Latent Growth Curve Models for Biomarkers of the Stress Response

Relationship between heart rate variability and differential patterns of cortisol response to acute stressors in mid-life adults: A data-driven investigation

Cortisol and heart rate variability (HRV) are well-established biomarkers of the human stress response system. While a relationship between cortisol and HRV is assumed, few studies have found evidence of their correlation within single study designs. One complication for isolating such a relationship may lie in individual variability in the cortisol response to stress such that atypical cortisol responding (i.e., elevated or blunted) occurs. To-date, studies on the cortisol response have employed traditional mean-difference-based approaches to examine average magnitude change in cortisol over time. Alternatively, data-driven trajectory modelling, such as latent growth mixture modelling, may be advantageous for quantifying cortisol based on patterns of response over time. Latent growth mixture modelling was used in N = 386 adults to identify subgroups based on trajectories of cortisol responses to stress. The relationship between cortisol and HRV was tested within subgroups. Results revealed a 'prototypical' subgroup characterised by expected rise and fall in cortisol response to stress (n = 309), a 'decline' subgroup (n = 28) that declined in cortisol after stress, and a 'rise' subgroup (n = 49) that increased in cortisol after stress. Within the 'prototypical' subgroup, greater HRV during stress was associated with decline in cortisol after stress from its maximum (r (306) = 0.19, p < 0.001). This relationship failed to emerge in the 'decline' and 'rise' subgroups (p > 0.271). Results document different patterns of cortisol response to stress; among those who exhibit a 'prototypical' response, changes in HRV during stress are related to changes in cortisol after stress.

Value-based decision-making predicts alcohol use and related problems in young men

BACKGROUND

Alcohol consumption is a leading cause of morbidity and mortality worldwide, disproportionately affecting young men. Heavy episodic drinking is particularly prevalent among men, with this behavior peaking between the ages of 20 and 24.

AIMS

We sought to identify dimensions of decision-making in men that would predict the development of hazardous alcohol use through emerging adulthood.

METHODS

This prospective observational study profiled value-based decision-making in 198 healthy men at age 18 and assessed their alcohol involvement annually until age 24. Latent growth curve modeling estimated individual variability in trajectories of alcohol involvement and regressed this variability on five choice dimensions.

RESULTS

Low loss aversion predicted sustained heavy episodic drinking from age 18 to 24. Both high delay discounting and risk-seeking for gains independently predicted a considerably higher cumulative alcohol use during these 6 years, with high delay discounting indicating escalating consumption from age 21. Risk-seeking for gains additionally predicted meeting more criteria for Alcohol Use Disorder in these 6 years. Risk-seeking for losses was not significantly related to alcohol outcomes. Choice preferences were largely independent of each other but were correlated with choice consistency, with low consistency predicting heavy episodic drinking from age 18 to 24 beyond these associations.

CONCLUSIONS

The predictive effects collectively suggest that overvaluing immediate and probabilistic incentives, rather than underestimating harm, drives hazardous drinking in young men. The differential relations of choice preferences and consistency to alcohol involvement through emerging adulthood provide distinct cognitive-behavioral patterns that warrant consideration in the development of harm reduction interventions.

Effects of 12 Weeks of At-Home, Application-Based Exercise on Health Care Workers' Depressive Symptoms, Burnout, and Absenteeism: A Randomized Clinical Trial

Importance

During the COVID-19 pandemic, health care workers (HCWs) reported a significant decline in their mental health. One potential health behavior intervention that has been shown to be effective for improving mental health is exercise, which may be facilitated by taking advantage of mobile application (app) technologies.

Objective

To determine the extent to which a 12-week app-based exercise intervention can reduce depressive symptoms, burnout, and absenteeism in HCWs, compared with a wait list control condition.

Design, Setting, and Participants

A 2-group randomized clinical trial was conducted, with participants screened from April 6 to July 4, 2022. Participants were recruited from an urban health care organization in British Columbia, Canada. Participants completed measures before randomization and every 2 weeks thereafter.

Interventions

Exercise condition participants were asked to complete four 20-minute sessions per week using a suite of body weight interval training, yoga, barre, and running apps. Wait-listed control participants received the apps at the end of the trial.

Main Outcomes and Measures

The primary outcome consisted of the between-group difference in depressive symptoms measured with the 10-item Center for Epidemiological Studies Depression Scale. The secondary outcomes corresponded to 3 subfacets of burnout (cynicism, emotional exhaustion, and professional efficacy) and absenteeism. Intention-to-treat analyses were completed with multilevel structural equation modeling, and Feingold effect sizes (ES) were estimated every 2 weeks.

Results

A total of 288 participants (mean [SD] age, 41.0 [10.8] years; 246 [85.4%] women) were randomized to either exercise (n = 142) or wait list control (n = 146) conditions. Results revealed that ESs for depressive symptoms were in the small to medium range by trial's end (week 12, -0.41 [95% CI, -0.69 to -0.13]). Significant and consistent treatment effects were revealed for 2 facets of burnout, namely cynicism (week 12 ES, -0.33 [95% CI, -0.53 to -0.13]) and emotional exhaustion (week 12 ES, -0.39 [95% CI, -0.64 to -0.14]), as well as absenteeism (r = 0.15 [95% CI, 0.03-0.26]). Adherence to the 80 minutes per week of exercise decreased from 78 (54.9%) to 33 (23.2%) participants between weeks 2 and 12.

