Chronic stress influences ambulatory blood pressure in adolescents

Personalized AI-Driven Real-Time Models to Predict Stress-Induced Blood Pressure Spikes Using Wearable Devices: Proposal for a Prospective Cohort Study

BACKGROUND

Referred to as the "silent killer," elevated blood pressure (BP) often goes unnoticed due to the absence of apparent symptoms, resulting in cumulative harm over time. Chronic stress has been consistently linked to increased BP. Prior studies have found that elevated BP often arises due to a stressful lifestyle, although the effect of exact stressors varies drastically between individuals. The heterogeneous nature of both the stress and BP response to a multitude of lifestyle decisions can make it difficult if not impossible to pinpoint the most deleterious behaviors using the traditional mechanism of clinical interviews.

OBJECTIVE

The aim of this study is to leverage machine learning (ML) algorithms for real-time predictions of stress-induced BP spikes using consumer wearable devices such as Fitbit, providing actionable insights to both patients and clinicians to improve diagnostics and enable proactive health monitoring. This study also seeks to address the significant challenges in identifying specific deleterious behaviors associated with stress-induced hypertension through the development of personalized artificial intelligence models for individual patients, departing from the conventional approach of using generalized models.

METHODS

The study proposes the development of ML algorithms to analyze biosignals obtained from these wearable devices, aiming to make real-time predictions about BP spikes. Given the longitudinal nature of the data set comprising time-series data from wearables (eg, Fitbit) and corresponding time-stamped labels representing stress levels from Ecological Momentary Assessment reports, the adoption of self-supervised learning for pretraining the network and using transformer models for fine-tuning the model on a personalized prediction task is proposed. Transformer models, with their self-attention mechanisms, dynamically weigh the importance of different time steps, enabling the model to focus on relevant temporal features and dependencies, facilitating accurate prediction.

RESULTS

Supported as a pilot project from the Robert C Perry Fund of the Hawaii Community Foundation, the study team has developed the core study app, CardioMate. CardioMate not only reminds participants to initiate BP readings using an Omron HeartGuide wearable monitor but also prompts them multiple times a day to report stress levels. Additionally, it collects other useful information including medications, environmental conditions, and daily interactions. Through the app's messaging system, efficient contact and interaction between users and study admins ensure smooth progress.

CONCLUSIONS

Personalized ML when applied to biosignals offers the potential for real-time digital health interventions for chronic stress and its symptoms. The project's clinical use for Hawaiians with stress-induced high BP combined with its methodological innovation of personalized artificial intelligence models highlights its significance in advancing health care interventions. Through iterative refinement and optimization, the aim is to develop a personalized deep-learning framework capable of accurately predicting stress-induced BP spikes, thereby promoting individual well-being and health outcomes.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/55615.

A multisystem model for understanding stress and adaptation in ethnically and racially diverse youth

Contemporary biological and contextually based theoretical frameworks have conceptualized how stress exposure may influence adaptation in youth. However, nearly all of this scholarship neglects the role of specific contextual features and/or biological processes that are involved in ethnic-racial minority youth's responses and adaptation to sociocultural stressors. Drawing on the theoretical principles of the developmental psychopathology framework and contemporary models of stress and adaptation, this article proposes a new multisystem model that explains how multiple levels and systems within and outside of individual youth influence their sociocultural adaptation. We provide empirical evidence to support components of this multisystem model. We propose that research based on our new theoretical framework will capture the sociocultural experiences of ethnic-racial minority youth by centering processes that are relevant to their lived experiences, coping, and adjustment. In doing so, this model will inform psychosocial interventions focused on promoting healthy adaptation among ethnic and racial diverse youth. Finally, we offer recommendations to guide future research on stress and adaptation among ethnic and racial diverse youth, in particular, and developmental psychopathology more broadly.

