Impact of caregiving for older people and pro-inflammatory biomarkers among caregivers: a systematic review

The influence of time-restricted eating/feeding on Alzheimer's biomarkers and gut microbiota

OBJECTIVES

Alzheimer's disease (AD) is a progressive neurodegenerative disorder affecting approximately 55 million individuals globally. Diagnosis typically occurs in advanced stages, and there are limited options for reversing symptoms. Preventive strategies are, therefore, crucial. Time Restricted Eating (TRE) or Time Restricted Feeding (TRF) is one such strategy. Here we review recent research on AD and TRE/TRF in addition to AD biomarkers and gut microbiota.

METHODS

A comprehensive review of recent studies was conducted to assess the impact of TRE/TRF on AD-related outcomes. This includes the analysis of how TRE/TRF influences circadian rhythms, beta-amyloid 42 (Aß42), pro-inflammatory cytokines levels, and gut microbiota composition.

RESULTS

TRE/TRF impacts circadian rhythms and can influence cognitive performance as observed in AD. It lowers beta-amyloid 42 deposition in the brain, a key AD biomarker, and reduces pro-ininflammatory cytokines. The gut microbiome has emerged as a modifiable factor in AD treatment. TRE/TRF changes the structure and composition of the gut microbiota, leading to increased diversity and a decrease in harmful bacteria.

DISCUSSION

These findings underscore the potential of TRE/TRF as a preventive strategy for AD. By reducing Aß42 plaques, modulating pro-inflammatory cytokines, and altering gut microbiota composition, TRE/TRF may slow the progression of AD. Further research is needed to confirm these effects and to understand the mechanisms involved. This review highlights TRE/TRF as a promising non-pharmacological intervention in the fight against AD.

Sleep quality of vulnerable elderly people: associated factors

OBJECTIVE

To identify factors associated with poor sleep quality in elderly dependent individuals in social vulnerability.

METHOD

Cross-sectional study with 59 elderly dependent individuals assisted by Family Health Units in São Carlos/SP. The following tools were used: Katz Index, Lawton and Brody Scale, Pittsburgh Sleep Quality Index, Addenbrooke's Cognitive Examination Revised, Fried's Frailty Phenotype, Geriatric Depression Scale (15 items), Perceived Stress Scale, Family APGAR, Social Support Scale from the Medical Outcomes Study, and World Health Organization Quality of Life, abbreviated and "old" versions.

RESULTS

The majority of participants were women (52.5%), aged 60-74 years (71.1%), and had poor sleep quality (76.2%). Stress (OR=1.12; 95%CI=1.02-1.22) and polypharmacy (OR=7.39; 95%CI=1.22-44.73) increased the chances of poor sleep quality, while physical activity decreased these chances (OR=0.15; 95%CI=0.02-0.79).

CONCLUSION

Stress and polypharmacy are associated with poor sleep quality in elderly dependent individuals.

Caregiving-Related Depression Increases Neuroinflammation in Spousal Caregivers to Individuals With Cognitive Impairment: A Longitudinal Study

BACKGROUND

The caregiving burden of the spousal caregivers (SCGs) to individuals with cognitive impairment poses public health challenges with adverse psychosocial and physiological effects. However, few studies have investigated the neurobiological impact of caregiving, particularly through the investigation of neuroinflammation and neurodegeneration.

METHODS

Using data from a longitudinal cohort at Chungnam National University Hospital, the relationship between caregiving burden, neuroinflammation, and neurodegeneration was examined in 38 older adult couples over a 16-month period. Caregiving burden was assessed through a multifaceted approach. For factors related to the care recipient, we assessed cognitive function and neuropsychiatric symptoms. Factors regarding the SCGs included the measurement of perceived depression. Glial fibrillary acidic protein (GFAP) was used as a plasma biomarker for neuroinflammation and neurofilament light chain (NfL) for neurodegeneration. Regression analyses were adjusted for age, sex, apolipoprotein E status, follow-up interval, vascular risk factors, and physical activity.

RESULTS

Changes in depression among SCGs were significantly correlated with increased GFAP levels (p = .003), indicating that greater depressive symptoms during caregiving are associated with increased neuroinflammation. In contrast, no significant correlations were found between changes in cognitive function or neuropsychiatric symptoms in care recipients and the plasma biomarker levels of SCGs. Additionally, there was no significant association between changes in depression and NfL levels in SCGs.

CONCLUSIONS

The psychological stress experienced by SCGs while caring for partners with cognitive impairment actively contributes to neuroinflammation, a well-known risk factor for various diseases. This study emphasizes the need to address psychological stress experienced by older adult caregivers.

