in 1.3% of the study population.Conclusions: Nebivolol 5 and 10 mg appear efficacious in Nigerian Africans with no negative metabolic effect and minimal side effect profile.Clinical Trial Registration: www.ClinicalTrials.gov, Study Identification: NCT 03598673.

A Pilot Study Evaluating the Effects of a Technology-Based and Positive Psychological Training Intervention on Blood Pressure in African Americans With Hypertension.

Behavioral interventions consolidating technology are underutilized and do not reach diverse populations such as African Americans with hypertension. This pilot study aimed to evaluate the effects of a theoretically derived, technology-based intervention in African Americans with hypertension. African Americans with hypertension (N = 18; age range 25-85; 72.22% females) were randomized to the technology-based plus positive psychological training (PPT) experimental group (n = 10) or the comparison group (n = 8) for 12 weeks. The technology-based intervention included analytic components (web-based education, self-monitoring of blood pressure [BP], and medication management using a commercially free app-Medisafe) and an emotional component (comprised of skills and behaviors directed at engaging 1 in positive activities to help build increasing healthy behaviors). The comparison group received the technology-based intervention alone. Demographic information, self-management cognitive processes, self-management behaviors, and health status outcomes were assessed. After completing the 12-week intervention, the groups did not significantly differ in health outcomes, health behavior outcomes, and technology utilization outcomes. Mean systolic BP decrease 6.02 mmHg (standard deviation [SD] = 22.75) in the comparison group and 1.1 mmHg (SD = 20.64; P = .439) in the experimental group. Diastolic BP decreased 0.1 mmHg (SD = 11.78) in the comparison group and 1.5 mmHg (SD = 12.7; P = .757) in the experimental group. Our findings suggest that behavioral interventions using technology have the potential to improve self-management outcomes among African American populations. Further research is warranted in a larger sample size and a longer time frame to identify the intervention’s effectiveness.

Association of Obstructive Sleep Apnea With Nighttime Blood Pressure in African Americans: The Jackson Heart Study.

Obstructive sleep apnea (OSA), nocturnal hypertension, and nondipping systolic blood pressure (BP) are each highly prevalent among African Americans. However, few data are available on the association between OSA and nighttime BP in this population. We examined the association of OSA with nighttime BP among African Americans who completed 24-hour ambulatory BP monitoring (ABPM) at Exam 1 (2000-2004) of the Jackson Heart Study (JHS) and subsequently participated in the JHS Sleep Study (2012-2016). Type 3 home sleep apnea testing was used to assess OSA measures, including respiratory event index (REI4%) and percent sleep time <90% oxygen saturation (nocturnal hypoxemia). Nocturnal hypertension was defined as mean asleep systolic BP (SBP) ≥120 mm Hg or diastolic BP (DBP) ≥70 mm Hg. Multivariable linear regression models were fit to estimate the association between each OSA measure and nighttime SBP and DBP. Among 206 participants who completed ABPM and participated in the Jackson Heart Sleep Study, 50.5% had nocturnal hypertension and 26.2% had moderate to severe OSA (REI4% ≥15 events/hour). After multivariable adjustment, each SD (13.3 events/hour) increase in REI4% was associated with 1.75 mm Hg higher nighttime DBP (95% confidence interval (CI): 0.38, 3.11) and a prevalence ratio of 1.11 (95% CI: 1.00, 1.24) for nocturnal hypertension. Each SD (10.4%) increase in nocturnal hypoxemia was associated with a 1.91 mm Hg higher nighttime SBP (95% CI: 0.15, 3.66). Severity of OSA and nocturnal hypoxemia were associated with high nighttime BP in African American participants in the JHS.

Do the Same Central Anthropometric Variables that Best Predict Blood Pressure in European Americans also Best Predict Blood Pressure in African Americans?

The purpose of this study was to determine if central anthropometric variables that best estimate blood pressure risks in European Americans also best estimate blood pressure risks in African Americans. The participants were 357 normotensive African and European American volunteers with a mean age of 32.6 ± 12.4 years. Participants were evaluated for central adiposity with dual energy X-ray absorptiometry, abdomen and thigh skinfolds, waist and hip circumferences, waist/hip ratio, waist/height ratio, body mass index, and systolic and diastolic blood pressures. Descriptive statistics, partial correlations, ANOVA and stepwise regressions were used to analyze the data. Central adiposity anthropometric indices made different contributions to blood pressure in African and European American men and women. When weight was held constant, waist circumference shared stronger partial relationships with blood pressure in African Americans (r = .30 to .47) than in European Americans (r = .11 to .32). Waist circumference in combination with other indices was a predictor of systolic and diastolic blood pressures in European American men (P<.05) but only a predictor for diastolic blood pressure in African American men and women (P<.01). Hip circumference was the only predictor for systolic blood pressure (P<.01) in African American men and women. Further research on the relative contributions of central anthropometric indices to blood pressure in African and European Americans is warranted. A better understanding of this relationship may help reduce hypertensive morbidity and mortality disparities between African and European Americans.

