Biomedical subjects

J R Jennings

Publications and source records attributed to J R Jennings.

At least 37 records · Page 2Linked to original sources

PubMed1997

Exaggerated blood pressure responses during mental stress are associated with enhanced carotid atherosclerosis in middle-aged Finnish men: findings from the Kuopio Ischemic Heart Disease Study.

BACKGROUND: Exaggerated cardiovascular reactivity to mental stress is hypothesized to increase atherosclerotic risk. We examined this hypothesis using cross-sectional data from the Kuopio Ischemic Heart Disease study, a population-based epidemiological sample. METHODS AND RESULTS: 901 Eastern Finnish men from four age cohorts (age, 42 to 60 years) were administered a standardized testing battery to assess cardiovascular reactivity to mental stress. Ultrasound measures of intima-medial thickness (IMT) and plaque height from the common carotid arteries were used as noninvasive markers of atherosclerosis. Diastolic blood pressure (DBP) responses to mental stress were significantly associated with mean IMT (b=.021, P=.006), maximum IMT (b=.026, P=.013), and mean plaque height (b=.017, P=.041). Significant associations were also shown between stress-related systolic blood pressure (SBP) reactivity and mean IMT (b=.0151, P=.042). When examined separately by age, associations with IMT were significant only in the youngest half of the sample (age, 46 and 52 years, n=433; for mean IMT, DBP b=.033, P=.0002, SBP b=.0266, P=.003; for maximum IMT, DBP b=.039, P=.002, SBP b=.032, P=.011). Results remained significant in the younger subjects after adjustment for smoking, lipid profiles, fasting glucose, and resting blood pressure (b=.024, P=.011); results also remained significant in a subgroup of unmedicated younger subjects without symptomatic cardiovascular disease (n=135; for SBP reactivity, b=.031, P=.036; for DBP, b=.037, P=.007). CONCLUSIONS: The tendency to show exaggerated pressor responses to mental stress is a significant independent correlate of atherosclerosis in this population sample of Finnish men. The effect does not appear to be accounted for by the confounding influence of other risk factors or preexisting clinical disease.

Adult↗

PubMed1997

Mnemonic search, but not arithmetic transformation, is associated with psychophysiological inhibition.

The possibility that mnemonic search and arithmetic transformation induce transient heart rate (HR) slowing was studied. Transient HR slowing was assumed to result from the inhibition of premature responding during information processing. Twenty young men performed a 2-step reaction time task. Two precues were followed by a choice cue: 2 additional precues and 1 final choice cue. Choice cues were varied to compare spatial and perceptual-motor processing with mnemonic or arithmetic processing. Cardiac interbeat interval and impedance cardiograph measures were taken beat by beat. The preparation for the respond cue was associated with HR slowing followed by HR speeding associated with response initiation. Mnemonic search induced a transient HR slowing before the speeding initiated by the motor response. Arithmetic transformation did not, but processing of the arithmetic series decreased cue-induced transient HR slowing. Mnemonic search may be associated with a psychophysiological inhibition analagous to that observed in perceptual-motor tasks during response selection.

Adolescent↗

PubMed1997

Aging or disease? Cardiovascular reactivity in Finnish men over the middle years.

Cardiovascular responses to psychological events may mediate the influence of stress on cardiovascular disease. In this study the authors asked whether cardiovascular responses to psychological challenge changed with age and whether such changes were intrinsic to aging or could be attributed to the influence of disease and medications. Cardiovascular reactivity to mental challenge was examined in 902 men ranging in age from 46 to 64 years who participated in the Kuopio Ischemic Heart Disease Risk Factor Study. A battery of 4 tasks was used to induce cardiovascular responses. Current disease status, age, and medication use were entered into hierarchical regression analyses to assess their relation with measures of cardiovascular reactivity. Age and hypertension contributed independent, approximately equal, but small amounts of variance in the cardiac and vascular reactivity indexes. Medications also influenced reactivity independently of age and disease. Performance on the tasks was more consistently altered by age than by disease or medication. Cardiac and vascular reactivity increased with increasing age and the presence of hypertension. The authors conclude that both age and disease state must be considered when examining cardiovascular reactivity as a risk factor for disease.