Conclusions and Relevance

Although exercise was able to reduce depressive symptoms among HCWs, adherence was low toward the end of the trial. Optimizing adherence to exercise programming represents an important challenge to help maintain improvements in mental health among HCWs.

Trial Registration

ClinicalTrials.gov Identifier: NCT05271006.

Heterogeneity in resilience patterns and its prediction of 1-year quality of life outcomes among patients with newly diagnosed cancer: An exploratory piecewise growth mixture model analysis

PURPOSE

This study was designed to explore the impact of a new cancer diagnosis on resilience of patients and whether the resilience patterns could predict Quality of Life (QoL) in the first year.

METHODS

An exploratory linear piecewise growth mixture modeling (PGMM) with one hypothetical dot (3 months since diagnosis, T1) was employed to identify different resilience patterns and growth in 289 patients with different cancer diagnoses at five assessment occasions (T0-T4). Logistic regression analysis was performed to select potential predictors and receiver operating characteristic (ROC) curve analysis was utilized to test PGMM's discriminative ability against 1-year QoL.

RESULTS

Five discrete resilience trajectories with two growing trends were identified, including "Transcendence" (7.3%), "Resilient" (47.4%), "Recovery" (18.7%), "Damaged" (14.9%) and "Maladaption" (11.8%). Advanced stage, colorectal cancer, and receiving surgery therapy were significant predictors of negative resilience trajectories ("Damaged" or "Maladaption"). Discriminative ability was good for PGMM (AUC = 0.81, 95%CI, 0.76-0.85, P < 0.0001).

CONCLUSION

Heterogeneity is identified in resilience growth before and after 3 months since diagnosis. 26.7% newly diagnosed patients need additional attention especially for those with advanced colorectal cancer and receiving surgery therapy.

Latent growth analysis of children's height growth trajectories

Characterizing and quantifying the trajectories of variables of interest through time in their field of study is of interest to a range of disciplines. The aim of this study was to investigate the growth speed in height of children and its determinants. A total of 3401 males and 3200 females from four low- and middle-income countries with measured height on five occasions from 2002 to 2016 were included in the study. Data were analyzed using a latent growth model. The results of the study reported that children in four low- and middle-income countries exhibited substantial growth inequalities. There was a significant gender difference in change of growth with males had a higher baseline, rate of change, and acceleration in height growth than females. Comparing the component of slopes across countries, the growth change inequalities were observed among children. These inequalities were statistically significant, with the highest rate of change observed in Peru and Vietnam.

Internal but not external locus of control predicts acute stress response

Fluctuation patterns of physiological response after acute stress might indicate one's coping potential with stress, yet this relationship has not been widely examined. The present study investigated how Locus of Control (LOC) can influence cortisol and HR responses in an uncontrollable stressful situation. Seventy-three participants were exposed to acute stress through the Trier Social Stress Test (TSST) after finishing the LOC measures. Multilevel regression results suggested that a curvilinear function best captured the shape of the cortisol trajectories which was further moderated by the level of internal LOC. Moreover, higher internality was associated with greater cortisol reactivity and faster recovery. Our study reveals the link between internal control and endocrine stress response. Finally, cortisol upregulation was discussed, as well as the internality-related accelerated recovery of cortisol, which may be involved in the effect of motivation arousal for better adaptation.

Companion: A Pilot Randomized Clinical Trial to Test an Integrated Two-Way Communication and Near-Real-Time Sensing System for Detecting and Modifying Daily Inactivity among Adults >60 Years-Design and Protocol

Supervised personal training is most effective in improving the health effects of exercise in older adults. Yet, low frequency (60 min, 1-3 sessions/week) of trainer contact limits influence on behavior change outside sessions. Strategies to extend the effect of trainer contact outside of supervision and that integrate meaningful and intelligent two-way communication to provide complex and interactive problem solving may motivate older adults to "move more and sit less" and sustain positive behaviors to further improve health. This paper describes the experimental protocol of a 16-week pilot RCT (N = 46) that tests the impact of supplementing supervised exercise (i.e., control) with a technology-based behavior-aware text-based virtual "Companion" that integrates a human-in-the-loop approach with wirelessly transmitted sensor-based activity measurement to deliver behavior change strategies using socially engaging, contextually salient, and tailored text message conversations in near-real-time. Primary outcomes are total-daily and patterns of habitual physical behaviors after 16 and 24 weeks. Exploratory analyses aim to understand Companion's longitudinal behavior effects, its user engagement and relationship to behavior, and changes in cardiometabolic and cognitive outcomes. Our findings may allow the development of a more scalable hybrid AI Companion to impact the ever-growing public health epidemic of sedentariness contributing to poor health outcomes, reduced quality of life, and early death.

