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Biomedical subjects

A Steptoe

Publications and source records attributed to A Steptoe.

At least 109 records · Page 6Linked to original sources

The inhibition of cardiovascular responses to mental stress following aerobic exercise.

The effects of exercise on subsequent psychophysiological responses to mental stress were assessed in a study of 30 normotensive male volunteers. Participants were randomly allocated to three experimental conditions--20-min exercise at 100 Watts (high exercise), 20-min exercise at 25 Watts (low exercise), or 20-min no exercise (control). After a recovery period of 20 min, all subjects performed a mental arithmetic task for four 5-min trials. Blood pressure and heart rate were monitored continuously using a Finapres, and respiration and electrodermal activity were also recorded. Baroreceptor reflex control of heart rate was assessed using power spectrum analysis. Exercise produced consistent increases in systolic blood pressure, heart rate, and subjective tension, together with reductions in systemic resistance and baroreflex sensitivity. The systolic and diastolic blood pressure and heart rate reactions to mental arithmetic were significantly blunted in the high exercise compared with control conditions, with the low exercise group showing an intermediate pattern. Subjective responses to mental stress were unaffected by prior exercise. The pattern of hemodynamic response was not a result of changes in baroreflex sensitivity. The mechanisms underlying this result are discussed in relation to the discrepancies between subjective and physiological responses to mental stress, and the implications for the use of exercise in stress management.

Adult↗

Methodology of mental stress testing in cardiovascular research.

Many issues related to the selection, reliability, and validity of mental stress testing in cardiovascular research are discussed. Five categories of mental stress testing are distinguished: problem-solving tasks, information-processing tasks, psychomotor tasks, affective conditions, and aversive or painful conditions. A series of practical and theoretical criteria are outlined for the selection of appropriate tests, and the measurement of a range of dependent variables is emphasized. The temporal stability of cardiovascular responses to mental stress tests is examined through an analysis of test-retest correlations (weighted for sample size) in 28 comparisons with intervals between sessions varying from 1 day to more than 1 year. Heart rate reactions to tasks show an average-weighted Z of 0.732 +/- 0.031 (r = 0.62), with Z = 0.575 +/- 0.034 (r = 0.52) for systolic blood pressure and Z = 0.313 +/- 0.035 (r = 0.30) for diastolic blood pressure. It is argued that the validity of mental stress tests can be judged in relation to several different aspects, specifically, methodological, ecological, diagnostic, prognostic, and therapeutic validities. The nature of these standards is described, and pertinent literature is presented.

Cardiovascular Diseases↗

Psychophysiological stress testing in postinfarction patients. Psychological correlates of cardiovascular arousal and abnormal cardiac responses.

The psychophysiological responses to two mental stress tests (mental arithmetic and an interactive concentration task) were assessed in 168 unmedicated, male, postinfarction patients 36-69 years old. Patients also completed a standard battery of psychological tests. Psychophysiological responses were generally unrelated to age and education. Comparison of patients scoring high (more than 75%) and low (less than 25%) relative to the normal population on psychological measures indicated that heart rate and blood pressure responses to mental stress tests were significantly greater in those reporting low than in those reporting high neuroticism. The study population was subsequently divided into high, medium, and low cardiovascular responders on the basis of rate-pressure product reactions to the two stress tests. The three cardiovascular response groups did not differ in age, interval between myocardial infarction and stress testing, ejection fraction, incidence of exercise-induced ischemia, or ischemic signs during Holter monitoring. However, the high cardiovascular responders were more likely to manifest possible or definite electrocardiographic signs of ischemia or significant arrhythmia during mental stress testing than were the medium or low cardiovascular responders (50% versus 19.6% and 7%, respectively). High cardiovascular responders also reported lower levels of trait anxiety, neuroticism, psychophysiological symptoms, and depression.

Arousal↗

Cognitive and somatic anxiety.

