The HPA axis response to stress in women: effects of aging and fitness

Androgen and glucocorticoid profiles throughout extended uniparental paternal care in the eastern hellbender salamander (Cryptobranchus a. alleganiensis)

The behavioral endocrinology associated with reproduction and uniparental male care has been studied in teleosts, but little is known about hormonal correlates of uniparental male care in other ectotherms. To address this gap, we are the first to document the seasonal steroid endocrinology of uniparental male hellbender salamanders during the transition from pre-breeding to nest initiation, and through the subsequent eight months of paternal care. In doing so, we investigated the correlates of nest fate and clutch size, exploring hellbenders' alignment with several endocrinological patterns observed in uniparental male fish. Understanding the endocrinology of hellbender paternal care is also vital from a conservation perspective because high rates of nest failure were recently identified as a factor causing population declines in this imperiled species. We corroborated previous findings demonstrating testosterone and dihydrotestosterone (DHT) to be the primary androgens in hellbender reproduction, and that cortisol circulates as the most abundant glucocorticoid. However, we were unable to identify a prolactin or a "prolactin-like" peptide in circulation prior to or during parental care. We observed ∼ 80 % declines in both primary androgens during the transition from pre-breeding to nest initiation, and again as paternal care progressed past its first month. In the days immediately following nest initiation, testosterone and DHT trended higher in successful individuals, but did not differ with males' clutch size. We did not observe meaningful seasonality in baseline glucocorticoids associated with breeding or nesting. In contrast, stress-induced glucocorticoids were highest at pre-breeding and through the first two months of care, before declining during the latter-most periods of care as larvae approach emergence from the nest. Neither baseline nor stress-induced glucocorticoids varied significantly with either nest fate or clutch size. Both stress-induced cortisol and corticosterone were positively correlated with total length, a proxy for age in adult hellbenders. This is consistent with age-related patterns in some vertebrates, but the first such pattern observed in a wild amphibian population. Generally, we found that nesting hellbenders adhere to some but not all of the endocrinological patterns observed in uniparental male teleosts prior to and during parental care.

Eight weeks of high-intensity interval training versus stretching do not change the psychoneuroendocrine response to a social stress test in emotionally impulsive humans

PURPOSE

Research supports physical activity as a method to heighten stress resistance and resilience through positive metabolic alterations mostly affecting the neuroendocrine system. High-intensity interval training (HIIT) has been proposed as a highly effective time-saving method to induce those changes. However, existing literature relies heavily on cross-sectional analyses, with few randomised controlled trials highlighting the necessity for more exercise interventions. Thus, this study aims to investigate the effects of HIIT versus an active control group on the stress response to an acute psychosocial stressor in emotionally impulsive humans (suggested as being strong stress responders).

METHODS

The study protocol was registered online (DRKS00016589) before data collection. Sedentary, emotionally impulsive adults (30.69 ± 8.20 y) were recruited for a supervised intervention of 8 weeks and randomly allocated to either a HIIT (n = 25) or a stretching group (n = 19, acting as active controls). Participants were submitted to a test battery, including saliva samples, questionnaires (self-efficacy- and perceived stress-related), visual analogue scales (physical exercise- and stress-related), and resting electroencephalography and electrocardiography assessing their reaction to an acute psychological stressor (Trier Social Stress Test) before and after the exercise intervention.

RESULTS

HIIT increased aerobic fitness in all participants, whereas stretching did not. Participants from the HIIT group reported perceiving exercising more intensively than those from the active control group (ƞp2 = 0.108, p = 0.038). No further group differences were detected. Both interventions largely increased levels of joy post-TSST (ƞp2 = 0.209, p = 0.003) whilst decreasing tension (ƞp2 = 0.262, p < 0.001) and worries (ƞp2 = 0.113, p = 0.037). Finally, both interventions largely increased perceived levels of general self-efficacy (ƞp2 = 0.120, p = 0.029).

CONCLUSION

This study suggests that 8 weeks of HIIT does not change the psychoneuroendocrine response to an acute psychological stress test compared to an active control group in emotionally impulsive humans. Further replications of supervised exercise studies highly powered with active and passive controls are warranted.

Adult age differences in the psychophysiological response to acute stress

Age-related differences in the psychophysiology of the acute stress response are poorly understood given the limited number of studies and the high heterogeneity of findings. The present study contributes by investigating age differences in both the psychological and physiological responses to acute stress in a sample of healthy younger (N = 50; 18-30; M_age = 23.06; SD = 2.90) and older adults (N = 50; 65-84; M_age = 71.12; SD = 5.02). Specifically, the effects of psychosocial stress (i.e., age-adapted Trier Social Stress Test) were investigated at numerous timepoints throughout the stress response phases (i.e., baseline, anticipation, reactivity, recovery) on cortisol, heart rate, subjective stress, and anticipatory appraisal of the stressful situation. The study was conducted in a between-subject (younger vs. older) cross-over (stress vs. control) design. Results revealed age-related differences in both physiological and psychological variables: older adults had overall lower salivary cortisol levels in the stress and control conditions and lower stress-induced cortisol increase (i.e., AUCi). In addition, older adults' cortisol reactivity was delayed compared to younger adults. Older adults showed a lower heart rate response in the stress condition while no age differences were observed in the control condition. Finally, older adults reported less subjective stress and a less negative stress appraisal during the anticipation phase than younger adults, which could potentially explain lower physiological reactivity in this age group. Results are discussed in relation to the existing literature, potential underlying mechanisms, and future directions for the field.

A smart healthcare-based system for classification of dementia using deep learning

Objectives

This study aims to develop a deep learning-based classification model for early detection of dementia using a wearable device that can measure the electrical conductivity of the skin, temperature, and movement as factors related to dementia, interlocking them with an application, and analyzing the collected data.

Methods

This study was conducted on 18 elderly individuals (5 males, 13 females) aged 65 years or older who consented to the study. The Korean Mini-Mental State Examination survey for cognitive function tests was conducted by well-trained researchers. The subjects were first grouped into high- or low-risk group for dementia based on their Korean Mini-Mental State Examination score. Data obtained by wearable devices of each subject were then used for the classification of the high- and low-risk groups of dementia through a smart healthcare-based system implementing a deep neural network with scaled principal component analysis. The correlation coefficients between the Korean Mini-Mental State Examination score and the featured data were also investigated.

Results

Our study showed that the proposed system using a deep neural network with scaled principal component analysis was effective in detecting individuals at high risk for dementia with up to 99% accuracy and which performance was better compared with commonly used classification algorithms. In addition, it was found that the electrical conductivity of skin had the closest correlation with the results of the Korean Mini-Mental State Examination score among data collected through wearable devices in this study.

Conclusions

Our proposed system can contribute to effective early detection of dementia for the elderly, using a non-invasive and easy-to-wear wearable device and classification algorithms with a simple cognitive function test. In the future, we intend to have more subjects participate in the experiment, to include more relevant variables in the wearable device, and to analyze the effectiveness of the smart healthcare-based dementia classification system over the long term.

