Major depressive disorder at adolescent age is associated with impaired cardiovascular autonomic regulation and vasculature functioning

Cardiovascular adverse complications represent a risk factor for increased cardiovascular morbidity and mortality in patients with major depressive disorder (MDD). However, there is little knowledge of adolescent MDD. We aimed to study complex cardiovascular autonomic regulation and early atherosclerotic damage with a focus on an analysis of heart rate variability (HRV), blood pressure variability (BPV), systolic time intervals, and measures of early atherosclerotic changes in adolescent MDD. Ninety depressive adolescents (34 boys, age 15.8 ± 1.3 yrs.) and 90 age-/gender-matched controls were examined. Evaluated parameters: HRV - time and spectral parameters, BPV - mean, systolic, and diastolic blood pressure, spectral systolic parameters; haemodynamic indices - stroke volume, cardiac output, total peripheral resistance, systolic time intervals - left ventricular ejection time, pre-ejection period; atherosclerotic indices - ankle-brachial index (ABI), pulse wave velocity, brachial-ankle pulse wave velocity, cardio-ankle vascular index; growth factors - epidermal growth factor (EGF), vascular endothelial growth factor associated with monocyte chemoattractant protein-1. Our results showed that the MDD group had significantly reduced HRV and higher BPV measures, shortened systolic time intervals, lower ABI, and higher EGF compared to controls. Concluding, our study revealed that adolescent MDD is associated with cardiovascular dysregulation and early vasculature dysfunction as preclinical markers of higher risk for cardiovascular morbidity, thus adolescence seems to represent an important age period for early diagnosis and prevention of later MDD-linked cardiovascular diseases manifesting in adulthood.

Exhausted Heart Rate Responses to Repeated Psychological Stress in Women With Major Depressive Disorder

Past research links depression and blunted cardiac vagal reactivity to chronic stress. Yet, to our knowledge no experiment investigates heart rate (variability) responses to a repeated laboratory stressor in patients with depression. Repeated exposure may provide valuable information on stress reactivity in depression. Fifty-nine women (30 inpatients diagnosed with depression and 29 matched controls) underwent two consecutive runs of a mental arithmetic stress paradigm consisting of one baseline and two exposures to control, stress, and recovery phases of 5 min each, in a case-control design. Subjective stress and electrocardiography were recorded. Variance of heart rate (HR) and root mean square of successive RR interval differences (RMSSD) were analyzed using linear mixed models. Overall, physiological parameters (HR and RMSSD) and subjective stress showed a strong group effect (all p < 0.001). In both groups, subjective stress and HR increased in response to stress, but the subjective stress levels of patients with depression did not return to baseline levels after the first stressor and for the remainder of the experiment (all p < 0.004 compared to baseline). Patients' HR reactivity responded oppositely: while HR recovered after the first stress exposure, no reactivity was observed in response to the second exposure. These findings may suggest that the often-reported blunted HR/HRV response to stressors results from exhaustion rather than an incapacity to react to stress. The altered HR reactivity could indicate allostatic (over-) load in depression.

Short-term cerebral blood flow variability in major depressive disorder

BACKGROUND

Previous research has documented reduced heart rate and blood pressure variability in major depressive disorder (MDD), suggesting a limited capacity for cardiovascular regulation and diminished homeostatic resources in the disorder. This study aimed to complement this knowledge by investigating short-term cerebral blood flow (CBF) variability in MDD.

METHODS

Using transcranial Doppler sonography, blood flow velocities in the middle cerebral arteries of both hemispheres were recorded in 35 MDD patients and 35 healthy controls, at rest and during serial subtraction task-induced mental stress. CBF variability was represented by the root mean square of successive differences (RMSSD) in the beat-to-beat mean, systolic and diastolic flow velocity.

RESULTS

Patients, as compared to controls, exhibited smaller mean and diastolic blood flow variability in MCA both at rest and during mental stress. Mean, systolic and diastolic blood flow variability were greater during the task than at rest. CBF variability did not differ between patient subgroups composed according to medication use.

LIMITATIONS

Potential effects of blood pressure and respiration on CBF variability could not be investigated.

CONCLUSIONS

The study revealed evidence of reduced short-term CBF variability in MDD. The task-induced CBF variability increase may be ascribed to neural activity associated with arithmetic processing. Lower blood pressure variability and deficient autonomic cardiovascular control may contribute to the reduction of short-term CBF variability seen in MDD. Short-term CBF variability reflects preserved interplay of regulatory mechanisms ensuring optimal blood and energy supply to the brain. Therefore, the results suggest impaired cerebroprotective mechanisms, associated with suboptimal cerebral performance.

The cardiac, vasomotor, and myocardial branches of the baroreflex in fibromyalgia: Associations with pain, affective impairments, sleep problems, and fatigue

This study investigated the cardiac, vasomotor, and myocardial branches of the baroreflex in fibromyalgia using the spontaneous sequence method. Systolic blood pressure (SBP), interbeat interval (IBI), stroke volume (SV), pre-ejection period (PEP), and total peripheral resistance (TPR) were continuously recorded in 40 fibromyalgia patients and 30 healthy individuals during a cold pressor test and a mental arithmetic task. Sequences of covariation between SBP and IBI (cardiac branch), SV and PEP (myocardial branch), and TPR (vasomotor branch) were identified. Baroreflex sensitivity (BRS) was represented by the slope of the regression line between values in the sequences; baroreflex effectiveness (BEI) was indexed by the proportion of progressive SBP changes that elicited reflex responses. Patients exhibited lower BRS in the three branches, lower BEI in the cardiac and vasomotor branches, and reduced reactivity in cardiac BRS and BEI, SBP, IBI, SV, and PEP. Moreover, BRS and BEI were inversely related to clinical pain, cold pressor pain, depression, trait anxiety, sleep problems, and fatigue. Reduced function of the three baroreflex branches implies diminished resources for autonomic inotropic, chronotropic, and vascular regulation in fibromyalgia. Blunted stress reactivity indicates a limited capacity for autonomic cardiovascular adjustment to situational requirements. The associations of BRS and BEI with pain perception may reflect the antinociceptive effects arising from baroreceptor afferents, where reduced baroreflex function may contribute to the hyperalgesia characterizing fibromyalgia. The associations with affective impairments, sleep problems, and fatigue suggest that baroreflex dysfunctions are also involved in the secondary symptoms of the disorder.