The association between self-reported stress and cardiovascular measures in daily life: A systematic review

Wearable EEG-Based Brain-Computer Interface for Stress Monitoring

Detecting stress is important for improving human health and potential, because moderate levels of stress may motivate people towards better performance at cognitive tasks, while chronic stress exposure causes impaired performance and health risks. We propose a Brain-Computer Interface (BCI) system to detect stress in the context of high-pressure work environments. The BCI system includes an electroencephalogram (EEG) headband with dry electrodes and an electrocardiogram (ECG) chest belt. We collected EEG and ECG data from 40 participants during two stressful cognitive tasks: the Cognitive Vigilance Task (CVT), and the Multi-Modal Integration Task (MMIT) we designed. We also recorded self-reported stress levels using the Dundee Stress State Questionnaire (DSSQ). The DSSQ results indicated that performing the MMIT led to significant increases in stress, while performing the CVT did not. Subsequently, we trained two different models to classify stress from non-stress states, one using EEG features, and the other using heart rate variability (HRV) features extracted from the ECG. Our EEG-based model achieved an overall accuracy of 81.0% for MMIT and 77.2% for CVT. However, our HRV-based model only achieved 62.1% accuracy for CVT and 56.0% for MMIT. We conclude that EEG is an effective predictor of stress in the context of stressful cognitive tasks. Our proposed BCI system shows promise in evaluating mental stress in high-pressure work environments, particularly when utilizing an EEG-based BCI.

Perceived control predicts lower end-of-day stress through engagement in moderate or vigorous physical activity: A daily diary study in a US adult sample

Perceived control (PC) is associated with lower perceived stress, but the mechanisms of this relationship have not yet been established. The current study examined whether moderate or vigorous intensity physical activity (MVPA) mediated the relationship between PC and daily stress in a sample of US adults. Participants (N = 264, Mage = 34.08, 61.4% female) completed a baseline measure of two dimensions of PC (i.e., mastery and constraints), followed by 11 days of daily surveys that assessed daily MVPA and perceived stress. We employed linear mixed effects modelling to estimate the within-and between-person indirect effects (IE) of MVPA on the relationships between each dimension of PC and daily perceived stress. Greater PC (i.e., higher mastery and lower constraints) was associated with a higher frequency of MVPA engagement, and participants reported lower levels of end-of-day perceived stress on the days in which they had engaged in MVPA. We observed within-person mediating effects of MVPA on the relationship between both PC dimensions and daily stress (mastery: within-person IE = -0.03, 95% CI: [-0.06, -0.01]; constraints: within-person IE = 0.03, 95% CI: [0.01, 0.06]). These findings suggest that MVPA is a potential mechanism through which US adults with greater PC experience reduced levels of daily stress. The current study illuminates a key pathway for the stress-reducing impact of PC to inform future research and interventions targeting stress and its associated sequelae.

Reduced heart rate variability is related to fluctuations in psychological stress levels in daily life

Laboratory-based studies have shown that psychological stress caused by response to various stressors triggers acute changes in the cardiovascular system. A better understanding is needed of the emerging evidence on temporal associations between psychological stress and cardiovascular responses in natural settings. This study examined the association of psychological stress and heart rate variability (HRV) in daily life, at high resolution over 2 weeks, taking the effect of physical activity into account. Participants (n = 34) completed ecological momentary assessments (EMA) 6 times per day, reporting levels of perceived stress, low-arousal negative affect (LNA), and high-arousal negative affect. Chest-mounted heart-rate monitors were worn to assess HRV. Multilevel models were used to examine the association between psychological stress levels and preceding/subsequent HRV. Reduced time domain HRV measures (mean and standard deviation of R-wave to R-wave intervals) during the prior hour predicted higher levels of perceived stress. Frequency domain HRV measures higher low to high frequency (LF/HF) and lower HF to total power (HF nu) ratios during the preceding 10 min predicted higher perceived stress levels, suggesting the dominance of sympathetic nervous system activity. EMA reports of higher perceived stress levels were associated with reduced time domain HRV measures during the following 10 min. On the other hand, higher LNA were related to increased HRV measures, such as lower LF/HF and higher HF nu during the following hour. The dynamic associations observed may have therapeutic implications for 'just-in-time' interventions in the management of daily stress and cardiovascular health.

Can pre-visit exposure to virtual tours of healthcare facilities help reduce child and parent anxiety during outpatient surgical procedures?