Epigenetic aging and perceived psychological stress in old age

Adverse effects of psychological stress on physical and mental health, especially in older age, are well documented. How perceived stress relates to the epigenetic clock measure, DNA methylation age acceleration (DNAmAA), is less well understood and existing studies reported inconsistent results. DNAmAA was estimated from five epigenetic clocks (7-CpG, Horvath's, Hannum's, PhenoAge and GrimAge DNAmAA). Cohen's Perceived Stress Scale (PSS) was used as marker of psychological stress. We analyzed data from 1,100 Berlin Aging Study II (BASE-II) participants assessed as part of the GendAge study (mean age = 75.6 years, SD = 3.8 years, 52.1% women). In a first step, we replicated well-established associations of perceived stress with morbidity, frailty, and symptoms of depression in the BASE-II cohort studied here. In a second step, we did not find any statistically significant association of perceived stress with any of the five epigenetic clocks in multiple linear regression analyses that adjusted for covariates. Although the body of literature suggests an association between higher DNAmAA and stress or trauma during early childhood, the current study found no evidence for an association of perception of stress with DNAmAA in older people. We discuss possible reasons for the lack of associations and highlight directions for future research.

Exercise as a Moderator of Persistent Neuroendocrine Symptoms of COVID-19

Precipitated by chronic psychological stress, immune system dysregulation, and a hyperinflammatory state, the sequelae of postacute COVID-19 (long COVID) include depression and new-onset diabetes. We hypothesize that exercise counters the neuropsychiatric and endocrine sequelae of long COVID by inducing the release of circulating factors that mediate the anti-inflammatory response, support brain homeostasis, and increase insulin sensitivity.

Motivation Levels and Goals for the Practice of Physical Exercise in Five Different Modalities: A Correspondence Analysis

The identification of the practitioner’s profile regarding their motivation level for physical exercise engagement could be a behavioral strategy to increase exercise adherence. The present study investigates the associations between motivation levels, modalities practiced, and goals concerning the practice of physical exercise among physical exercise practitioners. A total of 100 physical exercise practitioners, of which 67 were women, took part in this study. The participants were engaged in extreme fitness program, strength training, fight training, Pilates, and functional training. Motivation level (BREQ-3) and expectations regarding regular physical exercise (IMPRAF-54) were assessed. A multiple correspondence analysis demonstrates preferential relationships between descriptive and non-inferential variables. Strength training and fight training practitioners seek these modalities with the goals of “Health” and “Aesthetics,” demonstrating low autonomy in relation to the behavior for the practice of physical exercise. Extreme conditioning program and functional training practitioners have as goal “Pleasure,” demonstrating medium and high levels of autonomy for such practice and Pilates practitioners have the goal of “Stress Control.” To promote and encourage the regular practice of physical exercise, this strategy could be used to take actions that increase the public’s intention to start or continue in a physical exercise program.

Changes in serum copeptin in the early onset of type 2 diabetes

Copeptin (C-terminal fragment of pro-arginine vasopressin) levels change as fasting plasma glucose (FPG) and blood pressure change. To explore the clinical significance of changes in copeptin levels in development of type 2 diabetes mellitus (T2DM), we enrolled patients undergoing physical health examinations who met diagnostic criteria for prediabetes and T2DM. Subjects were divided into eight subgroups based on FPG levels and presence or absence of hypertension, including: a normal group (NGT), FPG < 5.6 mmol/L; prediabetes A, 5.6 mmol/L ≤ FPG < 6.1 mmol/L; prediabetes B, 6.1 mmol/L ≤ FPG < 7.0 mmol/L; and T2DM, FPG ≥ 7.0 mmol/L; participants were further into two subgroups by whether they had hypertension or not. Measures included biochemical indicators, fasting insulin (FINS), and copeptin. Copeptin levels in prediabetes A, prediabetes B, and T2DM groups increased significantly compared to NGT group ( P < 0.01). No significant differences were found in copeptin levels between normal blood pressure and hypertension subgroups in all four groups. Copeptin levels correlated positively with systolic blood pressure, glycosylated hemoglobin (HbA1c), FPG, FINS, and insulin resistance index (HOMA-IR; P < 0.05–0.001), and negatively with insulin secretion index ( P < 0.05–0.001). Stepwise regression analysis revealed that copeptin levels correlated independently with elevated HbA1c and aggravated HOMA-IR ( P < 0.001). Increase in copeptin levels may aggravate insulin resistance, finally leading to T2DM.

Stress and cancer: mechanisms, significance and future directions

The notion that stress and cancer are interlinked has dominated lay discourse for decades. More recent animal studies indicate that stress can substantially facilitate cancer progression through modulating most hallmarks of cancer, and molecular and systemic mechanisms mediating these effects have been elucidated. However, available clinical evidence for such deleterious effects is inconsistent, as epidemiological and stress-reducing clinical interventions have yielded mixed effects on cancer mortality. In this Review, we describe and discuss specific mediating mechanisms identified by preclinical research, and parallel clinical findings. We explain the discrepancy between preclinical and clinical outcomes, through pointing to experimental strengths leveraged by animal studies and through discussing methodological and conceptual obstacles that prevent clinical studies from reflecting the impacts of stress. We suggest approaches to circumvent such obstacles, based on targeting critical phases of cancer progression that are more likely to be stress-sensitive; pharmacologically limiting adrenergic-inflammatory responses triggered by medical procedures; and focusing on more vulnerable populations, employing personalized pharmacological and psychosocial approaches. Recent clinical trials support our hypothesis that psychological and/or pharmacological inhibition of excess adrenergic and/or inflammatory stress signalling, especially alongside cancer treatments, could save lives.

Exercise and adrenergic regulation of immunity

Exercise training has a profound impact on immunity, exerting a multitude of positive effects in indications such as immunosenescence, cancer, viral infections and inflammatory diseases. The immune, endocrine and central nervous systems work in a highly synergistic manner and it has become apparent that catecholamine signaling through leukocyte β-adrenergic receptors (β-ARs) is a key mechanism by which exercise mediates improvements in immune function to help mitigate numerous disease conditions. Central to this is the preferential mobilization and redistribution of effector lymphocytes with potent anti-viral and anti-tumor activity, their interaction with muscle-derived cytokines, and the effects of catecholamine signaling on mitochondrial biogenesis, immunometabolism and the resulting inflammatory response. Here, we review the impact of acute and chronic exercise on adrenergic regulation of immunity in the context of aging, cancer, viral infections and inflammatory disease. We also put forth our contention that exercise interventions designed to improve immunity, prevent disease and reduce inflammation should consider the catecholamine-AR signaling axis as a therapeutic target and ask whether or not the adrenergic signaling machinery can be 'trained' to improve immune responses to stress, disease or during the normal physiological process of aging. Finally, we discuss potential strategies to augment leukocyte catecholamine signaling to boost the effects of exercise on immunity in individuals with desensitized β-ARs or limited exercise tolerance.

The Cortisol and ACTH Response to Dex/CRH Testing in Women With and Without Perimenopausal Depression

CONTEXT

Abnormalities in the hypothalamic-pituitary-adrenal (HPA) axis are frequent accompaniments of depression, and studies have documented the role of stress and stressful life events in the ontogeny of perimenopausal depressions (PMD). Because HPA axis function in women is further modulated both by aging and ovarian steroids, it is possible that a dysregulated HPA axis contributes to the increased risk of PMD.

OBJECTIVE

We examined HPA axis function in perimenopausal women with and without depression using the combined dexamethasone-corticotropin-releasing hormone (Dex/CRH) test.

METHODS

Dex/CRH tests were performed on 20 women with PMD and 20 women who were also perimenopausal but without current or past depression (control women). Main outcome measures were plasma levels of cortisol and adrenocorticotropin (ACTH) and 24-hour urinary free cortisol (UFC). Five women took chronic stable medications, otherwise all women were medically healthy, and both groups were comparable with respect to reproductive stage and age. Standardized symptom rating scales were administered to each woman prior to Dex/CRH testing.

