PubMed Health⌕ Search

Biomedical subjects

M F Muldoon

Publications and source records attributed to M F Muldoon.

At least 55 records · Page 3Linked to original sources
PubMed1993

Relationship of cardiovascular reactivity and anger expression to serum lipid concentrations in healthy young men.

The relationship between behaviorally evoked cardiovascular reactivity, preferred mode of anger expression, and serum lipid concentrations was examined in 63 healthy, young adult males. Subjects derived from three studies, each evaluating cardiovascular response to laboratory stressors. All participants completed the Spielberger Anger Expression Scale and provided fasting blood samples for lipid determinations. A significant negative correlation, calculated by meta-analytic procedures, was noted between a baseline-free measure of heart rate reactivity and high density lipoprotein-cholesterol (HDL-C) concentrations (r = -0.26, p = 0.05). However, the previously reported relationship between cardiovascular reactivity and elevated total serum cholesterol (TSC) was not found. Additionally, men scoring high on a self-report measure of the tendency to express anger outwardly had significantly higher HDL-C concentrations than men scoring low on this measure (r = 0.30, p = 0.02); when subjects were stratified by level of cardiovascular reactivity, this relationship was apparent only among those showing the greatest magnitude of heart rate and blood pressure responses to acute mental stress.

Adolescent↗
PubMed1993

Family history studies in hypertension research. Review of the literature.

Reviewed in the present article are over 150 family history studies of essential hypertension. By comparing normotensive individuals with and without a family history of hypertension, these investigations seek to identify potential pathophysiologic factors that predate the development of high blood pressure. The research literatures summarized here represent four general areas: 1) cellular salt transport mechanisms, 2) dietary sodium, intravascular volume, and renal function, 3) cardiovascular morphology and physiology, and 4) cardiovascular reactivity. There is strong evidence of early cardiac morphologic changes (greater left ventricular wall thickness and mass) and altered peripheral vascular capacity and responsivity to pressor stimuli among normotensive individuals with a positive family history. In contrast, cardiac output, sodium consumption, intravascular volume, and cardiovascular responses to isometric exercise and standing do not differ in persons with and without a family history of hypertension. Other articles are characterized by inconsistent results, which may be a reflection of the heterogeneity of essential hypertension, but also may be due to methodological weaknesses. The latter include failure to confirm the blood pressure status of ostensibly hypertensive or normotensive family members and the use of relatively weak study designs (eg, where a positive history is defined by a single, hypertensive first-degree relative).

Biological Transport↗
PubMed1992

Acute cholesterol responses to mental stress and change in posture.

BACKGROUND: Serum lipid levels vary widely within individuals, but the causes of these fluctuations are poorly understood. One area of research concerns elevations in cholesterol concentration in response to emotional stress. In a laboratory-based experiment, we compared the effects of acute mental stress and postural change (standing) on serum cholesterol concentration. In addition, plasma volume was indirectly monitored to determine whether cholesterol changes with mental stress, if present, were a function of hemoconcentration. METHODS: Twenty-six men attended two laboratory sessions, each consisting of baseline (30 minutes), task (20 minutes), and recovery (30 minutes) periods. Subjects rested in the supine position during the baseline and recovery periods. During the task period of one session, subjects performed a mental task (Stroop test and mental arithmetic); during the other session, the subjects stood for the task period. RESULTS: Both mental stress and standing elicited significant elevations in heart rate, blood pressure, and plasma catecholamine concentrations, relative to the baseline and recovery periods. Both the mental and orthostatic tasks also significantly increased serum cholesterol concentration (by 0.10 and 0.57 mmol/L [3.7 and 21.9 mg/dL], respectively), as well as hemoglobin level and hematocrit. Cholesterol elevations with standing were reversible, while those resulting from mental stress persisted through the recovery period. When values were corrected for concomitant hemoconcentration, no net change in serum cholesterol level occurred during either task. CONCLUSIONS: Acute mental stress can produce rapid elevations in serum cholesterol concentration. It can also increase hemoglobin concentration and hematocrit (ie, reduce plasma volume). Therefore, increases in serum cholesterol level after acute mental stress are analogous to those with standing and may reflect hemoconcentration rather than altered lipoprotein metabolism.

