Sydney B. Miller

Perceived racial discrimination and hypertension: A comprehensive systematic review.

OBJECTIVE Discrimination is posited to underlie racial disparities in hypertension. Extant literature suggests a possible association between racial discrimination and blood pressure, although inconsistent findings have been reported. The aim of this comprehensive systematic review was to quantitatively evaluate the association between perceived racial discrimination with hypertensive status and systolic, diastolic, and ambulatory blood pressure. METHOD Electronic database search of PubMed and PsycINFO (keywords: blood pressure/hypertension/diastolic/systolic, racism/discrimination/prejudice/unfair treatment) was combined with descendancy and ascendancy approaches. Forty-four articles (N = 32,651) met inclusion criteria. Articles were coded for demographics, hypertensive diagnosis, blood pressure measurement, discrimination measure and constructs, study quality, and effect sizes. RESULTS Random effects meta-analytic models were tested based on Fishers Z, the derived common effect size metric. Overall, perceived racial discrimination was associated with hypertensive status, Zhypertension = 0.048, 95% CI [.013, .087], but not with resting blood pressure, Zsystolic = 0.011, 95% CI [-.006, .031], Zdiastolic = .016, 95% CI [-.006, .034]. Moderators that strengthened the relation included sex (male), race (Black), age (older), education (lower), and hypertensive status. Perceived discrimination was most strongly associated with nighttime ambulatory blood pressure, especially among Blacks. CONCLUSIONS Despite methodological limitations in the existing literature, there was a small, significant association between perceived discrimination and hypertension. Future studies should consider ambulatory nighttime blood pressure, which may more accurately capture daily variation attributable to experienced racial discrimination. Perceived discrimination may partly explain racial health disparities.

Ambulatory blood pressure nondipping status in salt-sensitive and salt-resistant black adolescents*

This study examined the relationship between salt sensitivity and ambulatory blood pressure in 53 healthy black adolescents. Salt sensitivity was defined as an increase in mean blood pressure greater than or exceeding 5 mm Hg from a 5-day low-salt diet (50 mmol/24 h) to a 10-day high-salt diet (150 mmol/24 h NaCl supplement). Sixteen subjects were salt sensitive and 37 subjects were salt resistant (showed < 5 mm Hg increase in mean blood pressure). Subjects were classified as dippers (> or =10% decrease in blood pressure from awake to asleep) based on their 24-h ambulatory blood pressure values. Nondippers showed higher systolic, diastolic, and mean asleep blood pressures than dippers (P < .05 for all). Salt-sensitive subjects showed greater daytime diastolic and mean blood pressures than salt-resistant subjects (P < .05 for both). A significantly greater percentage of nondippers were salt sensitive, compared with salt resistant for diastolic blood pressure (P < .001) and mean blood pressure (P < .05). For both of these blood pressure measures, 50% of the salt-sensitive subjects had a nondipping status, compared with only 5.4% of the salt-resistant subjects for diastolic blood pressure, and 18.9% of the salt-resistant subjects for mean blood pressure. These results are the first to indicate that salt sensitivity is associated with nondipper blood pressure status in a black normotensive adolescent population.

Does the addition of functional status indicators to case-mix adjustment indices improve prediction of hospitalization, institutionalization, and death in the elderly?

Background:Case-mix adjustment is widely used in health services research to ensure that groups being compared are equivalent on variables predicting outcome. There has been considerable development and testing of comorbidity indices derived from diagnostic codes recorded in administrative databases, but increasingly, the benefit of clinical information and patient reported ratings of health and functional status is being recognized. One type of information that is highly valued but has so far not been captured by administrative health databases is functional status indicators (FSI). Objective:The purpose of this study was to estimate the extent to which prediction of health outcomes can be improved on by including information on functional status indicators (FSI). Research Design:The data for the current study was obtained from a clustered randomized trial evaluating computerized decision support for managing drug therapy in the elderly, conducted from 1997 to 1998. A total of 107 primary care physicians participated in this trial and 6465 of their patients (51%) completed a generic health status measure—the SF-12—before the intervention. C statistics and R2 were used to compare the predictive value of sociodemographic factors, 2 comorbidity indices, and 11 FSI predictor variables derived from the SF-12 and coded (possible for 8) using the International Classification of Functioning (ICF). Results:Using stepwise logistic regression, FSI, particularly limitation in stair climbing or doing moderate activities like housework, were found to be strong and independent predictors of all outcomes, even after controlling for sociodemographics and comorbidity. Conclusion:This study indicates that FSI provided as robust a prediction of health events as did complex comorbidity indices. Additionally, the ICF coding system provides a mechanism whereby information on FSI could be incorporated into administrative databases through the use of electronic health records that include a health or functional status measure.