RESULTS

No group differences were present in either baseline or stimulated ACTH and cortisol secretion. Baseline plasma measures of estradiol, progesterone, and 24-hour UFC levels similarly did not differ in PMD and control women.

CONCLUSION

Despite reports of increased stress responsiveness in PMD, we observed no abnormalities of HPA axis activity associated with PMD compared with women without depression. These findings suggest that PMD is not uniformly associated with HPA dysregulation and could reflect underlying pathophysiologic processes that are distinct from women with nonreproductive-related depressions.

Stress and Loss of Ovarian Function: Novel Insights into the Origins of Sex-Based Differences in the Manifestations of Respiratory Control Disorders During Sleep

The respiratory system of women and men develops and functions in distinct neuroendocrine milieus. Despite differences in anatomy and neural control, homeostasis of arterial blood gases is ensured in healthy individuals regardless of sex. This convergence in function differs from the sex-based differences observed in many respiratory diseases. Sleep-disordered breathing (SDB) results mainly from episodes of upper airway closure. This complex and multifactorial respiratory disorder shows significant sexual dimorphism in its clinical manifestations and comorbidities. Guided by recent progress from basic research, this review discusses the hypothesis that stress is necessary to reveal the sexual dimorphism of SDB.

The effects of exercise intensity on the cortisol response to a subsequent acute psychosocial stressor

OBJECTIVE

The aim of this experimental study was to determine the extent to which the intensity of a single 30 min bout of exercise alters the salivary cortisol (sCort) response to a subsequently induced acute psychosocial stressor. The study further aimed to elucidate a physiological mechanism through which exercise intensity exerts stress-mitigating effects.

METHODS

Eighty-three healthy men (M_age = 21.04 SD = 2.89) were randomly assigned to exercise on a treadmill at either 30%, 50% or 70% of their heart rate reserve (HRR) for 30 min and then underwent the Trier Social Stress Test 45 min later. sCort was measured repeatedly throughout and following the exercise bout and stressor task.

RESULTS

ANCOVA and Multilevel Growth Curve Analysis determined that vigorous (70% HRR) exercise elicited dampened sCort responses to the stressor task, marked by lower total sCort levels, diminished sCort reactivity, and faster recovery to baseline values, as compared to less intense exercise. Moreover, exercise elicited a sCort response in proportion to the intensity at which it was performed, and this exercise-associated HPA-axis response was inversely proportional to the sCort response to the subsequent stressor task.

CONCLUSIONS

This study revealed that exercise-intensity dampens the HPA-axis stress response in a dose-dependent manner, with evidence that the cortisol released from exercising intensely suppresses the subsequent cortisol response to a psychosocial stressor.

Resting Heart Rate and Risk of Cancer Mortality

BACKGROUND

Increased resting heart rate (RHR) is a predictor of mortality. RHR is influenced by cardiorespiratory fitness (CRF). Little is known about the combined associations of RHR and CRF on cancer mortality.

METHODS

50,108 men and women (mean age 43.8 years) were examined between 1974 and 2002 at the Cooper Clinic in Dallas, Texas. RHR was measured by electrocardiogram and categorized as <60, 60-69, 70-79, or ≥80 beats/minute. CRF was quantified by maximal treadmill test and dichotomized as unfit and fit corresponding to the lower 20% and the upper 80%, respectively, of the age- and sex-specific distribution of treadmill exercise duration. The National Death Index was used to ascertain vital status. Cox regression was used to compute HRs and 95% confidence intervals (CI) for cancer mortality across RHR categories.

RESULTS

During a mean follow-up of 15.0 ± 8.6 years, 1,090 cancer deaths occurred. Compared with RHR <60 beats/minute, individuals with RHR ≥80 beats/minute had a 35% increased risk of overall cancer mortality (HR, 1.35; 95% CI, 1.06-1.71) after adjusting for confounders, including CRF. Compared with "fit and RHR <80 beats/minute", HRs (95% CI) for cancer mortality were 1.41 (1.20-1.66), 1.51 (1.11-2.04), and 1.78 (1.30-2.43) in "unfit and RHR <80," "fit and RHR ≥80," and "unfit and RHR ≥80 beats/minute," respectively.

CONCLUSIONS

RHR ≥80 beats/minute is associated with an increased risk of overall cancer mortality. High CRF may help lower the risk of cancer mortality among those with high RHR.

IMPACT

RHR along with CRF may provide informative data about an individual's cancer mortality risk.

Resistance training as an acute stressor in healthy young men: associations with heart rate variability, alpha-amylase, and cortisol levels

Regular resistance training has been shown to have many physiological and psychological health benefits. However, the underlying physiological processes are not yet fully understood. One explanation is that resistance training acts like an acute stressor and modulates physiological pathways that are associated with the stress response such as the sympathetic nervous system (SNS), the parasympathetic nervous system (PNS), and the hypothalamic-pituitary-adrenal (HPA) axis. This was systematically investigated in our study. Participants were 45 healthy men who had been doing resistance training regularly for at least nine months. Salivary α-amylase and heart rate that were used as markers for SNS activity increased during the training and decreased afterwards. PNS activity that was assessed by means of heart rate variability parameters decreased during the training and increased after it. Salivary cortisol that was used as marker for HPA axis activity decreased throughout the session. Furthermore, an improvement of positive affect was found after the training. However, additional analyses indicated that the physiological response patterns were found for participants who chose upper-body exercises (in contrast to lower-body exercises) only. Therefore, we were able to show that an upper-body resistance training acts partially like an acute stressor which leads to the typical SNS and PNS - but not HPA axis - stress responses. We conclude that resistance trainings might be an alternative to classical relaxation programs which would have the additional advantage that it is a physical training at the same time. However, more research is needed to develop specific trainings which entirely fulfill this goal.

Comparison of Military Recruit and Incumbent Physical Characteristics and Performance: Potential Implications for Through-Career Individual Readiness and Occupational Performance

Drain, JR, Debenedictis, T, Bulmer, S, and Michael, S. comparison of military recruit and incumbent physical characteristics and performance: Potential implications for through-career individual readiness and occupational performance. J Strength Cond Res XX(X): 000-000, 2020-After basic military training, physical training practices among incumbent personnel differ substantially, potentially precipitating varied physical capacity and operational readiness. The purpose of this retrospective investigation was to compare physical characteristics and physical performance between recruits and incumbent personnel. Data were collected for 222 army recruits (REC: 197 men/25 women) nearing completion of basic training and 280 incumbent army personnel from combat arms (CA: 142 men) and noncombat arms trades (NCA: 113 men/25 women). Height, mass, and body mass index (BMI) were recorded together with performance measures including predicted V[Combining Dot Above]O2max and 1 repetition maximum box lift. Compared with REC, male incumbents were older (21.8 ± 0.6 vs. 27.6 ± 1.2 years; mean ± 95% confidence interval), had greater body mass (77.6 ± 1.3 vs. 82.6 ± 1.5 kg) and BMI (24.2 ± 0.3 vs. 25.8 ± 0.5 kg·m), similar relative V[Combining Dot Above]O2max, and lower box lift (49.7 ± 1.4 vs. 47.2 ± 2.4 kg). Male CA demonstrated greatest physical performance while male NCA demonstrated the highest BMI and poorest physical performance. Compared with REC, female incumbents were older (22.8 ± 1.6 vs. 31.9 ± 4.4 years), had similar body mass, higher BMI (24.1 ± 0.7 vs. 26.1 ± 2.4 kg·m), as well as lower V[Combining Dot Above]O2max (42.0 ± 1.3 vs. 37.9 ± 2.1 ml·kg··min) and box lift (27.8 ± 2.1 vs. 23.3 ± 2.4 kg). More than 97% of men and approximately 75% of women were able to achieve the box lift and V[Combining Dot Above]O2max baseline standards. The older age category (26 + vs. 18-25 years) typically demonstrated higher BMI and lower physical performance. Through-career maintenance of physical capacity is important for military personnel to support individual readiness and occupational performance, preserve health, and mitigate musculoskeletal injury risk.