Aging↗

PubMed1997

Psychological stress and the progression of carotid artery disease.

BACKGROUND: We examined the relation between cardiovascular reactivity (the response of the cardiovascular system to psychological stress) and the severity and progression of carotid atherosclerosis. METHODS: Using duplex ultrasonography, we measured the change in the area of all detectable plaques in the extracranial carotid arteries during 2 years. Cardiovascular reactivity was assessed by measuring changes in hemodynamics during a frustrating cognitive task (the Stroop Color Word Interference Task). Established risk factors for atherosclerosis were measured by interviewing patients, a physical examination, and blood assays for 351 subjects with a wide range of types of atherosclerotic disease. RESULTS: Atherosclerotic plaques were present in the carotid arteries of 273 (78%) subjects. In a forward stepwise multiple regression analysis, it was found that greater age (beta = 0.46), a history of hypertension (beta = 0.20), use of lipid level-lowering agents (beta = 0.18), a longer history of smoking (beta = 0.13), a larger cholesterol:high-density lipoprotein ratio (beta = 0.13), a smaller change in heart rate during the task (beta = -0.12), and a higher resting systolic blood pressure (SBP; beta = 0.11) were associated significantly with a greater plaque area (R2 = 0.35). In 136 untreated subjects who were followed up for 2 years, a greater change in SBP during the task (beta = 0.28), a higher total cholesterol: high-density lipoprotein ratio (beta = 0.23), a shorter resting preejection period (beta = -0.19), and a lower body mass index (beta = -0.17) were significant predictors of the change in atherosclerosis, after controlling for age and initial plaque area in a stepwise multiple regression analysis (R2 = 0.24). CONCLUSIONS: These results support the hypothesis that hemodynamic responses under conditions of mental stress may influence the progression of atherosclerosis.

Adult↗

PubMed1997

Self-reported levels of anxiety do not predict neuropsychological performance in healthy men.

It is widely believed that even mild to moderately severe levels of anxiety have a negative impact on neuropsychological performance. To test that possibility, we used scores from Spielberger's State and Trait Anxiety scales to predict performance on measures of attention, learning, memory, mental flexibility, and eye-hand coordination. Two samples of healthy young and middle-aged men were studied. Sample 1 consisted of 125 university students (M age = 20.37); Sample 2 consisted of 50 men recruited from the community (M age = 40.64). Results of multiple regression analyses revealed no significant associations in either sample, after controlling for age, education, and average alcohol consumption. These findings suggest an absence of relationship between self-reported symptoms of anxiety and neuropsychological function in healthy men.

Journal Article↗

PubMed1996

Hypertension and neuropsychological performance in men: interactive effects of age.

Potentially interactive effects of hypertension and age on the performance of neuropsychological and information processing tests were examined in 123 untreated hypertensive and 50 normotensive men. After covarying education, average alcohol consumption, trait anxiety, and depression scores, results indicated an interaction of age and hypertension. Young hypertensive men (23-40 years) scored significantly worse than young normotensive men on tests of attention/executive function and working memory; middle-aged hypertensive (41-56 years) and normotensive participants were not distinguished by any measures. Hypertensive men performed significantly more poorly than normotensive men on tests of manual dexterity. Results suggest that neuropsychological sequelae of hypertension are more pronounced in young than in middle-aged hypertensive individuals and are independent of various demographic, psychosocial, and alcohol-related factors.

Adult↗

PubMed1996

Phase-sensitive interaction of cardiac and respiratory timing in humans.

We asked whether the heart rate response to respiratory change varied as a function of timing within the cardiac cycle. Respiratory and electrocardiographic data were collected from seven men and seven women during three weekly sessions under conditions of normal and visually paced breathing. Results revealed that, when inspiration began sooner than 500 ms before the subsequent heart beat, inspiration had little effect on the subsequent interbeat interval. However, the timing of the subsequent beat was accelerated when inspiration began later than 450 ms before this heart beat. Similar relationships were observed for expiratory onset. Results were not attributable to volitional control or rate of breathing. The modulation of respiratory sinus arrhythmia by the timing of respiratory events in the cardiac cycle has implications for the role of vagal control in the synchronization of heart rate with respiratory and behavioral actions.

