Socioeconomic and psychosocial factors mediate race differences in nocturnal blood pressure dipping

Examining the Role of Psychosocial Stressors in Hypertension

Despite advances in medicine and preventive strategies, fewer than 1 in 5 people with hypertension have the problem under control. This could partly be due to gaps in fully elucidating the etiology of hypertension. Genetics and conventional lifestyle risk factors, such as the lack of exercise, unhealthy diet, excess salt intake, and alcohol consumption, do not fully explain the pathogenesis of hypertension. Thus, it is necessary to revisit other suggested risk factors that have not been paid due attention. One such factor is psychosocial stress. This paper explores the evidence for the association of psychosocial stressors with hypertension and shows that robust evidence supports the role of a chronic stressful environment at work or in marriage, low socioeconomic status, lack of social support, depression, anxiety, post-traumatic stress, childhood psychological trauma, and racial discrimination in the development or progression of hypertension. Furthermore, the potential pathophysiological mechanisms that link psychosocial stress to hypertension are explained to address the ambiguity in this area and set the stage for further research.

Racial and ethnic differences in blood pressure before and after the 2016 United States general election

OBJECTIVES

The 2016 U.S. presidential election was a major source of stress among many adults. Psychosocial stress can manifest physiologically in elevated blood pressure (BP). Little is known regarding the association of macro-level sociopolitical events with BP changes at the population-level. This study sought to characterize population-level changes in BP following the 2016 U.S. presidential election.

METHODS

Using 2015-2018 National Health and Nutrition Examination Survey, we included participants aged ≥18 years during the same periods prior to (May to October 2015/2016) and after (May to October 2017/2018) the election. Survey-weighted data were analyzed to compare population-level systolic BP (SBP) and diastolic BP (DBP) pre- and post-election, stratified by race/ethnicity. Sex differences were also investigated.

RESULTS

We observed significant increases in SBP among non-Hispanic (NH) Asian participants (+3.4 mmHg; p = .046), but not among other racial/ethnic participants. DBP increased among NH Black participants (+2.3 mmHg; p = .049) and Mexican American participants (+2.9 mmHg; p = .007), but not among other racial/ethnic participants. These changes appeared attributable to differential BP changes by sex.

CONCLUSIONS

At the population-level, variable changes in BP were observed by race/ethnicity following the 2016 U.S. presidential election, possibly driven by SBP elevations among women.

Diurnal dynamic range as index of dysregulation of system dynamics. A cortisol examplar using data from the Study of Midlife in the United States

We discuss the importance of including measures of dysregulated system dynamics in the operationalization of allostatic load. The concept of allostatic load, as originally proposed by McEwen and Stellar, included dysregulation not only in the resting state of physiological systems, but also in system dynamics. We describe previous work on cortisol diurnal dynamic range (peak to nadir spread) as an index of the health of the hypothalamic-pituitary-adrenal axis, with compression of dynamic range being a marker of dysregulation. In particular, we review the evidence for a) diurnal dynamic range compression in people from disadvantaged backgrounds, b) cross-sectional association of cortisol diurnal dynamic range compression with dysregulation in other systems' resting states, and c) cross-sectional association of cortisol diurnal dynamic range compression with lower scores on cognitive testing. Then, we present new data from the Study of Midlife in the United States (MIDUS) on longitudinal associations of cortisol dynamic range compression with subsequent cognitive decline and all-cause mortality. Briefly, each standard deviation decrement in cortisol diurnal dynamic range is associated with adjusted mortality hazard ratio of 1.35 (95% confidence interval: 1.19, 1.54). Among those who scored at median or lower in executive functioning at baseline and survive, each standard deviation decrement in cortisol dynamic range is associated with 1% greater decline in executive functioning over a decade (95% confidence interval: 0.4%, 2.0%). We conclude that including measures of system dynamics like diurnal dynamic range in the next generation of allostatic load measurement will likely advance understanding of the cumulative physiological burden of chronic stress and life experiences, and improve the prediction of future health consequences.

Is there an association between socioeconomic status and the degree of diurnal variation in heart rate?

BACKGROUND

Disruption in circadian rhythms is associated with cardiovascular disease and may play a role in socioeconomic differences in cardiovascular disease prevalence. However, it is unclear whether low SES is associated with a lower diurnal rhythm in autonomic activity markers. We investigated the association between SES and the amplitude of the daily fluctuation of heart rate.

METHODS

We included data of 450 participants of a HELIUS sub-study in Amsterdam, the Netherlands. Participants wore an Actiheart monitor (CamNtech), a chest-worn monitor which measures heart rate every 15 s for several days. Cosinor analysis was performed on the time series of heart rate within each participant. We analyzed the association between the cosinor parameters (amplitude, midline and peak time of the diurnal HR rhythm) and SES indicators (education, occupational class and a proxy of income) in multivariate linear regression models, adjusting for age, sex and ethnicity.

RESULTS

There was a clear diurnal rhythm in the average heart rates, with a peak between noon and 18:00 and a trough between 04:00 and 06:00. This rhythm was present for all categories of education, occupation and income proxy. The estimates for the cosinor parameters did not differ consistently and significantly between categories of education, occupation or income proxy.

CONCLUSIONS

We did not find any consistent evidence to support our hypothesis of a diminished amplitude in the diurnal variation of heart rate in individuals with lower SES. Future studies should explore SES differences in the diurnal variation in markers of autonomic activity other than heart rate.