Intergenerational Caregiving Patterns and Cognitive Health among the Sandwich Generation Within Four-Generation Families

This study aims to investigate whether generational differences in intergenerational caregiving patterns (caring for parents only, caring for grandchildren only, and caring for parents and grandchildren simultaneously) are associated with cognitive health disparities among the sandwich generation within four-generation families, drawing upon the theories of intergenerational solidarity and intergenerational stake. Moreover, this study seeks to identify mediators that help explain these disparities. A nationally representative sample of 8,065 respondents was drawn from the 2011 and 2018 waves of the China Health and Retirement Longitudinal Study. The findings reveal that the sandwich generation caring for grandchildren only, as well as those caring for grandchildren and parents simultaneously, exhibit better cognitive health. However, caregiving for parents only is not significantly related to their cognitive health. This study identifies the inability to reduce depressive symptoms as a mediator explaining the insignificant association between caregiving for parents only and the cognitive health of the sandwich generation. The findings underscore the importance of offering support to the sandwich generation within four-generation families to enhance their cognitive health. Moreover, it is imperative to distinguish between different intergenerational caregiving patterns based on generational differences among the sandwich generation, with a specific emphasis on allocating public resources aimed at promoting cognitive health for those engaged in caring for parents.

Impact of caregiving on frailty in older spousal caregivers: A retrospective cohort study

Older spousal caregivers bear the dual burden of managing health changes and caring for their partners. This study aimed to investigate the association between spousal caregiving and frailty in older adults. A retrospective cohort study with a 4-year follow-up was conducted using seven waves of data from the Health and Retirement Study (2006-2018). The mean age of participants was 65.1 years. A significant correlation was found between spousal caregiving and frailty increase. Multilevel analysis demonstrated a significant difference in the changes in frailty index over 12 years between caregivers and non-caregivers. This study uncovered a significant association between spousal caregiving and frailty in older adults, suggesting that becoming a spousal caregiver is not only linked to higher levels of frailty but also accelerates its progression. Healthcare providers can tailor support services to assist caregivers in managing challenges and promoting healthy aging.

Psychoneuroimmunology in multiple myeloma and autologous hematopoietic stem cell transplant: Opportunities for research among patients and caregivers

Multiple myeloma (MM) is an incurable cancer and is the leading indication for autologous hematopoietic stem cell transplantation (HSCT). To be eligible for HSCT, a patient must have a caregiver, as caregivers play a central role in HSCT preparation and recovery. MM patients remain on treatment indefinitely, and thus patients and their caregivers face long-term challenges including the intensity of HSCT and perpetual therapy after transplant. Importantly, both patients and their caregivers show heightened depressive and anxiety symptoms, with dyadic correspondence evidenced and caregivers' distress often exceeding that of patients. An extensive psychoneuroimmunology (PNI) literature links distress with health via immune and neuroendocrine dysregulation as well as biological aging. However, data on PNI in the context of multiple myeloma - in patients or caregivers - are remarkably limited. Distress in MM patients has been associated with poorer outcomes including higher inflammation, greater one year post-HSCT hospital readmissions, and worse overall survival. Further, anxiety and depression are linked to biological aging and may contribute to the poor long-term health of both patients and caregivers. Because MM generally affects older adults, individual differences in biological aging may represent an important modifier of MM biology and HSCT treatment outcomes. There are a number of clinical scenarios in which biologically younger people could be prescribed more intensive therapies, with potential for greater benefit, by using a personalized cancer therapy approach based on the quantification of physiologic reserve. Further, despite considerable psychological demands, the effects of distress on health among MM caregivers is largely unexamined. Within this context, the current critical review highlights gaps in knowledge at the intersection of HSCT, inflammation, and biological aging in the context of MM. Research in this area hold promise for opportunities for novel and impactful psychoneuroimmunology (PNI) research to enhance health outcomes, quality of life, and longevity among both MM patients and their caregivers.

Associations of perceived stress, depressive symptoms, and caregiving with inflammation: a longitudinal study

OBJECTIVES

Higher inflammation has been linked to poor physical and mental health outcomes, and mortality, but few studies have rigorously examined whether changes in perceived stress and depressive symptoms are associated with increased inflammation within family caregivers and non-caregivers in a longitudinal design.

DESIGN

Longitudinal Study.

SETTING

REasons for Geographic And Racial Differences in Stroke cohort study.

PARTICIPANTS

Participants included 239 individuals who were not caregivers at baseline but transitioned to providing substantial and sustained caregiving over time. They were initially matched to 241 non-caregiver comparisons on age, sex, race, education, marital status, self-rated health, and history of cardiovascular disease. Blood was drawn at baseline and approximately 9.3 years at follow-up for both groups.

MEASUREMENTS

Perceived Stress Scale, Center for Epidemiological Studies-Depression, inflammatory biomarkers, including high-sensitivity C-reactive protein, D dimer, tumor necrosis factor alpha receptor 1, interleukin (IL)-2, IL-6, and IL-10 taken at baseline and follow-up.

RESULTS

Although at follow-up, caregivers showed significantly greater worsening in perceived stress and depressive symptoms compared to non-caregivers, there were few significant associations between depressive symptoms or perceived stress on inflammation for either group. Inflammation, however, was associated with multiple demographic and health variables, including age, race, obesity, and use of medications for hypertension and diabetes for caregivers and non-caregivers.

CONCLUSIONS

These findings illustrate the complexity of studying the associations between stress, depressive symptoms, and inflammation in older adults, where these associations may depend on demographic, disease, and medication effects. Future studies should examine whether resilience factors may prevent increased inflammation in older caregivers.