Adult↗

PubMed1996

Does the heart know what the ears hear? A heart rate analysis of auditory selective attention.

Between- and within-channel auditory selective attention were examined by presenting subjects with tone pips randomly to opposite ears; some pips had a slightly different pitch. Subjects were instructed to count rare, deviant tone pips at one ear and ignore all input to the other ear. Heart rate was sampled twice: once for the attended tone pips and once for the nonattended stimulus series. Heart rate responded differently to attended tone pips. While subjects were waiting for the rare stimulus to occur, heart rate slowed until the deviant stimulus was detected, which was followed by heart rate acceleration. Anticipatory heart rate deceleration was largely absent for nonattended series, and rare tone pips presented at the nonattended ear were not followed by acceleratory recovery. All tone pips elicited cardiac cycle time effects, that is, stimuli presented at short delays after the R wave prolonged the concurrent interbeat interval more than stimuli presented later. The cardiac cycle time effect was not altered by stimulus relevance (attended vs. nonattended) or significance (standard vs. rare). These results suggest that all stimuli receive preliminary perceptual analysis, but only attended stimuli are processed for further evaluation.

Acoustic Stimulation↗

PubMed1995

REM sleep enhancement by bupropion in depressed men.

OBJECTIVE: The authors compared the effects of bupropion, fluoxetine, and cognitive behavior therapy on EEG sleep in depressed subjects. METHOD: All-night sleep EEG studies were performed before treatment and after partial or full remission on 18 men with depression diagnosed according to Research Diagnostic Criteria and randomly assigned to treatment with either bupropion (N = 7) or fluoxetine (N = 11). Response to these drugs was measured by changes in Hamilton Depression Rating Scale scores. Pre- and posttreatment EEG sleep study results before and after treatment with cognitive behavior therapy were also available for 18 men matched in age and severity of Hamilton depression scale score, and one-time EEG sleep measures were available for 36 men who were not depressed. RESULTS: REM latency was reduced and REM sleep percent and REM time increased after treatment in the depressed men given bupropion. These effects contrasted with the effects of fluoxetine and cognitive behavior therapy. CONCLUSIONS: This study represents the first report of an antidepressant medication that shortens REM latency and increases REM sleep. If confirmed, this finding may require a revision of our current understanding of the relation among depression, REM sleep, and anti-depressant mechanisms.

Adult↗

PubMed1994

Affect intensity and phasic REM sleep in depressed men before and after treatment with cognitive-behavioral therapy.

This article explored the relationship between daytime affect and REM sleep in 45 depressed men before and after treatment with cognitive-behavioral therapy and in a control group of 43 healthy subjects. The intensity of daytime affect (as measured by the sum of positive and negative affects) in depressed men correlated significantly and positively with phasic REM sleep measures at both pre- and posttreatment. This relationship was not found in healthy control subjects. In depressed men, both affect intensity and phasic REM sleep measures decreased over the course of treatment. The results suggest a relationship between phasic REM sleep and intensity of affect reported by depressed men. On the basis of this preliminary observation, it was hypothesized that abnormalities in phasic REM sleep in depressed patients are related, in part, to fundamental alterations in the intensity of their affective experience.

Adult↗

PubMed1994

A multidimensional measurement model for cardiovascular reactivity: stability and cross-validation in two adult samples.

The factor structure for measures of stress-related cardiovascular reactivity was examined in 2 samples: a university campus employee sample (N = 72) and a sample of young adult twins (N = 113). In both samples, 5 noninvasive cardiovascular measures were monitored during a series of challenging laboratory tasks. We developed a 2-factor model depicting vascular and cardiac influences on responding. With confirmatory factor analysis, this model was shown to be consistent with the data across both samples, across 2 testing sessions, and across 2 sets of tasks. Latent variables measuring cardiac and vascular reactivity were highly reliable on retest as well. Individual differences in cardiovascular reactivity to mental stress may be characterized by a stable, 2-dimensional pattern of response.

Adolescent↗

PubMed1994

Polysomnographic studies of unmedicated depressed men before and after cognitive behavioral therapy.