LGCM and PLS-SEM in Panel Survey Data: A Systematic Review and Bibliometric Analysis

The application of Latent Growth Curve Model (LGCM) and Partial Least Square Structural Equation Modeling (PLS-SEM) has gained much attention in panel survey studies. This study explores the distributions and trends of LGCM, and PLS-SEM used in panel survey data. It highlights the gaps in the current and existing approaches of PLS-SEM practiced by researchers in analyzing panel survey data. The integrated bibliometric analysis and systematic review were employed in this study. Based on the reviewed articles, the LGCM and PLS-SEM showed an increasing trend of publication in the panel survey data. Though the popularity of LGCM was more outstanding than PLS-SEM for the panel survey data, LGCM has several limitations such as statistical assumptions, reliable sample size, number of repeated measures, and missing data. This systematic review identified five different approaches of PLS-SEM in analyzing the panel survey data namely pre- and post-approach with different constructs, a path comparison approach, a cross-lagged approach, pre- and post-approach with the same constructs, and an evaluation approach practiced by researchers. None of the previous approaches used can establish one structural model to represent the whole changes in the repeated measure. Thus, the findings of this paper could help researchers choose a more appropriate approach to analyzing panel survey data.

Gratitude, affect balance, and stress buffering: A growth curve examination of cardiovascular responses to a laboratory stress task

Previous research has indicated that gratitude and affect-balance play key stress-buffering roles. However, to date there is limited research on the impact of gratitude and affect balance on cardiovascular recovery from acute psychological stress, and whether affect balance moderates the relationship between gratitude and cardiovascular reactions to acute psychological stress. In this study, 68 adults completed measures of state gratitude, positive and negative affect, and completed a laboratory-based cardiovascular stress-testing protocol. This incorporated a 20-minute acclimatization period, a 10-minute baseline, a 6-minute arithmetic stress task, and an 8-minute recovery period. Mixed-effects growth curve models were fit and the results indicated that state gratitude predicted lower systolic blood pressure responses throughout the stress-testing period. Affect balance was found to moderate the association between state gratitude and diastolic blood pressure responses to stress, amplifying the effects of state gratitude. These findings suggest that state gratitude has a unique stress-buffering effect on both reactions to and recovery from acute psychological stress.

Long-term psychological profile of general population following COVID-19 outbreak: symptom trajectories and evolution of psychopathological network

AIMS

COVID-19 has long-term impacts on public mental health, while few research studies incorporate multidimensional methods to thoroughly characterise the psychological profile of general population and little detailed guidance exists for mental health management during the pandemic. This research aims to capture long-term psychological profile of general population following COVID-19 by integrating trajectory modelling approaches, latent trajectory pattern identification and network analyses.

METHODS

Longitudinal data were collected from a nationwide sample of 18 804 adults in 12 months after COVID-19 outbreak in China. Patient Health Questionnaire-9, Generalised Anxiety Disorder-7 and Insomnia Severity Index were used to measure depression, anxiety and insomnia, respectively. The unconditional and conditional latent growth curve models were fitted to investigate trajectories and long-term predictors for psychological symptoms. We employed latent growth mixture model to identify the major psychological symptom trajectory patterns, and ran sparse Gaussian graphical models with graphical lasso to explore the evolution of psychopathological network.

RESULTS

At 12 months after COVID-19 outbreak, psychological symptoms generally alleviated, and five psychological symptom trajectories with different demographics were identified: normal stable (63.4%), mild stable (15.3%), mild-increase to decrease (11.7%), mild-decrease to increase (4.0%) and moderate/severe stable (5.5%). The finding indicated that there were still about 5% individuals showing consistently severe distress and approximately 16% following fluctuating psychological trajectories, who should be continuously monitored. For individuals with persistently severe trajectories and those with fluctuating trajectories, central or bridge symptoms in the network were mainly 'motor abnormality' and 'sad mood', respectively. Compared with initial peak and late COVID-19 phase, aftermath of initial peak might be a psychologically vulnerable period with highest network connectivity. The central and bridge symptoms for aftermath of initial peak ('appetite change' and 'trouble of relaxing') were totally different from those at other pandemic phases ('sad mood').

CONCLUSIONS

This research identified the overall growing trend, long-term predictors, trajectory classes and evolutionary pattern of psychopathological network of psychological symptoms in 12 months after COVID-19 outbreak. It provides a multidimensional long-term psychological profile of the general population after COVID-19 outbreak, and accentuates the essentiality of continuous psychological monitoring, as well as population- and time-specific psychological management after COVID-19. We believe our findings can offer reference for long-term psychological management after pandemics.

The dynamic experience of taking an examination: Ever changing cortisol and expectancy for success

BACKGROUND

This study examined the relations between students' expectancies for success and a physiological component of test anxiety, salivary cortisol, during an authentic testing setting.

AIMS

The aim of the study was to better understand the connection between shifts in students' control appraisals and changes in the physiological component of test anxiety.

SAMPLE

The study comprised 45 undergraduate engineering majors in the United States.

METHODS

Survey data concerning students' expectancy for success and saliva samples were taken before, during and after the practice midterm examination prior to their actual in-class examination.

RESULTS

Students' expectancy for success declined during the examination while cortisol levels declined from the beginning to middle of the examination and began to increase again as a function of time. Although students' initial levels of expectancy for success and cortisol were not correlated, there was a negative relation between change in cortisol and change in expectancy for success.