A Systematic Review of the Association Between Psychological Stress and Dementia Risk in Humans

Background: It has been estimated that one third of dementia cases may be preventable through modifiable lifestyle interventions. Epidemiological evidence suggests a link between stressful life events and aging-related cognitive decline and dementia; however, inherent methodological limitations in examining subjective and biological measures of stress separately leads to interpretive constraints. Objective: The aim of the current study was to conduct a systematic review of the research literature investigating the effect of perceived and biological measures of stress on dementia risk. Methods: A systematic review was conducted of cohort, case-control, longitudinal prospective or retrospective studies examining the association between stress and risk of developing dementia. Studies were identified from a systematic search across major electronic databases from inception to February 2020. Results: Overall, 22 studies were identified including a total of 496,556 participants, approximately 50% were females, with sample sizes ranging from 62–270,977. There was considerable heterogeneity in the definition and measurement of stress. Most of the identified studies reported a significant positive association between stress and dementia risk. Conclusion: Evidenced from the current review is that personality traits linked to increased perceived stress and elevated reported perceived stress, are associated with greater statistical risk for dementia. However, this review highlights that caution must be exhibited in interpreting these findings, as methodological issues with confounding adjustment may mediate these results. Future research should focus on the investigation of stress on dementia risk with a full range of confounding adjustment, and on biological measures of stress.

Forty-eight-hour fasting declines mental flexibility but improves balance in overweight and obese older women

The purpose of this study was to investigate the effects of a 48-h fast on evoked stress, mood, and cognitive and motor functions in overweight and obese older women. Eleven women (body mass index >25 kg/m²) aged 63-80 years were tested under two randomly allocated conditions: 48-h zero-calorie diet with water provided ad libitum and 48-h usual diet. Autonomic function, cortisol levels, mood state, cognitive performance, visuomotor coordination, motor speed, and balance were evaluated before and after each diet. Fasting increased (P < 0.05) cortisol levels, whereas no changes were observed in heart rate and its variability. Fasting increased (P < 0.05) fatigue, prolonged (P < 0.05) reaction time in the two-choice reaction time test and decreased (P < 0.05) the velocity vector of the center of pressure with eyes closed, whereas no changes in performance were observed in the pursuit tracking and finger tapping tests. Thus, although a 48-h fast resulted in greater hypothalamic-pituitary-adrenal axis activity in overweight and obese older women, autonomic nervous system activity was not affected. Fasting increased fatigue and decreased mental flexibility, but improved balance.

Wild chimpanzees exhibit humanlike aging of glucocorticoid regulation

Cortisol, a key product of the stress response, has critical influences on degenerative aging in humans. In turn, cortisol production is affected by senescence of the hypothalamic-pituitary-adrenal (HPA) axis, leading to progressive dysregulation and increased cortisol exposure. These processes have been studied extensively in industrialized settings, but few comparative data are available from humans and closely related species living in natural environments, where stressors are very different. Here, we examine age-related changes in urinary cortisol in a 20-y longitudinal study of wild chimpanzees (n = 59 adults) in the Kanyawara community of Kibale National Park, Uganda. We tested for three key features of HPA aging identified in many human studies: increased average levels, a blunted diurnal rhythm, and enhanced response to stressors. Using linear mixed models, we found that aging was associated with a blunting of the diurnal rhythm and a significant linear increase in cortisol, even after controlling for changes in dominance rank. These effects did not differ by sex. Aging did not increase sensitivity to energetic stress or social status. Female chimpanzees experienced their highest levels of cortisol during cycling (versus lactation), and this effect increased with age. Male chimpanzees experienced their highest levels when exposed to sexually attractive females, but this effect was diminished by age. Our results indicate that chimpanzees share some key features of HPA aging with humans. These findings suggest that impairments of HPA regulation are intrinsic to the aging process in hominids and are side effects neither of extended human life span nor of atypical environments.

Perinatal exposure to bisphenol A at the intersection of stress, anxiety, and depression

Endocrine-disrupting compounds (EDCs) are common contaminants in our environment that interfere with typical endocrine function. EDCs can act on steroid and nuclear receptors or alter hormone production. One particular EDC of critical concern is bisphenol A (BPA) due to its potential harm during the perinatal period of development. Previous studies suggest that perinatal exposure to BPA alters several neurotransmitter systems and disrupts behaviors associated with depression and anxiety in the rodent offspring later in life. Thus, dysregulation in neurotransmission may translate to behavioral phenotypes observed in mood and arousal. Many of the systems disrupted by BPA also overlap with the stress system, although little evidence exists on the effects of perinatal BPA exposure in relation to stress and behavior. The purpose of this review is to explore studies involved in perinatal BPA exposure and the stress response at neurochemical and behavioral endpoints. Although more research is needed, we suggest that perinatal BPA exposure is likely inducing variations in behavioral phenotypes that modulate their action through dysregulation of neurotransmitter systems sensitive to stress and endocrine disruption.

Cardiorespiratory fitness, sleep, and physiological responses to stress in women

Epidemiological studies suggest that cardiorespiratory fitness (CRfitness) is associated with reduced risk of depression and anxiety in women, however, the mechanisms by which CRfitness may be protective against the development of these disorders are less clear. Because sleep problems are associated with both a higher risk for mental illness and altered physiological responses to stress, this study investigated whether sleep quality might influence the relationship between CRfitness and physiological stress responses in women. Thirty healthy women (18-45 y) who were medication-free, with regular menstrual cycles completed: (1) enrolment visit [including the assessment of CRfitness via maximal oxygen consumption during exercise]; (2) one-week sleep monitoring period including subjective (daily sleep diaries) and objective (wrist actigraphy) sleep measures; and (3) psychosocial stressor protocol (the Trier Social Stress Test; TSST) for the collection of heart rate (HR), blood pressure (BP), and salivary cortisol stress responses. Higher CRfitness was associated with reduced wake after sleep onset (WASO) duration (r = -.38, p = 0.04), higher self-reported sleep quality (higher scores reflect poorer sleep quality; r = -.37, p = 0.05), and lower HR (r = -.43, p = 0.02) during the stressor. Higher sleep quality was associated with a lower HR during the stressor (r = .44, p = 0.01). Increased WASO duration and WASO number were associated with blunted cortisol output during the stressor (r = -.44, p = 0.02, and r = -.46, p = 0.02, respectively). Results suggest that, in women, CRfitness may be protective against the deleterious effects of stress via improved sleep quality.

Midnight salivary cortisol secretion associated with high systolic blood pressure in type 1 diabetes

OBJECTIVE

To explore associations between high midnight salivary cortisol (MSC) secretion and high blood pressure (BP) in type 1 diabetes (T1D).

