Socioeconomic status is associated with nocturnal blood pressure dipping

A longitudinal study of blood pressure circadian rhythm from childhood to early adulthood

Altered blood pressure (BP) circadian rhythmicity has been increasingly linked with cardiovascular risk. However, little is known about BP circadian rhythm change with age and its possible sociodemographic, anthropometric, and genetic moderators. Twenty-four-hour ambulatory BP was measured up to 16 times over a 23-year period in 339 European Americans (EAs) and 293 African Americans (AAs), with an average age of 15 years at the initial visit. BP circadian rhythms were indexed by amplitude and percent rhythm (a measure of rhythm integrity) and calculated using Fourier analysis. BP amplitude and percent rhythm increased with age and average BP (BP mesor). AAs were more likely to have lower BP amplitude and percent rhythm than their EA counterparts. BP amplitude and percent rhythm also decreased with adiposity (BMI and waist circumference). The summer season was associated with lower BP amplitude in AAs and lower percent rhythm in both AAs and EAs. Sex, height, socioeconomic status, physical activity, and family history of essential hypertension did not have an independent impact on BP amplitude or percent rhythm. The results of the present study suggest that BP circadian rhythm increases with age and BP mesor from childhood to young adulthood, decreases with adiposity, and that AAs are more likely to have lower circadian rhythm than EAs. Furthermore, we demonstrated that the summer season is associated with lower BP rhythmicity.

Subjective social status and nocturnal blood pressure dipping

OBJECTIVE

Low social status has been linked to cardiovascular disease. Subjective social status (SSS), which represents one's perceived position in a social hierarchy, has been suggested to predict health outcomes beyond objective measures of socioeconomic status. The present study examined if lower SSS is related to reduced nocturnal blood pressure (BP) dipping, a risk factor for cardiovascular disease.

METHODS

In this cross-sectional study, a community sample of 53 healthy adults underwent 24-h ambulatory BP monitoring. All participants provided information on SSS and objective measures of socioeconomic status (i.e., education, occupation, and income). SSS was measured in comparison to others in the country (national SSS) as well as in comparison to one's social environment (local SSS) using the German versions of the MacArthur Scales.

RESULTS

Analyses found that participants with low local SSS exhibited attenuated nocturnal diastolic blood pressure dipping (β = 0.29, 95% CI [0.01, 0.57], p = .043) and mean arterial pressure dipping (β = 0.29, 95% CI [0.01, 0.57], p = .041). These associations remained significant after adjusting for objective socioeconomic status. No significant associations between national SSS and cardiovascular measures were observed.

CONCLUSION

In conclusion, one's perceived social position in the social environment (i.e., local SSS) is associated with nocturnal BP dipping. Therefore, local SSS may be an important psychosocial factor linking social inequality and cardiovascular health.

Socioeconomic status impacts blood pressure response to positive airway pressure treatment

STUDY OBJECTIVES

Positive airway pressure (PAP) treatment of obstructive sleep apnea (OSA) reduces blood pressure (BP). Retrospective data suggest that African Americans (AA), a group at high-risk for hypertensive organ dysfunction, may have a greater BP response to PAP therapy than European Americans (EA). We examined the difference in 24-hour BP response to three months of PAP treatment between AA and EA.

METHODS

Participants (N=259, 161 AA and 98 EA) with apnea-hypopnea index (AHI) ≥15/hour from two prospective cohorts were included. T-tests and multiple linear regression were used to examine BP outcomes in AA vs. EA, adjusting for PAP adherence, socioeconomic status (SES), and baseline characteristics.

RESULTS

Participants were middle-aged (mean ± standard deviation, 53.8±9.3 years), 86% (227) men, AHI 35.6±19.2/hour, and PAP adherence of 3.36±2.24 hours/day. The reductions in 24-hour systolic and diastolic BP (mm Hg) were not different in AA vs. EA (systolic=-1.13±12.1 vs. -0.61±12.8, p=0.80 and diastolic=-0.74±7.9 vs. -0.80±7.4, p=0.96), and race was not a predictor of 24-hour systolic or diastolic BP reduction (p=0.75 and 0.54). SES and PAP adherence demonstrated a significant interaction; low SES was associated with an increase in 24-hour systolic BP (β=19.3, p=0.03) in the absence of PAP use but a greater reduction in 24-hour systolic BP with higher PAP adherence (β=-3.96, p=0.03).

CONCLUSIONS

24-hour BP response to PAP treatment is similar in AA and EA. Adherence to PAP treatment is more effective in improving 24-hour systolic BP in those with low SES.

