Adolescent vulnerability to cardiovascular consequences of chronic emotional stress: Review and perspectives for future research

Psychosocial and environmental risk factors of obesity and hypertension in children and adolescents-a literature overview

Childhood obesity has become a worldwide epidemic in the 21st century. Its treatment is challenging and often ineffective, among others due to complex, often not obvious causes. Awareness of the existence and meaning of psychosocial and environmental risk factors seems to be an essential element in the prevention and treatment of obesity and its complications, especially arterial hypertension. In this review, we will discuss the role of that risk factors linking obesity and increased cardiovascular disorders including the role of nutritional factors (including the role of unhealthy diet, inadequate hydration), unhealthy behaviors (e.g. smoking, alcohol and drugs, sedentary behavior, low physical activity, disrupted circadian rhythms, sleep disorders, screen exposure), unfavorable social factors (such as dysfunctional family, bullying, chronic stress, mood disorders, depression, urbanization, noise, and environmental pollution), and finally differences in cardiovascular risk in girls and boys.

Vulnerability and resilience to cardiovascular and neuroendocrine effects of stress in adult rats with historical of chronic stress during adolescence

AIMS

This study investigated the influence of exposure to stress during adolescence in autonomic, cardiovascular, neuroendocrine and somatic changes evoked by chronic stress in adult rats.

MAIN METHODS

Animals were subjected to a 10-days protocol of repeated restraint stress (RRS, habituating) or chronic variable stress (CVS, non-habituating) during adolescence, adulthood, or repeated exposure to either RRS or CVS in adolescence and adulthood (adolescence+adulthood group). The trials to measure autonomic, cardiovascular, neuroendocrine and somatic changes in all experimental groups were performed in adulthood.

KEY FINDINGS

CVS increased basal circulating corticosterone levels and caused adrenal hypertrophy in the adolescence+adulthood group, an effect not identified in animals subjected to this stressor only in adulthood or adolescence. CVS also caused a sympathetically-mediated resting tachycardia in the adulthood group. This effect of CVS was not identified in the adolescence+adulthood group once the increased cardiac sympathetic activity was buffered by a decrease in intrinsic heart rate in these animals. Moreover, the impairment in baroreflex function observed in the adulthood group subjected to CVS was shifted to an improvement in animals subjected to repeated exposure to this stressor during adolescence and adulthood. The RRS in the adolescence+adulthood group caused a sympathetically-mediated resting tachycardia, which was not observed in the adulthood group.

SIGNIFICANCE

Our findings suggest that enduring effects of adverse events during adolescence included a vulnerability to neuroendocrine changes and a resilience to autonomic and cardiovascular dysfunctions caused by the CVS. Furthermore, results of RRS indicated a vulnerability to cardiovascular and autonomic changes evoked by homotypic stressors.

Negative Impact of the UEFA European Soccer Championship on Central Hemodynamics and Arterial Stiffness: A Multicenter Study

(1) Background: watching sporting events may trigger cardiovascular events by elevating emotional stress levels. The underlying reasons and specific populations at risk are not well defined. (2) Methods: we conducted a multicenter prospective trial at three German sites during the UEFA Soccer EC 2012 and 2021 comprising 52 healthy participants (noCVD) and 18 patients hospitalized with cardiovascular disease (CVD). Subjects were studied during matches of the German national team (GP) as well as corresponding matches without German participation (noGP). Peripheral and central blood pressure (BP) and parameters of arterial stiffness were measured (Mobil-O-Graph™, I.E.M., Stolberg, Germany) before, during, and after the matches. (3) Results: in terms of CVD, peripheral as well as central BP and heart rate increased significantly during GP as well as noGP matches and remained elevated beyond the end of the matches. Likewise, arterial stiffness parameters and vascular resistance were higher during the matches and remained elevated after the matches. No consistent significant differences were found between GP and noGP matches. (4) Conclusions: this is the first study on real-life changes in hemodynamics during sport-associated emotional stress, with comparison between noCVD and CVD. We found that alterations were profound in CVD and remained elevated even after the matches.

Altered Development of Prefrontal GABAergic Functions and Anxiety-like Behavior in Adolescent Offspring Induced by Prenatal Stress

Maternal stress can afflict fetal brain development, putting the offspring at risk of cognitive deficits, including anxiety. The prefrontal cortex (PFC), a protracted maturing region, is notably affected by prenatal stress (PS). However, it remains unclear how PS interferes with the maturation of the GABAergic system, considering its functional adjustment in the PFC during adolescence. The present study thus investigated the long-lasting consequences of PS on the prefrontal GABAergic functions of adolescent offspring. Pregnant Sprague–Dawley rats were divided into controls and the PS group, which underwent restraint stress during the last week of gestation. Male pups from postnatal days (PND) 40–42 were submitted to the elevated plus maze (EPM) test. Proteins essentially involved in GABAergic signaling were then examined in PFC tissues, including the K+-Cl− cotransporter (KCC2), Na+-K+-Cl− cotransporter (NKCC1), α1 and α5 subunits of GABA type A receptors (GABAA receptors), and parvalbumin (PV), along with cAMP response element-binding protein phosphorylation (pCREB), which reacts in the plasticity regulation of PV-positive interneurons. The results revealed that the higher anxiety-like behavior of PS adolescent rats concurred with the significant decreases of the KCC2 and α1 subunits, with PV- and pCREB-lowered levels. The findings suggested that PS disrupts the continuance of PFC maturity by reducing the essential elements of GABAergic functions. These changes likely underlie the anxiety emerging in adolescence, possibly progressing to mental disorders.