METHODS

Cross-sectional study of 196 adult patients with T1D (54% men). Associations between high MSC (≥9.3 nmol/L) and high systolic BP (>130 mmHg), and high diastolic BP (>80 mmHg) were explored for all patients, users and non-users of antihypertensive drugs (AHD). Adjustments were performed for age, sex, diabetes-related variables, p-creatinine, smoking, physical inactivity, depression and medication.

RESULTS

The prevalence of high MSC differed between patients with high and low systolic BP in all 196 patients: 39 vs 13% (P = 0.001); in 60 users of AHD: 37 vs 12% (P = 0.039), and in 136 non-users of AHD: 43 vs 13% (P = 0.012). Significant associations with high systolic BP were for all patients: physical inactivity (adjusted odds ratio (AOR) 6.5), high MSC (AOR 3.9), abdominal obesity (AOR 3.7), AHD (AOR 2.9), age (per year) (AOR 1.07), and p-creatinine (per µmol/L) (AOR 1.03); for 60 users of AHD: high MSC (AOR 4.1) and age (per year) (AOR 1.11); for 136 non-users of AHD: abdominal obesity (AOR 27.4), physical inactivity (AOR 14.7), male sex (AOR 9.0), smoking (AOR 7.9), and age (per year) (AOR 1.08). High MSC was not associated with high DBP.

CONCLUSIONS

In adult patients with T1D, high systolic BP was associated with physical inactivity, high MSC secretion, abdominal obesity, p-creatinine, age, and AHD, the latter indicating treatment failure.

Activation of Adrenal Steroidogenesis and an Improvement of Mood Balance in Postmenopausal Females after Spa Treatment Based on Physical Activity

Spa treatment can effectively reestablish mood balance in patients with psychiatric disorders. In light of the adrenal gland’s role as a crossroad of psychosomatic medicine, this study evaluated changes in 88 circulating steroids and their relationships with a consolidation of somatic, psychosomatic and psychiatric components from a modified N-5 neurotic questionnaire in 46 postmenopausal 50+ women with anxiety-depressive complaints. The patients underwent a standardized one-month intervention therapy with physical activity and an optimized daily regimen in a spa in the Czech Republic. All participants were on medication with selective serotonin reuptake inhibitors. An increase of adrenal steroidogenesis after intervention indicated a reinstatement of the hypothalamic-pituitary-adrenal axis. The increases of many of these steroids were likely beneficial to patients, including immunoprotective adrenal androgens and their metabolites, neuroactive steroids that stimulate mental activity but protect from excitotoxicity, steroids that suppress pain perception and fear, steroids that consolidate insulin secretion, and steroids that improve xenobiotic clearance. The positive associations between the initial values of neurotic symptoms and their declines after the intervention, as well as between initial adrenal activity and the decline of neurotic symptoms, indicate that neurotic impairment may be alleviated by such therapy provided that the initial adrenal activity is not seriously disrupted.

Associations among tourist camp management, high and low tourist seasons, and welfare factors in female Asian elephants in Thailand

This study investigated how camp management and tourist activities affect body condition, adrenocortical function, lipid profiles and metabolic status in female tourist elephants. We compared twice monthly serum insulin, glucose, fructosamine, total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL), high density lipoprotein (HDL), and fecal glucocorticoid metabolite (FGM) concentrations to body condition scores (BCS) at five camps with different management styles (e.g., tourist activities, work type, diet) between the High (November–February) and Low (March–October) tourist seasons. There were significant camp effects on health parameters, with BCS, TC, HDL, insulin and glucose being among the highest, and G:I being the lowest (less heathy) in elephants at an observation camp compared to those at camps where elephants received exercise by providing rides to tourists. Differences between High and Low tourist season months also were found for all measures, except TG and FGM concentrations. Both work time and walking distance were negatively correlated to glucose, fructosamine and insulin, while walking distance was negatively related to FGM concentrations. By contrast, positive associations were found between tourist number and BCS, TG, and insulin, perhaps related to tourists feeding elephants. Quantity of supplementary diet items (e.g., bananas, sugar cane, pumpkin) were positively correlated with FGM concentrations, glucose, fructosamine, and insulin. This study provides evidence that body condition, adrenal activity, metabolic markers, and lipid profiles in captive elephants may be affected by visitor numbers, work activities, and the amount of supplementary foods offered by tourists. Some activities appear to have negative (e.g., feeding), while others (e.g., exercise) may have positive effects on health and welfare. We conclude that camps adopting a more hands-off approach to tourism need to ensure elephants remain healthy by providing environments that encourage activity and rely on more natural diets or foraging.

Plasma prolactin levels are associated with the severity of illness in drug-naive first-episode psychosis female patients

Patients with schizophrenia frequently present hyperprolactinemia as a consequence of antipsychotic treatment. However, an increase in circulating prolactin levels has also been shown in patients without previous treatment. Our objective was to compare prolactin levels between antipsychotic-naive first-episode psychosis (AN-FEP) patients and healthy controls (HC). As part of an FEP program (Programa Asistencial Fases Iniciales de Psicosis [PAFIP]), 270 AN-FEP patients and 153 HC were eligible for this study. Serum prolactin levels were measured by an automated immunochemiluminescent assay. Subjects' sex and having an AN-FEP diagnosis both had an effect on prolactin levels, with higher levels in women than in men, and in AN-FEP patients than in HC. Moreover, plasma prolactin levels showed a negative correlation with the SAPS scores in AN-FEP female patients. AN-FEP patients have increased levels of prolactin, which might be stress-induced. This, together with the association of higher prolactin with a lower severity of the disease, suggests that prolactin might play a neuroprotective role, especially in women.

Weathering, Drugs, and Whack-a-Mole: Fundamental and Proximate Causes of Widening Educational Inequity in U.S. Life Expectancy by Sex and Race, 1990-2015

Discussion of growing inequity in U.S. life expectancy increasingly focuses on the popularized narrative that it is driven by a surge of "deaths of despair." Does this narrative fit the empirical evidence? Using census and Vital Statistics data, we apply life-table methods to calculate cause-specific years of life lost between ages 25 and 84 by sex and educational rank for non-Hispanic blacks and whites in 1990 and 2015. Drug overdoses do contribute importantly to widening inequity for whites, especially men, but trivially for blacks. The contribution of suicide to growing inequity is unremarkable. Cardiovascular disease, non-lung cancers, and other internal causes are key to explaining growing life expectancy inequity. Results underline the speculative nature of attempts to attribute trends in life-expectancy inequity to an epidemic of despair. They call for continued investigation of the possible weathering effects of tenacious high-effort coping with chronic stressors on the health of marginalized populations.