The study was a clinical trial. Clinical Trial Registration: NCT01960465 and NCT01578031.

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.

Identifying patterns of diurnal blood pressure variation among ELSA-Brasil participants

Ambulatory blood pressure monitoring (ABPM) is the gold standard method for the diagnosis of hypertension. ABPM provides a set of repeated measurements for blood pressure (BP), usually over 24 h. Traditional approaches characterize diurnal BP variation by single ABPM parameters such as average and standard deviation, regardless of the temporal nature of the data. In this way, information about the pattern of diurnal BP variation and relationship between parameters is lost. The objective of this study was to identify and characterize daily BP patterns considering the set of repeated measures from 24-h ABPM. A total of 859 adult participants of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) performed a 24-h ABPM record. Hypertension, sex, age, race/color, education, marital status, smoking, alcohol, physical activity, and BMI were the covariables analyzed. Techniques for longitudinal clustering, multinomial models, and models with mixed effects were used. Three daily BP patterns were identified. Daily BP patterns with high BP presented higher standard deviation and morning surge and lower nocturnal dipping. They showed greater systolic BP variability and faster rise than fall in diastolic BP during sleep. Hypertensive, "pardos," and men had greater odds to present these patterns. Daily BP patterns with high BP presented the worst profile concerning ABPM parameters associated with cardiovascular risk. The daily BP patterns identified contribute to the characterization of diurnal BP variation.

More than a feeling: A unified view of stress measurement for population science

Stress can influence health throughout the lifespan, yet there is little agreement about what types and aspects of stress matter most for human health and disease. This is in part because "stress" is not a monolithic concept but rather, an emergent process that involves interactions between individual and environmental factors, historical and current events, allostatic states, and psychological and physiological reactivity. Many of these processes alone have been labeled as "stress." Stress science would be further advanced if researchers adopted a common conceptual model that incorporates epidemiological, affective, and psychophysiological perspectives, with more precise language for describing stress measures. We articulate an integrative working model, highlighting how stressor exposures across the life course influence habitual responding and stress reactivity, and how health behaviors interact with stress. We offer a Stress Typology articulating timescales for stress measurement - acute, event-based, daily, and chronic - and more precise language for dimensions of stress measurement.

Gender differences in the relationships between psychosocial factors and hypertension

Gender differences in the epidemiology, pathophysiology, clinical manifestations and outcomes of cardiovascular disease are well established but there is still a lack of awareness of this both in the general population and among healthcare providers. In addition to the traditionally recognized cardiovascular risk factors, more recently psychosocial risk factors such as stress, mood disorders, low socioeconomic status and sleep disorders have been linked to cardiovascular diseases and hypertension. Psychosocial factors may have different cardiovascular consequences in men and women; thus further efforts are required to explore pathophysiological mechanisms, to obtain gender-specific data from clinical trials and to translate this knowledge into everyday clinical practice.

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.

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.

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.

Relationships among acculturative stress, sleep, and nondipping blood pressure in Korean American women

Generally blood pressure (BP) should drop or dip by 10-20% during sleep. The phenomenon of nondipping BP during sleep has gained interest because of its association with various damaging effects to end-organs. This exploratory study examined nighttime nondipping BP, acculturative stress and quality of sleep in 30 Korean American women. Acculturative stress and sleep quality were measured using the Revised Social, Attitudinal, Familial, and Environmental Acculturative Stress Scale (R-SAFE) and the Pittsburg Sleep Quality Index (PSQI), respectively. Participants' BP was monitored over a 24-hour period. Participants were categorized as dippers and nondippers based on the drop in nocturnal systolic BP. Of the 30 women, 8 (26.7%) were nondippers. A shorter sleep duration and more disturbed sleep were associated with nondipping and, interestingly, less acculturative stress was also associated with nondipping BP. Our finding supports that sleep evaluation is needed in caring for individuals with nondipping BP.

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.

Behavioural and psychosocial correlates of nondipping blood pressure pattern among middle-aged men and women at work

The underlying pathogenetic mechanisms of nondipping blood pressure (BP) pattern are not completely understood. Especially the role of psychosocial correlates remains unclear. The aim was to assess the association between nondipping BP pattern, behavioural and psychosocial factors in a sample of working men and women. The study sample included 167 working men and women aged 40-64 years from the BELSTRESS cohort. Socio-demographic, behavioural and psychosocial factors were assessed by self-administered questionnaires. Participants were medically examined and underwent an ambulatory BP monitoring during 24 h. Nondipping was defined when the average nocturnal decline in BP was <10%. The prevalence of nondipping for both systolic and diastolic BP was 7.8%. Nondipping was not significantly related to smoking, alcohol consumption and leisure time physical activity. A crude significant association was observed between nondipping and sleep problems. After adjusting for gender, education and body mass index, the risk for nondipping was associated with job strain, living alone, being unsatisfied about the contact with one's children, depressive symptoms and vital exhaustion. Nondipping BP pattern was consistently related to psychosocial factors in this study: positive associations were observed with measures of job strain, poor private life support (living alone and being unsatisfied about the contact with one's children) and mental health problems (depressive symptoms and vital exhaustion).