AIM

The study aims to evaluate the impact of exposure to a highly realistic virtual facility tour prior to the on-site visit on patients and their parent/care partner's self-reported anxiety and physiological measures on the day of the procedure.

BACKGROUND

Preoperative anxiety impacts pediatric surgical outcomes; therefore, it is important for healthcare providers to address and manage preoperative anxiety in pediatric patients to promote better outcomes and overall wellbeing. Providing patients with a preview of the care setting before the actual procedure can be highly beneficial in mitigating preoperative anxiety.

METHODOLOGY

In this pilot randomized experimental study, sixteen patient-care partner dyads scheduled to undergo a gastrointestinal procedure either received a virtual tour identical to the places experienced on the day of the procedure (experimental group) or received no virtual tour (control group). Self-reported measures of anxiety were collected from participants before and on the day of the procedure. Physiological measures of heart rate variability and skin conductance were collected on the day of the procedure from both groups.

RESULTS

There were no significant differences between the self-reported and physiological measures of anxiety between the child groups. However, parents in the control group reported lower levels of anxiety and demonstrated lower levels of stress based on their physiological measures.

CONCLUSION

Exposure to virtual facility tours days before the surgery was not helpful in positively impacting the psychological measures related to preoperative anxiety levels for the participants.

Environmental drivers of increased ecosystem respiration in a warming tundra

Arctic and alpine tundra ecosystems are large reservoirs of organic carbon1,2. Climate warming may stimulate ecosystem respiration and release carbon into the atmosphere3,4. The magnitude and persistency of this stimulation and the environmental mechanisms that drive its variation remain uncertain5-7. This hampers the accuracy of global land carbon-climate feedback projections7,8. Here we synthesize 136 datasets from 56 open-top chamber in situ warming experiments located at 28 arctic and alpine tundra sites which have been running for less than 1 year up to 25 years. We show that a mean rise of 1.4 °C [confidence interval (CI) 0.9-2.0 °C] in air and 0.4 °C [CI 0.2-0.7 °C] in soil temperature results in an increase in growing season ecosystem respiration by 30% [CI 22-38%] (n = 136). Our findings indicate that the stimulation of ecosystem respiration was due to increases in both plant-related and microbial respiration (n = 9) and continued for at least 25 years (n = 136). The magnitude of the warming effects on respiration was driven by variation in warming-induced changes in local soil conditions, that is, changes in total nitrogen concentration and pH and by context-dependent spatial variation in these conditions, in particular total nitrogen concentration and the carbon:nitrogen ratio. Tundra sites with stronger nitrogen limitations and sites in which warming had stimulated plant and microbial nutrient turnover seemed particularly sensitive in their respiration response to warming. The results highlight the importance of local soil conditions and warming-induced changes therein for future climatic impacts on respiration.

Stressful life events and heart disease and stroke: A study among Portuguese older adults

The link between stressful life events (SLE) and cardiovascular diseases (CVD) remains underexplored. This study aimed to examine the association between SLE and the diagnosis of heart disease or stroke, among older adults. Data from 678 participants from the population-based cohort EPIPorto, with ≥60 years and complete information regarding SLE and heart disease or stroke, were analysed. Stressful life events were measured through the 'Stressful Life Events Screening Questionnaire'. A previous diagnosis of heart disease or stroke was self-reported. Adjusted odds ratios (OR) with the respective 95% confidence intervals were computed through logistic regression. Almost a fourth of the participants never experienced any SLE throughout life, 30.0% experienced at least one event, 17.5% experienced two and 27.7% had experienced three or more SLE. A dose-effect association between SLE and the diagnosis of heart disease or stroke was observed, statistically significant for those who had at least 3 types of SLE, independently of confounders (≥3SLE vs. 0SLE: OR = 2.00; 95% CI: 1.12-3.57). This cross-sectional study suggests that cumulative exposure to different types of SLE during the life course was associated with a higher likelihood of having a diagnosis of heart disease or a stroke at a later age. Future longitudinal studies should better deepen this association, particularly by evaluating which type of SLE is more related to a higher prevalence of heart disease and stroke, and how the timing of the SLE influence this relation.

Perceived Stress From Childhood to Adulthood and Cardiometabolic End Points in Young Adulthood: An 18-Year Prospective Study

BACKGROUND

We investigated how childhood-to-adulthood perceived stress patterns predict adult cardiometabolic risk.