Responsive parental support buffers the link between chronic stress and cardiometabolic risk among adolescents

Youth exposed to chronic stress exhibit increased cardiometabolic risk which parental social support may attenuate. Notably, theories emphasize that support should be delivered responsively for it to exert buffering effects, but this has not been thoroughly tested empirically. This study examined whether timing of support is an important but unrecognized element of responsiveness during adolescence in buffering the link between chronic stress and cardiometabolic risk. Participants were 242 adolescents aged 15 years (63 % female, 38 % Black). Adolescents completed assessments of chronic stress (Life Stress Interview), and trained personnel collected anthropometric measures and blood samples to assess cardiometabolic risk (reflected in low-grade inflammation and metabolic syndrome). Adolescents also completed an eight-day diary assessment to report daily stressor exposure and parental support. Using the diary data, responsiveness of parental support was operationalized as the within-individual difference in parental support received on stressor (vs. non-stressor) days, such that increased parental support on stressor days reflected more timely support. Results suggest that responsive parental support buffered the link between chronic stress and cardiovascular risk. Specifically, chronic stress was associated with greater risk only when parental support was not temporally aligned with stress exposure, but this association was not observed among adolescents who received timely parental support. These findings shed light on why parental support may not always exert buffering effects during adolescence, highlighting the importance of taking a developmental approach to understanding protective effects.

Measuring Adolescent Chronic Stress: A Review of Established Biomarkers and Psychometric Instruments

Adolescence is a period of stressful physiological and psychosocial changes. Exposure to chronic stress can cause specific structural and functional changes in an organism, which can be appraised objectively. Some of these alterations are an expected reaction of the body in its attempt to adapt to a stressful situation, while others are signs of possible disease development. The aim of this review was to present the most widely used methods of stress evaluation in adolescence research. Primary biomarkers associated with different biological systems, such as the stress hormones glucocorticoids, and catecholamines, as well as the available methods of extraction and assessment of each biomarker, are presented. This work also includes secondary outcomes, which can also provide an estimation of an individual's stress level. Also, most available psychometric instruments of stress, constructed to address specifically this period of life, are presented and discussed. In addition, this paper addresses possible confounding factors that may affect stress measurements, which should be taken under consideration when conducting stress research. To objectively evaluate stress, it is of great importance for a researcher to be familiar with the condition under examination and its representative stress indices. Adequate evaluation of adolescents with the selection of proper psychometric tests and biological markers can help design targeted interventions aiming to prevent or reverse the effects of physical and mental stressors that occur during adolescence, effects that can be carried into adulthood with detrimental consequences.

Are adherence to the Mediterranean diet and siesta individually or jointly associated with blood pressure in Spanish adolescents? Results from the EHDLA study

Background

Both dietary and sleep patterns can influence both blood pressure levels and heart rate, but these associations have been understudied in adolescents. Furthermore, it is not known whether diet and sleep could exert a synergistic effect with respect to the maintenance of optimal BP levels in this population.

Objective

To investigate the relationship of blood pressure levels with the combination of higher adherence to the Mediterranean diet and the habit of siesta (daytime napping) in Spanish adolescents.

Methods

A cross-sectional study was conducted with data obtained through personal interviews and physical examination from a representative sample of 1,378 adolescents (12-17 years of age) from the Valle de Ricote (Region of Murcia, Spain) selected using a simple random sampling technique. Adherence to the Mediterranean diet was assessed with the Mediterranean Diet Quality Index in Children and Adolescents, and the frequency and duration of siesta were self-reported. Objective measurements of systolic and diastolic blood pressure were obtained under standardized conditions. Statistical procedures were performed with SPSS software (v.25) and included logistic and generalized regression models adjusted for sex, age, socioeconomic status, body mass index, total energy intake, nighttime sleep duration, and moderate-to-vigorous physical activity.