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.

Unfair treatment and trait anger in relation to nighttime ambulatory blood pressure in African American and white adolescents

OBJECTIVE

To determine if ambulatory blood pressure (ABP) at night relative to day ABP among adolescents is influenced by unfair treatment and trait anger, and whether these associations are stronger in African Americans and adolescents from lower socioeconomic status (SES) families and neighborhoods.

METHODS

A total of 189 healthy white and African American adolescents (ages = 14-16 years, standard deviation = 0.62, 50% female) completed 2 days and 1 night of ABP monitoring and unfair treatment and trait anger questionnaires. SES was measured using 1) parental education and 2) a composite neighborhood SES score based on U.S. Census tract data for neighborhood poverty and education. The night/day ABP ratio was calculated by dividing the night ABP mean (readings from the self-reported bedtime of each participant through 5 AM) by the day ABP mean (8:30 AM until self-reported bedtime).

RESULTS

Higher trait anger was associated with a higher night/day diastolic blood pressure (DBP) ratio in the full sample, B = 0.003, SE = 0.001, t = 2.20, p = .03. A significant interaction effect for Race x Unfair Treatment on the night/day DBP ratio, B = 0.01, SE = 0.003, t = 3.17, p = .002, followed by post hoc tests indicated that greater unfair treatment was associated with a higher night/day DBP ratio among African Americans, B = 0.006, SE = 0.002, t = 2.56, p = .01. Further, among African American adolescents living in lower SES neighborhoods, greater unfair treatment predicted a higher night/day DBP ratio, B = 0.008, SE = 0.003, t = 3.15, p = .002, and higher trait anger scores predicted a higher night/day DBP ratio, B = 0.008, SE = 0.002, t = 3.19, p = .002.

CONCLUSIONS

Trait anger may be a factor leading to elevated nighttime DBP in both African Americans and whites. Unfair treatment and trait anger are important predictors of elevated night/day ABP ratios among African American adolescents living in lower SES neighborhoods. These factors may contribute to the onset of hypertension in African Americans at a younger age.

Racial differences in the impact of social support on nocturnal blood pressure

OBJECTIVE

To investigate whether black and white adults benefit similarly from perceived social support in relation to blood pressure (BP) dipping during sleep.

METHODS

The Interpersonal Support Evaluation List (ISEL, 12-item version), which measures the perceived availability of several types of functional social support, was examined for interactive effects with race on dipping of mean arterial pressure (MAP), systolic blood pressure (SBP), and diastolic blood pressure (DBP) derived from 24-hour ambulatory blood pressure monitoring (ABPM). The sample consisted of 156 young to middle-aged adults (61 blacks, 95 whites; mean age = 35.7 years).

RESULTS

Mean ISEL scores did not differ between racial groups. Controlling for age, body mass index (BMI), resting BP, and socioeconomic status (SES), the interaction of social support by race yielded associations with nighttime dipping in MAP and DBP (p < .001) as well as SBP (p < .01). As ISEL scores increased among white participants, the extent of dipping increased in MAP, SBP, and DBP (p < .01), explaining 10%, 10%, and 8% of the variance, respectively. Conversely, black participants exhibited associations between increasing ISEL scores and decreasing levels of dipping in MAP, SBP, and DBP (p < .05), accounting for 9%, 8%, and 8% of the variance, respectively.

CONCLUSION

As perceived social support increased, white adults received cardiovascular benefits as suggested by enhanced nocturnal dipping of BP, but black adults accrued risks as evidenced by blunted declines in BP during sleep.

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

BACKGROUND

Reduced nocturnal blood pressure (BP) dipping is more prevalent among blacks living in the United States than whites and is associated with increased target organ damage and cardiovascular risk. The primary aim of this study was to determine whether socioeconomic and psychosocial factors help to explain racial differences in dipping. In order to address the limited reproducibility of dipping measures, we investigated this question in a sample of participants who underwent multiple ambulatory BP monitoring (ABPM) sessions.

METHODS

The study sample included 171 black and white normotensive and mildly hypertensive participants who underwent three ABPM sessions, each 1 month apart, and completed a battery of questionnaires to assess socioeconomic and psychosocial factors.