CONCLUSIONS

Our study demonstrates a relation between salivary cortisol, a physiological component of test anxiety and students' expectancy for success in an authentic testing context. Most students saw a decrease in cortisol during the examination, suggesting anticipatory anxiety prior to the test and a return to homeostasis as the examination progressed. Some students, however, did not see a declination in cortisol, suggesting they may not have recovered from pre-examination anxiety. The negative relation between change in cortisol and expectancy for success suggests that students who had the greatest decrease in expectancy for success saw the smallest recovery in cortisol.

Studying latent change process in height growth of children in Ethiopia, India, Peru and Vietnam

BACKGROUND

Anthropometric measurements of healthy children differ in different parts of the world due to the diverse ethnicity and cultural backgrounds of families. In longitudinal studies, appropriate modeling of repeated anthropometric measures can improve the understanding of patterns of change, determinants of patterns, and variations in patterns of change over time. The objective of this study was to examine the latent change in physical height of children in Ethiopia, India, Peru, and Vietnam.

METHOD

Longitudinal data of 6601 children aged 1 to 15 years were obtained from the Young Lives cohort study. The data were analyzed using a latent basis growth curve model.

RESULTS

The findings of the study revealed that the rates of growth did not remain constant across the time intervals, which indicates the nonlinearity of the growth trajectory over time. For instance, children had the highest rate of growth between age 1 and 5 years, then between age 8 and 12 years, and a low rate of growth was observed between age 12 and 15 years. At the first measurement occasion (age 1 year) females were 0.826 cm (p < 0.0001) times shorter than males. The mean height at one year of age ranged from 72.13 cm in Ethiopia to 72.62 cm in India. Children in India and Vietnam had higher mean height at age one year. However, no significant difference in mean height at age one year was found between Ethiopian and Peruvian children, ([Formula: see text]). Peruvian and Vietnamese children grew at a faster rate, while Indian children grew at a slower rate than Ethiopian children.

CONCLUSION

We found substantial latent growth variations among children in four low- and middle-income countries. The latent trajectories differed by gender and country. The outcomes of the study could aid in detecting inequalities in children's height growth.

Accessibility to Digital Mental Health Services among the General Public throughout COVID-19: Trajectories, Influencing Factors and Association with Long-Term Mental Health Symptoms

Digital mental health services (DMHSs) have great potential for mitigating the mental health burden related to COVID-19, but public accessibility (ease of acquiring services when needed) to DMHSs during the pandemic is largely unknown. Accessibility to DMHSs was tracked longitudinally among a nationwide sample of 18,804 adults in China from before to one year after COVID-19 outbreak. Unconditional and conditional latent growth curve models and latent growth mixture models were fitted to explore the overall growth trend, influencing factors, and latent trajectory classes of accessibility to DMHSs throughout COVID-19. Generalized estimating equation models and generalized linear mixed models were employed to explore the association between accessibility to DMHSs and long-term mental health symptoms. We found that people generally reported increased difficulty in accessing DMHSs from before to one year after COVID-19 outbreak. Males, youngsters, individuals with low socioeconomic status, and individuals greatly affected by COVID-19 reported greater difficulty in accessing DMHSs. Four DMHS accessibility trajectory classes were identified: “lowest–great increase” (6.3%), “moderate low–slight increase” (44.4%), “moderate high–slight decrease” (18.1%) and “highest–great decrease” (31.2%). Trajectory classes reporting greater difficulty in accessing DMHSs were at higher risk for long-term mental symptoms. In conclusion, an overall increase in difficulty in accessing DMHSs is observed throughout COVID-19, and heterogeneity exists in DMHS accessibility trajectories. Our results suggest that easy access to DMHSs should be consistently facilitated. Moreover, access gaps should be reduced across demographic groups, and target populations for service allocation should alter as the pandemic evolves.

Measurement invariance testing of longitudinal neuropsychiatric test scores distinguishes pathological from normative cognitive decline and highlights its potential in early detection research

OBJECTIVE

Alzheimer's disease (AD) is a growing challenge worldwide, which is why the search for early-onset predictors must be focused as soon as possible. Longitudinal studies that investigate courses of neuropsychological and other variables screen for such predictors correlated to mild cognitive impairment (MCI). However, one often neglected issue in analyses of such studies is measurement invariance (MI), which is often assumed but not tested for. This study uses the absence of MI (non-MI) and latent factor scores instead of composite variables to assess properties of cognitive domains, compensation mechanisms, and their predictability to establish a method for a more comprehensive understanding of pathological cognitive decline.

METHODS

An exploratory factor analysis (EFA) and a set of increasingly restricted confirmatory factor analyses (CFAs) were conducted to find latent factors, compared them with the composite approach, and to test for longitudinal (partial-)MI in a neuropsychiatric test battery, consisting of 14 test variables. A total of 330 elderly (mean age: 73.78 ± 1.52 years at baseline) were analyzed two times (3 years apart).

RESULTS

EFA revealed a four-factor model representing declarative memory, attention, working memory, and visual-spatial processing. Based on CFA, an accurate model was estimated across both measurement timepoints. Partial non-MI was found for parameters such as loadings, test- and latent factor intercepts as well as latent factor variances. The latent factor approach was preferable to the composite approach.