Stress, adherence, and blood pressure control: A baseline examination of Black women with hypertension participating in the SisterTalk II intervention

The prevalence of hypertension is highest among Black women, but treatment adherence is reportedly low. Stress unique to the experiences of Black Americans may be associated with low adherence and poor blood pressure control, but few studies have examined the relationships between stress, adherence, and blood pressure control among hypertensive Black women. This study seeks to fill gaps in research by examining the association between stress, adherence, and blood pressure control. The baseline sample (n = 571) of at-risk or hypertensive Black women from the SisterTalk II RCT (Northeastern USA, 2004-2006) to improve adherence to recommendations for hypertension was analyzed. Participants self-reported stress, pharmacological adherence, non-pharmacological adherence (i.e. lifestyle management such as diet and exercise), and demographics. Blood pressure and anthropometrics (BMI and waist circumference) were measured. Statistical analysis included ANOVA, t-tests, linear regression. Tests of mediation examined if adherence mediated the relationship between stress and blood pressure control. This study found that stress was associated with lower age (p < .001) and being a single parent (p < .001). Stress was also associated with higher systolic blood pressure (p = .029), and poor blood pressure control (p = .043). Participants who reported higher stress also reported lower non-pharmacological adherence (p = .042). Non-pharmacological adherence was found to mediate the association between stress and blood pressure control. Hence, results document a relationship between stress with non-pharmacological adherence and blood pressure control among Black American women. More research is necessary to examine the relationship between stress and treatment adherence.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Associations of Nocturnal Blood Pressure With Cognition by Self-Identified Race in Middle-Aged and Older Adults: The GENOA (Genetic Epidemiology Network of Arteriopathy) Study

Background

Whether the association of blood pressure (BP) during sleep (nocturnal BP) with cognition differs by race is unknown.

Methods and Results

Participants in the GENOA (Genetic Epidemiology Network of Arteriopathy) Study underwent ambulatory BP measurements, brain magnetic resonance imaging, and cognitive function testing (the Rey Auditory Verbal Learning Test, the Digit Symbol Substitution Task, and the Trail Making Test Part B) between 2000 and 2007. We examined multivariable linear regression models of the nocturnal BP‐cognition association. Among 755 participants (mean age, 63 years; 64% women; 42% self‐identified black race; 76% taking antihypertensive medication), mean nocturnal systolic BP (SBP)/diastolic BP was 126/69 mm Hg, daytime SBP/diastolic BP level was 139/82 mm Hg, and mean reduction in SBP from day to night (dipping) was 9%. Among the entire sample, a race interaction was observed in Digit Symbol Substitution Task and Trail Making Test Part B (both P<0.15). Race‐stratified analyses showed that a 1‐SD increase in nocturnal SBP levels was associated with poorer Digit Symbol Substitution Task and log‐transformed Trail Making Test Part B scores (unstandardized regression coefficient [95% confidence interval]: −1.98 [−3.28 to −0.69] and 0.06 [0.004–0.12]; both P<0.05) in black but not white individuals. Additional adjustments for white matter hyperintensity volumes or brain atrophy, measured via brain magnetic resonance imaging, did not change the results. Results were similar when nocturnal SBP dipping was assessed as the exposure, yet daytime SBP levels yielded no association with cognition.

Conclusions

Nocturnal SBP measurements may be useful in assessing the potential risk for lower cognitive function in middle‐aged and older adults, particularly in black individuals.

Social support and ambulatory blood pressure in older people

OBJECTIVE

Social support has been associated with greater nocturnal decline (dipping) in blood pressure (BP) in younger and middle-aged individuals. However, it is uncertain if aggregated measures of social support are related to ambulatory SBP in older adults, where high SBP is frequent and clinically challenging.

METHODS

We studied 1047 community-living individuals aged at least 60 years in Spain. Twenty-four-hour ambulatory BP was determined under standardized conditions. Social support was assessed with a seven-item questionnaire on marital status, cohabitation, frequency of contact with relatives, or with friends and neighbors, emotional support, instrumental support, and outdoor companionship. A social support score was built by summing the values of the items that were significantly associated with SBP variables, such that the higher the score, the better the support.

RESULTS

Participants' mean age was 71.7 years (50.8% men). Being married, cohabiting, and being accompanied when out of home were the support items significantly associated with SBP variables. After adjustment for sociodemographic (age, sex, education), behavioral (BMI, alcohol, tobacco, salt consumption, physical activity, Mediterranean diet score), and clinical variables [sleep quality, mental stress, comorbidity, BP medication, and ambulatory BP levels and heart rate (HR)], one additional point in the social support score built with the abovementioned three support variables, was associated with a decrease of 0.93 mmHg in night-time SBP (P = 0.039), totaling 2.8 mmHg decrease for a score of 3 vs. 0. The three-item social support score was also inversely associated with the night/day SBP ratio (β = -0.006, P = 0.010).

CONCLUSION

In older adults, social support is independently associated with lower nocturnal SBP and greater SBP dipping. Further research is needed in prospective studies to confirm these results.

Racial differences in nocturnal dipping status in diabetic kidney disease: Results from the STOP-DKD (Simultaneous Risk Factor Control Using Telehealth to Slow Progression of Diabetic Kidney Disease) study

While racial variation in ambulatory blood pressure (BP) is known, patterns of diurnal dipping in the context of diabetic kidney disease have not been well defined. The authors sought to determine the association of race with nocturnal dipping status among participants with diabetic kidney disease enrolled in the STOP-DKD (Simultaneous Risk Factor Control Using Telehealth to Slow Progression of Diabetic Kidney Disease) trial. The primary outcome was nocturnal dipping-percent decrease in average systolic BP from wake to sleep-with categories defined as reverse dippers (decrease <0%), nondippers (0%-<10%), and dippers (≥10%). Twenty-four-hour ambulatory BP monitoring was completed by 108 participants (54% were nondippers, 24% were dippers, and 22% were reverse dippers). In adjusted models, the common odds of reverse dippers vs nondippers/dippers and reverse dippers/nondippers vs dippers was 2.6 (95% confidence interval, 1.2-5.8) times higher in blacks than in whites. Without ambulatory BP monitoring data, interventions that target BP in black patients may be unable to improve outcomes in this high-risk group.