METHODS AND RESULTS

This study included 276 participants from the Southern California Children's Health Study (2003-2014), and a follow-up assessment (2018-2021). Perceived stress (Perceived Stress Scale) was initially reported by participants' parents for themselves during early childhood (mean age, 6.3 years), and later self-reported during adolescence (13.3 years) and young adulthood (23.6 years). Participants were grouped into 4 stress patterns: consistently high, decreasing, increasing, and consistently low. Cardiometabolic risk was assessed in young adulthood by carotid artery intima-media thickness, systolic and diastolic blood pressure, obesity, percent body fat, android/gynoid ratio, and glycated hemoglobin. A cardiometabolic risk score was generated by summing the clinically abnormal markers. Multivariable linear and logistic regression models were used to (1) examine the associations between Perceived Stress Scale at 3 time points and adult cardiometabolic risk, and (2) assess the impact of stress pattern on adult cardiometabolic risk. Findings suggested that in adulthood, higher Perceived Stress Scale score was associated with increased overall cardiometabolic risk (β=0.12 [95% CI, 0.01-0.22]), carotid artery intima-media thickness (β=0.01 [95% CI, 0.0003-0.02]), systolic blood pressure (β=1.27 [95% CI, 0.09-2.45]), and diastolic blood pressure (β=0.94 [95% CI, 0.13-1.75]). Individuals with a consistently high adolescence-to-adulthood stress pattern had greater overall cardiometabolic risk (β=0.31 [95% CI, 0.02-0.60]), android/gynoid ratio (β=0.07 [95% CI, 0.02-0.13]), percent body fat (β=2.59 [95% CI, 0.01-5.17]), and greater odds of obesity (odds ratio, 5.57 [95% CI, 1.62-19.10]) in adulthood, compared with those with a consistently low Perceived Stress Scale score.

CONCLUSIONS

Consistently high perceived stress from adolescence to adulthood may contribute to greater cardiometabolic risk in young adulthood.

Designing daily-life research combining experience sampling method with parallel data

BACKGROUND

Ambulatory monitoring is gaining popularity in mental and somatic health care to capture an individual's wellbeing or treatment course in daily-life. Experience sampling method collects subjective time-series data of patients' experiences, behavior, and context. At the same time, digital devices allow for less intrusive collection of more objective time-series data with higher sampling frequencies and for prolonged sampling periods. We refer to these data as parallel data. Combining these two data types holds the promise to revolutionize health care. However, existing ambulatory monitoring guidelines are too specific to each data type, and lack overall directions on how to effectively combine them.

METHODS

Literature and expert opinions were integrated to formulate relevant guiding principles.

RESULTS

Experience sampling and parallel data must be approached as one holistic time series right from the start, at the study design stage. The fluctuation pattern and volatility of the different variables of interest must be well understood to ensure that these data are compatible. Data have to be collected and operationalized in a manner that the minimal common denominator is able to answer the research question with regard to temporal and disease severity resolution. Furthermore, recommendations are provided for device selection, data management, and analysis. Open science practices are also highlighted throughout. Finally, we provide a practical checklist with the delineated considerations and an open-source example demonstrating how to apply it.

CONCLUSIONS

The provided considerations aim to structure and support researchers as they undertake the new challenges presented by this exciting multidisciplinary research field.

Detecting Prolonged Stress in Real Life Using Wearable Biosensors and Ecological Momentary Assessments: Naturalistic Experimental Study

BACKGROUND

Increasing efforts toward the prevention of stress-related mental disorders have created a need for unobtrusive real-life monitoring of stress-related symptoms. Wearable devices have emerged as a possible solution to aid in this process, but their use in real-life stress detection has not been systematically investigated.

OBJECTIVE

We aimed to determine the utility of ecological momentary assessments (EMA) and physiological arousal measured through wearable devices in detecting ecologically relevant stress states.

METHODS

Using EMA combined with wearable biosensors for ecological physiological assessments (EPA), we investigated the impact of an ecological stressor (ie, a high-stakes examination week) on physiological arousal and affect compared to a control week without examinations in first-year medical and biomedical science students (51/83, 61.4% female). We first used generalized linear mixed-effects models with maximal fitting approaches to investigate the impact of examination periods on subjective stress exposure, mood, and physiological arousal. We then used machine learning models to investigate whether we could use EMA, wearable biosensors, or the combination of both to classify momentary data (ie, beeps) as belonging to examination or control weeks. We tested both individualized models using a leave-one-beep-out approach and group-based models using a leave-one-subject-out approach.