Three hundred and forty adults (including sports players, recreational exercisers, mediators and sedentary controls) completed three inventories purporting to measure cognitive and somatic aspects of anxiety. These were the Cognitive-Somatic Anxiety Questionnaire (CSAQ) devised by Schwartz, Davidson & Goleman (Psychosomatic Medicine, 40, 321-328, 1978), the Worry-Emotionality Scale (WES, Morris, Davis & Hutchens, Journal of Educational Psychology, 73, 541-555, 1981) and the Lehrer-Woolfolk (1982) Anxiety Symptom Questionnaire (LWASQ). Factor analysis of the CSAQ and WES identified distinct cognitive and somatic anxiety factors in both inventories. Higher somatic than cognitive ratings were recorded on the CSAQ and WES, while the pattern was reversed on the LWASQ. The CSAQ can tentatively be recommended as a useful measure of these two anxiety components. We were unable to confirm an observation made previously in the literature that practice of meditation is associated with reduced cognitive anxiety, or that exercise is linked with lower somatic anxiety.

Adolescent↗

Age-related differences in cardiovascular reactions to mental stress tests in women.

Tested 84 healthy, sedentary women in the laboratory during performance of difficult and easy problem-solving tasks. They were divided into three age groups: 19 to 32 years, 33 to 43 years, and 44 to 60 years (n = 28 women per group). Baseline systolic blood pressure (SBP) and diastolic blood pressure increased with age, whereas skin conductance level was lower in older women. In addition, initial SBP reactions to tasks were positively related to age, even after controlling for baseline blood pressure, aerobic fitness, and Framingham Type A Scale behavior scores. There were no differences in heart rate (HR) or "additional" HR reactions, so the anticipated decline in cardiac sympathetic response with age was not observed. The mechanisms underlying age-related reactions to mental stress are discussed.

Adult↗

Cardiac baroreflex function during postural change assessed using non-invasive spontaneous sequence analysis in young men.

STUDY OBJECTIVE: The aim was to assess the value of baroreflex sensitivity estimates calculated from analyses of spontaneous systolic blood pressure and pulse interval sequences derived from continuous non-invasive finger blood pressure recordings during sitting and active standing. DESIGN: Continuous recordings of digital systolic blood pressure and pulse interval were obtained non-invasively using a Finapres FD5 during 5 min trials of sitting and standing. SUBJECTS: Subjects were healthy males aged 19-28, divided into those with "high" normal (n = 18) and "low" normal (n = 17) blood pressure. MEASUREMENTS AND MAIN RESULTS: Recordings were scanned for spontaneous sequences of three or more cardiac cycles over which systolic blood pressure increased progressively in conjunction with prolonged pulse interval, or decreased while pulse interval became shorter. Regressions between blood pressure and pulse interval (r greater than 0.80) provided estimates of cardiac baroreceptor reflex control. Computations were carried out with concurrent blood pressure and pulse interval measurements, and with a delay or lag of one and two cycles between the two variables. Pulse interval was reduced from an average 870.3 ms sitting to 571.3 ms on standing. Mean baroreflex sensitivity while sitting averaged 17.5 ms.mm Hg-1 at a delay of one cycle, failing to 7.65 ms.mm Hg-1 with standing. The decrease in sensitivity was correlated with the change in pulse interval between trials. The number of sequences was also significantly reduced with standing as opposed to sitting. Three cycle sequences were most frequent, with a lesser number of sequences involving 4, 5, and 6 or more cycles. No significant differences between "high" and "low" normal blood pressure groups were observed. CONCLUSIONS: The analysis of spontaneous sequences from non-invasive recordings may provide useful information concerning cardiac baroreflex control in different postural and behavioural states. A lag of one cycle between systolic blood pressure and pulse interval may provide the most representative estimates of baroreflex sensitivity.

Adult↗

Aerobic fitness, physical activity, and psychophysiological reactions to mental tasks.

The association between aerobic fitness, exercise, and psychophysiological reactivity was assessed in cross-sectional and prospective analyses. Seventy-five healthy but sedentary adults carried out a sub-maximal exercise test and easy and difficult problem solving tasks. Blood pressure, heart rate, skin conductance level, respiration rate, tidal volume, and oxygen consumption were monitored and additional heart rate was also computed. Differences between relatively fit and unfit individuals were found in respiration rate during tasks and in skin conductance level during post-task recovery periods, with a tendency toward diminished heart rate reactivity in fitter people. Subjects were subsequently allocated to four conditions: high intensity aerobic training, moderate intensity aerobic training, an undemanding strength and flexibility program (designed as an attention-placebo condition), and waiting list control. Training programs were conducted over a 10-week period, and were followed by a second laboratory session. Appropriate changes in aerobic performance over the training period were observed in the 12-min run/walk test. There were no important modifications in psychophysiological stress reactions associated with the different experimental conditions. These results are discussed in relation to the literature concerning the effects of fitness and physical activity on physiological response patterns.