Results

Of the 698 adolescents finally studied (mean age 13.9 ± 1.5 years; 56.2% female), 37.1% (n = 259) had high adherence to the Mediterranean diet and 19.6% (n = 137) reported frequent siesta. In the completely adjusted models, compared to adolescents with low Mediterranean diet adherence and no or infrequent siesta, those with high Mediterranean diet adherence and frequent siesta were less likely to have high-normal blood pressure or hypertension (odds ratio = 0.47; 95% confidence interval: 0.26, 0.88) and showed slightly lower systolic blood pressure (ß-coef. = -2.60; 95% CI: -5.18, -0.02).

Conclusion

Greater adherence to the Mediterranean diet and frequent siesta have a synergistic effect on maintaining lower blood pressure levels in adolescence. These findings reinforce that adherence to both Mediterranean lifestyle behaviors early in life may be an important strategy to prevent hypertension throughout adulthood.

Effects of Life Events and Social Isolation on Stroke and Coronary Heart Disease

The current coronavirus disease 2019 (COVID-19) pandemic represents a severe, life-changing event for people across the world. Life changes may involve job loss, income reduction due to furlough, death of a beloved one, or social stress due to life habit changes. Many people suffer from social isolation due to lockdown or physical distancing, especially those living alone and without family. This article reviews the association of life events and social isolation with cardiovascular disease, assembling the current state of knowledge for stroke and coronary heart disease. Possible mechanisms underlying the links between life events, social isolation, and cardiovascular disease are outlined. Furthermore, groups with increased vulnerability for cardiovascular disease following life events and social isolation are identified, and clinical implications of results are presented.

Correlates of elevated blood pressure in healthy children: a systematic review

The prevalence of hypertension in children is increasing globally. Addressing this will require a robust understanding of associated risk factors. To this end, we conducted a systematic review to identify correlates of elevated blood pressure (BP) in children. Literature searches were conducted using pre-defined search terms from three academic databases. The abstract and full text of identified studies were screened for eligibility by two independent reviewers. A total of 100 studies were included in this systematic review. An assessment tool was first used to assess study quality; a narrative synthesis was then performed. We found a broad range of physiological, social and behavioural factors associated with elevated BP in children. The most common correlate observed was adiposity, suggesting that childhood obesity may be implicated in the increased prevalence of hypertension observed in children. However, the broad range of other factors identified underscores the multi-factorial aetiology of hypertension. Data from a broad range of studies showed that the correlates of hypertension in children are multi-factorial. Therefore, approaches aimed at preventing hypertension must in turn be multi-factorial to ensure that the burden of hypertension in childhood is addressed.

Chronic Stress in Children and Adolescents: A Review of Biomarkers for Use in Pediatric Research

PROBLEM

Incorporating biomarkers of chronic stress into pediatric research studies may help to explicate the links between exposure to adversity and lifelong health, but there are currently very few parameters to guide nurse researchers in choosing appropriate biomarkers of chronic stress for use in research with children and adolescents.

METHODS

Biomarkers of chronic stress are described, including primary mediators (glucocorticoids, catecholamines, and cytokines) and secondary outcomes (neurologic, immune, metabolic, cardiovascular, respiratory, and anthropometric) of the chronic stress response.

RESULTS

Evidence of the use of each biomarker in pediatric research studies is reviewed. Recommendations for pediatric researchers, including selection of appropriate biomarkers, measurement considerations, potential moderators, and future directions for research, are presented.

DISCUSSION

A wide range of biomarkers is available for use in research studies with children. While primary mediators of chronic stress have been frequently measured in studies of children, measurement of secondary outcomes, particularly immune and metabolic biomarkers, has been limited. With thoughtful and theoretically based approaches to selection and measurement, these biomarkers present an important opportunity to further explore the physiologic pathways linking exposure to chronic stress with later health and disease.

CONCLUSION

The incorporation of chronic stress biomarkers into pediatric research studies may provide valuable insight into the mechanisms through which stressful environments "get under the skin" and ultimately inform efforts to promote health and reduce inequities among children exposed to adversity.