CONCLUSION

The overall assessment of non-MI latent factors may pose a possible target for this field of research. Hence, the non-MI of variances indicated variables that are especially suited for the prediction of pathological cognitive decline, while non-MI of intercepts indicated general aging-related decline. As a result, the sole assessment of MI may help distinguish pathological from normative aging processes and additionally may reveal compensatory neuropsychological mechanisms.

The association between early reports to Child Protective Services and developmental trajectories through middle childhood

BACKGROUND

Longitudinal studies on resilience among children who have experienced maltreatment indicate that resilience is multi-dimensional. However, most research consolidates diverse developmental domains comprising resilience into a single score, which does not allow for detection of potentially heterogeneous associations between risk factors and outcomes of resilience processes.

OBJECTIVE

This study seeks to improve our understanding of the association between early child maltreatment and development through middle childhood (6-12 years) using individual domains considered to be outcomes of resilience processes.

PARTICIPANTS AND SETTING

Participants are 499 children from the Longitudinal Studies of Child Abuse and Neglect.

METHODS

We used latent growth curve models to explore patterns of socialization and daily living skills, and internalizing and externalizing behaviors - outcomes of resilience processes - across three time points in middle childhood, and their association with early maltreatment, defined as referral to Child Protective Services (CPS) before age 6.

RESULTS

In fully adjusted models, children experiencing early maltreatment had poorer baseline scores in activities of daily living (-4.22, 95% CI [-7.38, -1.46]) and externalizing behavior (2.95, 95% CI [1.05, 4.86]), but maltreatment was not associated with change over time in these domains. However, maltreatment was associated with increases in internalizing behavior over time (0.42, 95% CI [0.06, 0.77]).

CONCLUSION

Heterogeneity in patterns of association between maltreatment and outcomes of resilience processes support the utility of examining developmental domains individually, versus as a composite, to identify specific targets for intervention.

Early Adverse Experiences and Repeated Wheezing From 6 to 30 Months of Age: Investigating the Roles of Hypothalamic-Pituitary-Adrenal Axis Functioning, Child Sex, and Caregiving Sensitivity

This study examined associations among early adversity, diurnal cortisol, child sex, and caregiver sensitivity at age 6 months in relation to wheezing in children (47% male) followed to 30 months. Analyses included 676 mother-child dyads, 393 of whom completed an observational caregiver sensitivity measure. Participants were primarily ethnic minorities (42.7% Black, 25.4% Hispanic); 22.1% of children had ≥ 1 wheezing episode. Higher adversity was associated with increased wheeze frequency and blunted diurnal cortisol slope. The indirect effect of adversity on wheezing through cortisol slope was significant for females, but not males. Higher caregiver sensitivity was protective against wheezing for males, but not females, with high cortisol. Findings suggest complex associations among adversity, cortisol, child sex, and caregiver sensitivity in predicting wheezing.

Critical Care Nurse Burnout in Veterans Health Administration: Relation to Clinician and Patient Outcomes

BACKGROUND

Critical care nurses have a burnout rate among the highest of any nursing field. Nurse burnout may impact care quality. Few studies have considered how temporal patterns may influence outcomes.

OBJECTIVE

To test a longitudinal model of burnout clusters and associations with patient and clinician outcomes.

METHODS

An observational study analyzed data from annual employee surveys and administrative data on patient outcomes at 111 Veterans Health Administration intensive care units from 2013 through 2017. Site-level burnout rates among critical care nurses were calculated from survey responses about emotional exhaustion and depersonalization. Latent trajectory analysis was applied to identify clusters of facilities with similar burnout patterns over 5 years. Regression analysis was used to analyze patient and employee outcomes by burnout cluster and organizational context measures. Outcomes of interest included patient outcomes (30-day standardized mortality rate and observed minus expected length of stay) for 2016 and 2017 and clinician outcomes (intention to leave and employee satisfaction) from 2013 through 2017.

RESULTS

Longitudinal analysis revealed 3 burnout clusters among the 111 sites: low (n = 37), medium (n = 68), and high (n = 6) burnout. Compared with sites in the low-burnout cluster, those in the high-burnout cluster had longer patient stays, higher employee turnover intention, and lower employee satisfaction in bivariate models but not in multivariate models.

CONCLUSIONS

In this multiyear, multisite study, critical care nurse burnout was associated with key clinician and patient outcomes. Efforts to address burnout among nurses may improve patient and employee outcomes.

Weak and uneven associations of home, neighborhood, and school environments with stress hormone output across multiple timescales

The progression of lifelong trajectories of socioeconomic inequalities in health and mortality begins in childhood. Dysregulation in cortisol, a stress hormone that is the primary output of the hypothalamus-pituitary-adrenal (HPA) axis, has been hypothesized to be a mechanism for how early environmental adversity compromises health. However, despite the popularity of cortisol as a biomarker for stress and adversity, little is known about whether cortisol output differs in children being raised in socioeconomically disadvantaged environments. Here, we show that there are few differences between advantaged and disadvantaged children in their cortisol output. In 8-14-year-old children from the population-based Texas Twin Project, we measured cortisol output at three different timescales: (a) diurnal fluctuation in salivary cortisol (n = 400), (b) salivary cortisol reactivity and recovery after exposure to the Trier Social Stress Test (n = 444), and (c) cortisol concentration in hair (n = 1210). These measures converged on two moderately correlated, yet distinguishable, dimensions of HPA function. We tested differences in cortisol output across nine aspects of social disadvantage at the home (e.g., family socioeconomic status), school (e.g., average levels of academic achievement), and neighborhood (e.g., concentrated poverty). Children living in neighborhoods with higher concentrated poverty had higher diurnal cortisol output, as measured in saliva; otherwise, child cortisol output was unrelated to any other aspect of social disadvantage. Overall, we find limited support for alteration in HPA axis functioning as a general mechanism for the health consequences of socioeconomic inequality in childhood.