Adult↗

The effects of exercise training on mood and perceived coping ability in anxious adults from the general population.

A comparison was carried out of the psychological effects of a moderate aerobic training programme (n = 24) and an attention-placebo strength and flexibility training programme (n = 23) in previously inactive anxious adults from the general population. Training consisted of one supervised and three unsupervised sessions per week for 10 weeks. Effects were assessed with the Profile of Mood States, the State-Trait Anxiety Inventory and questionnaires indexing perceived coping ability. Seven participants dropped out of each condition during the training period. Expectations of benefit assessed pre-training, and satisfaction assessed post-training, did not differ between conditions. The moderate exercise programme led to significant improvements in aerobic fitness, and was associated with significantly greater reductions in tension-anxiety, depression and other moods than the attention-placebo condition, together with increases in perceived ability to cope with stress. Psychological responses were not correlated with changes in fitness assessed with bicycle ergometry or the 12 min walk/run test. These effects were maintained on 3 month follow up.

Adaptation, Psychological↗

The effects of exercise training on mental well-being in the normal population: a controlled trial.

This study was designed to compare the effects of two aerobic training programmes of differing intensities on mood and mental well-being with those of a credible attention-placebo condition. One hundred and nine sedentary adult volunteers from the local population were assigned to four conditions: high intensity aerobic training, moderate intensity aerobic training, attention-placebo and waiting list. Training was carried out over a 10 week period. Subjects were assessed before and after training with psychological measures and the 12 min walk-run test, and follow-up evaluations were undertaken after 3 months. Ninety-four subjects began the programme and the adherence rate averaged 80%, with no significant differences in number of drop-outs between conditions. Appropriate changes in estimated maximum oxygen consumption were observed in the three active conditions with the 12 min walk-run test. Psychological benefits were seen with the moderate exercise condition but not in the high exercise or attention-placebo conditions. These effects were manifest immediately after training on measures of tension/anxiety and confusion, and at follow-up on measures of perceived coping ability. The mechanisms underlying this pattern of results are discussed and the relative importance for health of vigorous activity and physical fitness is considered.

Adaptation, Psychological↗

Assessment of baroreceptor reflex function during mental stress and relaxation.

This paper describes a method of measuring baroreceptor cardiac reflex sensitivity noninvasively from spontaneous patterns of blood pressure and interbeat interval, and the application of this technique in psychophysiology. Baroreflex function was assessed in 24 female volunteers during relaxation and performance of the cold pressor test and a non-verbal mental arithmetic task. Blood pressure and interbeat interval were monitored continuously from the finger using the vascular unloading technique. Sequences of three or more cardiac cycles were identified over which systolic blood pressure increased progressively in conjunction with lengthening interbeat interval, or systolic blood pressure decreased as interbeat interval was reduced. The regression between systolic blood pressure and interbeat interval was computed as an index of baroreflex sensitivity. Relaxation was associated with a small prolongation of interbeat interval, whereas baroreflex sensitivity increased from 17.1 to 19.8 ms/mmHg. Baroreflex sensitivity was reduced significantly during mental arithmetic (mean 14.2 ms/mmHg) but not during the cold pressor test (mean 17.4 ms/mmHg). The difference between mental arithmetic and the cold pressor test may be related to the relative intensity of cardiac and vascular responses in the two situations. The implications of these results for the understanding of behavioural influences on haemodynamic function are discussed and the advantages of noninvasive methods are considered.

Adult↗

Acute effects of aerobic exercise on mood.