Adrenal Aging and Its Implications on Stress Responsiveness in Humans

Normal aging results in subtle changes both in ACTH and cortisol secretion. Most notable is the general increase in mean daily serum cortisol levels in the elderly, without a noteworthy alteration in the normal circadian rhythm pattern. Glucocorticoid excess seen in the elderly population can have serious consequences in both the structural and functional integrity of various key areas in the brain, including the hippocampus, amygdala, prefrontal cortex, with consequent impairment in normal memory, cognitive function, and sleep cycles. The chronically elevated glucocorticoid levels also impinge on the normal stress response in the elderly, leading to an impaired ability to recover from stressful stimuli. In addition to the effects on the brain, glucocorticoid excess is associated with other age-related changes, including loss of muscle mass, hypertension, osteopenia, visceral obesity, and diabetes, among others. In contrast to the increase in glucocorticoid levels, other adrenocortical hormones, particularly serum aldosterone and DHEA (the precursor to androgens and estrogens) show significant decreases in the elderly. The underlying mechanisms for their decrease remain unclear. While the adrenomedullary hormone, norephinephrine, shows an increase in plasma levels, associated with a decrease in clearance, no notable changes observed in plasma epinephrine levels in the elderly. The multiplicity and complexity of the adrenal hormone changes observed throughout the normal aging process, suggests that age-related alterations in cellular growth, differentiation, and senescence specific to the adrenal gland must also be considered.

A comparative study of the effect of stress on the cognitive parameters in women with increased body mass index before and after menopause

Background

The increasing prevalence of overweight and obesity is a critical public health problem for women. The negative effect of stress on memory and cognitive functions has been widely explored for decades in numerous research projects using a wide range of methodology. Deterioration of memory and other brain functions is a hallmark of Alzheimer’s disease. Estrogen fluctuations and withdrawal have myriad direct effects on the central nervous system that have the potential to influence cognitive functions. The present study aims to compare the effect of stress on the cognitive functions in overweight/obese women before and after menopause.

Methods

A total of 142 female subjects constituting women before menopause between the ages of 18 and 44 years and women after menopause between the ages of 45 and 60 years were included in the sample. Participants were categorized into overweight/obese groups based on the body mass index. The major tool perceived stress scale was used for measuring the perception of stress. On the basis of the stress scale measurement, each group was classified into with stress and without stress. Addenbrooke’s Cognitive Examination-III was used for measuring the cognitive functions.

Results

Premenopausal women with stress showed a significant (p<0.05) decrease in the cognitive parameters such as attention and orientation, fluency, language and visuospatial ability. Memory did not show any significant changes in this group. Whereas, in the postmenopausal stressed women, all the cognitive functions except fluency showed a significant (p<0.05) decrease.

Conclusions

Stress is a significant factor on the cognitive functions of obese and overweight women before and after menopause. Practice of yoga and encouragement in activities like gardening, embroidery, games and relaxation techniques should be recommended to prevent stress. Insights into the neurobiology before and after menopause can be gained from future studies examining the effect on the hypothalamic-pituitary-adrenal axis in relation to cognition and stress.

Acute hydrocortisone administration reduces cardiovagal baroreflex sensitivity and heart rate variability in young men

KEY POINTS

A surge in cortisol during acute physiological and pathophysiological stress may precipitate ventricular arrhythmia and myocardial infarction. Reduced cardiovagal baroreflex sensitivity and heart rate variability are observed during acute stress and are associated with an increased risk of acute cardiac events. In the present study, healthy young men received either a single iv bolus of saline (placebo) or hydrocortisone, 1 week apart, in accordance with a randomized, placebo-controlled, cross-over study design. Hydrocortisone acutely increased heart rate and blood pressure and reduced cardiovagal baroreflex sensitivity and heart rate variability in young men. These findings suggest that, by reducing cardiovagal baroreflex sensitivity and heart rate variability, acute surges in cortisol facilitate a pro-arrhythmic milieu and provide an important mechanistic link between stress and acute cardiac events ABSTRACT: Surges in cortisol concentration during acute stress may increase cardiovascular risk. To better understand the interactions between cortisol and the autonomic nervous system, we determined the acute effects of hydrocortisone administration on cardiovagal baroreflex sensitivity (BRS), heart rate variability (HRV) and cardiovascular reactivity. In a randomized, placebo-controlled, single-blinded cross-over study, 10 healthy males received either a single iv bolus of saline (placebo) or 200 mg of hydrocortisone, 1 week apart. Heart rate (HR), blood pressure (BP) and limb blood flow were monitored 3 h later, at rest and during the sequential infusion of sodium nitroprusside and phenylephrine (modified Oxford Technique), a cold pressor test and a mental arithmetic stress task. HRV was assessed using the square root of the mean of the sum of the squares of differences between successive R-R intervals (rMSSD). Hydrocortisone markedly increased serum cortisol 3 h following infusion and also compared to placebo. In addition, hydrocortisone elevated resting HR (+7 ± 4 beats min^-1 ; P < 0.001) and systolic BP (+5 ± 5 mmHg; P = 0.008); lowered cardiovagal BRS [geometric mean (95% confidence interval) 15.6 (11.1-22.1) ms/mmHg vs. 26.2 (17.4--39.5) ms/mmHg, P = 0.011] and HRV (rMSSD 59 ± 29 ms vs. 84 ± 38 ms, P = 0.004) and increased leg vasoconstrictor responses to cold pressor test (Δ leg vascular conductance -45 ± 20% vs. -23 ± 26%; P = 0.023). In young men, an acute cortisol surge is accompanied by increases in HR and BP, as well as reductions in cardiovagal BRS and HRV, potentially providing a pro-arrhythmic milieu that may precipitate ventricular arrhythmia or myocardial infarction and increase cardiovascular risk.

A Role for Exercise in Attenuating Unhealthy Food Consumption in Response to Stress

It is well established that both acute and chronic stress can be detrimental to health and wellbeing by directly increasing the risk of several chronic diseases and related health problems. In addition, stress may contribute to ill-health indirectly via its downstream effects on individuals’ health-related behaviour, such as promoting the intake of unhealthy palatable foods high in fat and sugar content. This paper reviews (a) the research literature on stress-models; (b) recent research investigating stress-induced eating and (c) the potential physiological and psychological pathways contributing to stress-induced eating. Particular attention is given to (d) the role of physical exercise in attenuating acute stress, with exploration of potential mechanisms through which exercise may reduce unhealthy food and drink consumption subsequent to stressor exposure. Finally, exercise motivation is discussed as an important psychological influence over the capacity for physical exercise to attenuate unhealthy food and drink consumption after exposure to stressors. This paper aims to provide a better understanding of how physical exercise might alleviate stress-induced unhealthy food choices.

Black-White Disparities in Breast Cancer Subtype: The Intersection of Socially Patterned Stress and Genetic Expression

Hormone receptor negative (HR-) breast cancer subtypes are etiologically distinct from the more common, less aggressive, and more treatable form of estrogen receptor positive (ER+) breast cancer. Numerous population-based studies have found that, in the United States, Black women are 2 to 3 times more likely to develop HR- breast cancer than White women. Much of the existing research on racial disparities in breast cancer subtype has focused on identifying predisposing genetic factors associated with African ancestry. This approach fails to acknowledge that racial stratification shapes a wide range of environmental and social exposures over the life course. Human stress genomics considers the role of individual stress perceptions on gene expression. Yet, the role of structurally rooted biopsychosocial processes that may be activated by the social patterning of stressors in an historically unequal society, whether perceived by individual black women or not, could also impact cellular physiology and gene expression patterns relevant to HR- breast cancer etiology. Using the weathering hypothesis as our conceptual framework, we develop a structural perspective for examining racial disparities in breast cancer subtypes, integrating important findings from the stress biology, breast cancer epidemiology, and health disparities literatures. After integrating key findings from these largely independent literatures, we develop a theoretically and empirically guided framework for assessing potential multilevel factors relevant to the development of HR- breast cancer disproportionately among Black women in the US. We hypothesize that a dynamic interplay among socially patterned psychosocial stressors, physiological & behavioral responses, and genomic pathways contribute to the increased risk of HR- breast cancer among Black women. This work provides a basis for exploring potential alternative pathways linking the lived experience of race to the risk of HR- breast cancer, and suggests new avenues for research and public health action.