Hedonic Preferences to Audio and Visual Stimulation in Seniors with Cognitive Impairments

BACKGROUND

Hedonic (or aesthetic) preferences to repeated sensory stimulation can remain stable over time (Island of Stability Effect, ISE) or vary with prior exposures (Mere Exposure Effect, MEE).

OBJECTIVE

Here we compared the liking ratings of seniors with cognitive impairments (mostly mild-to-moderate dementia, DPs) and neurotypical senior controls (CNs) to audio and visual stimuli and examined whether those ratings conformed to the ISE or the MEE predictions.

METHOD

Participants (n = 212) rated sets of stimuli repeated three times at weekly intervals: images of Picasso's paintings, PANTONE color cards, and avant-garde music clips.

RESULTS

The aggregated liking ratings of DPs and CNs were stable over time, in line with the ISE model. However, latent growth modeling indicated that those stable responses might have masked differences at the individual level, since seniors in both cohorts exhibited clusters of different responses over the time evaluated, supporting the predictions of the MEE. Notably, there was a dampening of hedonic experiences in DPs comparatively to CNs.

CONCLUSION

The presence of hedonic responses (and individual variations) in DPs is relevant not only to their wellbeing and therapy interventions involving audio and visual stimulation, but also to the design of spaces that offset the downturn in hedonic experiences affecting seniors with cognitive impairments.

Treelet transform analysis to identify clusters of systemic inflammatory variance in a population with moderate-to-severe traumatic brain injury

BACKGROUND

Inflammatory cascades following traumatic brain injury (TBI) can have both beneficial and detrimental effects on recovery. Single biomarker studies do not adequately reflect the major arms of immunity and their relationships to long-term outcomes. Thus, we applied treelet transform (TT) analysis to identify clusters of interrelated inflammatory markers reflecting major components of systemic immune function for which substantial variation exists among individuals with moderate-to-severe TBI.

METHODS

Serial blood samples from 221 adults with moderate-to-severe TBI were collected over 1-6 months post-injury (n = 607 samples). Samples were assayed for 33 inflammatory markers using Millipore multiplex technology. TT was applied to standardized mean biomarker values generated to identify latent patterns of correlated markers. Treelet clusters (TC) were characterized by biomarkers related to adaptive immunity (TC1), innate immunity (TC2), soluble molecules (TC3), allergy immunity (TC4), and chemokines (TC5). For each TC, a score was generated as the linear combination of standardized biomarker concentrations and cluster load for each individual in the cohort. Ordinal logistic or linear regression was used to test associations between TC scores and 6- and 12-month Glasgow Outcome Scale (GOS), Disability Rating Scale (DRS), and covariates.

RESULTS

When adjusting for clinical covariates, TC5 was significantly associated with 6-month GOS (odds ratio, OR = 1.44; p-value, p = 0.025) and 6-month DRS scores (OR = 1.46; p = 0.013). TC5 relationships were attenuated when including all TC scores in the model (GOS: OR = 1.29, p = 0.163; DRS: OR = 1.33, p = 0.100). When adjusting for all TC scores and covariates, only TC3 was associated with 6- and 12-month GOS (OR = 1.32, p = 0.041; OR = 1.39, p = 0.002) and also 6- and 12-month DRS (OR = 1.38, p = 0.016; OR = 1.58, p = 0.0002). When applying TT to inflammation markers significantly associated with 6-month GOS, multivariate modeling confirmed that TC3 remained significantly associated with GOS. Biomarker cluster membership remained consistent between the GOS-specific dendrogram and overall dendrogram.

CONCLUSIONS

TT effectively characterized chronic, systemic immunity among a cohort of individuals with moderate-to-severe TBI. We posit that chronic chemokine levels are effector molecules propagating cellular immune dysfunction, while chronic soluble receptors are inflammatory damage readouts perpetuated, in part, by persistent dysfunctional cellular immunity to impact neuro-recovery.

Day-to-day and longer-term longitudinal associations between physical activity, sedentary behavior, and sleep in children

STUDY OBJECTIVES

To determine the day-to-day and longer-term longitudinal associations between daytime physical activity and night-time sleep.

METHODS

We used data from a 2-year longitudinal study which included three time points (i.e. baseline, year 1, and year 2). Participants were recruited from primary schools and included 1059 children (50% girls) with a mean age of 8.81-years-old (SD = 0.72) at baseline. Sleep variables included sleep duration, sleep efficiency, time in bed, sleep onset, and wake time. Physical activity variables included light, moderate, moderate-to-vigorous, and vigorous physical activity as well as sedentary time. We objectively assessed physical activity and sleep behaviors using the GENEActiv wrist-worn accelerometer over an 8-day period at each timepoint for a potential 21 190 observed days.

