Family history of hypertension and cardiovascular changes during high and low affect provocation

Cardiovascular reactivity and family history of hypertension: A meta-analysis

A regression-based meta-analysis examined the degree to which the effects of a family history of hypertension on cardiovascular reactivity are moderated by the magnitude of cardiovascular responses elicited in challenge/task conditions. Mean change scores for negative family history groups were regressed on mean change scores for positive family history groups. The slopes of separate regression lines obtained for systolic and diastolic blood pressure and heart rate were significantly less than 1.0 and the y-intercepts for these regression lines were significantly greater than zero. This pattern indicates that family history differences in cardiovascular reactivity to stress are greatest in situations that elicit the smallest baseline-stressor change scores in non-family-history groups.

Association analysis of two tyrosine hydroxylase gene polymorphisms in normotensive offspring from hypertensive families

OBJECTIVE

We have studied possible association between predisposition to essential hypertension, plasma noradrenaline level and two polymorphisms of the gene for tyrosine hydroxylase (TH), the rate-limiting enzyme of catecholamine biosynthesis.

DESIGN AND METHODS

One hundred and one normotensive sons from normotensive parents (SN) and 107 normotensive sons of hypertensive families (SH) were studied. Tetranucleotide TCAT repeat and Va181Met polymorphisms of the TH gene were determined by polymerase chain reaction (PCR) technique.

RESULTS

SH had higher systolic BP and plasma noradrenaline concentration than the SN group. No significant difference was found between the allele and genotype frequencies in the SH and SN groups for both polymorphisms. The two polymorphisms were in tight linkage disequilibrium. The CD genotype of the microsatellite marker was associated with increased plasma noradrenaline concentration in both groups. Genotypes AB, AE and BB of the TCAT repeat polymorphism and genotypes VM and MM of the Va181Met polymorphism exhibited the greatest difference in plasma noradrenaline concentration between the SH and SN groups.

CONCLUSION

The studied TH polymorphisms do not appear to be associated with family history of essential hypertension. Nevertheless, some genotypes of TH might be related to disturbance of plasma noradrenaline concentration.

A case for the usefulness of laboratory social stressors

Although laboratory stress research is a popular and vibrant area of research activity, there is surprisingly little evidence that laboratory stress models are clinically useful (i.e. that they can explain and predict the development of disease). This article summarizes evidence that the usefulness of lab stress research can be improved with the use of social stressors. Two lines of evidence are presented in support of this argument: (a) studies comparing physiological reactivity to different lab stressors with ambulatory activity, and (b) a meta-analysis of investigations of cortisol responses to laboratory stressors. Further issues of importance in understanding social stressors are gender differences and the vulnerability (i.e. weak reliability) of social stressor impact to relatively small changes in the experimental protocol itself.

Psychophysiological effects of interviews about emotional events on offspring of hypertensives and normotensives

Normotensive individuals with a parental history of hypertension have been found to exhibit greater cardiovascular reactivity to a variety of laboratory stressors than offspring of normotensives. To examine the possible generalization of these differences to real-life stressors, subjects were administered four brief interviews about different emotional events in their lives. Regardless of emotional content, offspring of hypertensives displayed greater systolic blood pressure responses to the non-verbal recollection and verbal description of personal emotional events, but not to the imagination of standardized emotional scenes or reading a non-emotional advertisement. This suggests that group differences in reactivity may generalize to real-world situations. Evidence of significantly greater vasoconstriction during interviews about sad topics was also observed, contributing to the literature on the physiological differentiation of emotional states.

Relationships between startle and cardiovascular reactivity

Although startle and cardiovascular reactivity have been studied extensively, little is known about their relationship. In the present study, we examined cardiovascular responses and affective startle modulation in 112 normotensive individuals varying in self-reported fearfulness and parental cardiovascular health history. An initial intense noise burst elicited a phasic cardiac acceleration that was larger for fearful individuals. Startle blink responses were larger during aversive than during pleasant relaxing imagery but did not differ with fear group. Cognitive challenge tasks elicited heart rate and blood pressure increases that were unrelated to fearfulness or parental health history. However, greater startle potentiation by aversive imagery predicted larger pressor responses to cognitive challenge, especially among men. The observed relationship between startle and cardiovascular reactivity suggests a common mechanism for their affective modulation.