RESULTS

During stressful high-stakes examination (versus control) weeks, participants reported increased negative affect and decreased positive affect. Intriguingly, physiological arousal decreased on average during the examination week. Time-resolved analyses revealed peaks in physiological arousal associated with both momentary self-reported stress exposure and self-reported positive affect. Mediation models revealed that the decreased physiological arousal in the examination week was mediated by lower positive affect during the same period. We then used machine learning to show that while individualized EMA outperformed EPA in its ability to classify beeps as originating from examinations or from control weeks (1603/4793, 33.45% and 1648/4565, 36.11% error rates, respectively), a combination of EMA and EPA yields optimal classification (1363/4565, 29.87% error rate). Finally, when comparing individualized models to group-based models, we found that the individualized models significantly outperformed the group-based models across all 3 inputs (EMA, EPA, and the combination).

CONCLUSIONS

This study underscores the potential of wearable biosensors for stress-related mental health monitoring. However, it emphasizes the necessity of psychological context in interpreting physiological arousal captured by these devices, as arousal can be related to both positive and negative contexts. Moreover, our findings support a personalized approach in which momentary stress is optimally detected when referenced against an individual's own data.

The importance of high-quality partner support for reducing stress during pregnancy and postpartum bonding impairments

The current study investigated the extent to which interparental support reduced pregnancy stress and subsequent postpartum bonding impairments with infant. We hypothesized that receiving higher quality partner support would be associated with decreased maternal pregnancy-related concerns, and less maternal and paternal pregnancy stress which, in turn, would predict fewer parent-infant bonding impairments. One hundred fifty-seven cohabiting couples completed semi-structured interviews and questionnaires once during pregnancy and twice postpartum. Path analyses with tests of mediation were employed to test our hypotheses. Higher quality support received by mothers was associated with lower maternal pregnancy stress which, in turn, predicted fewer mother-infant bonding impairments. An indirect pathway of equal magnitude was observed for fathers. Dyadic pathways also emerged such that higher quality support received by fathers was associated with lower maternal pregnancy stress which reduced mother-infant bonding impairments. Similarly, higher quality support received by mothers reduced paternal pregnancy stress and subsequent father-infant bonding impairments. Hypothesized effects reaching statistical significance (p < .05) were small to moderate in magnitude. These findings have important theoretical and clinical implications in demonstrating the critical role of both receiving and providing high-quality interparental support to reduce pregnancy stress and subsequent postpartum bonding impairments for mothers and fathers. Results also highlight the utility of investigating maternal mental health in the couple context.

Does anxiety explain why math-anxious people underperform in math?

Math-anxious people consistently underperform in math. The most widely accepted explanation for why this underperformance occurs is that math-anxious people experience heightened anxiety when faced with math, and this in-the-moment anxiety interferes with performance. Surprisingly, this explanation has not been tested directly. Here, using both self-report and physiological indices of anxiety, we directly test how much in-the-moment anxiety explains math-anxious underperformance. Results indicate that in-the-moment anxiety indeed explains why math-anxious people underperform-but only partially, suggesting a need to seriously consider alternative mechanisms. Results also showed that while some highly math-anxious individuals-those with high levels of heart rate variability-experienced less in-the-moment anxiety, they nevertheless performed no better at math. For these individuals, math-anxious underperformance must occur for reasons unrelated to in-the-moment anxiety. More broadly, our findings point to substantial individual heterogeneity in the mechanisms underlying math-anxious underperformance. Accounting for this mechanistic heterogeneity may prove vital for optimally boosting math performance in math-anxious individuals.

Recovery After Stress-Autonomic and Subjective Arousal in Individuals With Psychosis Compared to Healthy Controls

BACKGROUND AND HYPOTHESIS

Heightened stress levels in individuals with psychosis (PSY) are associated with psychotic symptom occurrence and may be partially attributed to well-established deficits in resting-state heart rate variability (HRV) and emotion regulation. In healthy participants, resting-state HRV and self-reported emotion regulation skills have been linked to recovery after a stressor; however, it is unclear whether stress recovery is altered in PSY. Thus, we compared the autonomic and subjective recovery of PSY to healthy controls (HC) and investigated the predictive value of resting-state HRV and emotion regulation skills.

