The Relationship between Allostatic Load and Psychosocial Characteristics among Women Veterans

Allostatic Load Measurement: A Systematic Review of Reviews, Database Inventory, and Considerations for Neighborhood Research

BACKGROUND

Neighborhoods are critical to understanding how environments influence health outcomes. Prolonged environmental stressors, such as a lack of green spaces and neighborhood socioeconomic disadvantage, have been associated with higher allostatic load levels. Since allostatic load levels experienced earlier in life have stronger associations with mortality risk, neighborhoods may be uniquely suited to monitor and mitigate the impacts of environmental stressors. Researchers often study allostatic load in neighborhoods by utilizing administrative boundaries within publicly accessible databases as proxies for neighborhoods.

METHODS

This systematic review of reviews aims to identify commonly used biomarkers in the measurement of allostatic load, compare measurement approaches, inventory databases to study allostatic load, and spotlight considerations referenced in the literature where allostatic load is studied in neighborhoods. The review was conducted using the search term "allostatic load" in the MEDLINE, CINAHL, and PsychINFO databases. The search results were filtered to include reviews.

RESULTS

The search returned 499 articles after deduplication. Overall, 18 synthesis reviews met the inclusion criteria and were retained for extraction. The synthesis reviews analyzed represented 238 studies published from 1995 to 2020. The original ten biomarkers were most often used to measure allostatic load. More recently, body mass index and C-reactive protein have additionally been frequently used to measure allostatic load burden.

CONCLUSIONS

The scientific contributions of this study are that we have identified a clear gap in geographic considerations when studying allostatic load. The implication of this study is that we have highlighted geographic concepts when conducting neighborhood-level research using administrative databases as a neighborhood proxy and outlined emerging future trends that can enable future study of allostatic load in the neighborhood context.

Measuring allostatic load: Approaches and limitations to algorithm creation

OBJECTIVE

Allostatic load literature has proliferated over the past three decades, and a growing body of research demonstrates that higher levels of allostatic load are associated with a wide range of negative physical and mental health outcomes. However, there remain significant challenges with operationalization of the concept. A scoping review of the methods employed to create an allostatic load algorithm was conducted and recommendations for future research with an orientation towards advancing clinical application of the theory are discussed.

METHODS

A search of seven electronic databases (PubMed, PsycINFO, Social Work Abstracts, Social Service Abstracts, Social Sciences Citation Index (Web of Science), Sociological Abstracts, Scopus) was completed with the search term "allostatic load." Studies were reviewed, and if they met the inclusion criteria, data was extracted, complied, and presented in the narrative, table, and figures.

RESULTS

The initial searches yielded 5280 results with the final sample of 395 non-duplicate articles that met the inclusion criteria. More than half (52.5%) of all included publications employed biomarker cutoffs based on the high-risk quartiles of the sample distribution, 11.1% employed the sum of at-risk clinical scores, and the remainder of studies utilized a range of different algorithms.

CONCLUSION

Allostatic load literature has grown at an exponential rate in recent years, but researchers continue to operationalize the concept via algorithms that may have limited utility moving forward. More nuanced statistical approaches are emerging and should be considered, as should a shift towards an approach that can provide additional clinical utility.

The association between allostatic load and brain: A systematic review

Allostatic load (AL) refers to prolonged dysregulation related to chronic stress that affects brain regions such as the hippocampus, amygdala, and prefrontal cortex (PFC). Higher levels of AL have been associated with poor health outcomes, including psychiatric disorders, cognitive decline, and chronic somatic conditions. However, still little is known about the relationship between AL and the brain, and the mechanisms explaining the damaging effects of stress-related biological dysregulations. Therefore, we aimed to perform a systematic review of studies investigating the association of the AL index with brain structure and functioning in adult populations. PubMed/MEDLINE, CINAHL, Academic Search Complete and Web of Science were searched from their inception until August, 9th 2021. A total of 13 studies were included in the qualitative synthesis. There was a high between-study heterogeneity with respect to the methods used to calculate the AL index and brain parameters. All studies confirmed the associations between a higher AL index and alterations in various brain areas, especially: 1) the hippocampus, white matter volume, gray matter volume, and density in the older adults; 2) the cortex, fornix, hippocampus and choroid plexus in patients with schizophrenia spectrum disorders; and 3) whole-brain white matter tracts, cortical gray matter volume, and cortical thickness in overweight subjects. Overall, the findings of this systematic review imply that an elevated AL index might be associated with various neurostructural and neurofunctional alterations. Some of these associations may appear regardless of clinical or non-clinical populations being investigated (e.g., white matter tracts), whereas others may appear in specific populations (e.g., cortical thinning in overweight/obesity and schizophrenia spectrum disorders). However, additional studies utilizing a consistent approach to calculating the AL index are needed to extend these findings and indicate populations that are most vulnerable to the damaging effects of AL.