Thirty-two female students participated in a single-session experiment during which they carried out two 8-min trials of high-intensity exercise and two 8-min trials of low-intensity exercise. One high- and one low-exercise trial were accompanied by music; the other two trials were accompanied by metronome. Mood was assessed with a modification of the Profile of Mood States before and immediately after each trial. The purpose of the experiment was disguised to reduce the influence of subject expectations on mood responses. Participants were divided into fit and unfit groups based on heart rate responses during high-exercise trials. Overall, high-intensity exercise led to increases in tension/anxiety and fatigue, whereas positive mood changes (vigor and exhilaration) were seen following low-intensity exercise only. No group differences in mood responses were observed. Explanations of these results are considered in light of other literature concerning the acute effects of exercise on mood.

Adolescent↗

Exaggerated blood pressure responses to submaximal exercise in normotensive adolescents with a family history of hypertension.

Twenty-four adolescent boys with a positive and 40 boys with a negative parental history of hypertension (PH+ and PH-, respectively) were studied at rest and during exercise on a bicycle ergometer at work loads ranging from 25 to 150 W. Each group was divided into fit and unfit categories on the basis of oxygen consumption at a heart rate (HR) of 150 beats/min. Blood pressure (BP) at rest averaged 114.2/68.8 mmHg in the PH+ group and 110.9/70.3 mmHg in the PH- group. Age and body weight did not differ between subgroups, although resting HR was lower in fit than in unfit subjects (P less than 0.01). Oxygen consumption increased with exercise but did not differ between groups at any work level. However, systolic BP was significantly higher in the PH+ group than in the PH- group at both 100 W (163.1 +/- 12.3 versus 156.7 +/- 12.2 mmHg) and 150 W (174.3 +/- 12.5 versus 166.6 +/- 10.4 mmHg, P less than 0.05). These results suggest that the exaggerated BP responses to exercise, characteristic of hypertensive patients, may be present in normotensive adolescents with an increased risk of developing the disorder, and may reflect pathophysiological changes that precede sustained BP elevation.

Adolescent↗

The assessment of sympathetic nervous function in human stress research.

The methods currently available for measuring sympathetic nervous system activity in human stress research are critically reviewed. The advantages and limitations of catecholamine measurements in plasma and urine are considered. The contribution of skeletal muscle sympathetic activity to noradrenaline concentration in venous blood represents a serious drawback of this measure, and under many circumstances, urinary assay may reflect arterial catecholamine levels more accurately. The potential benefits of assessing noradrenaline clearance are described. Other methods of assessing sympathetic activity are also reviewed, including microneurographic techniques and the use of pharmacological blockade. General recommendations are given about the methods of greatest value in human stress research.

Action Potentials↗

Stage fright in orchestral musicians: a study of cognitive and behavioural strategies in performance anxiety.

A questionnaire study was carried out with three groups of musicians: experienced professional orchestral players (n=65), music students (n=41), and members of an amateur orchestra (n=40). Musical performance anxiety was assessed together with neuroticism, everyday fears, self-statements and behavioural coping strategies. Performance anxiety was lowest in the professional group and highest among students. In all three groups, performance anxiety was related to neuroticism and everyday fears, notably fear of crowds and social situations. A negative association between age, performing experience and stage fright was observed in professional musicians but not other groups. Six clusters of self-statements were identified. Catastrophizing was positively linked with performance anxiety in all groups, while realistic appraisal of the performance situation was used most commonly by those with moderate levels of stage fright. Implications for the conceptualization and management of stage fright are discussed.

Adaptation, Psychological↗

Physiological and subjective stress responses in surgical patients.

Autonomic responses, mood and psychological coping were assessed in two groups of orthopaedic patients during hospitalisation for major or minor surgery. Eight patients admitted for total hip replacement and seven patients undergoing knee arthroscopy were seen daily for two days before surgery until discharged from hospital. Mood and coping questionnaires were administered on each session, while pain, heart rate, blood pressure, skin conductance level, palmar sweat prints and forearm EMG were also recorded. Heart rate increased from pre- to post-operative assessments, while skin conductance and palmar sweating fell to low levels on the days immediately following surgery, returning to basal values only after several days. Self ratings of anxiety, fatigue, depression and pain were highest on the immediate post-operative days. Patients utilised the coping factors Rational Cognition and Behavioural Action to the greatest extent, but ratings on coping factors fluctuated little over the study period. The interrelations between these measures and possible explanations of the results are discussed.

Adaptation, Psychological↗