STUDY DESIGN

We assessed resting-state HRV and self-reported emotion regulation one week prior to a combined physical and cognitive stress induction. After the stress exposure, we assessed the autonomic (decrease in heart rate [HR], increase in HRV) and subjective (decrease in subjective stress and negative affect) recovery in PSY (n = 50) and HC (n = 50) over 60 min.

STUDY RESULTS

Repeated-measures ANOVA revealed the expected interaction of time × group for subjective stress but not negative affect or autonomic stress. Resting-state HRV predicted recovery of HR, and emotion regulation skills predicted recovery of HRV but not of the other parameters.

CONCLUSIONS

Although subjective stress recovery was delayed in PSY, the absence of autonomic recovery deficits suggests that a prolonged stress response may not contribute to heightened stress levels to the expected extent. Improving resting-state HRV and emotion regulation may support autonomic recovery, but further investigation is required to test the impact of such improvements on psychotic symptoms.

Physiological reactions to acute stressors and subjective stress during daily life: A systematic review on ecological momentary assessment (EMA) studies

OBJECTIVE

This review aims to provide an overview of ecological momentary assessment (EMA) studies analyzing stress reactivity during daily life in terms of direct and moderated influence of acute stress on physiological responses.

MATERIALS AND METHODS

A systematic literature search was performed on November 29, 2021 using Web of Science, MEDLINE and PsycINFO to identify prospective EMA studies targeting acute stressors or stress under naturalistic conditions, without restrictions of publication date or population. Study quality was assessed for multiple EMA-specific sources of bias.

RESULTS

Out of 4285 non-duplicate records, 107 publications involving 104 unique studies were included. The majority of studies assessed acute physiological stress responses primarily through salivary cortisol (n = 59) and cardiovascular outcomes (n = 32). Most studies performed at least three measurements per day (n = 59), and had a moderate risk of recall bias (n = 68) and confounding (n = 85). Fifty-four studies reported a compliance of ≥80%. Direct, non-moderated positive associations were observed between acute stress exposure and concurrent cortisol levels (44%, n = 11/25), systolic (44%, 8/18) and diastolic blood pressure (53%, 8/15) and heart rate (53%, 9/17). Several inter- and intra-individual moderators were identified, such as age, gender, health status, chronic stress, work-related resources, physical activity and stress coping indicators.

CONCLUSIONS

About half of the reviewed EMA studies demonstrated direct associations between everyday acute stress exposure and physiological responses, including increased cortisol levels, blood pressure and heart rate. Results further suggested various moderator variables that could help develop tailored prevention strategies and identify groups at higher risk for dysfunctional stress responses.

REGISTRATION

PROSPERO-Reg.-No.: PROSPERO 2020 CRD42020163178.

Self-monitoring of psychological stress-induced blood pressure in daily life using a wearable watch-type oscillometric device in working individuals with hypertension

This study investigated psychological stress-induced blood pressure (BP) elevation according to self-measured data obtained by a wearable watch-type oscillometric device for multiple days in 50 working hypertension patients (mean ± SD age: 60.5 ± 8.9 years; 92.0% men; 96% treated for hypertension). Participants were asked to self-measure their BPs at five predetermined times as well as at any additional time points at their own discretion under ambulatory conditions for a maximum of 7 days. At the time of each BP measurement, participants self-reported their location, emotion, and degree of stress. A total of 1220 BP readings with self-reported situational information were obtained from 50 participants over 5.5 ± 1.2 days. Systolic BP (SBP) and diastolic BP (DBP) measured during moments of self-reported negative emotions (i.e., anger, tension, anxiety, or sadness) were significantly higher (5.0 ± 1.3 and 2.0 ± 0.8 mmHg, both p < 0.05) than those during moments of self-reported positive emotions (i.e., happiness or calm). SBP/DBP were significantly increased under a moderate or high degree of stress by [4.5 ± 1.1]/[2.5 ± 0.7] and [10.2 ± 3.0]/[4.7 ± 1.8] mmHg, respectively. As a result, it was estimated that SBP/DBP increased 15.2/8.5 mmHg in the presence of highly stressful negative emotions. In conclusion, self-measurement of BP monitoring with a wearable device for multiple days is a feasible method to detect daily stress-induced BP elevation in working adults.