Ambulatory blood pressure responses and the circumplex model of mood: a 4-day study.

BACKGROUND: The relation between mood or emotions and concurrent ambulatory blood pressure responses holds both fundamental and clinical interest. METHODS: The primary sample consisted of 69 normotensive or borderline hypertensive but otherwise healthy adult males. The validation sample consisted of 85 healthy male undergraduate college students. Both samples underwent half-hourly 24-hour ambulatory blood pressure measurements on four separate workdays, 1 week apart. At each ambulatory measurement, subjects recorded their behavior, environment, and mood. The circular mood scale, a circular visual analogue scale based on the circumplex model of mood, was used to reflect the totality of a participant's affective state space. Longitudinal random effects regression models were applied in the data analysis. RESULTS: The results for both samples were quite similar. Sleep and posture had the greatest influence on ambulatory blood pressure and heart rate. The effects of the environmental setting, social setting, and consumption were modest but statistically significant. Independent of these covariates, mood exerted a significant effect on blood pressure and heart rate. Relative to the "mellow" default category, blood pressure increased both for "anxious/annoyed" and "elated/happy" and decreased during "disengaged/sleepy" mood. The range of mood-related blood pressure estimates was 6.0/3.7 mm Hg. CONCLUSIONS: The pattern of blood pressure responses suggests that they were related to the degree of engagement of a mood rather than the degree of unpleasantness. The hypothesis that posits that negative affect-related cardiovascular reactivity mediates the observed correlation between negative affect and disease risk should be reconsidered.     

The influence of happiness, anger, and anxiety on the blood pressure of borderline hypertensives

Differences in blood pressure associated with reported happiness, anger, and anxiety are examined among 90 borderline hypertensives during 24-hr blood pressure monitoring. There were 1152 individual ambulatory blood pressure readings for which subjects classified their emotional state as happy (n = 628), angry (n = 67), or anxious (n = 457) on scales from one (low) to ten (high). Pressures were transformed to z-scores using the subject's 24-hr mean and standard deviation to assess relative elevation during reported emotional arousal. The results show that emotional arousal significantly increases systolic and diastolic pressure (p less than 0.00001), an effect independent of posture and location of subject during measurement (at work, home, or elsewhere). On average, pressures during reported angry or anxious states were higher than those during a happy state (p less than 0.01). Examination of arousal intensity showed that scores on the happiness scale were inversely related to systolic pressure (p less than 0.01) whereas the degree of anxiety was positively associated with diastolic pressure (p less than 0.02). Emotional effects were also related to the degree of individual daily pressure variation such that the greater the variability, the larger the blood pressure change associated with the emotions. The results suggest that happiness, anger, and anxiety increase blood pressure to differing degrees and that emotional effects may be greater in individuals with more labile blood pressure.     

Baseline and reactivity measures of blood pressure and negative affect in borderline hypertension

Measures of blood pressure (BP) and negative affect were taken prior to, immediately following, and ten minutes after a cognitive stressor in groups of normotensive (group N; n = 15) and borderline hypertensive (group B; n = 15) young adults. Two testing sessions, one week apart, involved performance of a simple, congruent color-word ("easy") and a cognitive stress-inducing, incongruent color-word ("difficult") version of the Stroop test. In both sessions, group B showed significantly higher baseline systolic and diastolic BP, higher systolic responses to the difficult Stroop task, and higher recovery measures of systolic and diastolic BP than group N. In general, group B had significantly elevated baseline and reactivity scores on state measures of negative affect in both sessions. Correlations revealed strong positive associations between blood pressure and mood reactivity only for borderline subjects. Depressed mood was more strongly and consistently related to blood pressure reactivity than was hostility. Borderline hypertension appears to be associated with stable, perhaps clinically significant elevations in negative affect, and with dysphoric response to mild cognitive stress.     