OBJECTIVE: Differentiation of stable, trait-like characteristics from more episodic or state-dependent disturbances will be helpful in gaining a better understanding of the pathophysiology of depression. However, research in this area has been complicated by artifactual and clinical problems associated with pharmacologic treatment. In this investigation the authors used EEG sleep studies to assess medication-free depressed male patients before and after cognitive behavioral therapy. METHOD: Forty-five male patients with the diagnosis of major depression according to the DSM-III-R criteria and the Research Diagnostic Criteria underwent EEG sleep studies before and after 16 weeks of cognitive behavioral therapy, during which they were free of medication. In addition to the documentation of changes within these patients, the findings were compared with those for 47 healthy subjects, including 15 who were restudied 12-24 months after their baseline assessments. RESULTS: The EEG sleep profiles of the depressed patients showed a significant reduction in REM sleep density after treatment, suggesting "normalization" of an abnormal state-dependent process. By contrast, slow wave sleep and tonic REM measures, including reduced REM latency, were unchanged after treatment. CONCLUSIONS: These findings suggest that early in remission there is disaggregation of irreversible, trait-like correlates of depression (e.g., diminished slow wave sleep and reduced REM latency) from more reversible disturbances (e.g., increased REM density).

Adult↗

PubMed1994

Do depressed men and women respond similarly to cognitive behavior therapy?

OBJECTIVE: A great majority of the evidence pertaining to the effectiveness of the time-limited psychotherapies as treatments of major depression are derived from studies of either predominantly or entirely female subject groups. Depressed men and women differ in a number of important respects that may alter the course of affective disorder, and as a result, they may also differ in their responses to psychotherapy. In this study the outcomes of 40 men and 44 women treated with cognitive behavior therapy were compared. METHOD: The patients were interviewed with the Schedule for Affective Disorders and Schizophrenia and diagnosed according to the Research Diagnostic Criteria and DSM-III-R criteria. Subsequently, they were assessed every other week (with the Hamilton Depression Rating Scale, Beck Depression Inventory, and Global Assessment Scale) during a standardized, time-limited cognitive behavior therapy protocol. The outcomes of the men and women were compared by means of a series of analyses of variance and covariance and survival analyses. RESULTS: There were several significant pretreatment differences, and the men attended significantly fewer therapy sessions than the women. Although the men and women generally had comparable responses, patients with higher pretreatment levels of depressive symptoms, particularly women, had poorer outcomes. CONCLUSIONS: This study provides further evidence of gender-specific differences in depressed patients' symptoms and treatment utilization. Cognitive behavior therapy appears to be a comparably useful outpatient treatment for men and women. However, either more intensive cognitive behavior therapy or alternative methods of treatment may be warranted for patients with more severe syndromes.

Adult↗

PubMed1993

Sexual function in depressed men. Assessment by self-report, behavioral, and nocturnal penile tumescence measures before and after treatment with cognitive behavior therapy.

Clinicians have long associated depression with alterations in sexual function, predominantly loss of sexual interest. In a longitudinal study measuring self-report, behavioral, and nocturnal penile tumescence variables before and after treatment with cognitive behavior therapy in an unmedicated sample of 40 outpatient depressed men, we found, contrary to expectation, that sexual activity per se was not reduced during the depressed state. Rather, loss of sexual interest appeared to be related to the cognitive set of depression, ie, loss of sexual satisfaction that then improved with remission from depression. Depressed men were heterogeneous, however, with respect to sexual behavior, eg, an anxious and more chronically depressed subgroup of men who did not have remissions with cognitive behavior therapy reported increased sexual interest and sexual activity. Also, contrary to expectation, nocturnal penile tumescence abnormalities in depressed men did not reverse when measured in early remission, nor did nocturnal penile tumescence measures correlate significantly with behavioral measures of sexual function. Nocturnal penile tumescence alterations in depression may thus be similar to other persistent electroencephalographic sleep abnormalities seen in depressed patients in remission, in being more trait-like than statelike.

Adult↗

PubMed1993

Correlation of nocturnal penile tumescence and daytime affect intensity in depressed men.