Race and sex differences in ambulatory blood pressure measures among HIV+ adults

Ambulatory blood pressure monitoring (ABPM) can identify phenotypes that cannot be measured in the clinic. Determining race and sex disparities in ABPM measures among HIV+ individuals may improve strategies to diagnose and treat hypertension in this high-risk population. We compared ABPM measures between 24 African-American and 25 white HIV+ adults (36 men and 13 women). Awake systolic blood pressure (SBP) and diastolic blood pressure (DBP) were similar in African-Americans and whites. After multivariable adjustment, sleep SBP and DBP were 9.7 mm Hg (95% confidence interval [95% CI]: 4.7, 14.8) and 8.4 mm Hg (95% CI: 4.3, 12.5) higher, respectively, among African-Americans compared with whites. After multivariable adjustment, SBP and DBP dipping ratios were 5.2% (95% CI: 1.7%, 8.7%) and 6.1% (95% CI 2.0%, 10.3%) smaller among African-Americans compared with whites. After multivariable adjustment, awake and sleep SBP and DBP were higher in men compared to women. There was no difference in SBP or DBP dipping ratios comparing men and women. The prevalence of awake masked hypertension was 42% in men versus 17% in women, and the prevalence of sleep masked hypertension was 57% among African-Americans versus 18% among whites. These data suggest that ABPM measures differ by race and sex in HIV+ adults.

Psychosocial Correlates of Nocturnal Blood Pressure Dipping in African Americans: The Jackson Heart Study

BACKGROUND

African Americans exhibit a lower degree of nocturnal blood pressure (BP) dipping compared with Whites, but the reasons for reduced BP dipping in this group are not fully understood. The aim of this study was to identify psychosocial factors associated with BP dipping in a population-based cohort of African Americans.

METHODS

This cross-sectional study included 668 Jackson Heart Study (JHS) participants with valid 24-hour ambulatory BP data and complete data on psychosocial factors of interest including stress, negative emotions, and psychosocial resources (e.g., perceived support). The association of each psychosocial factor with BP dipping percentage and nondipping status (defined as <10% BP dipping) was assessed using linear and Poisson regression models, respectively, with progressive adjustment for demographic, socioeconomic, biomedical, and behavioral factors.

RESULTS

The prevalence of nondipping was 64%. Higher depressive symptoms, higher hostility, and lower perceived social support were associated with a lower BP dipping percentage in unadjusted models and after adjustment for age, sex, body mass index, and mean 24-hour systolic BP (P < 0.05). Only perceived support was associated with BP dipping percentage in fully adjusted models. Also, after full multivariable adjustment, the prevalence ratio for nondipping BP associated with 1 SD (7.1 unit) increase in perceived support was 0.93 (95% CI: 0.88-0.99). No other psychosocial factors were associated with nondipping status.

CONCLUSIONS

Lower perceived support was associated with reduced BP dipping in this study. The role of social support as a potentially modifiable determinant of nocturnal BP dipping warrants further investigation.

Childhood Poverty: Understanding and Preventing the Adverse Impacts of a Most-Prevalent Risk to Pediatric Health and Well-Being

Poor children are at greater risk for worse health, less productivity, and harms to well-being that extend into adulthood and subsequent generations. Timing and duration of poverty matter and influence life course outcomes, especially for education, health, and lifetime productivity. This article focuses on interventions by policy advocacy and the pediatric health system, and protection of the health and well-being of families in economic hardship from disadvantages and trauma wrought by poverty. A framework is presented for child poverty prevention and its consequences for lifelong health and success on a national scale.

Nocturnal Blood Pressure in Young Adults and Cognitive Function in Midlife: The Coronary Artery Risk Development in Young Adults (CARDIA) Study

BACKGROUND

Nocturnal blood pressure (BP) is associated with risk for cardiovascular events. However, the relationship between nocturnal BP in young adults and cognitive function in midlife remains unclear.

METHODS

We used data from the ambulatory BP monitoring substudy of the Coronary Artery Risk Development in Young Adults Study, including 224 participants (mean age 30 years, 45% men, 63% African Americans). At the 20-year follow-up, the Stroop test (executive function), Digit Symbol Substitution Test (psychomotor speed), and Rey Auditory Verbal Learning Test (verbal memory) were assessed.

RESULTS

Baseline mean office, daytime, and nocturnal BP were 109/73, 120/74, and 107/59 mm Hg, respectively. Nocturnal BP dipping, calculated as (nocturnal systolic BP [SBP]--daytime SBP) × 100/daytime SBP, was divided into quartiles (Q1: -39.3% to -16.9%; Q2: -16.8% to -13.2%, Q3 [reference]: -13.1% to -7.8%, and Q4: -7.7% to +56.4%). In multiple regression analyses, the least nocturnal SBP dipping (Q4 vs. reference) and higher nocturnal diastolic BP level were associated with worse Stroop scores, with adjustments for demographic and clinical characteristics, and cumulative exposure to office BP during follow-up (β [standard error]: 0.37 [0.18] and 0.19 [0.07], respectively; all P < 0.05). Digit Symbol Substitution Test and Rey Auditory Verbal Learning Test were not significantly associated with nocturnal SBP dipping or nocturnal SBP/diastolic BP levels.

CONCLUSIONS

Among healthy young adults, less nocturnal SBP dipping and higher nocturnal diastolic BP levels were associated with lower executive function in midlife, independent of multiple measures of office BP during long-term follow-up.