The association of an adenine insertion variant in the 5’UTR of the endothelin-1 gene with hypertension and orthostatic hypotension

Introduction

An adenine insertion polymorphism in the 5’ untranslated region of the endothelin-1 gene is functional and increases the expression of endothelin mRNA and protein in the insertion homozygote. In the present study we hypothesized that this functional polymorphism might be associated with hypertension and/or orthostatic hypotension.

Material and methods

The adenine insertion polymorphism was genotyped in 381 untreated hypertensive patients and 298 normotensive subjects, all of whom underwent an upright posture study for orthostatic blood pressure measurements. Orthostatic hypotension was defined as a drop in blood pressure of 20/10 mm Hg or more within 3 min of assuming the upright posture.

Results

The allele frequency of the adenine insertion was similar in hypertensive and normotensive subjects (15.2% vs. 15.3%, p > 0.05). After adjustment for age, sex and body mass index, blood pressure levels did not differ significantly among the genotypes in both hypertensives and normotensives. No associations were found between the distribution of the adenine insertion genotypes and the risk of orthostatic hypotension in both hypertensive patients and normotensive subjects even after adjustment for demographic parameters and supine systolic or diastolic blood pressure. Neither hypertensive nor normotensive subjects showed significant differences in orthostatic systolic or diastolic blood pressure changes among the genotype groups (all p > 0.05).

Conclusions

We concluded that the functional adenine insertion polymorphism in the endothelin-1 gene is not associated with either hypertension or orthostatic hypotension risk in Chinese.     

Age Differences in Cardiovascular Reactivity Under Active Coping Conditions

This study investigated whether age and parental history of hypertension were related to increases in heart rate, systolic blood pressure, and diastolic blood pressure during an active coping task. The latter consisted of a 21-trial reaction-time task in which electric shock and monetary incentive were contingent upon adequate performance. Subjects consisted of 60 normotensive male volunteers aged 15–55 yrs. Results showed that age yielded a significant inverse relationship with increases in heart rate, accounting for 8% of the variance. However, no age association was found for increases in either systolic or diastolic blood pressure. Subjects with a parental history of hypertension showed greater responsivity in heart rate and systolic and diastolic blood pressure than subjects without a hypertensive parent. Results are discussed in terms of methodological considerations and potential mechanisms accounting for the age-related decline in heart rate during active coping.     

Effects of sex,age, weight,and heredity on blood pressure in baboons

Using data on a population of 498 pedigreed baboons, the effects of several covariates, including sex, age, weight, and subspecies, on arterial blood pressures were studied. Females had significantly higher systolic and diastolic arterial blood pressure than males. Both systolic and diastolic arterial blood pressures increased significantly with increasing weight, and for diastolic pressure, the increase was significantly greater in females than in males. Systolic arterial blood pressure significantly decreased with increasing age and the decrease was larger in males. There were significant differences in arterial blood pressures that corresponded with degree of subspecies admixture. © 1995 Wiley-Liss, Inc.     

The influence of user status and anxious disposition on the hypertensive effects of caffeine

The present study examined the influence of consumer status and anxious disposition on the hypertensive effects of caffeine. A secondary aim of the study was to investigate possible gender differences in response to caffeine. Sixty normotensive subjects were assigned to 4 groups representing high and low scorers on the variables of habitual caffeine consumption and anxious disposition. A randomized double-blind crossover design was used in which all subjects received a placebo (lactose) at one of two 120-min laboratory sessions and caffeine (6 mg/kg) at the other. Systolic and diastolic blood pressure, heart rate, hand steadiness, and EMG were monitored before and after exposure to a psychological stressor. Caffeine produced significant elevations in systolic and diastolic blood pressure, and these effects were additive to the pressor effects of stress and anxiety. While the general pattern of results was similar for both sexes, reactions to caffeine were more pronounced in males than in females. Notwithstanding the need for clarification of the chronic effects of caffeine, present findings add further weight to current concerns about the acute hypertensive effects of the drug.     