A Social Determinant of Health May Modify Genetic Associations for Blood Pressure: Evidence From a SNP by Education Interaction in an African American Population.

African Americans experience the highest burden of hypertension in the United States compared with other groups. Genetic contributions to this complex condition are now emerging in this as well as other populations through large-scale genome-wide association studies (GWAS) and meta-analyses. Despite these recent discovery efforts, relatively few large-scale studies of blood pressure have considered the joint influence of genetics and social determinants of health despite extensive evidence supporting their impact on hypertension. To identify these expected interactions, we accessed a subset of the Vanderbilt University Medical Center (VUMC) biorepository linked to de-identified electronic health records (EHRs) of adult African Americans genotyped using the Illumina Metabochip (n = 2,577). To examine potential interactions between education, a recognized social determinant of health, and genetic variants contributing to blood pressure, we used linear regression models to investigate two-way interactions for systolic and diastolic blood pressure (DBP). We identified a two-way interaction between rs6687976 and education affecting DBP (p = 0.052). Individuals homozygous for the minor allele and having less than a high school education had higher DBP compared with (1) individuals homozygous for the minor allele and high school education or greater and (2) individuals not homozygous for the minor allele and less than a high school education. To our knowledge, this is the first EHR -based study to suggest a gene-environment interaction for blood pressure in African Americans, supporting the hypothesis that genetic contributions to hypertension may be modulated by social factors.

Abstract P348: Validation of SGCD (rs2116737) Genotype-Discrimination Interaction as a Determinant of Blood Pressure Variation in the Jackson Heart Study

Introduction: Previous anthropological studies have demonstrated the utility of integrating genetic and psychosocial data, such as discrimination, to understand complex phenotypes such as blood pressure (BP). In these studies, including both single nucleotide polymorphisms (SNP) and psychosocial measures in the model only revealed significant SNPs after accounting for gene by social environment interactions. Methods: We sought to externally validate SNPs associated with BP in African Americans (AAs) identified in a study by Quinlan et al. in 2016 that incorporated novel measures of unfair treatment/discrimination and revealed new genes and biological pathways relevant to BP variation. Our validation was done using a larger cohort study of AAs, the Jackson Heart Study (JHS). Systolic and diastolic BP were measured twice in the same visit using a random-zero mercury sphygmomanometer and averaged. During this visit, perceived discrimination was assessed as lifetime occurrence of unfair treatment in nine social domains using the JHS discrimination instrument. Using available GWAS data, 28 significant SNPs were imputed from 1000 Genomes Project Phase 1 (version 3). Our analysis was conducted separately on participants who reported use of BP medications (n= 1532) and those who did not (n=1407). We similarly tested for associations of SNPs with BP using 3 linear regression models adjusting for global ancestry, sex, age, education, BMI, and relatedness. Model 1 tested only the SNPs, model 2 tested the SNPs and discrimination, and model 3 tested an interaction between SNPs and discrimination. Results: JHS participants were 62% female, with a mean age of 55 years, mean BMI of 32, mean systolic BP of 127 and mean diastolic BP of 76. Participants on average experienced unfair treatment in three domains in their lifetime. In participants not on BP medications, we found that rs2116737, in the gene SGCD , achieved Bonferroni-corrected significance (p &lt; 0.004) with systolic BP in a recessive genotype model (β= 11.92; p =2.00х10 -4 ) and was only identified through model 3, the gene-discrimination interaction model. No significant findings were seen in patients using BP medications. Conclusions: rs2116737 was validated in the JHS for a gene-discrimination interaction. rs2116737 is an intronic variant in SGCD , a gene that is highly expressed in arterial tissue, suggesting vascular regulation as a possible mechanism behind the interaction. In conclusion, the findings suggest accounting for a gene by social environment interaction can identify new SNPs that deserve further investigation in understanding BP variation.