Adolescent↗
PubMed1991

Neuropsychological correlates of hypertension: review and methodologic considerations.

Essential hypertension is a chronic disorder having many potential physical and behavioral sequelae. This article evaluates the impact of hypertension on neuropsychological test performance. First, cross-sectional and longitudinal studies that examine the neuropsychological correlates of hypertension are reviewed. In general, hypertensives are found to perform more poorly than normotensives, particularly on tests of memory, attention, and abstract reasoning, and less consistently on tests of perception, constructional ability, mental flexibility, and psychomotor speed. Next, the influence of variables that may moderate relationships between hypertension and neuropsychological performance--such as age, education, and medication usage--are examined. Finally, potential mechanisms, both physiological and psychological, underlying associations between hypertension and neuropsychological performance are discussed.

Brain↗
PubMed1991

Neurobehavioral effects of antihypertensive medications.

Although millions of hypertensive individuals receive chronic treatment with antihypertensive medication, the effect on the central nervous system by these drugs is poorly understood. Such treatment, while generally well tolerated, frequently produces symptoms of drowsiness, weakness, altered memory and impaired concentration. In addition to subjective evidence derived from patient reports, a large number of investigations have now been published which attempt to objectively assess the influence of antihypertensive medication on behavioral or cognitive performance. This paper summarizes and critically evaluates experimental studies of the effect of antihypertensive medication on subjects' performance of neuropsychological tasks and reviews the pharmacologic mechanisms by which these drugs may affect behavior. The literature is incomplete in its assessment of all domains of neuropsychological performance and all drug classes, and methodologic deficiencies are common. Nonetheless, the consensus of all studies and the findings of well-designed studies in particular do not identify any notable areas of performance impairment in patients receiving antihypertensive medication. Moreover, results suggest that, in certain instances, drug treatment may even enhance performance. In light of the limitations of the literature, however, an adequate understanding of the effects of antihypertensive therapy on behavioral functioning awaits completion of large, well-designed investigations including all major drug classes and thorough neurobehavioral assessments.

Adrenergic beta-Antagonists↗
PubMed1991

Neither awake nor sleep blood pressures better predict target-organ effect.

We sought to assess the strengths of commonly used ambulatory blood pressure (ABP) parameters as predictors of transmitral flow/velocity ratio (E/A) and the dimensions that govern the left ventricular (LV) mass index. ABP, E/A, and LV dimensions were assessed in 47 subjects, with inclusion of 45 in the final data analysis. The results of four weekly (96 h total) ABP studies were averaged for each subject. No single ABP parameter immerged as a "best predictor." Furthermore, casual blood pressures taken at the beginning of the echo examination had predictive strength for LV mass which was similar to that of the ambulatory data. In the present study, neither awake nor sleep ABPs differed significantly with respect to correlations with indices of LV structure.

Adult↗
PubMed1990

Lowering cholesterol concentrations and mortality: a quantitative review of primary prevention trials.

OBJECTIVE: To determine the effects of lowering cholesterol concentrations on total and cause specific mortality in randomised primary prevention trials. DESIGN: Qualitative (meta-analytic) evaluation of total mortality from coronary heart disease, cancer, and causes not related to illness in six primary prevention trials of cholesterol reduction (mean duration of treatment 4.8 years). PATIENTS: 24,847 Male participants; mean age 47.5 years. MAIN OUTCOME MEASURES: Total and cause specific mortalities. RESULTS: Follow up periods totalled 119,000 person years, during which 1147 deaths occurred. Mortality from coronary heart disease tended to be lower in men receiving interventions to reduce cholesterol concentrations compared with mortality in control subjects (p = 0.06), although total mortality was not affected by treatment. No consistent relation was found between reduction of cholesterol concentrations and mortality from cancer, but there was a significant increase in deaths not related to illness (deaths from accidents, suicide, or violence) in groups receiving treatment to lower cholesterol concentrations relative to controls (p = 0.004). When drug trials were analysed separately the treatment was found to reduce mortality from coronary heart disease significantly (p = 0.04). CONCLUSIONS: The association between reduction of cholesterol concentrations and deaths not related to illness warrants further investigation. Additionally, the failure of cholesterol lowering to affect overall survival justifies a more cautious appraisal of the probable benefits of reducing cholesterol concentrations in the general population.