Coronary-Prone Behavior Pattern and Cardiovascular Response

Two studies were carried out examining the relationship between coronary-prone behavior pattern and cardiovascular responses to an experimental stressor. Among 52 subjects of the Type A (coronary-prone) and Type B (non-coronary-prone) behavior patterns in Study I, Type A males showed greater elevations of systolic blood pressure than Type B males on exposure to a difficult cognitive task; no reliable differences were found for Type A and B females. Due to a conceptual similarity of the coronary-prone behavior pattern and the personality dimension of Internal External locus of control, 48 male subjects in Study II were selected with respect to four subject groups: Type A-Internals, Type A-Externals, Type B-Internals, and Type B-Externals. Again, Type As showed a more pronounced systolic response than subjects of the Type B pattern, though diastolic blood pressure and heart rate responses did not vary by coronary-prone behavior pattern. While locus of control-Internals tended to show greater task-related systolic elevations than Externals, this effect was not significant. Self-reports of anxiety increased during the period of the task, but revealed no differences among Type A and B subjects of either study. It was concluded that for male subjects the Type A-Type B dimension constitutes a salient variable of individual differences mediating the systolic pressor response.     

Cardiovascular and Metabolic Activity at Rest and During Psychological and Physical Challenge in Normotensives and Subjects With Mildly Elevated Blood Pressure

Heart rate, systolic and diastolic blood pressure, and respiratory and metabolic activity were recorded prior to and during mental arithmetic and a video game task in 20 young men with mildly elevated casual systolic blood pressures. Twenty-five unambiguously normotensive young men were tested under the same protocol. For pretask baseline physiological activity, group differences emerged for all cardiovascular and metabolic variables; thus the elevated blood pressure group displayed not only higher resting cardiovascular levels than normotensive subjects, but higher levels of metabolic activity too. With regard to change in physiological activity from rest to task, the group with mildly elevated blood pressure showed reliably larger increases in heart rate to the mental arithmetic task than the normotensive subjects. These effects, however, were not paralleled by group differences in metabolic activity increase. Physiological measures were also taken prior to and during graded dynamic exercise. The subsequent calculation of individual heart rate-oxygen consumption exercise regression lines allowed the comparison of actual and predicted heart rates during psychological challenge. The subjects with mildly elevated blood pressure displayed significantly greater discrepancies between actual and predicted heart rate values than normotensives during the psychological tasks in general and menta¹ arithmetic in particular. Group differences in physiological activity during exercise largely reflected the pattern seen at rest. A possible exception here was systolic blood pressure. Not only were systolic blood pressure levels higher throughout the exercise phase for mildly elevated blood pressure subjects, but this group evidenced more of an increase from rest to exercise than the normotensives.     

Cardiovascular reactivity to psychosocial stressors. A review of the effects of beta-blockade.

Fifty-nine studies examining the effects of beta-blockers on cardiovascular reactivity to psychosocial stressors are reviewed. Across all classifications of beta-blockers, heart rate reactivity was reduced (p less than 0.0001), while there were no significant changes in either systolic or diastolic blood pressure reactivity. Nonselective beta-blockers were more often associated with a reduction in heart rate reactivity than selective blockers (p less than 0.05). There was no evidence that drug lipophilicity or intrinsic sympathomimetic activity differentially affected blood pressure or heart rate reactivity; nor was there evidence that the reactivity of hypertensive subjects was differentially affected by blockade compared to the reactivity of normotensive subjects. While beta-blockers are effective in reducing resting blood pressure, they are not effective agents in reducing blood pressure reactivity to mild psychosocial stressors.     

Analysis of blood pressure responses during exercise by logistic function curve in hypertension: effects of age,gender and physical training