Heart rate variability in coronary artery disease patients with and without panic disorder

Panic disorder (PD) and coronary artery disease (CAD) often co-occur, and CAD patients with comorbid PD suffer greater cardiovascular morbidity and mortality relative to CAD patients without PD. However, the mechanisms underlying these associations are still unknown. Reduced heart rate variability (HRV), a non-invasive measure of cardiac autonomic modulation, is an important predictor of adverse cardiac events. Interestingly, reduced HRV has been observed in patients with panic-like anxiety and PD, as well as in various CAD populations. However, the extent to which HRV is altered in patients with both PD and CAD is unknown. This study evaluated HRV in 42 CAD patients with (n=20) and without (n=22) PD. Patients underwent 48-h electrocardiographic monitoring. Power spectral analysis of HRV indicated that CAD patients with PD exhibited significantly lower LF/HF ratios, which may reflect lower sympathetic modulation, compared with non-PD patients. Additionally, total power in PD patients was made up of a significantly higher proportion of HF power and a significantly lower proportion of VLF power than in non-PD patients. No other significant differences in HRV indices were observed. Results suggest that contrary to what has been observed in the majority of PD-only and CAD-only populations; patients with both PD and CAD appear to exhibit lower sympathetic modulation during ordinary daily life conditions. Though preliminary, these findings suggest that changes in HRV may not be the mechanism underlying greater cardiovascular morbidity and mortality among CAD patients with PD.

A ONE-HOUR ACTIVE COPING STRESSOR REDUCES SMALL BOWEL TRANSIT TIME IN HEALTHY YOUNG ADULTS

Objective To examine the effect of a prolonged active coping stressor on the transit of a substance from the mouth through small intestine in normal human volunteers. Method Twelve healthy undergraduate males were administered 10 g of the nonabsorbable carbohydrate lactulose in two experimental sessions. In normal individuals, lactulose produces hydrogen gas upon exposure to bacteria residing in the colon. Repeated measurements of breath hydrogen were obtained for 2 hours. In one session, subjects rested quietly for the 2-hour period. In the other counterbalanced session, subjects avoided mild electric shocks by playing videogames for the first hour. Results Stress produced a statistically and clinically significant reduction in mean transit time, from 79 to 55 minutes. The magnitude of stress-induced reduction in small bowel transit time was significantly correlated with change in an index of cardiac sympathetic activity, pulse transit time. Conclusions A prolonged active coping stressor with minimal motor requirements produced a decrease in small bowel transit time comparable with that observed in several studies of the effects of physical exercise and in comparisons between normal controls and patients with diarrhea-predominant irritable bowel syndrome.

Cardiopulmonary baroreflex stimulation and blood pressure-related hypoalgesia.

Results from both experimental animals and humans suggest that baroreflex stimulation may be involved in blood pressure-related hypoalgesia. However, most of this research, especially in the area of human experimentation, has focused on sinoaortic baroreceptors. Cardiopulmonary baroreflex stimulation may also be an important moderator of pain. Sixty-six healthy male undergraduates varying in risk for hypertension participated in an experimental protocol in which painful mechanical finger pressure was presented three times in a counterbalanced fashion. One pain stimulus was preceded by 6 min of supine rest, another by a period of rest interspersed with periodic Valsalva manoeuvres, and another by a period in which cardiopulmonary baroreceptors were stimulated by passive leg elevation. Significantly lower pain was reported by men with relatively elevated systolic blood pressure following leg elevation but not the other conditions. Cardiopulmonary baroreflex stimulation was documented by increased forearm blood flow and other data obtained via impedance cardiography. These results suggest that blood pressure related hypoalgesia may be at least partially related to cardiopulmonary baroreflex stimulation.

Estradiol, progesterone and cardiovascular response to stress

The present study examined the relationship between endogenous estradiol and progesterone levels and cardiovascular activity at rest and during stress in healthy young women. Subjects were tested in both the follicular and luteal phases of the menstrual cycle. Results indicated that, during the luteal phase, higher levels of estradiol were associated with lower levels of cardiac output responses to the combined video game and speech tasks, and lower levels of heart rate and systolic blood pressure responses to the cold pressor; estradiol levels were also associated positively with PEP responses to the cold pressor but only under high levels of progesterone. Additionally, during the luteal phase, higher levels of progesterone were associated with higher TPR and lower stroke volume responses to the cold pressor. In contrast, during the follicular phase, higher levels of progesterone were associated with lower vascular resistance responses to the cold pressor. Consistent with data from studies using exogenous estrogens, these results suggest that estradiol may contribute to a lowering of cardiovascular responses to stress.