Aged↗
PubMedDate not supplied

Neuropsychological consequences of antihypertensive medication use.

A growing proportion of the general population is being prescribed antihypertensive medications for the long-term treatment of essential hypertension. Untreated hypertensive individuals exhibit some neuropsychological performance decrements, and numerous researchers have sought to determine whether drug therapy for hypertension worsens, improves, or leaves unaltered objectively measured cognitive skills. These issues may be especially important in the elderly, among whom both high blood pressure and compromised cognitive function are common. In this review, we collate the findings of more than 50 clinical studies according to class of antihypertensive medication studied and domains of neuropsychological performance assessed. Special attention is given to investigations of elderly subjects, and a critical summary is provided.

Antihypertensive Agents↗
PubMedDate not supplied

Lymphocyte subset and cellular immune responses to a brief experimental stressor.

To evaluate effects of acute mental stress on aspects of cellular immunity, lymphocyte populations and phytohemagglutinin (PHA)-stimulated T-cell mitogenesis were measured in 33 healthy young men, both before and immediately following subjects' performance of a frustrating, 21-minute laboratory task (Stroop test). Relative to baseline evaluations, post-task measurements showed a significant reduction in mitogenesis and alterations in various circulating lymphocyte populations; the latter included a diminished T-helper/T-suppressor cell ratio and an elevation in the number of natural killer cells. Eleven subjects assigned to a control (unstressed) condition exhibited no changes in lymphocyte populations, but did show an increase in T-cell proliferation, compared with pretask measurements.

Adult↗
PubMedDate not supplied

Blood platelet responsivity to acute mental stress.

To evaluate the effects of mental stress on blood platelet activity, platelet secretion and aggregation were measured in 40 healthy young men, assigned in a 3:1 ratio to an experimental and control condition. After a baseline period, experimental subjects participated in a 21-minute, frustrating computer task (the Stroop test), while control subjects remained seated quietly for the same duration. Blood was drawn from all subjects immediately before and after the task period for assessment of platelet activity (secretion of ATP and aggregation in response to 5 and 20 microM ADP). Heart rate and blood pressure were also assessed at baseline and throughout the task period. Results indicated that measures of platelet secretion, heart rate, and blood pressure rose significantly from baseline to posttask assessments in subjects exposed to the experimental stressor (p < .05), but not among controls. These findings are consistent with the hypothesis that stress may potentiate coronary disease pathogenesis, in part, via activation of blood platelets and their associated effects on coronary artery occlusion and/or constriction.

Adenosine Triphosphate↗
PubMedDate not supplied

Cardiovascular reactivity and the course of immune response to an acute psychological stressor.

This study evaluated the temporal nature of cellular immune responses, as well as the effects of cardiovascular reactivity on immune responses after exposure to an acute psychological stressor. Lymphocyte subsets and lymphocyte proliferative response to phytohemagglutinin were assessed at baseline and at 5 and 21 minutes after stressor onset in the experimental group and at the same time points in a nonstressor control group. By 5 minutes after stressor onset, the number of CD8 suppressor/cytotoxic T and CD16/56 natural killer cells increased and proliferative response to phytohemagglutinin decreased. These changes were maintained at 21 minutes. Those subjects showing the greatest cardiovascular reactivity had the largest immune alterations. These data did not indicate that gender significantly moderated immune responses. Results are consistent with the hypothesis that sympathetic activation mediates stressor-induced quantitative alterations of peripheral blood lymphocyte subpopulations and nonspecific mitogen stimulated proliferation.

Adolescent↗