Factors That Influence Blood Pressure in 3- to 5-Year-Old Children: A Pilot Study

While incident elevations in blood pressure (BP) are apparent in preschool years, factors influencing BP in this population have received little attention. The purposes of this pilot study were to determine the feasibility of collecting data from preschoolers and their mothers and to determine effect sizes of relationships between BP and sex, race, birth status, body mass index (BMI), waist circumference (WC), geographic location, serum C-reactive protein (CRP), and salivary cortisol (morning, afternoon). A hypothesis-generating correlational design was used; 56 children, aged 3–5 years, were enrolled from six rural and urban Head Start programs in a southeastern state. On Day 1 of data collection, mothers completed demographic questionnaires and children had blood drawn by finger stick. On Day 2, children gave saliva samples for cortisol, were measured for height by stadiometer, weight by digital scales, and WC by tape measure and had their BP measured by Dinamap. Incident elevations in BP were found in 30% of children (17/56), the majority of which were of systolic BP; 65% of those with elevations were of normal weight. Data collection was feasible with few problems. Small-to-medium effect sizes were noted for BP status (normal, prehypertensive, and hypertensive) and cortisol p.m. and birth status (parent-reported prematurity or term); small effect sizes were seen for BP status and BMI, race, sex, and geographic location. CRP and cortisol had medium- and small-to-medium effect sizes, respectively, with diastolic blood pressure. Studies with larger, more diverse samples need to be conducted to test hypotheses posited from these estimated effect sizes.

Household income and adolescent blood pressure in a Chinese birth cohort: "Children of 1997"

The inconsistent relation of national income with population blood pressure raises questions as to whether social comparisons of relative income at individual or neighbourhood level may be more relevant than absolute income. We examined the associations of absolute household income (income per se), absolute neighbourhood median income (average income among geographically-proximate households), relative household income [deprivation using Yitzhaki index, or rank by position] (differences in income or rank compared with others) and relative neighbourhood income inequality [Gini coefficient] (income gap within a neighbourhood) with blood pressure z-score, prehypertension or hypertension at ∼13 years using a fixed effects multilevel linear or logistic model in a Chinese birth cohort (n = 5063, 61% of follow-up). Absolute household or neighbourhood income was not associated with adolescent blood pressure. Greater relative household income deprivation was associated with higher diastolic blood pressure (0.01 z-score per USD 128 difference in Yitzhaki index, 95% confidence interval (CI) 0.005 to 0.02), so was lower relative household income rank (-0.10, 95% CI -0.15 to -0.04), but relative neighbourhood income inequality was not, when considering each income measure separately. Such associations remained when considering all income measures together. Income measures were not associated with prehypertension or hypertension. Relative household income (greater deprivation or lower rank) were positively associated with adolescent blood pressure independent of absolute household income while absolute or relative neighbourhood income had little contribution, suggesting social comparisons at a key developmental stage could be relevant. Clarifying specific effects of socioeconomic position across the life-course could inform interventions.

Sexual orientation disparities in cardiovascular biomarkers among young adults

BACKGROUND

Emerging evidence from general population studies suggests that lesbian, gay, and bisexual (LGB) adults are more likely to experience adverse cardiovascular outcomes relative to heterosexuals. No studies have examined whether sexual orientation disparities exist in biomarkers of early cardiovascular disease risk.

PURPOSE

To determine whether sexual orientation disparities in biomarkers of early cardiovascular risk are present among young adults.

METHODS

Data come from Wave IV (2008-2009) of the National Longitudinal Study for Adolescent Health (N=12,451), a prospective nationally representative study of U.S. adolescents followed into young adulthood (mean age=28.9 years). A total of 520 respondents identified as lesbian, gay, or bisexual. Biomarkers included C-reactive protein, glycosylated hemoglobin, systolic and diastolic blood pressure, and pulse rate. Analyses were conducted in 2012.