Hostility, sodium consumption, and cardiovascular response to interpersonal stress.

Objective Previous studies have reported poorer health behaviors in high vs. low hostile subjects. The role of stress in these observed differences has not been explored although interpersonal stress does increase cardiovascular response in high hostiles. Given evidence that stress may induce increased salt-intake, this study examined the role of hostility and interpersonal stress in increasing sodium consumption in addition to cardiovascular reactivity. Method Sixty-nine male undergraduates were categorized into high (HiHo) and low hostile (LoHo) groups based on Buss-Durkee Hostility Inventory scores. Subjects engaged in either a math task with harassment, math task without harassment, or a control/rest condition. Sodium intake was assessed posttask by having subjects ingest a sodium-free soup that was presented with a saltshaker without any comments. Cardiovascular measures were also recorded. Results HiHo subjects consumed more salt than LoHo subjects irrespective of experimental condition. HiHo subjects who were harassed also exhibited greater cardiac output, systolic blood pressure, and forearm blood flow than did HiHo nonharassed, HiHo control, or LoHo subjects. Conclusion HiHo subjects exhibited increased salt-intake, although evidence for stress-induced salt-intake was not obtained. Nonetheless, the combination of salt and stress may contribute to the cardiovascular hyperreactivity and risk for cardiovascular disease in hostile individuals.

Anger, negative emotions, and cardiovascular reactivity during interpersonal conflict in women

OBJECTIVE In order to evaluate the relationship between womens subjective emotional discomfort with anger and cardiovascular responses to stress, cardiovascular and affective responses were examined during two anger-provoking conditions: one in which anger would be in self-defense, and one in which anger would be in defense of a significant other. METHODS A total of 42 healthy, normotensive women aged 18-35 years recruited a close female friend to participate in the study with them, and were randomly assigned to one of two harassment conditions: (i) Self-Harass, where women were harassed while performing a math task; (ii) Friend-Harass, where women witnessed a close female friend being harassed while their friend performed a math task. RESULTS Self-Harass and Friend-Harass women reported feeling equally angry, annoyed, and irritated (all Ps<.01) during their respective anger-provocation conditions. However, Self-Harass women reported experiencing significantly greater increases in feelings of depression and guilt during anger provocation (Ps<.05) relative to Friend-Harass women. Interestingly, it was also the Self-Harass women who exhibited significantly greater elevations in heart rate (HR), cardiac output (CO), systolic blood pressure (SBP), forearm blood flow (FBF), and significant reductions in forearm vascular resistance (FVR; Ps<.001) relative to Friend-Harass women during anger provocation. CONCLUSIONS Results suggest that women may experience other negative emotions (e.g., guilt, depression) when anger is in self-defense relative to when it is in defense of others, and that these emotions may play a more important role than anger in moderating cardiovascular reactivity (CVR) during interpersonal conflict.

DIMENSIONS OF HOSTILITY AND CARDIOVASCULAR RESPONSE TO INTERPERSONAL STRESS

Emerging research suggests that hostility is a multidimensional construct with different dimensions conferring different cardiovascular disease risk. This study examined two dimensions of hostility, expressive and neurotic, and their hemodynamic response patterns upon exposure to interpersonal stress. Fifty-seven male undergraduates were categorized into high and low expressive hostility (HiEH, LoEH) and high and low neurotic hostility (HiNH, LoNH) groups based on their Buss-Durkee Hostility Inventory scores. Subjects engaged in a mathematical subtraction task, with half of the subjects harassed through anger-provoking statements. Separate analyses were conducted for the expressive and neurotic hostility groupings. For expressive hostility, results indicated that HiEH/harassed subjects exhibited greater systolic blood pressure, heart rate, and cardiac output responses than did HiEH/nonharassed subjects or LoEH subjects irrespective of harassment. Neurotic hostility analyses revealed elevated forearm blood flow in HiNH/harassed subjects as compared to HiNH/nonharassed subjects or LoNH subjects in either harassment condition. The hemodynamic response pattern of expressive hostiles is consistent with their risk for heart disease. The response pattern of neurotic hostiles may indicate risk for hypertension, though this remains to be established.