Practical and Emotional Peer Support Tailored for Life's Challenges: Personalized Support for Progress Randomized Clinical Pilot Trial in a Veterans Health Administration Women's Clinic

INTRODUCTION

Women Veterans experience a broad range of stressors (e.g., family, relationship, and financial) and high rates of mental health and physical health conditions, all of which contribute to high levels of stress. Personalized Support for Progress (PSP), an evidence-based intervention, is well suited to support women Veterans with high stress as it involves a card-sort task to prioritize concerns as well as pragmatic and emotional support to develop and implement a personalized plan addressing those concerns. Our aims were to explore the population and context for delivery and evaluate the feasibility, acceptability, and utility of PSP delivered by a peer specialist to complement existing services in a Veterans Health Administration (VHA) Women's Wellness Center.

MATERIALS AND METHODS

This randomized controlled pilot trial compared treatment as usual plus PSP to treatment as usual and used the a priori Go/No-Go criteria to establish success for each outcome. We interviewed staff regarding the population and delivery context at a VHA Women's Wellness Center and analyzed interviews using a rapid qualitative approach. For the rapid qualitative analysis, we created templated summaries of each interview to identify key concepts within each a priori theme, reviewed each theme's content across all interviews, and finally reviewed key concepts across themes. We evaluated feasibility using recruitment and retention rates; acceptability via Veteran satisfaction, working relationship with the peer, and staff satisfaction; and utility based on the proportion of Veterans who experienced a large change in outcomes (e.g., stress, mental health symptoms, and quality of life). The Syracuse VA Human Subjects Institutional Review Board approved all procedures.

RESULTS

Staff interviews highlight that women Veterans have numerous unmet social needs and concerns common among women which increase the complexity of their care; call for a supportive, consistent, trusting relationship with someone on their health care team; and require many resources (e.g., staff such as social workers, services such as legal support, and physical items such as diapers) to support their needs (some of which are available within VHA but may need support for staffing or access, and some of which are unavailable). Feasibility outcomes suggest a need to modify PSP and research methods to enhance intervention and assessment retention before the larger trial; the recruitment rate was acceptable by the end of the trial. Veteran acceptability of PSP was high. Veteran outcomes demonstrate promise for utility to improve stress, mental health symptoms, and quality of life for women Veterans.

CONCLUSIONS

Given the high acceptability and promising outcomes for utility, changes to the design to enhance the feasibility outcomes which failed to meet the a priori Go/No-Go criteria are warranted. These outcomes support future trials of PSP within VHA Women's Wellness Centers.

Associations between Allostatic Load and Posttraumatic Stress Disorder: A Scoping Review

Traumatic events may lead to the development of PTSD or PTSD symptomology that can negatively impact health outcomes. Allostatic load, which represents the cumulative biological wear and tear of exposure to stress, can be employed to better understand the physiological etiology of PTSD. A scoping review, informed by the PRISMA Extension for Scoping Reviews, was completed to identify published and unpublished empirical studies that explored the relationship of allostatic load and PTSD. Eight databases were searched yielding four studies, with the results summarized narratively and in tabular form. Findings were mixed as to the association between allostatic load and PTSD. Allostatic load was positively associated with PTSD diagnosis; however, studies measuring only PTSD symptomatology found no relationship. Few PTSD researchers have tested the relationship of a comprehensive measure of allostatic load to PTSD. Among those who have, studies show that allostatic load can be a beneficial tool and applicable theoretical framework for understanding the biological changes associated with PTSD. Future research should focus on standardizing measures of both allostatic load and PTSD and identifying potential confounders. A better understanding of the physiological changes associated with PTSD could lead to more effective prevention and treatment efforts.

Adverse childhood experiences and low socioeconomic status with respect to allostatic load in adulthood: A systematic review

Early-life psychosocial stress primes a number of health risk behaviors, and contributes to the development of various mental and somatic disorders in adulthood. It has been reported that adverse childhood experiences (ACEs) and low socioeconomic status (SES) might be associated with allostatic load (AL) in adulthood. In turn, elevated AL index has been found to predict a number of unfavorable health outcomes. Therefore, we aimed to perform a systematic review of studies investigating the association of ACEs and childhood SES with AL in adult populations. Independent online searches covered the publication period up to 20th Jun 2021. A total of 27 studies were included in qualitative synthesis. The majority of eligible studies showed that ACEs (14 out of 19 studies recording ACEs, 73.7%) and low childhood SES (11 out of 12 studies recording childhood SES, 91.7%) are associated with elevated AL in adults. However, several processes were found to mediate or moderate this association. These include educational attainments, social support, health behaviors, adult stress, post-traumatic stress disorder, coping strategies and aging. Moreover, a substantial methodological heterogeneity of approaches to calculating the AL index was observed. Apart from reports from overlapping samples, none of eligible studies used the same set of biomarkers. Findings from this systematic review imply that early-life psychosocial stress might have a lasting impact on biological dysregulations captured by the AL index. Future studies need to explore whether the association between early-life stress and the AL index accounts for the development of specific health outcomes.