During exercise blood pressure fluctuates from minute to minute and does not rise linearly with time. Blood pressure responses were evaluated during exercise by a logistic function curve. Thirty-nine hypertensive patients underwent exercise testing with an ergometer, employing a multistage method (25 watts increment, every 3 min). We plotted the exercise duration on the X-coordinate and systolic blood pressure on the Y-coordinate and blood pressure was assumed to form a logistic curve for exercise duration. The relationship of systolic blood pressure vs. exercise duration was better fitted into a logistic function curve than a linear regression model. The logistic curve was defined by lower plateau, upper plateau, SPX (the X-coordinate at the shift point) and df (SPX), the maximal slope at the shift point. The effects of aging, gender and physical training were then analyzed on the curve. Aging did not affect lower plateau, upper plateau and SPX but augmented df (SPX), indicating greater blood pressure responses in older subjects during exercise. In females the curve was shifted to the left compared to males (SPX: 4.9 vs. 8.3 min, P < 0.05) without changes in plateaux and df (SPX), indicating greater blood pressure responses than males. Physical training for 3 weeks decreased the lower plateau from 157 to 144 mmHg (P < 0.05) and shifted the curve to the right (SPX: 7.1 vs. 8.6 min, P < 0.05), indicating unchanged blood pressure responses after training because of the opposite effects by decreases in the lower plateau vs. the curve shift to the right. In conclusion, blood pressure during exercise is better delineated by a logistic function curve than a linear regression model. The biological or physiological significance of df (SPX) is not clear at present and needs further investigations.     

Cardiovascular Reactivity in Borderline Hypertensives during Behavioural and Orthostatic Stress

Blood pressure and heart rate were measured in 16 borderline hypertensive and 10 normotensive subjects during mental arithmetic and reaction time tests, on standing, and during the pre-test period and instructions preceding these tests. The reliability of responses was assessed on 3 consecutive days. Increases in systolic blood pressure and heart rate during mental arithmetic instructions, increases in systolic blood pressure during the mental arithmetic test, and increases in diastolic blood pressure on standing were greater in borderline hypertensives. These differences persisted throughout the 3 experimental sessions. Apart from stress ratings for the reaction time test, other behavioural measures, including number of mental arithmetic mistakes and reaction times, did not differ between normotensives and borderline hypertensives. The possibility that the parasympathetic nervous system exerts a restraining influence on sympathetic overactivity in borderline hypertension was discussed.     

Characteristics of sodium sensitivity in Korean populations

Sodium sensitivity (SS) is a variable response of blood pressure (BP) to changes in sodium intake. The present study evaluated the existence and the characteristics of subjects with SS in Koreans. One hundred one subjects with (n = 31, 57.7 ± 9.8 yr) or without hypertension (n = 70, 40.8 ± 16.5 yr) were given a low-sodium dietary approache to stop hypertension (DASH) diet (LSD) for 7 days and a high-sodium DASH diet (HSD) for the following 7 days. The prevalence of SS in the present study population was 27.7% (17.6% in the non-hypertensive subjects and 51.6% in the hypertensive subjects). Analysis of the non-hypertensive subjects showed that systolic BP, diastolic BP, and mean arterial pressure at baseline and after HSD were higher in the subjects with SS than the subjects without SS, and there were no differences after LSD. In the hypertensive subjects, there was no difference in the BP at baseline and after HSD whether or not the subjects had SS. However, the systolic BP of hypertensive subjects with SS was lower than hypertensive subjects without SS after LSD. In the present study population, subjects with SS have distinctive BP features unlike to subjects without SS.     

Anger, harassment, and cardiovascular reactivity among Chinese and Indian men in Singapore

OBJECTIVE: This experiment examined psychological and cardiovascular responses to experimental harassment among Chinese and Indian men in Singapore who differed in levels of dispositional anger. METHODS: Eighty-four Chinese and Indian men participated in a laboratory experiment on cardiovascular reactivity in which mood was rated and heart rate and blood pressure were measured during computer tasks in which they were either harassed or allowed to complete the tasks without interruption. RESULTS: Comparison of systolic reactivity to harassment and nonharassment indicated, as expected, that reactivity was greater after harassment. Furthermore, a significant race by dispositional anger by harassment effect was obtained for systolic reactivity that indicated different patterns of reactivity for Chinese and Indian participants. In the absence of harassment, Chinese participants showed low systolic reactivity regardless of their level of dispositional anger, whereas systolic reactivity increased as a function of dispositional anger when they were harassed. For Indians, however, systolic reactivity was a positive function of dispositional anger both when they were harassed and not harassed. CONCLUSIONS: These results suggest stronger cardiovascular reactivity to stress among Indian than among Chinese men. This seems to be particularly true for Indians high in dispositional anger.     