Alexithymia, defensiveness and cardiovascular reactivity to stress

This article attempts to further our understanding of alexithymia by testing two conceptual questions about the construct: (a) Is alexithymia characterized by reduced autonomic activity? and (b) Can it be clearly distinguished from defensiveness? Eighty healthy university students completed a battery of personality scales including the Toronto Alexithymia Scale, measures of self-deception and impression management, depression, and anger-in. They also participated in three lab stress tasks: isometric handgrip; mental arithmetic; and a negative affect provocation task. Blood pressure and heart rate were monitored throughout the lab procedure. Analyses were conducted with tercile groups of low, medium, and high alexithymia scorers. The "high alexithymia" tercile showed smaller heart rate responses to the stress tasks and more anger-in behavior. Blood pressure responses did not differentiate the low/ medium/high alexithymia subgroups. Alexithymia scores were unrelated to defensiveness, that is, there was no relationship between alexithymia and impression management or self-deception, and alexithymia was unrelated to depression. We conclude that students defined as "high alexithymia" on the Toronto Alexithymia Scale are not self-deceptive nor do they try to leave a particular impression; they tend to be somewhat hypoaroused autonomically, and they report as many psychological distress symptoms as do subjects with lower TAS scores.

Stress management for patients with heart disease: a pilot study

OBJECTIVE

To conduct a feasibility study on stress management for patients with heart disease; more specifically, to test the availability of patients, determine dropout rates, and investigate the sensitivity to change of a large number of psychologic and biologic stress indexes.

DESIGN

Random assignment, two-group clinical trial.

SETTING

Pacific Northwest university-affiliated teaching hospital.

PATIENTS

Forty-five patients with heart disease (mean age 56 years), who either had a myocardial infarction or coronary bypass surgery.

OUTCOME MEASURES

Hostility, subjective distress, resting electrocardiogram, resting blood pressure and blood pressure reactivity to a psychologic stressor, and blood lipid, cortisol, and catecholamine levels.

INTERVENTION

Patients were randomly assigned to either (1) exercise rehabilitation (ER) and an 8-week stress management (SM) program (ER + SM) or (2) ER only. Although the recruitment rate was satisfactory, 67% of patients assigned to the control condition and 40% of the SM subjects were not available for posttesting.

RESULTS

Computed effect sizes indicated that blood pressure reactivity to a psychologic challenge was reduced after treatment in the ER + SM group but not in ER group. The ER + SM group showed improvement in perceived health status and had clinically meaningful reductions in triglyceride levels, whereas the ER group did not. The ER group had a reduction in high-density lipoproteins, whereas the high-density lipoprotein levels of the ER + SM group did not change.

CONCLUSIONS

Patients randomly assigned to a control condition may be less willing to participate in time-consuming and invasive posttests than treated patients. Reducing the invasiveness of measurement may increase cost-effectiveness and reduce the dropout rate under controlled conditions. Blood pressure reactivity to a psychologic stress test and changes in serum lipid levels may be sensitive and cost-effective measures to include in future studies of cardiac rehabilitation.

Laboratory reactivity models as predictors of ambulatory blood pressure and heart rate

We attempted to validate the usefulness of the laboratory reactivity paradigm by examining responses to three distinct lab tasks and an overall lab average as predictors for ambulatory blood pressure. Subjects were 126 university students. We assessed ambulatory blood pressure, heart rate and perceived distress during an 8-hr working day. In the lab, all subjects responded to three standardized 5-min tasks: isometric handgrip, mental arithmetic, and a structured discussion of a recent interpersonal conflict situation. The analyses used absolute task levels, change scores, a composite index of reactivity, and a mean value for all obtained lab measures. Task levels correlated significantly with means of the ambulatory cardiovascular indices; the scores ranged from 0.35 to 0.49 for SBP, from 0.45 to 0.58 for DBP, and from 0.57 to 0.65 for HR. Only the DBP change score associated with the discussion task correlated with the ambulatory mean. The correlations between lab task levels and ambulatory measures were strongest for the discussion task and the composite score; the task level for the math task was consistently the weakest predictor of ambulatory activity. When lab resting values were forced into a step-wise multiple regression as step one, only the response to the discussion added significantly (3% each for SBP and DBP) to the variance in ambulatory pressure that was not already explained by resting values. The overall lab mean for SBP was a better predictor of the ambulatory mean than was any combination of resting values and reactivity indices.