RESULTS

As expected, blacks showed less dipping than whites, after adjusting for age, sex, body mass index (BMI), and mean 24-h BP level (mean difference = 3.3%, P = 0.002). Dipping was related to several of the socioeconomic and psychosocial factors examined, with higher education and income, being married, and higher perceived social support, each associated with a larger dipping percentage. Of these, marital status and education were independently associated with dipping and together accounted for 36% of the effect of race on dipping.

CONCLUSIONS

We identified a number of socioeconomic and psychosocial correlates of BP dipping and found that reduced dipping among blacks vs. whites is partially explained by marital status (being unmarried) and lower education among blacks. We also present results suggesting that repeated ABPM may facilitate the detection of associations between dipping and other variables.

Does socioeconomic status affect blood pressure goal achievement?

Hypertension is a major cause of disease burden in all racial, ethnic, and socioeconomic groups in developing and developed regions and countries. Differences in blood pressure likely begin early in life and reflect a complex relationship of biologic, genetic, social, and environmental interactions. The relationship between socioeconomic status and hypertension is complex and difficult to measure. Instituting lifestyle changes for the primary prevention and treatment of hypertension among the general population would decrease prevalence, improve blood pressure control, and be effective in eliminating many socioeconomic differences in risk factors for cardiovascular disease. Health care providers can potentially impact blood pressure control by incorporating knowledge of socioeconomic factors and mechanisms in care delivery. This review highlights socioeconomic status in the prevalence and incidence of hypertension and identifies contributing factors associated with blood pressure control.

Early socioeconomic status is associated with adult nighttime blood pressure dipping

OBJECTIVE

To examine the prognostic significance of early socioeconomic status (SES) on 24-hour blood pressure (BP) during early adulthood. Low SES has been related to poor health outcomes, in particular, cardiovascular morbidity and mortality. Recent cross-sectional research has also linked low levels of SES with several cardiovascular risk factors including poor nighttime BP dipping.

METHODS

A total of 174 undergraduate university students whose childhood SES was assessed by highest level of education completed by their parents underwent 24-hour ambulatory BP monitoring.

RESULTS

Initial correlation analyses revealed positive associations between childhood SES and BP dipping, indicating that lower levels of childhood SES were associated with less systolic BP (SBP) (r = .29, p < .01) and diastolic BP (DBP) dipping (r = .38, p < .01). A stepwise multiple regression analyses indicated that childhood SES explained 6.9% of the variance in SBP dipping and 11.5% of the variance in DBP dipping above and beyond other lifestyle-related factors including daytime BP, body mass index, alcohol use, smoking, and current SES.

CONCLUSIONS

These findings suggest that irrespective of adult achievement, childhood SES may have lasting health implications.

Diurnal cortisol variation is associated with nocturnal blood pressure dipping

OBJECTIVE

To investigate if diurnal cortisol variation is associated with nocturnal blood pressure (BP) dipping.

METHODS

In this study, 302 healthy adults (51% female; average age 31 years) underwent 24-hour ambulatory BP assessment with BP measured randomly approximately every 20 minutes during waking hours and every hour during sleep. Salivary cortisol was obtained at five time points. Cortisol and BP have natural diurnal variations and disruptions in these diurnal variations are related to pathological conditions, such as greater risk for cardiovascular disease. A lack of a drop in cortisol from day to night and a lack of a drop in BP from waking to sleeping have both been associated with negative outcomes. It is not known, however, if diurnal variations in cortisol and BP are related, or if changes in cortisol from day to night influence BP dipping.

RESULTS

Diurnal cortisol variation was a significant predictor of BP dipping. Controlling for gender, body mass index, age, phase of menstrual cycle, sleep quality, morning cortisol, and daytime measures of the relevant cardiovascular assessments did not significantly affect the results. Cortisol variation was found to have a stronger relationship with BP dipping than any of the covariates measured.

CONCLUSION

Decreased diurnal variation in cortisol is associated with decreased diurnal variation in BP. Future studies could benefit from examining how these two variables interact in predicting disease outcomes.

Ethnic and gender differences in ambulatory blood pressure trajectories: results from a 15-year longitudinal study in youth and young adults

BACKGROUND

Cross-sectional studies demonstrated ethnic and gender differences in ambulatory blood pressure patterns, but little is known about the longitudinal development of these differences.