Although depressed patients have been shown to have diminished nocturnal penile tumescence (NPT), there remains considerable variability of NPT in depression. We hypothesized that affective experience during the day accounts for some of this variability. Forty-five depressed men had assessments of affect intensity and affect balance, NPT, and daytime sexual function, both before and after treatment with Beck's cognitive behavior therapy (CBT). Forty-three normal control subjects were studied for comparison. Daytime affect intensity in depressed men, but not in control subjects, correlated significantly and positively with measures of NPT duration and rigidity both before and after treatment, regardless of the adequacy of daytime sexual function. When the effect of daytime affect on REM activity was controlled, the observed correlations became nonsignificant at pretreatment, but remained significant at posttreatment. Neuropharmacologically mediated changes in arousal responsivity associated with depression may underlie the observed relation between daytime affect intensity, rapid eye movement activity, and NPT.

Adult↗

PubMed1993

How are tonic and phasic cardiovascular changes related to central motor command?

We examined the influence of central motor command on heart rate, respiration, and peripheral vascular activity. Central command was enhanced or reduced using tendon vibration. Muscle tension was held constant permitting the examination of variation in central command. Experiment 1 demonstrated in 13 college-aged males an enhancement of heart rate and vascular responses to an isometric, extensor contraction when vibration of the flexor tendon was added. Experiment 2 asked whether changes in central command interacted with phasic cardiovascular changes such as stimulus-linked anticipatory cardiac deceleration. Twenty college-aged males performed either an isometric flexor or extensor contraction with or without flexor tendon vibration. As expected, vibration enhanced cardiovascular change with extensor contraction more than with flexor contraction. Relative to control contractions, however, the flexor change was not an absolute decrease in cardiovascular change. More importantly, tendon vibration failed to alter phasic cardiovascular changes. Force and central commands for force induce cardiovascular change, but this change seems independent of phasic changes induced by the anticipation and processing of environmental stimuli.

Adolescent↗

PubMed1993

Stability of cardiac impedance measures: aortic opening (B-point) detection and scoring.

The accurate assessment of cardiac stroke volume measured by impedance cardiography depends on the reliable measurement of dZ/dtmax and the accurate detection of the relevant points on the impedance cardiogram. In one study, impedance cardiograms were collected for 75 subjects during resting conditions and during four psychologically challenging tasks, in two identical testing sessions. The reliability of stroke volumes calculated from dZ/dtmax measured from the electrical baseline and from the dZ/dt B-point on the waveforms were assessed for the two testing sessions. Consistently higher (but not statistically different) test-retest correlations were observed for the measures calculated using values of dZ/dtmax measured from the B-point. In a second study, dZ/dt waveforms with no B-point reversal from 21 subjects were scored using two alternative B-point detection algorithms: the reversal of the second derivative of delta Z and the peak of the third derivative of delta Z. Both algorithms demonstrated high reliability compared with an expert human operator. The reversal on the second derivative may better locate an inflection point on the dZ/dt signal and the third derivative may provide a good B-point estimation in the absence of any inflection point.

Adult↗

PubMed1993

Age and sleep modify finger temperature responses to facial cooling.

BACKGROUND: The increased incidence of hypothermia with age suggests that healthy 80-year-olds might show impaired responsivity to transient, localized thermal stimulation. Such a deficit might be particularly clear during sleep, when behavioral thermoregulation is less likely. METHODS: We examined finger temperature cooling in response to local cooling of the face--a response presumed to be centrally mediated. Nineteen healthy 80-year-olds (12 female) and twenty-seven 20-year-olds (10 female) were exposed to repetitive 20-minute cooling and rewarming cycles across a night of sleep deprivation and a night of sleep occurring three nights later. We sought to determine whether thermal responsivity was altered by age and sleep, but by design avoided inducing core temperature hypothermia. RESULTS: In response to facial cooling during sleep deprivation, finger temperature decreased significantly more in the young than in old. This suggested relatively greater heat retention in the young. During non-REM sleep the thermal responsivity of both groups decreased and age-related differences were no longer present. Changes in core temperature induced by the stimulation were minimal. CONCLUSIONS: The results suggest that the capability of retaining heat via peripheral vasoconstriction while awake decreases with age. Despite this vulnerability, responsivity during non-REM sleep as well as average core temperature were comparable between age groups.

Adult↗