Hostility, Social Support, and Ambulatory Cardiovascular Activity

The present study compared ambulatory blood pressure in male and female subjects preselected for high and low hostility levels and investigated interpersonal daily stress as a possible mediational mechanism. Ambulatory blood pressure and heart rate were measured in 48 male and female students previously classified as high or low on the Cook-Medley Hostility (Ho) Scale. Subjects wore an ambulatory monitor for a working day and also completed measures of perceived social support, daily interpersonal stress, and health behavior information. Results indicated that subjects scoring high on the Ho scale had higher mean levels of ambulatory systolic blood pressure than low Ho subjects, even when controlling for traditional risk factors, such as cigarette smoking. High Ho subjects also reported greater daily interpersonal stress and less social support than low Ho subjects. Perceived interpersonal stress partially accounted for the relationship between hostility and blood pressure. Subjects high in hostility showed greater mean ambulatory systolic blood pressure levels. Consistent with the transactional model of hostility and health, the relationship between hostility and blood pressure appears to be partially accounted for by the daily experience of interpersonal stress.     

Intra-Arterial Blood Pressure Response in Hypertensive Subjects during Low- and High-Intensity Resistance Exercise

OBJECTIVE:

The aim of this study was to describe blood pressure responses during resistance exercise in hypertensive subjects and to determine whether an exercise protocol alters these responses.

INTRODUCTION:

Resistance exercise has been recommended as a complement for aerobic exercise for hypertensive patients. However, blood pressure changes during this kind of exercise have been poorly investigated in hypertensives, despite multiple studies of normotensives demonstrating significant increases in blood pressure.

METHODS:

Ten hypertensive and ten normotensive subjects performed, in random order, two different exercise protocols, composed by three sets of the knee extension exercise conducted to exhaustion: 40% of the 1-repetition maximum (1RM) with a 45-s rest between sets, and 80% of 1RM with a 90-s rest between sets. Radial intra-arterial blood pressure was measured before and throughout each protocol.

RESULTS:

Compared with normotensives, hypertensives displayed greater increases in systolic BP during exercise at 80% (+80±3 vs. +62±2 mmHg, P<0.05) and at 40% of 1RM (+75±3 vs. +67±3 mmHg, P<0.05). In both exercise protocols, systolic blood pressure returned to baseline during the rest periods between sets in the normotensives; however, in the hypertensives, BP remained slightly elevated at 40% of 1RM. During rest periods, diastolic blood pressure returned to baseline in hypertensives and dropped below baseline in normotensives.

CONCLUSION:

Resistance exercise increased systolic blood pressure considerably more in hypertensives than in normotensives, and this increase was greater when lower-intensity exercise was performed to the point of exhaustion.     

Depressed mood and blood pressure: The moderating effect of situation-specific arousal levels

Previous studies are inconclusive with regard to the relationship between variations in blood pressure (BP) and affect. In the present study we evaluated the hypothesis that inconsistencies in previous findings may be attributed to the moderating role of variations in psychological or physical conditions during BP measurement. Change in depressive symptoms was examined in 1046 individuals at two points in time, at inclusion into the study, when BP was measured repeatedly under higher (standing posture or anticipation of interview) and lower (supine posture or recovery after interview) arousal conditions, and at 4year follow-up. We observed that higher systolic BP levels measured under high arousal conditions and lower systolic BP levels measured under low arousal conditions at inclusion were both associated with a decrease in depressive mood across time in the study sample. The results suggest that higher or lower cardiovascular activity as indexed by systolic BP corresponds with higher or lower negative mood as a function of situation-specific arousal levels. This biobehavioural association between mood and BP might be related to the moderating effect of adaptive processes on physiological activity in different situations, which may in turn be associated with resilience to adversity.     