RESULTS

We used fixed-effects multilevel models and parallel latent growth curve modeling to examine day-to-day and longer-term associations, respectively. Day-to-day, physical activity, and sleep variables were significantly, positively, and bidirectionally associated, except for sleep efficiency, which showed little association with physical activity. Longer-term, we found little association between physical activity and sleep variables.

CONCLUSIONS

Overall, our findings indicate that there is a day-to-day association between the amount of time spent being physically active and improved sleep. The lack of a longer-term association indicates that a focus on children's daily behavior may be most appropriate to help children improve sleep and increase physical activity.

Higher Levels of Stress Are Associated With a Significant Symptom Burden in Oncology Outpatients Receiving Chemotherapy

CONTEXT

A cancer diagnosis and associated treatments, as well as the uncertainty of the disease course, are stressful experiences for most patients. However, little information is available on the relationship between stress and symptom burden.

OBJECTIVES

The study purpose was to evaluate for differences in the severity of fatigue, lack of energy, sleep disturbance, and cognitive function, among three groups of patients with distinct stress profiles.

METHODS

Patients receiving chemotherapy (n = 957) completed measures of general, cancer-specific, and cumulative life stress and symptom inventories. Latent profile analysis was used to identify subgroups of patients with distinct stress profiles.

RESULTS

Three distinct subgroups of patients were identified (i.e., stressed [39.3%], normative [54.3%], resilient [5.7%]). For cognitive function, significant differences were found among the latent classes (stressed < normative < resilient). For both sleep disturbance and morning and evening fatigue, compared to the normative and resilient classes, the stressed class reported higher severity scores. Compared to the normative and resilient classes, the stressed class reported low levels of morning energy. Compared to the normative class, the stressed class reported lower levels of evening energy.

CONCLUSIONS

Consistent with our a priori hypothesis, patients in the stressed class had the highest symptom severity scores for all four symptoms and all these scores were above the clinically meaningful cutoffs for the various instruments.

Sympathetic Markers are Different Between Clinical Responders and Nonresponders After Left Ventricular Assist Device Implantation

BACKGROUND

Clinical response to left ventricular assist devices (LVADs), as measured by health-related quality of life, varies among patients after implantation; however, it is unknown which pathophysiological mechanisms underlie differences in clinical response by health-related quality of life.

OBJECTIVE

The purpose of this study was to compare changes in sympathetic markers (β-adrenergic receptor kinase-1 [βARK1], norepinephrine [NE], and 3,4-dihydroxyphenylglycol [DHPG]) between health-related quality of life clinical responders and nonresponders from pre- to post-LVAD implantation.

METHODS

We performed a secondary analysis on a subset of data from a cohort study of patients from pre- to 1, 3, and 6 months after LVAD implantation. Clinical response was defined as an increase of 5 points or higher on the Kansas City Cardiomyopathy Questionnaire Clinical Summary score from pre- to 6 months post-LVAD implantation. We measured plasma βARK1 level with an enzyme-linked immunosorbent assay and plasma NE and DHPG levels with high-performance liquid chromatography with electrochemical detection. Latent growth curve modeling was used to compare the trajectories of markers between groups.

RESULTS

The mean (SD) age of the sample (n = 39) was 52.9 (13.2) years, and most were male (74.4%) and received LVADs as bridge to transplantation (69.2%). Preimplantation plasma βARK1 levels were significantly higher in clinical responders (n = 19) than in nonresponders (n = 20) (P = .001), but change was similar after LVAD (P = .235). Preimplantation plasma DHPG levels were significantly lower in clinical responders than in nonresponders (P = .002), but the change was similar after LVAD (P = .881). There were no significant differences in plasma NE levels.

CONCLUSIONS

Preimplantation βARK1 and DHPG levels are differentiating factors between health-related quality of life clinical responders and nonresponders to LVAD, potentially signaling differing levels of sympathetic stimulation underlying clinical response.

Effects of stress on 6- and 7-year-old children's emotional memory differs by gender

Understanding effects of emotional valence and stress on children's memory is important for educational and legal contexts. This study disentangled the effects of emotional content of to-be-remembered information (i.e., items differing in emotional valence and arousal), stress exposure, and associated cortisol secretion on children's memory. We also examined whether girls' memory is more affected by stress induction. A total of 143 6- and 7-year-old children were randomly allocated to the Trier Social Stress Test for Children (n = 103) or a control condition (n = 40). At 25 min after stressor onset, children incidentally encoded 75 objects varying in emotional valence (crossed with arousal) together with neutral scene backgrounds. We found that response bias corrected memory was worse for low-arousing negative items than for neutral and positive items, with the latter two categories not being different from each other. Whereas boys' memory was largely unaffected by stress, girls in the stress condition showed worse memory for negative items, especially the low-arousing ones, than girls in the control condition. Girls, compared with boys, reported higher subjective stress increases following stress exposure and had higher cortisol stress responses. Whereas a higher cortisol stress response was associated with better emotional memory in girls in the stress condition, boys' memory was not associated with their cortisol secretion. Taken together, our study suggests that 6- and 7-year-old children, more so girls, show memory suppression for negative information. Girls' memory for negative information, compared with that of boys, is also more strongly modulated by stress experience and the associated cortisol response.