Does positive affect mediate the association of multimorbidity on depressive symptoms?

Objectives Multimorbidity poses various challenges, and previous research has indicated a causal relation with depression. As multimorbidity is not curable, the underlying mechanisms are of great interest. Positive affect is a major resource for coping with chronic conditions and for the prevention of depression. Long-term multimorbidity, however, may deplete positive affect. The purpose of this paper is to investigate the role of positive affect in the association between multimorbidity and depressive symptoms.Method We used four consecutive waves (2008, 2011, 2014, 2017) of the nationally representative German Ageing Survey (DEAS) with a total of 1,558 older adults aged 40 and over. To account for time-varying confounding, exposure-induced mediator-outcome confounding, and reciprocities, we applied the mediational g-formula with inverse-probability weighting techniques. We also tested for exposure-mediator interaction to adjust for differences in mediation across the duration of multimorbidity.Results We confirmed a positive longitudinal relation between multimorbidity and depressive symptoms, both of which were negatively associated with while positive affect. The model without interaction indicated a share mediated of ca. 18.3% on the total effect of multimorbidity on depressive symptoms. Addition of interaction led to substantial differences for multimorbidity duration and levels of positive affect. Associations for long-term multimorbidity (at least two survey waves) were more substantial, and the share mediated doubled (>40%). Additionally, the direct effect of multimorbidity on depressive symptoms diminished for short-term multimorbidity.Conclusion Strengthening positive affect could reduce depressive symptoms in those facing multimorbidity. This study also discusses methodological challenges in performing longitudinal mediation analysis. We advise researchers to consider the mediational g-formula and exposure-mediator interaction.

The effect of depressive-like behavior in pregnant rat dams on the cardiovascular system in their offspring

Maternal depression during pregnancy affects 18-20% of women and is often associated with comorbidities and adverse health outcomes for the offspring. We have previously reported on neurodevelopmental delays in a rat model of maternal depression during pregnancy; current report presents echocardiographic (ECHO) data derived from the same experiment and focuses on cardiovascular response in the offspring to maternal perinatal depression. Rat dams were exposed to chronic mild stress (CMS) with repeated restraint before pregnancy. Cardiac functions were assessed in the 35-day-old offspring, derived from control (CO, n = 11) and stress-exposed dams (SO, n = 16), using echocardiography (ECHO). The expression of cardiac failure marker - B-type natriuretic peptide (BNP) was measured in the myocardium by RT-PCR. ECHO analysis revealed a significant increase in heart rate (HR) and impairment of left ventricular diastolic function parameters. Importantly, a significant increase in mitral valve flow E wave velocity (MVE) and a decrease of mitral valve deceleration time of E wave (MV DT) were observed in SO. The expression of BNP was significantly higher in SO. These results suggest that maternal depression during pregnancy impacts offspring cardiovascular function, and specifically the diastolic cardiac functions of the left ventricle.

Cardiovascular outcomes related to social defeat stress: New insights from resilient and susceptible rats

Stress exposure is an important risk factor for psychiatric and cardiovascular disorders. Two phenotypes related to coping with stress can be observed in rodents that experience chronic social defeat stress (SDS): susceptible, showing social avoidance and behavioral changes related to depression, and resilient, showing none of these alterations. Moreover, a strong correlation exists between depression and the development of or mortality due to cardiovascular diseases. Nevertheless, little is known about cardiovascular alterations related to SDS exposure in those phenotypes or their correlation with depressive-like behaviors. Using a chronic SDS protocol followed by the social interaction test, we identified Wistar rats as resilient or susceptible to SDS. Susceptible animals showed increased depressive-like behaviors with resting tachycardia and decreased heart rate variability (HRV) due to increased sympathetic tone in the heart and a less effective baroreflex. In contrast, resilient rats were protected from these alterations by increased vagal tone, resulting in greater HRV values. To our knowledge, our study is the first to indicate that harmful cardiovascular outcomes are related to depressive-like behaviors in susceptible rats and to suggest a mechanism by which resilient rats are protected from these changes. Also, our results suggest that enhanced HRV and vagal tone may be an important trait in resilient individuals.

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Cardiovascular alterations are correlated to depressive-like behaviors.

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Susceptible rats show increased sympathetic tone to the heart and lower HRV.

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Baroreflex effectiveness in susceptible rats is impaired.

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Resilient rats show an increased vagal tone to the heart and greater values of HRV.