Allostatic Load and Its Impact on Health: A Systematic Review

INTRODUCTION

Allostatic load refers to the cumulative burden of chronic stress and life events. It involves the interaction of different physiological systems at varying degrees of activity. When environmental challenges exceed the individual ability to cope, then allostatic overload ensues. Allostatic load is identified by the use of biomarkers and clinical criteria.

OBJECTIVE

To summarize the current knowledge on allostatic load and overload and its clinical implications based on a systematic review of the literature.

METHODS

PubMed, PsycINFO, Web of Science, and the Cochrane Library were searched from inception to December 2019. A manual search of the literature was also performed, and reference lists of the retrieved articles were examined.We considered only studies in which allostatic load or overload were adequately described and assessed in either clinical or non-clinical adult populations.

RESULTS

A total of 267 original investigations were included. They encompassed general population studies, as well as clinical studies on consequences of allostatic load/overload on both physical and mental health across a variety of settings.

CONCLUSIONS

The findings indicate that allostatic load and overload are associated with poorer health outcomes. Assessment of allostatic load provides support to the understanding of psychosocial determinants of health and lifestyle medicine. An integrated approach that includes both biological markers and clinimetric criteria is recommended.

A test of the fear avoidance model to predict chronic pain outcomes in a polytrauma sample

BACKGROUND

Chronic musculoskeletal pain is a complex problem, particularly for individuals with head injury and comorbid psychiatric conditions. The Fear Avoidance Model offers one of the strongest opportunities to conceptualize comorbid traumatic injury and pain, but this model is largely untested.

OBJECTIVE

This study tests the Fear Avoidance Model of chronic pain using a sample from a study of polytrauma patients in a large Department of Veterans Affairs facility who participated in a federally-funded study of interdisciplinary chronic pain management.

METHODS

The present study comprises a secondary analysis of 93 veterans with chronic pain, head injury, posttraumatic stress symptoms and a history of persistent opioid use. Standardized measures of Fear Avoidance Model risk factors (e.g., pain catastrophizing, fear avoidance beliefs, anxiety, depression) were examined as cross-sectional predictors of pain-related disability.

RESULTS

Secondary data analysis revealed that Fear Avoidance Model factors accounted for almost 40% of the variance in pain-related disability, with pain catastrophizing and depression demonstrating the strongest relationships with disability. A summary variable combining all four factors revealed a 6% increase in disability for each factor that was clinically significant for the sample patients.

CONCLUSIONS

This study represents the first attempt to examine a complex, theoretical model of pain in a comorbid pain and TBI sample. Findings revealed a strong relationship between this model and pain-related disability that outperforms pain intensity ratings. This model could be used to guide better treatment for comorbid pain and TBI.

Allostatic load and women's brain health: A systematic review

Allostatic load represents the 'wear and tear' of chronic stress on the brain and body that may differ between men and women. A small but growing number of studies are assessing allostatic load in relation to mental health. The objective of this systematic review was to (1) assess sex differences in allostatic load and (2) identify allostatic load associations that are specific to women. We systematically searched for allostatic load studies that included psychosocial causes and/or psychiatric consequences. Our search focused on allostatic load studies that disaggregated by sex and that include women. Sixty-two studies were included in this systematic review. First, men appear to have higher allostatic load than women. Second, women show gender-specific variation for numerous factors such as age, race/ethnicity, adversities, social support, and health behaviors that influence associations between allostatic load and mental health. Recommendations are made to guide researchers advance sex and gender approaches.

A Longitudinal Analysis of Allostatic Load among a Multi-Ethnic Sample of Midlife Women: Findings from the Study of Women's Health Across the Nation

OBJECTIVES

We examined longitudinal patterns and sociodemographic correlates of allostatic load (AL), a measure of cumulative biological risk and aging, in a sample of midlife women consisting of non-Hispanic White, African American, Chinese, and Japanese women.

METHODS

Longitudinal cohort data from the Study of Women's Health Across the Nation were used to examine AL patterns in midlife women ages 42-53 (n = 1,932). AL measures were created using 10 biomarkers representing cardiovascular, inflammatory, neuroendocrine, and metabolic system functioning. We used longitudinal random effects Poisson regression models to assess change in AL over the 7-year follow-up period and associations between sociodemographic factors and AL.

RESULTS

On average, a woman's AL score increased 2% each year over the course of the study. Baseline measures of African American race, low family income, older age, and ability to read and speak only in English were significantly associated with higher levels of AL over the study period. We did not observe significant differences in rates of change in AL by race/ethnicity or socioeconomic status.

CONCLUSIONS

This study demonstrates that AL increases in a cumulative manner as women age. Midlife is an especially important time in women's life course with respect to health maintenance and healthy aging. AL can be an early warning indicator of subsequent disease burden, pointing to subclinical conditions and the need for implementation of medical and public health interventions earlier in the disease process.