Linking preschoolers' parasympathetic activity to maternal early adversity and child behavior: An intergenerational perspective

Increasing evidence suggests intergenerational effects of maternal early adversity on offspring self-regulation. Prior work has demonstrated associations between maternal adverse childhood experiences (ACEs) and infant respiratory sinus arrhythmia (RSA), a parasympathetic biomarker associated with emotional and behavioral self-regulation. The present study examined these associations and additional potential pathways including children's violence exposure and maternal psychopathology among 123 biological mother-child dyads. Families were low-income and oversampled for violence exposure; children were 3-5 years old. RSA was examined during dyadic interaction using latent growth curve modeling (LGCM). On average, females exhibited greater RSA reactivity. Greater RSA withdrawal across the interaction was associated with greater child negative affect during the interaction, linking RSA reactivity to concurrent child behavior. Consistent with previous findings among infants, high maternal ACEs were associated with lower child RSA at task initiation but not with RSA reactivity across the interaction. Findings suggest that the association between high maternal ACEs and a lower set point for offspring RSA persists into the early childhood period, beyond the influence of maternal psychopathology and children's own violence exposure. These data provide further evidence for the biological embedding of maternal early adversity across generations as well as for the relevance of RSA to child behavioral regulation.

Campylobacter infection and household factors are associated with childhood growth in urban Bangladesh: An analysis of the MAL-ED study

The dual burden of enteric infection and childhood malnutrition continues to be a global health concern and a leading cause of morbidity and death among children. Campylobacter infection, in particular, is highly prevalent in low- and middle-income countries, including Bangladesh. We examined longitudinal data to evaluate the trajectories of change in child growth, and to identify associations with Campylobacter infection and household factors. The study analyzed data from 265 children participating in the MAL-ED Study in Mirpur, Bangladesh. We applied latent growth curve modelling to evaluate the trajectories of change in children's height, as measured by length-for-age z-score (LAZ), from age 0-24 months. Asymptomatic and symptomatic Campylobacter infections were included as 3- and 6-month lagged time-varying covariates, while household risk factors were included as time-invariant covariates. Maternal height and birth order were positively associated with LAZ at birth. An inverse association was found between increasing age and LAZ. Campylobacter infection prevalence increased with age, with over 70% of children 18-24 months of age testing positive for infection. In the final model, Campylobacter infection in the preceding 3-month interval was negatively associated with LAZ at 12, 15, and 18 months of age; similarly, infection in the preceding 6-month interval was negatively associated with LAZ at 15, 18, and 21 months of age. Duration of antibiotic use and access to treated drinking water were negatively associated with Campylobacter infection, with the strength of the latter effect increasing with children's age. Campylobacter infection had a significant negative effect on child's growth and this effect was most powerful between 12 and 21 months. The treatment of drinking water and increased antibiotic use have a positive indirect effect on linear child growth trajectory, acting via their association with Campylobacter infection.

Application of multiple-group latent growth model to determine the effect of shift work on body mass index among petrochemical industries staff

Background: Shift work can be defined as work activity scheduled in which employees work outside standard daytime hours. Some reports have shown that shift work is associated with several health problems. The main objective of this research was to explore the effect of shift work on body mass index (BMI) over time among Iranian petroleum industry staff.

Methods: This longitudinal study sample was consisted of 3,686 (1,872 day workers and 1,814 shift workers) petrochemical industries staff in Mahshahr, southwest of Iran, from 2012 to 2015. The weight and height of these staff were measured using standard techniques and equipment. Multiple-group latent growth curve modeling was used to determine the effect of shift working on BMI trajectories over this period of time via Mplus software, version 6.0.

Results: The mean (±SD) age of the shift workers and day workers were 38.96 (±8.36) and 43.33 (±8.35) years, respectively. Findings from the modeling approach showed that the slope of BMI in shift workers on average was 0.14 kg/m2 greater than the day workers in years under study (p<0.001).

Conclusion: The findings of the current study suggest that shift work can be considered as a potential risk indicator for higher weight gain in petrochemical staff. Hence, health policy-makers should organize health screening programs and periodical checkups to find high-risk staff and control unhealthy lifestyle factors in these industries.

Binge drinking in adolescence predicts an atypical cortisol stress response in young adulthood

Adolescence is a sensitive developmental period in which substance use can exert long-term effects on important biological systems. Emerging cross-sectional research indicates that problematic alcohol consumption may be associated with dysregulated neuroendocrine system functioning. The current study evaluated the prospective effects of binge drinking in adolescence on cortisol stress reactivity in young adulthood among individuals who had experienced parental divorce in childhood (N = 160; Mean age = 25.55, SD = 1.22; 46.9% Female; 88.8% White Non-Hispanic). Youth completed validated measures of problematic drinking during adolescence (aged 15-19) and participated in a standardized social stress task nine years later in young adulthood. Latent growth modeling was conducted within a structural equation modeling framework. Greater binge drinking during adolescence was associated with a significantly lower cortisol stress response in young adulthood, controlling for young adult drinking, sex, childhood externalizing problems, and socioeconomic status. Findings suggest problematic alcohol consumption during mid-to-late adolescence may have important effects on the neuroendocrine stress response system at subsequent developmental stages.