Racial differences in abnormal ambulatory blood pressure monitoring measures: Results from the Coronary Artery Risk Development in Young Adults (CARDIA) study

BACKGROUND

Several ambulatory blood pressure monitoring (ABPM) measures have been associated with increased cardiovascular disease risk independent of clinic blood pressure (BP). African Americans have higher clinic BP compared with Whites but few data are available on racial differences in ABPM measures.

METHODS

We compared ABPM measures between African American (n = 178) and White (n = 103) participants at the Year 5 Coronary Artery Risk Development in Young Adults study visit. BP was measured during a study visit and the second and third measurements were averaged. ABPM was conducted over the following 24 hours.

RESULTS

Mean ± SD age of participants was 29.8 ± 3.8 years and 30.8 ± 3.5 years for African Americans and Whites, respectively. Mean daytime systolic BP (SBP) was 3.90 (SD 1.18) mm Hg higher among African Americans compared with Whites (P < 0.001) after age-gender adjustment and 1.71 (SD 1.03) mm Hg higher after multivariable adjustment including mean clinic SBP (P = 0.10). After multivariable adjustment including mean clinic SBP, nighttime SBP was 4.83 (SD 1.11) mm Hg higher among African Americans compared with Whites (P < 0.001). After multivariable adjustment, the African Americans were more likely than Whites to have nocturnal hypertension (prevalence ratio: 2.44, 95% CI: 0.99-6.05) and nondipping (prevalence ratio: 2.50, 95% CI: 1.39-4.48). The prevalence of masked hypertension among African Americans and Whites was 4.4% and 2.1%, respectively, (P = 0.49) and white coat hypertension was 3.3% and 3.9%, respectively (P = 0.99). Twenty-four hour BP variability on ABPM was higher among African Americans compared with Whites.

CONCLUSIONS

These data suggest racial differences in several ABPM measures exist.

Pistachio nut consumption modifies systemic hemodynamics, increases heart rate variability, and reduces ambulatory blood pressure in well-controlled type 2 diabetes: a randomized trial

Background

Managing cardiovascular risk factors is important for reducing vascular complications in type 2 diabetes, even in individuals who have achieved glycemic control. Nut consumption is associated with reduced cardiovascular risk; however, there is mixed evidence about the effect of nuts on blood pressure (BP), and limited research on the underlying hemodynamics. This study assessed the effect of pistachio consumption on BP, systemic hemodynamics, and heart rate variability in adults with well‐controlled type 2 diabetes.

Methods and Results

We enrolled 30 adults (40 to 74 years) with type 2 diabetes in a randomized, crossover, controlled feeding study. After a 2‐week run‐in period, participants consumed a low‐fat control diet (27% fat) containing low‐fat/high‐carbohydrate snacks and a moderate‐fat diet (33% fat) containing pistachios (20% of total energy) for 4 weeks each, separated by a 2‐week washout. Following each diet period, we assessed BP, systemic hemodynamics, and heart rate variability at rest and during acute mental stress, and, in a subset of participants (n=21), 24‐hour ambulatory BP. BP at rest and during stress did not differ between treatments. The pistachio diet significantly reduced total peripheral resistance (−3.7±2.9%, P=0.004), increased cardiac output (3.1±2.3%, P=0.002), and improved some measures of heart rate variability (all P<0.05). Systolic ambulatory BP was significantly reduced by 3.5±2.2 mm Hg (P=0.046) following the pistachio diet, with the greatest reduction observed during sleep (−5.7±2.6 mm Hg, P=0.052).

Conclusions

A moderate‐fat diet containing pistachios modestly improves some cardiovascular risk factors in adults with well‐controlled type 2 diabetes.

Clinical Trial Registration

URL: www.clinicaltrials.gov. Unique identifier: NCT00956735.

Neighborhood problems and nocturnal blood pressure dipping

OBJECTIVE

Living in adverse neighborhood conditions has been linked with greater prevalence of cardiovascular disease (CVD). We aimed to learn whether perceived neighborhood problems are related to attenuated nocturnal blood pressure (BP) dipping, a risk factor for CVD morbidity.

METHOD

A sample of 133 adults (71 male, 62 female; 80 White, 53 Black) underwent 24-hr ambulatory blood pressure monitoring. The neighborhood problem scale (NPS) was used to assess neighborhood environmental stressors.

RESULTS

Nocturnal dipping in systolic (SBP), diastolic (DBP) and mean arterial (MAP) blood pressure was reduced in individuals with higher NPS scores (p < .05). Hierarchical regression analyses revealed that neighborhood problems explained 4%-6% of the variance in SBP, DBP, and MAP dipping (p < .05) even after adjusting for several theoretical confounders such as social status, age, gender, race, body mass index (BMI), smoking, exercise, depression and discrimination.

CONCLUSION

Neighborhood problems may contribute to attenuated BP dipping beyond the effect of known risk factors.

Interactive influences of ethnicity, endothelin-1 gene, and everyday discrimination upon nocturnal ambulatory blood pressure

BACKGROUND

Everyday discrimination scale scores are associated with increased ambulatory blood pressure (BP) and reduced nocturnal dipping, and the endothelin-1 (ET-1)/Lys198Asn polymorphism is associated with increased resting BP and exaggerated BP reactivity among African Americans compared to European Americans. Combined influences of these factors on BP control are unknown.

PURPOSE

This study tested the hypothesis of a three-way interaction between ethnicity, ET-1 carrier status, and everyday discrimination upon ambulatory BP and nocturnal dipping.

METHODS

Baseline laboratory anthropometrics and the everyday discrimination scale were completed by 352 (175 African American) young adult normotensives, followed by 24-h ambulatory BP monitoring.

RESULTS

For nocturnal dipping, multiple regression models controlling for age, sex, ethnicity, and body mass index revealed significant three-way ET-1 × everyday discrimination × ethnicity interactions. Specifically, among African American ET-1 T-allele carriers, increases in everyday discrimination led to reduced nocturnal dipping.

