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T G Pickering

Publications and source records attributed to T G Pickering.

At least 307 records · Page 17Linked to original sources
PubMedDate not supplied

Social support effects on cardiovascular reactivity: is a stranger as effective as a friend?

OBJECTIVE: We investigated whether the effects on cardiovascular reactivity of social support from an audience member depend only on the behavior of that person or also depend on the relationship between the audience and the actor. That is, is there any added reduction in physiological response if the person who is nodding and smiling supportively is also a friend? METHOD: Ninety subjects gave a speech to an observer. In two of the conditions, this observer was a confederate of the experimenter and a stranger to the subject. This confederate acted in either a supportive or neutral manner during the speech. In the final condition, this observer was a friend, brought by the subject, who was then trained to show support in the same manner as the supportive confederate. The comparison of the two confederate conditions tested the effect of support, holding the relationship constant. The comparison of friend and confederate supportive conditions tested the effect of the relationship, holding the supportive behaviors constant. All participants were female. RESULTS: Both supportive conditions produced significantly smaller cardiovascular increases than the confederate-neutral condition, and the friend-supportive condition produced significantly smaller systolic blood pressure increases than the confederate-supportive (friend-supportive: 7.9 mm Hg: confederate-supportive: 14.9 mm Hg; confederate-neutral: 22.9 mm Hg). Differences for diastolic pressure and heart rate were not significant, although the data followed the same pattern. CONCLUSIONS: Social support from a friend attenuated cardiovascular reactivity in a laboratory setting to a greater degree than support from a stranger. The subjects' construal of the supportive behaviors can have an effect on reactivity, over and above the effects of the actual behaviors themselves.

Adolescent↗
PubMedDate not supplied

A longitudinal study of job strain and ambulatory blood pressure: results from a three-year follow-up.

OBJECTIVE: This study was conducted to investigate the hypothesis that exposure to "job strain" is related to increased ambulatory blood pressure (ABP). METHOD: Participants were 195 men who wore an ABP monitor for 24 hours on two occasions 3 years apart. Job strain status, evaluated at each assessment, was used to identify four groups: those not having job strain at either assessment (N = 138), those having job strain at both times (N = 15), and two crossover groups. Regression analysis was used to examine the cross-sectional associations of ABP with job strain, controlling for other known risk factors. Repeated-measures analysis of variance was used to examine the association of ABP change with the category of job strain change. RESULTS: The cross-sectional analysis of the Time 2 data yielded almost identical, highly significant effects of job strain on ABP as was shown in our previously published Time 1 analysis. Those in high strain jobs at both times had systolic/diastolic ABPs at work and at home that were, on average, 11/7 mm Hg higher than those with no job strain at both times; the crossover groups had intermediate levels of ABP. The longitudinal analysis showed that those with a high strain job at Time 1, but not at Time 2, had a significant decrease in work and home ABP of approximately 5/3 mm Hg. CONCLUSIONS: The previously reported cross-sectional association between job strain and ABP was replicated at follow-up. The group repeatedly exposed to job strain had higher levels of ABP at Time 2 than either crossover group. Furthermore, change in job strain status partially predicted change in ABP. These results provide new evidence supporting the hypothesis that job strain is an occupational risk factor in the etiology of essential hypertension.

Adult↗
PubMedDate not supplied

Psychological variables in hypertension: relationship to casual or ambulatory blood pressure in men.

OBJECTIVE: The evidence linking hypertension with personality or psychological characteristics, such as anger, anxiety, or depression, remains equivocal. This may be due in part to limitations of personality theory, confounding by awareness of hypertension, and/or inherent difficulties in measuring blood pressure. This study was designed to investigate the association between mild hypertension as defined by both ambulatory and casual (clinic) blood pressure measurements and various measures of personality and psychological characteristics. METHODS: We examined this association in a population-based sample of 283 men between the ages of 30 and 60 years from eight work sites in New York City, using an ambulatory blood pressure monitor and controlling for age, race/ethnicity, and body mass index. RESULTS: We found no consistent difference between participants with mild hypertension and those with normal blood pressure on any of the psychological variables assessed, including Type A behavior pattern, state and trait anger, anger expression, anxiety, symptoms of psychological distress, locus of control, or attributional style. Results were not due to the use of antihypertensive medication by some of the participants with hypertension nor to the dichotomization of blood pressure into those with and without mild hypertension. This contrasts with previous findings from this study showing a sizable association of ambulatory blood pressure and hypertension with job strain (a situational measure), age, and body mass index. CONCLUSIONS: These null results suggest that situational, biological, and perhaps behavioral factors are the primary determinants of mild hypertension and that the predictive significance of psychological or dispositional factors is low or negligible in those without overt cardiovascular disease.