Nighttime administration of high-dose, sustained-release melatonin does not decrease nocturnal blood pressure in African-American patients: Results from a preliminary randomized, crossover trial

ObjectivesThis preliminary study tested whether a high-dose, sustained-release form of melatonin reduced 24-hour blood pressure in African-Americans. DesignRandomized, placebo-controlled, crossover pilot study of 40 self-defined African-American patients with essential hypertension. Settings/locationUrban, academic medical center and associated outpatient clinics. InterventionsPatients ingested either melatonin (high dose [24 mg], sustained-release formulation] or placebo in randomized order over a 4-week period. Outcome measuresMean nighttime and daytime systolic and diastolic blood pressures, as measured with 24-hour ambulatory blood pressure monitors. The primary outcome was mean nighttime systolic blood pressure. ResultsThere were no statistically differences between melatonin and placebo conditions in mean nighttime or daytime systolic or diastolic blood pressures. ConclusionsIn contrast with studies in other populations, this preliminary study showed that nighttime dosing of continuous-release melatonin had no significant effect on nocturnal blood pressure in African Americans with essential hypertension when compared to placebo.

Abstract P170: Morning Surge and Cardiovascular Events in African Americans: The Jackson Heart Study

Introduction: A larger sleep-trough morning surge, defined as the mean two-hour post-awakening blood pressure (BP) minus the lowest asleep BP, has been associated with cardiovascular disease (CVD) events in Asians and Europeans. High asleep BP in African Americans (AA) may preclude a morning surge and an association with CVD due to a smaller BP change upon awakening. Objective: Determine the association of morning surge with CVD events in AAs. Methods: We analyzed participants from the Jackson Heart Study, a community-based cohort of AAs, with a complete 24-hour ambulatory BP monitoring recording and self-report asleep and awake times at baseline in 2000-2004 (n=767). Participants were grouped into tertiles of sleep-trough morning surge, two-hour post-awakening BP and lowest sleep BP. CVD events (nonfatal/fatal stroke, nonfatal myocardial infarction or fatal coronary heart disease; n=61) through December 2012 were adjudicated. Results: Participants’ mean age was 59.2 years and 32.1% were male. Multivariable adjusted hazard ratios (95% CI) for CVD events associated with Tertile 2 and 3 versus Tertile 1 of morning systolic BP (SBP) surge were 1.45 (0.71 – 2.97) and 2.03 (0.98 – 4.23), respectively; of post-awakening SBP were 2.01 (0.81 – 4.99) and 4.41 (1.85 – 10.50), respectively; and of lowest asleep SBP were 1.55 (0.68 – 3.52) and 2.22 (0.96 – 5.14), respectively ( Table ). Also, there was a graded increasing risk for CVD associated with Tertile 2 and 3 versus Tertile 1 of post-awakening diastolic BP (DBP), but not morning DBP surge and lowest asleep DBP. Conclusion: Higher morning SBP surge, post-awakening SBP and lowest asleep SBP and DBP were associated increased CVD risk in AAs.

Dietary Phosphorus and Ambulatory Blood Pressure in African Americans: The Jackson Heart Study.

Higher dietary phosphorus is associated with left ventricular hypertrophy and mortality, which are blood pressure (BP)-related outcomes. For this reason, we hypothesized that dietary phosphorus may be associated with adverse clinic and ambulatory BP patterns. Our study included 973 African American adults enrolled in the Jackson Heart Study (2000-2004) with 24-hour ambulatory BP monitoring (ABPM) data at baseline. We quantified dietary phosphorus from a validated Food Frequency Questionnaire as follows: (i) absolute daily intake, (ii) ratio of phosphorus-to-protein intake, (iii) phosphorus density, and (iv) energy-adjusted phosphorus intake. Using multivariable linear regression, we determined associations between dietary phosphorus intake and systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse pressure in clinic and over daytime, nighttime, and 24-hour periods from ABPM. Extent of nocturnal BP dipping was also assessed. Using logistic regression, we modeled relationships between dietary phosphorus intake and clinically relevant qualitative BP phenotypes, such as masked, sustained, or white-coat hypertension and normotension. There were no statistically significant associations between phosphorus intake and SBP or pulse pressure in adjusted models. Most metrics of higher phosphorus intake were associated with lower daytime, nighttime, and clinic DBP. Higher phosphorus intake was not associated with clinic or ABPM-defined hypertension overall, but most metrics of higher phosphorus intake were associated with lower odds of sustained hypertension compared to sustained normotension, white-coat hypertension, and masked hypertension. There were no associations between dietary phosphorus and nocturnal BP dipping. These data do not support a role for higher phosphorus intake and higher BP in African Americans.