CONCLUSIONS

African Americans that carry the ET-1/Lys198Asn T-allele and report higher everyday discrimination scores may be at particular risk for reduced nocturnal dipping.

Night/day ratios of ambulatory blood pressure among healthy adolescents: roles of race, socioeconomic status, and psychosocial factors

BACKGROUND

Elevated nighttime blood pressure (BP) predicts hypertension and its complications in adulthood.

PURPOSE

This study aimed to assess the independent effects of race and family income on night/day BP among adolescents and to examine whether negative emotions, low positive resources, and unpleasant interactions during the day are also related.

METHODS

Healthy African American and Caucasian high school students (N = 239) wore an ambulatory BP monitor for 48 h, recorded quality of ongoing interpersonal interactions, and completed questionnaires.

RESULTS

African Americans and those with lower family income had higher night/day BP ratios. African Americans reporting greater negative emotions, lower positive resources, and more unpleasant interactions had higher night/day BP ratios.

CONCLUSIONS

Racial differences in night BP emerge by adolescence, independent of family income. African Americans, especially those high in negative emotions and low in positive resources, may be at higher relative risk for hypertension later in life in part due to elevated night BP.

Correlates of isolated nocturnal hypertension and target organ damage in a population-based cohort of African Americans: the Jackson Heart Study

BACKGROUND

African Americans have higher rates of nocturnal hypertension and less nocturnal blood pressure (BP) dipping compared with whites. Although nocturnal hypertension is associated with increased cardiovascular morbidity and mortality, its clinical significance among those with normal daytime BP is unclear. This paper reports the prevalence and correlates of isolated nocturnal hypertension (INH) in a population-based cohort of African Americans enrolled in the Jackson Heart Study (JHS).

METHODS

The study sample included 425 untreated, normotensive and hypertensive JHS participants who underwent 24-hour ambulatory BP monitoring (ABPM), echocardiography, and 24-hour urine collection. Multiple logistic regression and 1-way analysis of variance models were used to test the hypothesis that those with INH have worse target organ damage reflected by greater left ventricular (LV) mass and proteinuria compared with normotensive participants.

RESULTS

Based on 24-hour ABP profiles, 19.1% of participants had INH. In age and sex-adjusted models, participants with INH had greater LV mass compared with those who were normotensive (P = 0.02), as well as about 3 times the odds of LV hypertrophy and proteinuria (Ps < 0.10). However, multivariable adjustment reduced the magnitude and statistical significance of each of these differences.

CONCLUSIONS

INH was associated with increased LV mass compared with normo tension in a population-based cohort of African Americans enrolled in the JHS. There were trends toward a greater likelihood of LV hyper trophy and proteinuria among participants with INH vs. those who were normotensive. The clinical significance of the noted target organ damage should be explored in this population.

Socioeconomic Inequality of Non-Communicable Risk Factors among People Living in Kurdistan Province, Islamic Republic of Iran

BACKGROUND

The most fundamental way to decrease the burden of noncommunicable diseases (NCDs) is to identify and control their related risk factors. The goal of this study is to determine socioeconomic inequalities in risk factors for NCDs using concentration index based on Non-Communicable Disease Surveillance Survey (NCDSS) data in Kurdistan province, Islamic Republic of Iran in 2005 and 2009.

METHODS

The required data for this study are taken from two NCDSSs in Kurdistan province in 2005 and 2009. A total of 2,494 persons in 2005 and 997 persons in 2009 were assessed. Concentration index was used to determine socioeconomic inequality. To assess the relationship between the prevalence of each risk factor and socioeconomic status (SES), logistic regression was used and odds ratio (OR) was calculated for each group, compared with the poorest group.

RESULTS

The concentration index for hypertension was -0.095 (-0.158, -0.032) in 2005 and -0.080 (-0.156, -0.003) in 2009. The concentration index for insufficient consumption of fruits and vegetables was -0.117 (-0.153, -0.082) in 2005 and -0.100 (-0.153, -0.082) in 2009. The concentration index for the consumption of unhealthy fat and oil was -0.034 (-0.049, -0.019) in 2005 and -0.108 (-0.165, -0.051) in 2009. The concentration index for insufficient consumption of fish was -0.070 (-0.096, -0.044) in 2005. The concentration index for physical inactivity was 0.008 (-0.057, 0.075) in 2005 and 0.139 (0.063, 0.215) in 2009. In all the cases, the OR of the richest group to the poorest group was significant.

CONCLUSION

Hypertension, insufficient consumption of fruits and vegetables, consumption of unhealthy fat and oil, and insufficient consumption of fish are more prevalent among poor groups. There was no significant socioeconomic inequality in the distribution of smoking, excess weight, and hypercholesterolemia. Physical inactivity was more prevalent among the rich groups of society in 2009. The reduction of socioeconomic inequalities must become a main goal in health-care policies.

Socioeconomic status, psychosocial factors, race and nocturnal blood pressure dipping in a Hispanic cohort

BACKGROUND

Little information is available about the relationship of socioeconomic status (SES) to blunted nocturnal ambulatory blood pressure (ABP) dipping among Hispanics and whether this relationship differs by race. We sought to characterize ABP nondipping and its determinants in a sample of Hispanics.

METHODS

We enrolled 180 Hispanic participants not on antihypertensive medications. SES was defined by years of educational attainment. All participants underwent 24-hour ABP monitoring. A decrease of <10% in the ratio between average awake and average asleep systolic BP was considered nondipping.