METHODS AND RESULTS

Twenty-four-hour ambulatory blood pressure was measured up to 12 times (5 times on average) over a 15-year period in 312 African Americans (AAs) and 351 European Americans aged 7 to 30 years. Multivariate individual growth curves across age were created for daytime and nighttime blood pressure jointly. For both daytime and nighttime systolic blood pressure (SBP), AAs and males had higher levels (P<0.001) than European Americans and females. Males also showed a greater increase with age (P<0.001) than females. For nighttime SBP, a faster increase of SBP with age (P<0.01) in AAs was additionally observed. The ethnic difference in nighttime SBP levels and its increase with age were significantly larger than in daytime SBP. For daytime and nighttime diastolic blood pressure, AAs had higher levels than European Americans (P<0.001), and this difference was significantly larger at night. From late adolescence onward, males showed a greater increase in diastolic blood pressure with age than females. Ethnic and gender differences persisted after adjustment for height, body mass index, socioeconomic status, and stress-related coping styles. Family history of essential hypertension explained ethnic differences in daytime SBP.

CONCLUSIONS

We observed significant ethnic and gender differences in longitudinal trajectories of ambulatory blood pressure in youth and young adults. The blunted nocturnal decline and its exacerbation with age in AAs corroborate and extend findings of cross-sectional studies.

Nondipping blood pressure patterns among individuals with essential hypertension: a review of the literature

BACKGROUND

Researchers have discovered that blood pressure (BP) varies in a diurnal manner throughout a 24-hour period, being higher during the day and lower at night. Most people have a dipping BP pattern characterized by a nighttime BP that is 10-20% lower than their daytime BP. Individuals who experience a less than 10% reduction in nighttime BP are described as having a nondipping BP pattern. Although controversial, there is a growing body of evidence suggesting that a nondipping BP pattern is associated with a greater risk of target organ damage among individuals with essential hypertension.

AIM

To review the literature on the most common factors associated with nondipping BP patterns among individuals with essential hypertension.

METHODS

CINAHL (1982-March 2006), PubMed (1950-March 2006) and Cochrane Library (1966-March 2006) databases were searched using the keywords: dipper, dipping, nondipper, nondipping, ambulatory blood pressure monitoring, ABPM, hypertension, essential hypertension, high blood pressure, blood pressure, nocturnal blood pressure, nighttime blood pressure, diurnal blood pressure, and blood pressure patterns. Published studies, abstracts, dissertations as well as the reference lists of retrieved articles were reviewed. Studies were included if they involved subjects with only treated or untreated essential hypertension or those with samples of both nomotensive and treated or untreated essential hypertensive individuals. Additionally, studies needed to evaluate 24-hour, daytime and nighttime BP patterns.

RESULTS

There is some evidence to suggest advanced age, African-American ethnicity, female sex, postmenopausal status, sodium sensitivity, sleep apnea, sleep quality, anger, hostility, depression, stress, social support, and socioeconomic status have an association with nondipping BP patterns.

CONCLUSION

Knowledge of the potential factors associated with an altered nighttime BP pattern is of importance because it can help identify persons at risk for nondipping BP patterns and potential target organ damage. Furthermore, knowledge of these factors associated with a nondipping BP profile will lay the foundation for interventions to prevent/treat alterations in nighttime BP patterns.

The association of social status and blood pressure with markers of vascular inflammation

OBJECTIVE

Low socioeconomic status (SES) is associated with low-grade inflammation. Vascular inflammation often accompanies high blood pressure (BP) and has clinical implications for future vascular diseases, including atherosclerosis. Elevated plasma levels of soluble intercellular adhesion molecule-1 (sICAM-1) and endothelin-1 (ET-1) are reliable indicators of vascular inflammation. We examined the associations among BP, social status, and sICAM-1 and ET-1 levels in 121 European American and African American men and women.

METHODS

Social status of the subjects was determined by using the Hollingshead Two Factor Index of Social Position scale, and plasma sICAM-1 and ET-1 levels were assessed using immunoassays.

RESULTS

Correlation analyses revealed positive correlations among plasma sICAM-1 levels, BP, and social status. Levels of ET-1 were also significantly correlated with BP (p < .01) and social status (p < .001). When subjects were categorized into three social classes, sICAM-1 levels were significantly higher in the lowest social class as compared with the upper (p < .05) or middle (p < .01) class. The levels of ET-1 were higher in the low (p < .01) and middle (p < .05) social classes as compared with the upper class. Multiple hierarchic regression analyses revealed that even after controlling for demographic and health characteristics (gender, ethnicity, age, body mass index, and smoking) and systolic BP, social status accounted for additional variance of sICAM-1 or ET-1 levels.

CONCLUSION

These results suggest that low-social-status individuals may incur risk for future vascular diseases through vascular inflammation.