Adult↗
PubMedDate not supplied

The substitutive role of ACTH in supporting aldosterone response to head-up tilt during acute renin suppression in patients with essential hypertension.

The relative contribution of the renin-angiotensin system, adenocorticotrophic hormone (ACTH) and plasma electrolytes in the response of plasma aldosterone to 30 minutes of 65 degrees head-up tilt was assessed in 10 essential hypertensive patients. Studies were carried out before and during acute blockade of renin release by propranolol, ACTH suppression by dexamethasone and combined renin and ACTH blockade. In control studies orthostasis induced significant increases only in plasma renin activity and aldosterone. In contrast, when the renin response to tilt was acutely suppressed by propranolol administration, the aldosterone response was nonetheless maintained but now appeared to be under ACTH control, since concurrent increases in cortisol were observed. During ACTH suppression aldosterone increased during tilt and so did renin. However, during combined ACTH and renin blockade aldosterone failed to increase during tilt. These studies suggest that the aldosterone secretory response to head-up tilt is normally mediated by the renin-angiotensin system but, when the renin response is suppressed, an ACTH response is elicited which assumes a backup role. However, when these two systems are blocked other factors appear unable to respond during tilt to support a normal aldosterone response.

Adrenergic beta-Antagonists↗
PubMedDate not supplied

Cardiovascular responses to isometric exercise and standing in normotensive subjects during converting enzyme inhibition with teprotide.

The hemodynamic responses to isometric exercise (hand grip) were investigated in normotensive subjects during a 150 mEq (n = 8) sodium diet and a 10 mEq (n = 6) sodium diet both before and after the administration of the converting enzyme inhibitor teprotide. Although teprotide significantly decreased the mean arterial pressure during both sodium intakes, the normal pattern of hemodynamic response to hand grip was preserved, that is mean arterial pressure was increased by hand grip mainly because of an increase in cardiac output. Changes of plasma catecholamines during hand grip were not affected by teprotide. In addition, the hemodynamic responses to standing were not substantially altered by teprotide. When fainting occurred (in the seated position) following the administration of teprotide, it was associated not only with a decrease in arterial pressure but also with a concurrent reduction in cardiac output. We conclude that angiotensin inhibition by teprotide does not significantly impair sympathetically mediated cardiovascular responses.

Adult↗
PubMedDate not supplied

Elevated blood viscosity in patients with borderline essential hypertension.

In patients with borderline hypertension, total peripheral resistance (TPR) is either elevated or abnormally related to cardiac output. Since blood viscosity is one determinant of TPR, we compared various components of blood viscosity in 25 patients with borderline hypertension and 25 normal subjects. Under all experimental blood flow conditions examined, blood viscosity directly correlated with systolic and diastolic blood pressure (p less than 0.05 or better) and was greater in the hypertensive than in normal subjects. Venous hematocrit and plasma viscosity were higher in the hypertensive patients. These latter rheologic abnormalities accounted for the increased blood viscosity at higher shear rates. At lower shear rates, increased red cell aggregation, primarily mediated by elevated fibrinogen concentration, accounted for the higher blood viscosity in the hypertensive subjects. We conclude that even relatively small elevations in arterial pressure are associated with increased viscous resistance of blood to flow, and that the increased blood viscosity is a consequence of increased hematocrit, plasma viscosity, and red cell aggregation.

Adult↗
PubMedDate not supplied

What is the value of home blood pressure measurement in patients with mild hypertension?

To investigate the value of home blood pressure (BP) measurements, the BP was recorded daily by the patient at home and compared with recordings in the physician's office and with a 24-hour BP recording taken with a noninvasive ambulatory BP recorder in a group of 93 patients with mild untreated hypertension. Office BPs (mean 148/94 mm Hg) were higher than either home (138/89 mm Hg) or average 24-hour BPs (131/89 mm Hg). For systolic BP, home and office measurements gave similar correlations with 24-hour BP (0.67 and 0.55). For diastolic BP, however, home readings were lower and more accurate (0.76 vs 0.36). Thus, our findings indicate that home readings reflect the overall level of BP more reliably than office readings, and if due consideration is given to the fact that they are usually lower than office readings, they may be used as an alternative and cost-effective means of evaluating patients with mild hypertension.