RESULTS

The mean age of the cohort was 67.1 ± 8.7, mean educational level was 9.4 ± 4.4 years, and 58.9% of the cohort was female. The cohort was comprised of 78.3% Caribbean Hispanics with the rest from Mexico and Central/South America; 41.4% self-identified as white Hispanic, 34.4% self-identified as black Hispanic, and 24.4% did not racially self- identify. The percentage of nondippers was 57.8%. Educational attainment (10.5 years vs. 8.6 years; P <0.01) was significantly higher among dippers than nondippers. In multivariable analyses, each 1-year increase in education was associated with a 9% reduction in the likelihood of being a nondipper (odds ratio [OR], 0.91; 95% confidence interval [CI], 0.84-0.98; P = 0.01). There were significantly greater odds of being a nondipper for black Hispanics than for white Hispanics (OR, 2.83, 95% CI, 1.29-6.23; P = 0.005). Higher SES was significantly protective of nondipping in white Hispanics but not black Hispanics.

CONCLUSIONS

These results document a substantial prevalence of nondipping in a cohort of predominantly normotensive Hispanics. Dipping status varied significantly by race. Lower SES is significantly associated with nondipping status, and race potentially impacts on this relation.

Social support and nocturnal blood pressure dipping: a systematic review

BACKGROUND

Attenuated nocturnal blood pressure (BP) dipping is a better predictor of cardiovascular disease (CVD) morbidity and mortality than resting BP measurements. Studies have reported associations between social support, variously defined, and BP dipping.

METHODS

A systematic review of the literature was conducted to investigate associations of functional and structural social support with nocturnal BP dipping assessed over a minimum of 24 hours.

RESULTS

A total of 297 articles were identified. Of these, 11 met criteria for inclusion; all studies were cross-sectional in design and included adult participants only (mean age = 19 to 72 years). Evidence was most consistent for an association between functional support and BP dipping, such that 5 of 7 studies reported statistically (or marginally) significant positive associations with BP dipping. Statistically significant functional support-BP dipping associations were moderate (standardized effect size (d) = 0.41) to large (d = 2.01) in magnitude. Studies examining structural support were fewer and relatively less consistent; however, preliminary evidence was observed for associations of marital status and social contact frequency with BP dipping. Statistically significant structural support findings were medium (d = 0.53) to large (d = 1.13) in magnitude.

CONCLUSIONS

Overall, findings suggest a link between higher levels of functional support and greater nocturnal BP dipping; preliminary evidence was also observed for the protective effects of marriage and social contact frequency. Nonetheless, the relatively small number of studies conducted to date and the heterogeneity of findings across meaningful subgroups suggest that additional research is needed to substantiate these conclusions.

Nocturnal blood pressure non-dipping, posttraumatic stress disorder, and sleep quality in women

Women with posttraumatic stress disorder (PTSD) have poor sleep quality and increased risk of cardiovascular disease (CVD). Non-dipping of nocturnal blood pressure may be an explanatory factor for the relationship between sleep and CVD found in previous research. The current study was designed to determine if non-dipping nocturnal blood pressure was associated with trauma exposure, PTSD diagnosis, PTSD symptoms, and sleep quality in a sample of women. Participants completed 24 hours of ABPM and self-report questionnaires. Non-dipping was defined as less than 10% reduction in blood pressure during sleep. The frequency of non-dippers did not differ by diagnostic status (d = .15). However, non-dippers endorsed more traumatic event categories (d = .53), more PTSD hyperarousal symptoms (d = .53), poorer overall sleep quality (d = .59), more frequent use of sleep medication (d = .62), greater sleep-related daytime dysfunction (d = .58), and longer sleep onset latencies (d = .55) than dippers. Increased attention to nocturnal blood pressure variation may be needed to improve blood pressure control in trauma-exposed women.

Socioeconomic status, nocturnal blood pressure dipping, and psychosocial factors: a cross-sectional investigation in Mexican-American women

BACKGROUND

Despite established links between reduced nocturnal blood pressure (BP) dipping and cardiovascular disease, BP dipping research in Hispanics is limited.

PURPOSE

This study investigated socioeconomic status (SES) as a predictor of BP dipping and the contributions of psychosocial factors to this relationship. Analyses were conducted for the overall sample and separately for higher and lower acculturated women.

METHODS

Mexican-American women (N = 291; 40-65 years) reported demographics and completed psychosocial assessments and 36-h ambulatory BP monitoring.

RESULTS

Lower SES related to reduced BP dipping in the overall sample and in more US-acculturated women (r's = .17-.30, p's < .05), but not in less-acculturated women (r's = .07, p's > .10). An indirect effect model from SES to BP dipping via psychosocial resources/risk fits well across samples.

CONCLUSIONS

In Mexican-American women, the nature of SES gradients in BP dipping and the roles of psychosocial resources/risk differ by acculturation level.

Stress, Cortisol, and Nighttime Blood Pressure Dipping in Nonhypertensive Black American Women

Black American women have among the highest hypertension (HTN) rates in the world. Research suggests that nighttime might be a critical period of vulnerability for the development of HTN in Blacks. In the present study, personal factors (age, body fat, income, family history), psychological factors (stress, emotions, and John Henryism), and physiological factors (salivary cortisol and blood pressure [BP]) were explored in 30 Black women, ages 26–51 years. Data were collected in participants' homes. BP was monitored while participants were awake and asleep. Cortisol samples were obtained within the first hour after awakening. The usual pattern for BP is a drop or dipping of 10–20% during sleep; however, the BP for about a third of the subjects did not dip adequately during sleep. Though not statistically significant, this nondipping was clinically relevant and was associated with positive family history of HTN, more stress, lower positive and higher negative affect scores, and higher early morning cortisol levels. These findings add to the HTN risk profile and support the need to further explore the relationship between nondipping nighttime BP and cardiovascular disease in Black women.