Effects of Coping on Blood Pressure Responses to Threat of Aversive Stimulation

The purpose of this study was to examine effects on systolic and diastolic blood pressure due to availability and difficulty of control over anticipated aversive auditory stimulation. In a 2 × 2 factorial design, 44 subjects were presented either of two instructional sets regarding control: a) that exposure to the aversive stimulus would be contingent on the subject's performance at a cognitive task (Control), or b) that the stimulus would occur at random during the task period (No Control). The experimental task consisted of problems in concept formation and was presented to Control and No Control subjects at either of two levels of difficulty (Difficult or Easy); task success was manipulated by the experimenter to assure equivalent performance across groups. Results indicated that within the Task Difficult condition, Control subjects evidenced greater systolic blood pressure elevations than subjects in the No Control group, whereas Control and No Control subjects in the Task Easy condition showed no reliable differences. Diastolic blood pressure did not vary by control or task difficulty. It was concluded that the availability of control responses may induce greater arousal in situations involving threat of aversive stimulation, but that this effect obtains only when subjects experience some degree of difficulty employing available coping strategies.     

Parental Hypertension and Cardiovascular Response to Stress in Healthy Young Adults

One indicator of elevated risk for subsequent development of essential hypertension is the presence of the disorder in either or both parents. Exaggerated cardiovascular responsivity to stress has also been suggested as a possible precursor to hypertension. This study examined the relationship between parental hypertension and the heart rate (HR), systolic (SBP), and diastolic blood pressure (DBP) levels of 103 healthy college-age men, during two resting conditions and stressful cold pressor and reaction time tasks. Sons of hypertensive parents (N = 25) showed higher HR and SBP than sons of normotensive parents (N = 78) during both rest and stress, but these differences were greatest during the stressful reaction time (RT) task. No reliable differences in DBP were seen. A subsample of 45 subjects, including 14 with hypertensive parents, were also monitored during a second stress, the cold pressor test; only trends toward HR or BP differences related to parental hypertension were seen for this stress, although HR and SBP differences during the RT task were still significant (p<.05) even in this smaller group. Since the incidence of high blood pressure is known to be greater among the offspring of hypertensive parents, these findings suggest that cardiovascular responses to certain types of stress (e.g., active coping tasks) may help predict future risk of hypertension.     

A Comparison of Thermoregulation With Creatine Supplementation Between the Sexes in a Thermoneutral Environment

OBJECTIVE: To compare the effect of creatine supplementation on thermoregulation in males and females during exercise in a thermoneutral environment. DESIGN AND SETTING: Male and female subjects participated in 30 minutes of cycle ergometry in nonsupplemented (NS) and creatine-supplemented (Cr) conditions at 70% to 75% of predetermined peak oxygen consumption. SUBJECTS: Ten male and ten female subjects were evaluated with and without creatine supplementation. MEASUREMENTS: Analyses were performed during exercise for core temperature and mean skin temperature using two 2 x 2 x 7 mixed-factorial analyses of variance (ANOVAs). We compared mean differences between NS and Cr conditions and sex for heart rate, systolic blood pressure, and diastolic blood pressure using 3 2 x 2 x 4 mixed-factorial ANOVAs. Three 2 x 2 mixed-factorial ANOVAs were computed to examine differences between sex and conditions for the following variables: nude body weight and blood urea nitrogen before and after exercise and urine specific gravity. RESULTS: Significant time effects were found for core temperature, skin temperature, heart rate, and diastolic blood pressure. Time effect and difference between the sexes for systolic blood pressure were both significant. Differences in nude body weight and blood urea nitrogen before and after exercise were greater for males, but there was no difference between conditions. No significant difference between sex and condition for urine specific gravity was noted. CONCLUSIONS: Short-term creatine supplementation did not affect thermoregulation between the sexes when exercising in a thermoneutral environment. Differences in changes in nude body weight before and after exercise may be due to a higher sweating rate in males versus females. Differences in blood urea nitrogen before and after exercise between the sexes may be due to a reduced glomerular filtration rate coupled with greater muscle creatine breakdown in males.