Social Defeat Stress, Sex, and Addiction-Like Behaviors

Social confrontation is a form of social interaction in animals where two conspecific individuals confront each other in dispute over territory, during the formation of hierarchies, and during breeding seasons. Typically, a social confrontation involves a prevailing individual and a yielding individual. The prevailing individual often exhibits aggressive postures and launches attacks, whereas the yielding individual often adopts postures of defeat. The yielding or defeated animals experience a phenomenon known as social defeat stress, in which they show exaggerated stress as well as autonomic and endocrine responses that cause impairment of both the brain and body. In laboratory settings, one can reliably generate social defeat stress by allowing a naïve (or already defeated) animal to intrude into a home cage in which its resident has already established a territory or is nursing. This resident-intruder paradigm has been widely used in both males and females to study mechanisms in the brain that underlie the stress responses. Stress has profound effects on drug reward for cocaine, methamphetamine, alcohol, and opioids. Particularly, previous experiences with social defeat can exaggerate subsequent addiction-like behaviors. The extent of these addiction-like behaviors depends on the intensity, duration, frequency, and intermittency of the confrontation episodes. This chapter describes four types of social defeat stress: acute, repeated, intermittent, and chronic. Specifically, it focuses on social defeat stress models used in laboratories to study individual, sex, and animal strain differences in addiction-like behaviors.

The relationship between stress and Alzheimer's disease

Stress is critically involved in the development and progression of disease. From the stress of undergoing treatments to facing your own mortality, the physiological processes that stress drives have a serious detrimental effect on the ability to heal, cope and maintain a positive quality of life. This is becoming increasingly clear in the case of neurodegenerative diseases. Neurodegenerative diseases involve the devastating loss of cognitive and motor function which is stressful in itself, but can also disrupt neural circuits that mediate stress responses. Disrupting these circuits produces aberrant emotional and aggressive behavior that causes long-term care to be especially difficult. In addition, added stress drives progression of the disease and can exacerbate symptoms. In this review, I describe how neural and endocrine pathways activated by stress interact with ongoing neurodegenerative disease from both a clinical and experimental perspective.

Involvement of endocannabinoid neurotransmission in the bed nucleus of stria terminalis in cardiovascular responses to acute restraint stress in rats

BACKGROUND AND PURPOSE

Endocannabinoid signalling has been reported as an important neurochemical mechanism involved in responses to stress. Previous studies provided evidence of endocannabinoid release in the bed nucleus of the stria terminalis (BNST) during aversive stimuli. Nevertheless, a possible involvement of this neurochemical mechanism in stress responses has never been evaluated. Therefore, in the present study we investigated the involvement of BNST endocannabinoid neurotransmission, acting via local CB1 receptors, in the cardiovascular responses to acute restraint stress in rats.

EXPERIMENTAL APPROACH

The selective CB1 receptor antagonist AM251 (1, 30 and 100 pmol 100 nL(-1) ) and/or the fatty acid amide hydrolase (FAAH) enzyme inhibitor URB597 (30 pmol 100 nL(-1) ) or the monoacylglycerol lipase (MAGL) enzyme inhibitor JZL184 (30 pmol 100 nL(-1) ) was microinjected into the BNST before the acute restraint stress.

KEY RESULTS

Microinjection of AM251 into the BNST enhanced the tachycardia caused by restraint stress, without affecting the increase in arterial pressure and the sympathetic-mediated cutaneous vasoconstrictor response. Conversely, the increased endogenous levels of AEA in the BNST evoked by local treatment with the FAAH enzyme inhibitor URB597 decreased restraint-evoked tachycardia. Inhibition of the hydrolysis of 2-arachidonoylglycerol (2-AG) in the BNST by local microinjection of the MAGL enzyme inhibitor JZL184 also decreased the HR response. These effects of URB597 and JZL184 were abolished by BNST pretreatment with AM251.

CONCLUSIONS AND IMPLICATIONS

These findings indicate an involvement of BNST endocannabinoid neurotransmission, acting via CB1 receptors, in cardiovascular adjustments during emotional stress, which may be mediated by the local release of either AEA or 2-AG.

Emotional Stress and Cardiovascular Complications in Animal Models: A Review of the Influence of Stress Type

Emotional stress has been recognized as a modifiable risk factor for cardiovascular diseases. The impact of stress on physiological and psychological processes is determined by characteristics of the stress stimulus. For example, distinct responses are induced by acute vs. chronic aversive stimuli. Additionally, the magnitude of stress responses has been reported to be inversely related to the degree of predictability of the aversive stimulus. Therefore, the purpose of the present review was to discuss experimental research in animal models describing the influence of stressor stimulus characteristics, such as chronicity and predictability, in cardiovascular dysfunctions induced by emotional stress. Regarding chronicity, the importance of cardiovascular and autonomic adjustments during acute stress sessions and cardiovascular consequences of frequent stress response activation during repeated exposure to aversive threats (i.e., chronic stress) is discussed. Evidence of the cardiovascular and autonomic changes induced by chronic stressors involving daily exposure to the same stressor (predictable) vs. different stressors (unpredictable) is reviewed and discussed in terms of the impact of predictability in cardiovascular dysfunctions induced by stress.