Ethnic differences in the effects of the DASH diet on nocturnal blood pressure dipping in individuals with high blood pressure

BACKGROUND

Ethnic differences in nocturnal blood pressure (BP) dipping may contribute to the increased risk for adverse cardiovascular events noted in African Americans (AAs). The DASH (Dietary Approaches to Stop Hypertension) diet has been shown to be efficacious in lowering clinic and ambulatory BP; however, the effect of the DASH diet on BP dipping is unclear.

METHODS

One hundred and eighteen men and women with high clinic BP (systolic BP (SBP) 130-159; diastolic BP 85-99) and above ideal body weight were randomized to a DASH diet intervention or to a usual diet control (UC) condition. Measures of 24-h ambulatory BP were obtained at baseline and at the end of the 4-month intervention period.

RESULTS

At baseline, AAs (n = 43) displayed blunted nocturnal SBP dipping compared to Caucasians (CAs; n = 75) and were more likely to be categorized as nondippers (<10% nocturnal decline in SBP, AAs: 51% vs. CAs: 27%). AAs randomized to the DASH diet intervention showed a significant improvement in SBP dipping postintervention compared to AAs in the UC condition (P = 0.04), whereas there was no appreciable change in SBP dipping in CAs (P = 0.72). Following the intervention, ethnic differences in SBP dipping were no longer statistically significant (nondipper status: AAs: 44% vs. CAs: 32%; P = 0.19).

CONCLUSIONS

Our study provides preliminary evidence suggesting that in overweight men and women with high BP, AAs may be especially likely to benefit from augmented SBP dipping associated with consumption of the DASH diet.

Socioeconomic position is positively associated with blood pressure dipping among African-American adults: the Jackson Heart Study

BACKGROUND

Blunted nocturnal blood pressure (NBP) dipping is a significant predictor of cardiovascular events. Lower socioeconomic position (SEP) may be an important predictor of NBP dipping, especially in African Americans (AA). However, the determinants of NBP dipping are not fully understood.

METHODS

The cross-sectional associations of individual and neighborhood SEP with NBP dipping, assessed by 24-h ambulatory BP monitoring, were examined among 837 AA adults (Mean age: 59.2 ± 10.7 years; 69.2% women), after adjustment for age, sex, hypertension status, body mass index (BMI), health behaviors, office, and 24-h systolic BP (SBP).

RESULTS

The mean hourly SBP was consistently lower among participants in the highest category of individual income compared to those in the lowest category, and these differences were most pronounced during sleeping hours. The odds of NBP dipping (defined as >10% decline in the mean asleep SBP compared to the mean awake SBP) increased by 31% (95% confidence interval: 13-53%) and 18% (95% confidence interval: 0-39%) for each s.d. increase in income and years of education, respectively, after multivariable adjustment.

CONCLUSIONS

NBP dipping is patterned by income and education in AA adults even after accounting for known risk factors. These results suggest that low SEP is a risk factor for insufficient NBP dipping in AA.

Neighborhood stressors and race/ethnic differences in hypertension prevalence (the Multi-Ethnic Study of Atherosclerosis)

BACKGROUND

The reasons for racial/ethnic disparities in hypertension (HTN) prevalence in the United States are poorly understood.

METHODS

Using data from the Multi-Ethnic Study of Atherosclerosis (MESA), we investigated whether individual- and neighborhood-level chronic stressors contribute to these disparities in cross-sectional analyses. The sample consisted of 2,679 MESA participants (45-84 years) residing in Baltimore, New York, and North Carolina. HTN was defined as systolic or diastolic blood pressure ≥140 or 90 mm Hg, or taking antihypertensive medications. Individual-level chronic stress was measured by self-reported chronic burden and perceived major and everyday discrimination. A measure of neighborhood (census tract) chronic stressors (i.e., physical disorder, violence) was developed using data from a telephone survey conducted with other residents of MESA neighborhoods. Binomial regression was used to estimate associations between HTN and race/ethnicity before and after adjustment for individual and neighborhood stressors.

RESULTS

The prevalence of HTN was 59.5% in African Americans (AAs), 43.9% in Hispanics, and 42.0% in whites. Age- and sex-adjusted relative prevalences of HTN (compared to whites) were 1.30 (95% confidence interval (CI): 1.22-1.38) for AA and 1.16 (95% CI: 1.04-1.31) for Hispanics. Adjustment for neighborhood stressors reduced these to 1.17 (95% CI: 1.11-1.22) and 1.09 (95% CI: 1.00-1.18), respectively. Additional adjustment for individual-level stressors, acculturation, income, education, and other neighborhood features only slightly reduced these associations.

CONCLUSION

Neighborhood chronic stressors may contribute to race/ethnic differences in HTN prevalence in the United States.

Diurnal blood pressure pattern and development of prehypertension or hypertension in young adults: the CARDIA study

Nondippers (people whose sleep systolic blood pressure [SBP] fails to decrease >10% from daytime SBP) have increased risk of cardiovascular disease. The prevalence of nondipping in younger adults has not been well studied, nor has its value for predicting hypertension. We examined the prevalence of nondipping in a substudy of the Coronary Artery Risk Development in Young Adults (CARDIA) Study. We used Cox regression to estimate the hazard ratio (HR) conferred by nondipping for incident prehypertension or hypertension (preHTN/HTN) over 15 years. Of the 264 nonhypertensive participants at baseline, 118 (45%) were nondippers. Blacks were more likely than whites to be nondippers (52% versus 33%, P = .004). The incidence rate of preHTN/HTN was 29.2/1000 person-years among dippers and 36.2/1000 person-years among nondippers. Compared with those in the lowest quartile of nighttime to daytime SBP, those in the highest quartile were more likely to develop preHTN/HTN (HR 1.61; P = .06), but this relationship was attenuated after adjustment (HR 1.34; P = .27). Our results demonstrate that nondipping is common in young, nonhypertensive adults, and is more common in blacks than whites. Nondipping might predate a meaningful clinically detected increase in BP in some people, but more research in larger study samples is needed.