Is Vigorous Exercise Training Superior to Moderate for CVD Risk after Menopause?

Postmenopausal women have an increased risk for cardiovascular disease through many factors, such as a sedentary lifestyle and reduced heart rate variability (HRV). Endurance training improves coronary risk but the role of exercise intensity is unclear. The purpose of this observational study was to evaluate the effects of moderate versus vigorous exercise on cardiovascular disease risk in postmenopausal women. Thirty-six postmenopausal women who self-reported training at moderate (3-5.9 METS; n=18; age 58.9±4.4yr) or vigorous intensities (>6 METS; n=18; age 59.7±5.2yr) participated. C-reactive protein (CRP), HRV, VO ₂ max, and stress (Perceived Stress Survey, Menopause Rating Scale) were measured. Groups were compared using independent samples t- tests, and associations of exercise intensities with CRP and HRV were assessed using multiple regression. CRP, HRV, and VO ₂ max were similar ( p >0.05). Vigorous exercise had lower stress subscale scores ( p <0.01) and higher counter-stress subscale scores compared to moderate ( p <0.05). There was a positive association between time spent in vigorous exercise and HRV ( p <0.05).Vigorous exercise may not confer additional benefits in CRP and HRV over moderate, except for stress reduction. However, more time spent in vigorous exercise was associated with higher HRV. Therefore, increased parasympathetic tone may provide cardioprotection after menopause.

Low vigorous physical activity is associated with increased adrenocortical reactivity to psychosocial stress in students with high stress perceptions

OBJECTIVES

The pathways by which physical activity impacts on participants' health are still not fully understood. The purpose of the present study was to go beyond existing research by combining methods from survey-based and experimental stress research, and by examining whether the potential of vigorous physical activity (VPA) to attenuate physiological and psychological stress responses is moderated by participants' subjective stress perception.

METHODS

The sample consisted of 42 undergraduate students (M=21.2±2.2 years, 52% women). Participants self-reported their stress and wore an accelerometer device for seven consecutive days. To examine differences in the adrenocortical, autonomic and psychological stress reactivity, salivary free cortisol, heart rate, state anxiety, mood and calmness were assessed prior to, during and after the Trier Social Stress Test (TSST). The cut-offs of the American College of Sports Medicine (ACSM) were used to distinguish between students below/above current VPA recommendations.

RESULTS

High levels of perceived stress combined with VPA levels below the ACSM's standards (<3×20min/week) were associated with an increased salivary cortisol response to the TSST (p<.05). No significant group differences existed for heart rate. However, students with high stress/low VPA experienced less favourable affect throughout the entire testing session (p<.05).

CONCLUSIONS

Our study suggests that VPA has a high stress-protective potential among undergraduate students with high stress levels. Our findings highlight that promoting VPA in young adults seems to be a promising strategy to increase physiological and psychological stress resilience.

The effects of aging in the hippocampus and cognitive decline

Aging is a natural process that is associated with cognitive decline as well as functional and social impairments. One structure of particular interest when considering aging and cognitive decline is the hippocampus, a brain region known to play an important role in learning and memory consolidation as well as in affective behaviours and mood regulation, and where both functional and structural plasticity (e.g., neurogenesis) occur well into adulthood. Neurobiological alterations seen in the aging hippocampus including increased oxidative stress and neuroinflammation, altered intracellular signalling and gene expression, as well as reduced neurogenesis and synaptic plasticity, are thought to be associated with age-related cognitive decline. Non-invasive strategies such as caloric restriction, physical exercise, and environmental enrichment have been shown to counteract many of the age-induced alterations in hippocampal signalling, structure, and function. Thus, such approaches may have therapeutic value in counteracting the deleterious effects of aging and protecting the brain against age-associated neurodegenerative processes.

Physical Activity Modulates Common Neuroplasticity Substrates in Major Depressive and Bipolar Disorder

Mood disorders (MDs) are chronic, recurrent mental diseases that affect millions of individuals worldwide. Although the biogenic amine model has provided some clinical utility, a need remains to better understand the interrelated mechanisms that contribute to neuroplasticity deficits in MDs and the means by which various therapeutics mitigate them. Of those therapeutics being investigated, physical activity (PA) has shown clear and consistent promise. Accordingly, the aims of this review are to (1) explicate key modulators, processes, and interactions that impinge upon multiple susceptibility points to effectuate neuroplasticity deficits in MDs; (2) explore the putative mechanisms by which PA mitigates these features; (3) review protocols used to induce the positive effects of PA in MDs; and (4) highlight implications for clinicians and researchers.

Exercise and Sports Medicine Issues in Underserved Populations

Primary care providers can make a strong argument for exercise promotion in underserved communities. The benefits are vitally important in adolescent physical, cognitive, and psychological development as well as in adult disease prevention and treatment. In counseling such patients, we should take into account a patient's readiness for change and the barriers to exercise.

Exercise training - A beneficial intervention in the treatment of alcohol use disorders?

BACKGROUND

A growing body of evidence suggests that exercise training may have multiple beneficial effects in individuals with mental health or substance use disorders. Yet, relatively little knowledge exists regarding the benefits of exercise training to augment treatment for alcohol use disorders (AUDs).

PURPOSE

The purpose of this narrative review is to present a summary of the growing body of published literature supporting exercise training as a treatment strategy for individuals with AUDs. We will provide evidence on the myriad of ways in which exercise may exert a positive effect on AUD outcomes including stress, anxiety, impulsivity, and depression. Further, we will explore how these mechanisms share common neurobiological pathways. The role of exercise in enhancing the social environment and increasing individual self-efficacy to reduce excess and/or inappropriate alcohol consumption will also be discussed.

DISCUSSION

We will conclude with a description of completed investigations involving exercise training and provide suggestions for next steps in this innovative field of study.

Relationship among stress, depression, cardiovascular and metabolic changes and physical exercise

Abstract Introduction: Stress is considered one of the most significant health problems in modern society. It can be characterized as any changes in the homeostasis of an individual that require an adaptive response. An imbalance in the secretion of the primary stress mediators may be responsible for the onset and development of several diseases. Thus, chronic stress has been recognized as a risk factor for depression as well as cardiovascular and metabolic diseases. Given the pathophysiological mechanisms associated with chronic stress and related cardiovascular and metabolic changes, it is necessary to implement measures to prevent, control and/or avoid their development. Physical exercise is a non-pharmacological resource that is widely used for this purpose. Its beneficial effects include the improvement of the emotional state as well as lipid and glycemic control. Objective: The aim of this review is to discuss the relationship between stress, depression, cardiovascular and metabolic changes, and highlight the importance of physical exercise in the prevention and treatment of resulting disorders. Materials and Methods: We searched MEDLINE and SCIELO from 2000 through 2012, using the terms chronic stress, mood disorders, depression, cardiovascular and metabolic changes, and exercise. Results: Most of the studies found in our literature search have shown that exercise can attenuate and/or reverse the deleterious effects of chronic stress. Conclusion: Regular physical exercise is useful for maintaining health, especially with respect to improving mood and mental stress.