West African Ancestry and Nocturnal Blood Pressure in African Americans: The Jackson Heart Study.

African Americans have a higher prevalence of nocturnal hypertension and nondipping blood pressure than European Americans, but the genetic contribution to these racial differences remains unclear. We assessed the association of the percentage West African genetic ancestry with nocturnal hypertension and nondipping blood pressure in 932 African Americans from the Jackson Heart Study. Using percentage West African ancestry determined from 389 ancestry informative markers, participants were categorized into tertiles (tertile 1 [low]: <79.3%, tertile 2: ≥79.3-86.3%, and tertile 3 [high]: >86.3%). Nocturnal hypertension was defined as mean nighttime (midnight-6 am) systolic (SBP)/diastolic blood pressure ≥120/70 mm Hg. Nondipping blood pressure was defined as mean nighttime-to-daytime (10 am-8 pm) SBP ratio >0.90. Nocturnal hypertension was present in 57.9% of participants; 66.6% had nondipping blood pressure. The mean age was 59.4 years, 32.8% were male, and 56.0% were taking antihypertensive medication. The prevalence ratios (95% confidence interval) adjusted for age, sex, cardiovascular disease risk factors, and socioeconomic and psychosocial factors comparing participants with moderate and high to those with low percentage West African ancestry for nocturnal hypertension were 0.98 (0.87-1.10) and 0.95 (0.84-1.08), respectively, and for nondipping blood pressure was 0.96 (0.86-1.07) and 0.98 (0.88-1.09), respectively. West African ancestry was not associated with nocturnal hypertension and nondipping blood pressure among African Americans. While rare genetic variants cannot be ruled out, these data highlight the need to better understand how environmental and behavioral factors contribute to differences in nocturnal blood pressure among African Americans compared with European Americans.

MicroRNAs in the miR-17 and miR-15 families are downregulated in chronic kidney disease with hypertension.

BackgroundIn older adults (aged 70–74 years), African-Americans have 4-fold higher risk of developing hypertension-attributed end-stage renal disease (ESRD) than European-Americans. A hypothesized mechanism linking hypertension and progressive chronic kidney disease (CKD) is the innate immune response and inflammation. Persons with CKD are also more susceptible to infection. Gene expression in peripheral blood can provide a view of the innate immune activation profile. We aimed to identify differentially expressed genes, microRNAs, and pathways in peripheral blood between cases with CKD and high blood pressure under hypertension treatment versus controls without CKD and with controlled blood pressure in African Americans.MethodsCase and control pairs (N = 15x2) were selected from those without diabetes and were matched for age, sex, body mass index, APOL1 risk allele count, and hypertension medication use. High blood pressure under hypertension treatment was defined as hypertension medication use and systolic blood pressure (SBP) ≥ 145 mmHg. CKD was defined as estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73m2. Cases were selected from those with CKD and high blood pressure under hypertension treatment, and controls were selected from those without CKD (eGFR: 75–120 mL/min/1.73m2 and urine albumin-to-creatinine ratio < 30mg/g) and with blood pressure controlled by hypertension medication use (SBP < 135 mmHg and D(diastolic)BP < 90 mm Hg). We perform RNA sequencing of mRNA and microRNA and conducted differential expression and co-expression network analysis.ResultsOf 347 miRNAs included in the analysis, 14 were significantly associated with case status (Benjamini-Hochberg adjusted p-value [BH p] < 0.05). Of these, ten were downregulated in cases: three of each belong to the miR-17 and miR-15 families. In co-expression network analysis of miRNA, one module, which included 13 of the 14 significant miRNAs, had significant association with case status. Of the 14,488 genes and 41,739 transcripts included in the analysis, none had significant association with case status. Gene co-expression network analyses did not yield any significant associations for mRNA.ConclusionWe have identified 14 differentially expressed miRNAs in the peripheral blood of CKD cases with high blood pressure under hypertension treatment as compared to appropriate controls. Most of the significant miRNAs were downregulated and have critical roles in immune cell functions. Future studies are needed to replicate our findings and determine whether the downregulation of these miRNAs in immune cells may influence CKD progression or complications.