RESULTS

In gender-stratified models adjusted for demographics (age, race/ethnicity); SES (income, education); health behaviors (smoking, regular physical activity, alcohol consumption); and BMI, gay and bisexual men had significant elevations in C-reactive protein, diastolic blood pressure, and pulse rate, compared to heterosexual men. Despite having more risk factors for cardiovascular disease, including smoking, heavy alcohol consumption, and higher BMI, lesbians and bisexual women had lower levels of C-reactive protein than heterosexual women in fully adjusted models.

CONCLUSIONS

Evidence was found for sexual orientation disparities in biomarkers of cardiovascular risk among young adults, particularly in gay and bisexual men. These findings, if confirmed in other studies, suggest that disruptions in core physiologic processes that ultimately confer risk for cardiovascular disease may occur early in the life course for sexual-minority men.

How can the study of physiological reactivity contribute to our understanding of adversity and resilience processes in development?

The focus of this article is to present current progress in understanding the interplay among adversity, physiological sensitivity to context, and adaptive functioning, with an emphasis on implications and future directions for resilience researchers. It includes a review of current literature that demonstrates (a) links between various levels of adversity exposure and variability in physiological reactivity, (b) how the interplay between children's physiological reactivity and different sources of risk and adversity relates to variability in adaptive functioning, and (c) various approaches for capturing a more dynamic nature of physiological reactivity and related processes. Throughout, important conceptual and empirical issues are highlighted.

Test anxiety and cardiovascular responses to daily academic stressors

Routine academic events may cause stress and produce temporary elevations in blood pressure. Students who experience test anxiety may be especially prone to cardiovascular activation in response to academic stress. This study drew on self-reported stress and ambulatory blood pressure measurements provided by 99 undergraduate participants (30% men, mean age=21 years) who participated over 4 days. Posture, activity level, recent consumption and the previous same-day reading were considered as covariates in a series of hierarchical linear models. Results indicate elevations in systolic blood pressure at times of acute academic stressors; neither diastolic blood pressure nor heart rate was linked with academic stress. In addition, those participants higher in test anxiety exhibited especially pronounced elevations in systolic blood pressure during times of acute academic stress. This research suggests that everyday academic stressors are linked with temporary increases in blood pressure and that test anxiety may contribute to these elevations. Test anxiety has implications for future academic and job success, and cardiovascular responses to everyday stress may contribute to health problems later in life.

Chronic stress and obesity in adolescents: scientific evidence and methodological issues for epidemiological research

AIMS

This review describes the role of chronic stress in the development of obesity and available methodologies for the assessment of chronic stress in humans, in particular adolescents, with the aim of developing a feasible methodology to implement in an epidemiological study.

DATA SYNTHESIS

Chronic stress seems to be associated with the aetiology of obesity by interacting with both mechanisms of energy intake (increase of appetite and energy intake) and expenditure (decrease of physical activity) and by stimulating visceral fat accumulation in favour of abdominal obesity. However, more research is necessary to unravel the underlying mechanisms of the obesity-inducing effects of chronic stress, especially in adolescents. In addition to experimental research, epidemiological observational studies, in particular cohort studies, are appropriate given their non-intervening character, lower budgetary costs and natural setting. In practice, stress can be assessed by means of either a subjective approach using stressor checklists or interviews, or an objective approach measuring biomarkers of stress. In epidemiological research in adolescents, a combination of both strategies is recommended, with a preference for a general stressor checklist for adolescents and measurement of salivary cortisol, one of the most used and well-characterized biomarkers of stress.

CONCLUSION

This review provides basic evidence for the positive association between chronic stress and obesity, but also points out the need for more research in adolescents to further elucidate the role of chronic stress in the aetiology of obesity in this crucial life period. Good, well-standardized epidemiological surveys could be of great benefit in this research area.

Do dispositional pessimism and optimism predict ambulatory blood pressure during school days and nights in adolescents?

