[Show abstract][Hide abstract] ABSTRACT: The present study examines a measure of cardiac autonomic function, the heart rate variability (HRV), in a group of depressed elderly. Cardiac autonomic abnormalities have been implicated as a potential mediator of cardiovascular events and sudden death in depression. Because aging is associated with decreased cardiac vagal activity, it is possible that autonomic abnormalities are even more pronounced in the older depressed patients.
Cross-sectional comparison between those with or without depression. The groups were compared using the Wilcoxon matched-pair sign-rank test. Setting: Advanced Center for Interventions and Services Research for Late-Life Mood Disorders at University of Pittsburgh Medical Center.
Fifty-three patients with major depression (mean age: 73.3; SD: 7.4; range: 60-93) and an equal number of age and gender-matched subjects as a comparison group.
Time domain and frequency domain measures of HRV.
The groups did not differ in any of the time domain or frequency domain measures of HRV. As expected, subjects without depression displayed decreasing cardiac vagal function with aging (Spearman correlation coefficient r(s) = -0.33, p = 0.02). However, there was no significant change in vagal function with age in the depressed (r = 0.12, p= 0.38). Post-hoc analysis using Fisher's z(r) transformation revealed that the relationship between age and cardiac vagal function was significantly different between the groups (z = 2.32, p = 0.02).
Our findings suggest that age has differential influence on vagal function in individuals with and without depression, a difference with implications for cardiovascular disease risk in depression. Prospective studies of cardiac vagal activity in depressed patients with or without preexisting cardiac disease in different age groups are needed to replicate and extend these findings.
The American journal of geriatric psychiatry: official journal of the American Association for Geriatric Psychiatry 12/2008; 16(11):861-6. · 3.35 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to evaluate cross-sectional relationships among symptoms of psychological stress, sleep, and physiological arousal during non-rapid eye movement (NREM) sleep in a sample of 30 patients with chronic, primary insomnia (mean age, 30.2 years, 60% female). Study measures included indexes of subjective stress, visually scored sleep, and physiological arousal during NREM sleep: quantitative electroencephalogram (QEEG) and quantitative electrocardiogram (QEKG) measures. Psychological stress was more strongly related to indexes of physiological arousal during NREM sleep than to visually scored measures of sleep. Higher levels of perceived stress were associated with decreased EEG delta power (rho = -0.50, p < .01) and increased EEG beta power (rho = 0.38, p < .05). Increased frequency of stress-related avoidance behaviors was associated with decreased EKG high-frequency power (rho = -0.46, p < .05). Although QEEG measures were significantly correlated with sleep maintenance (QEEG delta power rho = 0.45, p < .01; QEEG beta power rho = -0.54, p < .01) and time spent in delta sleep (QEEG delta power rho = 0.65, p < .001; QEEG beta power rho = -0.65, p < .001), QEKG measures were unrelated to visually scored measures of sleep. Perceived stress and stress-related avoidance behaviors were associated with multiple indexes of physiological arousal during NREM sleep in patients with chronic, primary insomnia.
Behavioral Sleep Medicine 01/2007; 5(3):178-93. · 1.13 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Although stress can elicit profound and lasting effects on sleep, the pathways whereby stress affects sleep are not well understood. In this study, we used autoregressive spectral analysis of the electrocardiogram (EKG) interbeat interval sequence to characterize stress-related changes in heart rate variability during sleep in 59 healthy men and women.
Participants (N = 59) were randomly assigned to a control or stress condition, in which a standard speech task paradigm was used to elicit acute stress in the immediate presleep period. EKG was collected throughout the night. The high frequency component (0.15-0.4 Hz Eq) was used to index parasympathetic modulation, and the ratio of low to high frequency power (0.04-0.15 Hz Eq/0.15-0.4 Hz Eq) of heart rate variability was used to index sympathovagal balance.
Acute psychophysiological stress was associated with decreased levels of parasympathetic modulation during nonrapid eye movement (NREM) and rapid eye movement sleep and increased levels of sympathovagal balance during NREM sleep. Parasympathetic modulation increased across successive NREM cycles in the control group; these increases were blunted in the stress group and remained essentially unchanged across successive NREM periods. Higher levels of sympathovagal balance during NREM sleep were associated with poorer sleep maintenance and lower delta activity.
Changes in heart rate variability associated with acute stress may represent one pathway to disturbed sleep. Stress-related changes in heart rate variability during sleep may also be important in association with chronic stressors, which are associated with significant morbidity and increased risk for mortality.
Psychosomatic Medicine 01/2004; 66(1):56-62. · 4.08 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Chemotherapy-induced nausea has been associated with a time-related decrease in cardiac parasympathetic activity. We tested the hypothesis that a time-related decrease in cardiac parasympathetic activity would also be associated with nausea and other motion sickness symptoms during illusory self-motion (vection). Fifty-nine participants (aged 18-34 years: 25 male) were exposed to a rotating optokinetic drum to induce vection. Symptoms of motion sickness and an estimate of cardiac parasympathetic activity (respiratory sinus arrhythmia; RSA) were obtained at baseline and throughout a drum-rotation period. As expected, motion sickness symptoms increased and RSA decreased over time during drum rotation. Moreover, greater decreases in RSA over time correlated with greater motion sickness severity. These results suggest that a time-related decrease in cardiac parasympathetic activity may be an important correlate of nausea and motion sickness across different evocative contexts.