Hypothalamo-pituitary adrenal axis and sympatho-adrenal medullary system responses to psychological stress were not attenuated in women with elevated physical fitness levels

It is not clear if higher levels of cardiorespiratory fitness are associated with lower hypothalamo-pituitary adrenal (HPA) axis and sympatho-adrenal medullary (SAM) system reactivity to psychological stress in women. The association between cardio-metabolic risk markers and acute physiological responses to psychological stress in women who differ in their cardiorespiratory fitness status has also not been investigated. Women with high (n = 22) and low (n = 22) levels of fitness aged 30-50 years (in the mid-follicular phase of the menstrual cycle) were subjected to a Trier Social Stress Test (TSST) at 1500 h. Plasma concentrations of cortisol, adrenaline (Adr), noradrenaline (NA), and dopamine (DA) were measured in samples collected every 7-15 min from 1400 to 1700 h. Heart rate and blood pressure were measured at the same time points. Low-fit women had elevated serum triglyceride, cholesterol/HDL ratio, fasting glucose, and HOMA-IR levels compared with high-fit women. While cortisol, Adr, NA, HR, and blood pressure all demonstrated a significant response to the TSST, the responses of these variables did not differ significantly between high- and low-fit women in response to the TSST. Dopamine reactivity was significantly higher in the low-fit women compared with high-fit women. There was also a significant negative correlation between VO2 max and DA reactivity. These findings suggest that, for low-fit women aged 30-50 years, the response of HPA axis and SAM system to a potent acute psychological stressor is not compromised compared to that in high-fit women.

High Cardiorespiratory Fitness Is Negatively Associated with Daily Cortisol Output in Healthy Aging Men

Physical fitness has salutary psychological and physical effects in older adults by promoting neuroplasticity and adaptation to stress. In aging, however, the effects of fitness on the hypothalamic-pituitary-adrenal (HPA) axis are mixed. We investigated the association between cardiorespiratory fitness and HPA activity in healthy elderly men (n = 22, mean age 68 y; smokers, obese subjects, those taking drugs or reporting recent stressful events were excluded), by measuring in saliva: i) daily pattern of cortisol secretion (6 samples: 30' post-awakening, and at 12.00, 15.00, 18.00, 21.00, 24.00 h); and ii) the cortisol response to a mental challenge. Cardiorespiratory fitness (VO2max) was estimated using the Rockport Walking Test and the participants were assigned to high-fit (HF, ≥60°, n = 10) and low-fit (LF, ≤35°, n = 12) groups according to age-specific percentiles of VO2max distribution in the general population. At all daytimes, basal cortisol levels were lower in the HF than the LF group, most notably in the evening and midnight samples, with a significant main effect of physical fitness for cortisol levels overall; the area-under-the-curve for total daily cortisol output was significantly smaller in the HF group. Among the subjects who responded to mental stress (baseline-to-peak increment >1.5 nmol/L; n = 13, 5 LF, 8 HF), the amplitude of cortisol response and the steepness of recovery decline displayed an increasing trend in the HF subjects, although between-group differences failed to reach the threshold for significance. In conclusion, cardiorespiratory fitness in healthy aging men is negatively correlated with daily cortisol output and contributes to buffering the HPA dysregulation that occurs with advancing age, thus possibly playing a beneficial role in contrasting age-related cognitive and physical decline.

Successful physical exercise-induced weight loss is modulated by habitual sleep duration in the elderly: results of a pilot study

Although it is widely accepted that physical exercise promotes weight loss, physical exercise alone had been found to result in only marginal weight loss compared to no treatment. Interestingly, both subjective and objective sleep duration have been shown to be negatively correlated to the body mass index (BMI). Despite this growing evidence of a relation between sleep duration and body weight, the role of habitual sleep duration in physical exercise-induced weight loss has not been studied so far. Twenty-two healthy elderly good sleepers aged 61-76 years (mean 68.36 years, 55 % female, BMI mean 25.15 kg/m²) either took part in a 12-week aerobic endurance training (3 × 30 min/week) or in a relaxation control (2 × 45 min/week). The BMI was assessed prior to and after intervention. Subjects maintained sleep logs every morning/evening during the training period, allowing for calculation of habitual sleep duration. Besides a significant main effect of the type of training, a significant interaction of type of training and habitual sleep duration was observed: while after treadmill training subjects who slept less than 7.5 h/night during intervention reduced their BMI by nearly 4 %, a comparable decrease in the BMI was found neither in subjects who slept more than 7.5 h nor after relaxation training independent of sleep duration. Sleep duration itself did not change in any group. Although results should be interpreted with caution due to the small sample size, this is the first study to indicate that physical exercise might compensate for disturbed body weight regulation associated with short sleep duration.

Identification of resilient individuals and those at risk for performance deficits under stress

Human task performance is affected by exposure to physiological and psychological stress. The ability to measure the physiological response to stressors and correlate that to task performance could be used to identify resilient individuals or those at risk for stress-related performance decrements. Accomplishing this prior to performance under severe stress or the development of clinical stress disorders could facilitate focused preparation such as tailoring training to individual needs. Here we measure the effects of stress on physiological response and performance through behavior, physiological sensors, and subjective ratings, and identify which individuals are at risk for stress-related performance decrements. Participants performed military-relevant training tasks under stress in a virtual environment, with autonomic and hypothalamic-pituitary-adrenal axis (HPA) reactivity analyzed. Self-reported stress, as well as physiological indices of stress, increased in the group pre-exposed to socioevaluative stress. Stress response was effectively captured via electrodermal and cardiovascular measures of heart rate and skin conductance level. A resilience classification algorithm was developed based upon physiological reactivity, which correlated with baseline unstressed physiological and self-reported stress values. Outliers were identified in the experimental group that had a significant mismatch between self-reported stress and salivary cortisol. Baseline stress measurements were predictive of individual resilience to stress, including the impact stress had on physiological reactivity and performance. Such an approach may have utility in identifying individuals at risk for problems performing under severe stress. Continuing work has focused on adapting this method for military personnel, and assessing the utility of various coping and decision-making strategies on performance and physiological stress.

Molecular consequences of psychological stress in human aging

Psychological stress has often been described as a feeling of being overwhelmed by the necessity of constant adjustment to an individual's changing environment. Stress affects people of all ages, but the lives of the elderly may particularly be affected. Major changes can cause anxiety leading to feelings of insecurity and/or loss of self-esteem and depression. The cellular mechanisms underlying psychological stress are poorly understood. This review focuses on the physical and molecular consequences of psychological stress linked to aging processes and, in particular, how molecular changes induced by psychological stress can compromise healthy aging.

Lipopolysaccharide-binding protein and leptin are associated with stress-induced interleukin-6 cytokine expression ex vivo in obesity

Obesity is associated with enhanced inflammation and mental stress, but limited information has addressed the potential additive effect of psychological stress on obesity-associated inflammation. This study examined whether obese subjects would elicit a greater host immune response (IL-6 mRNA and cytokine) to lipopolysaccharide (LPS) in response to mental stress. Blood samples for LPS-stimulated IL-6 mRNA and cytokine were collected prior to and following mental stress. Results showed that obese subjects elicited a greater LPS-induced IL-6 along with its mRNA expression following mental stress compared to normal-weight subjects. Stress-induced IL-6 cytokine response to LPS was correlated with the baseline levels of plasma LPS binding protein (LBP) and leptin. These findings are consistent with the idea that endogenous inflammatory agents (e.g., LBP and leptin), often elevated with obesity, enhance inflammatory responses to psychological stress.