We tested the hypotheses that (1) high pessimism and low optimism (LOT-R overall and subscale scores) would predict high ambulatory blood pressure (ABP) level and 24-hour load (percentage of ABP values exceeding the pediatric 95th percentile) among healthy Black and White adolescents (n=201; 14-16 yrs) across 2 consecutive school days and (2) that the relationships for the pessimism and optimism subscales would show nonlinear effects. The hypotheses were confirmed for pessimism but not for optimism. The results suggest that high pessimism may have different effects than low optimism on ABP and that even moderate levels of pessimism may effect blood pressure regulation. These results suggest that optimism and pessimism are not the opposite poles on a single continuum but ought to be treated as separate constructs.

Stress reactivity and adiposity of youth

OBJECTIVE

The relationship between stress reactivity and total or central adiposity in children has not been widely studied. Data from two studies were combined to determine the relationship between reactivity to interpersonal stress and the adiposity of children.

RESEARCH METHODS AND PROCEDURES

Stress reactivity to an interpersonal stressor (speech) was measured in 36 boys (9.8 +/- 1.3 years of age) and 27 girls (9.3 +/- 1.3 years of age). Total adiposity (percentage body fat) was estimated from skinfolds and central adiposity from the abdominal girth. Multiple regression was used to establish the associations of change in perceived stress and heart rate reactivity with adiposity. Age, sex, ethnicity, and baseline perceived stress and heart rate served as covariates for total adiposity. Fat mass was included as an additional covariate for the prediction of log abdominal girth (central adiposity).

RESULTS

Based on adjusted beta-weights, change in perceived stress (beta = 1.13, p <or= 0.001) and heart rate reactivity (beta = 0.14, p <or= 0.03) independently predicted percentage body fat. Heart rate reactivity (beta = 0.002, p <or= 0.04) independently predicted log abdominal girth.

DISCUSSION

Reactivity to psychological stress may initiate the antecedents of cardiovascular disease before adolescence by increasing total and central adiposity. Future studies should determine whether stress reactivity increases the adiposity of youth by increasing their consumption of energy-dense snack foods and decreasing their willingness to be physically active.

Sympathetic rhythms and nervous integration

1. The present review focuses on some of the processes producing rhythms in sympathetic nerves influencing cardiovascular functions and considers their potential relevance to nervous integration. 2. Two mechanisms are considered that may account for rhythmic sympathetic discharges. First, neuronal elements of peripheral or central origin produce rhythmic activity by phasically exciting and/or inhibiting neurons within central sympathetic networks. Second, rhythms arise within central sympathetic networks. Evidence is considered that indicates the operation of both mechanisms; the first in muscle and the second in skin sympathetic vasoconstrictor networks. 3. Sympathetic activity to the rat tail, a model for the nervous control of skin circulation, is regulated by central networks involved in thermoregulation and those associated with fear and arousal. In an anaesthetized preparation, activity displays an apparently autonomous rhythm (T-rhythm; 0.4-1.2 Hz) and the level of activity can be manipulated by regulating core body temperature. This model has been used to study rhythm generation in central sympathetic networks and possible functional relevance. 4. A unique insight provided by the T rhythm, into possible physiological function(s) underlying rhythmic sympathetic discharges is that the activity of single sympathetic post-ganglionic neurons within a population innervating the same target can have different rhythm frequencies. Therefore, the graded and dynamic entrainment of the rhythms by inputs, such as central respiratory drive and/or lung inflation-related afferent activity, can produce graded and dynamic synchronization of sympathetic discharges. The degree of synchronization may influence the efficacy of transmission in a target chain of excitable cells. 5. The T-rhythm may be generated within the spinal cord because the intrathecal application of 5-hydroxytryptamine at the L1 level of the spinal cord of a rat spinalized at T10-T11 produces a T-like rhythm. Thus, induction and modulation of spinal cord oscillators may be mechanisms that influence ganglionic and neuroeffector transmission. 6. The study of sympathetic rhythms may not only further understanding of sympathetic control, but may also inform on the relevance of rhythmic nervous activities in general.