Adolescent↗
PubMedDate not supplied

What is the role of ambulatory blood pressure monitoring in the management of hypertensive patients?

Noninvasive ambulatory blood pressure (BP) recording is now clinically available for the evaluation of hypertensive patients. It is well known that pressures measured in the office or clinic are unreliable and that repeated measurements are better at predicting outcome than are single measurements. Several studies have compared the correlation between target organ damage and different measures of BP, and in every instance ambulatory BP measurements have given better correlations than clinic readings. In one prospective study the ambulatory BP readings were more predictive of BP-related morbidity than were clinic readings. Data are now being obtained that will establish normal ranges of BP during ambulatory monitoring, against which values from patients being evaluated for hypertension can be compared. It is concluded that ambulatory BP monitoring is of clinical value for the evaluation of patients with mild hypertension.

Adult↗
PubMedDate not supplied

Increased cardiac performance in mild essential hypertension. Left ventricular mechanics.

To analyze cardiovascular dynamics in essential hypertension, 81 subjects with untreated mild essential hypertension (mean blood pressure, 112 +/- 14 mm Hg) and 87 normotensive subjects from the same working population were studied by echocardiography and simultaneous blood pressure determination. Hypertensive subjects had significantly higher pulse pressure, stroke volume index, cardiac index, left ventricular internal dimension, end-systolic pressure/volume ratio, end-systolic stress, left ventricular mass index, and relative wall thickness than normotensive subjects. Among both normotensive and hypertensive subjects, cardiac performance was closely dependent on afterload, as indicated by close inverse linear relationships between left ventricular fractional shortening and log end-systolic stress (r = -0.83 and -0.78 respectively; both, p less than 0.001). However, 19 of 81 hypertensive patients (23%) fell above the 95% confidence limits of this relationship in normotensive subjects (p less than 0.001 compared with that in normotensive subjects), with a bimodal distribution of fractional shortening as a percent of predicted in relation to end-systolic stress among patients with essential hypertension. This subgroup of hypertensive subjects, with increased resting cardiac performance independent of afterload, was similar in age to the remaining hypertensive subjects but had higher fractional shortening (41 +/- 5% vs 35 +/- 7%; p less than 0.001) and cardiac index (4.3 +/- 1.3 L/min/m2 vs 3.4 +/- 1.0 L/min/m2; p less than 0.005) and lower total peripheral resistance (1257 +/- 502 dyn sec cm-5 vs 1582 +/- 584 dyn sec cm-5 p less than 0.05) and left ventricular relative wall thickness (0.34 +/- 0.06 vs 0.42 +/- 0.10; p less than 0.005). Thus, analysis of cardiac mechanics detected a subset of patients with essential hypertension in whom increased cardiac function cannot be attributed either to relative youth or to supercompensatory left ventricular hypertrophy.

Adult↗
PubMedDate not supplied

Job strain and health behaviors: results of a prospective study.

PURPOSE: To assess the association between job demands, job decision latitude, and job strain (defined by Karasek as a combination of high demands and low decision latitude) and cardiovascular disease-related health behaviors such as cigarette smoking, alcohol use, lack of exercise, and overweight. DESIGN: Cross-sectional and prospective. SETTING: Nine New York City public and private sector worksites. SUBJECTS: Two hundred eighty-five male employees, aged 30 to 60, in a wide variety of white-collar and blue-collar job titles. MEASURES: Medical examinations and surveys, which included demographic, health behavior, and job characteristics data. RESULTS: Prospectively, among 189 men, increase in job decision latitude over 3 years was associated with decrease in cigarette smoking, by analysis of covariance, controlling for age, race, education, marital status, and number of children at home (F (8, 180) = 4.37, p = .005). The largest increase in latitude occurred among the 13 men who quit smoking. However, change in job characteristics was not associated with change in overweight or alcohol use. Cross-sectional analyses did not produce consistent associations. CONCLUSIONS: The effectiveness of smoking cessation may be aided by modification of structural features of the work environment, such as job decision latitude. This study is limited by the small number of subjects who were engaged in high risk behaviors.

Adult↗