Effects of sleep restriction on adiponectin levels in healthy men and women

OBJECTIVE

Population studies have consistently found that shorter sleep durations are associated with obesity and cardiovascular disease, particularly among women. Adiponectin is an adipocyte-derived, anti-inflammatory hormone that is related to cardiovascular disease risk. We hypothesized that sleep restriction would reduce adiponectin levels in healthy young adults.

METHODS

74 healthy adults (57% men, 63% African American, mean age 29.9years) completed 2 nights of baseline sleep at 10h time in bed (TIB) per night followed by 5 nights of sleep restricted to 4h TIB per night. An additional 8 participants were randomized to a control group that received 10h TIB per night throughout the study. Plasma adiponectin levels were measured following the second night of baseline sleep and the fifth night of sleep restriction or control sleep.

RESULTS

Sleep restriction resulted in a decrease in plasma adiponectin levels among Caucasian women (Z=-2.19, p=0.028), but an increase among African American women (Z=-2.73, p=0.006). No significant effects of sleep restriction on adiponectin levels were found among men. A 2×2 between-group analysis of covariance on adiponectin change scores controlling for BMI confirmed significant interactions between sleep restriction and race/ethnicity [F(1,66)=13.73, p<0.001], as well as among sleep restriction, race/ethnicity and sex [F(1,66)=4.27, p=0.043)].

CONCLUSIONS

Inflammatory responses to sleep loss appear to be moderated by sex and race/ethnicity; observed decreases in adiponectin following sleep restriction may be one avenue by which reduced sleep duration promotes cardiovascular risk in Caucasian women.

Chronic psychosocial stress and hypertension

Genetic and behavioral factors do not fully explain the development of hypertension, and there is increasing evidence suggesting that psychosocial factors may also play an important role. Exposure to chronic stress has been hypothesized as a risk factor for hypertension, and occupational stress, stressful aspects of the social environment, and low socioeconomic status have each been studied extensively. The study of discrimination is a more recent and rapidly growing area of investigation and may also help to explain the well-known racial disparities in hypertension. Research regarding mechanisms underlying stress effects on hypertension has largely focused on cardiovascular reactivity, but delayed recovery to the pre-stress level is increasingly being evaluated as another possible pathway. Recent findings in each of these areas are reviewed, and directions for future research are discussed.

Everyday discrimination and nocturnal blood pressure dipping in black and white americans

OBJECTIVE

To investigate whether an association exists between experiences of everyday discrimination and blood pressure (BP) dipping in a biracial sample of black and white adults. Attenuated nocturnal BP dipping is closely linked to cardiovascular morbidity and mortality. Self-reported experiences of everyday discrimination have also been associated with negative cardiovascular health outcomes.

METHODS

Seventy-eight hypertensive and normotensive women and men (n = 30 black and 48 white) reported on their experiences of everyday discrimination (Everyday Discrimination Scale) and underwent two separate 24-hour ambulatory BP monitoring (ABPM) sessions approximately 1 week apart.

RESULTS

Correlation analysis revealed that higher endorsement of everyday discrimination was significantly associated with less diastolic BP (DBP) and systolic BP (SBP) dipping (p < .05). Subsequent hierarchical regression analyses indicated that everyday discrimination explained 8% to 11% of the variance in SBP and DBP dipping above and beyond other demographic and life-style-related factors, including race, age, 24-hour BP, body mass index, and current socioeconomic status. The relationship between discrimination and dipping was significantly stronger on the second night of monitoring. Finally, analyses revealed that everyday discrimination mediated the relationship between race and BP dipping.

CONCLUSIONS

These findings suggest that experiences of everyday discrimination are associated with less nocturnal SBP and DBP dipping above and beyond the effect of known covariates. The use of multiple ABPM sessions may facilitate the detection of relationships between psychological variables and BP dipping.

Trust in physicians and blood pressure control in blacks and whites being treated for hypertension in the REGARDS study

OBJECTIVES

Among persons treated for hypertension, Blacks are more likely to have uncontrolled blood pressure compared to Whites. Few studies have focused on trust in physicians as a potential contributor to this disparity in blood pressure (BP) control. The primary objective of this study was to assess the relationship between trust in physicians and blood pressure control among Blacks and Whites being treated for hypertension.

DESIGN

Cross-sectional analysis of baseline data collected from the REasons for Geographic And Racial Differences in Stroke cohort, a US national, population-based cohort study. Participants were recruited by telephone from 2003-2007, completed a telephone survey, and had BP measured during an in-home visit.

PARTICIPANTS

2843 Black and White adults aged > 45 years with treated hypertension.

MAIN OUTCOME MEASURES

Uncontrolled blood pressure was defined as systolic blood pressure > 140 mm Hg or diastolic blood pressure > 90 mm Hg. For participants with diabetes, renal disease, or self-reported previous myocardial infarction, uncontrolled blood pressure was defined as systolic blood pressure > 130 mm Hg or diastolic blood pressure > 80 mm Hg.

RESULTS

Trust in physicians was not associated with uncontrolled blood pressure in either unadjusted (odd ratio [OR] 1.07; 95% confidence interval [CI) 0.92, 1.25) or adjusted analyses (OR 0.97; 0.83, 1.14). Both Black race (OR 1.58; 1.36, 1.84) and imperfect medication adherence (OR 1.56; 1.31,1.86) were associated with higher odds of uncontrolled blood pressure.

CONCLUSIONS

Trust in physicians was not related to blood pressure control among Blacks and Whites with treated hypertension in this sample. The racial disparity in blood pressure control was not completely explained by trust in physicians or medication adherence, and a better understanding of the mechanisms leading to this disparity is needed.