Associations Between Dysfunctional Thoughts, Leisure Activities, and IL-6 in Caregivers of Family Members With Dementia

OBJECTIVE

Dementia caregiving is associated with negative physical health consequences, including inflammation processes. The objective of this study was to analyze the associations between dysfunctional thoughts, frequency of leisure activities, and interleukin 6 (IL-6) in a sample of dementia family caregivers.

METHODS

One hundred forty dementia caregivers participated in this cross-sectional study. The relationships among caregivers' dysfunctional thoughts, leisure activities, and IL-6 were adjusted for demographic characteristics, stressors, and physical and mental health indicators in a linear regression analysis.

RESULTS

Higher levels of dysfunctional thoughts ( t = -2.02, p = .045) were significantly associated with lower frequency of leisure activities. In turn, lower frequency of leisure activities was significantly associated with higher levels of IL-6 ( t = -2.03, p = .045). Dysfunctional thoughts were no longer significantly associated with IL-6 levels when both dysfunctional thoughts and leisure activities were included in the same model ( t = 1.78, p = .076). A significant indirect effect was found for the association between higher levels of dysfunctional thoughts and higher levels of IL-6 (standardized indirect effect = 0.036, bootstrap standard error = 0.026, 95% confidence interval = 0.0001-0.1000) through its association with fewer leisure activities.

CONCLUSIONS

Our findings suggest that the direct effect of caregivers' dysfunctional thoughts on IL-6 may be mediated by the impact on caregivers' frequency of leisure activities. Results suggest that training caregivers in reducing dysfunctional thoughts to thereby increase leisure activities may be useful in reducing inflammation.

Transitions to Family Caregiving and Latent Variables of Systemic Inflammation Over Time

Circulating levels of inflammatory biomarkers may be influenced by chronic psychological stressors such as those experienced by family caregivers. However, previous studies have found mostly small and inconsistent differences between caregivers and control samples on individual measures of systemic inflammation. Latent variables of inflammation were extracted from six biomarkers collected from two blood samples over 9 years apart for 502 participants in a national cohort study. One-half of these participants transitioned into a sustained family caregiving role between the blood samples. Two latent factors, termed "up-regulation" and "inhibitory feedback," were identified, and the transition to family caregiving was associated with a lower increase over time on the inhibitory feedback factor indexed by interleukin (IL)-2 and IL-10. No caregiving effect was found on the up-regulation factor indexed primarily by IL-6 and C-reactive protein. These findings illustrate the advantages of using latent variable models to study inflammation in response to caregiving stress.

A randomized controlled trial of emotion regulation therapy for cancer caregivers: A mechanism-targeted approach to addressing caregiver distress

BACKGROUND

Caregivers of patients with cancer play a crucial role in the health of the person they care for, and in the healthcare system at large. Family caregivers receive minimal support, despite being at greater risk for anxiety and depression than patients themselves. Cognitive behavioral therapy (CBT), an effective therapy for anxiety and depression, has shown mixed efficacy when delivered to cancer caregivers. Emotion Regulation Therapy (ERT), a contemporary CBT, may uniquely target processes underlying distress associated with caregiving. Therefore, we adapted both CBT and ERT to target the needs of caregivers (i.e., CBT-C and ERT-C) and are conducting a multi-site randomized trial to examine the comparative efficacy of these interventions.

METHODS

Family cancer caregivers (n = 200) reporting distress related to caregiving are recruited from two academic cancer centers and randomly assigned to either ERT-C or CBT-C. Caregivers in both interventions engage in eight weekly one-hour sessions by videoconference with a trained interventionist. Caregiver participants complete study assessments at baseline, post-treatment, 3-and 6-months follow-up. Patients of each caregiver can also enroll in the study and complete assessments at baseline and 3-months follow-up. Outcome measures include psychosocial constructs such as anxiety, depression, quality of life, as well as proposed mechanistic constructs and salivary markers of stress and inflammation.

CONCLUSIONS

The results of this study will advance the science of caregiving interventions in cancer by addressing a critical gap in our ability to mitigate anxiety and depression in caregivers, as well as further our understanding of how these changes may influence patients' outcomes.

Cognitive behavioral therapy versus general health education for family caregivers of individuals with heart failure: a pilot randomized controlled trial

Background

While support from family caregivers is essential in the care of patients with heart failure (HF), caregiving places a considerable burden on family caregivers. We examined the preliminary effects of cognitive behavioral therapy (CBT) for caregivers of individuals with HF.

Methods

In this pilot randomized controlled trial, patients with HF and their primary family caregivers (30 dyads) were randomized into CBT (n = 15) or general health education (GHE, n = 15) groups. Caregivers received 8 weekly individual sessions of either CBT (intervention) or GHE (attention control condition). Caregivers completed questionnaires at baseline, post-intervention, and 6 months. Saliva samples collected from caregivers at baseline and post-intervention were analyzed for salivary cortisol. The cortisol awakening response (CAR) and area under the curve (AUC) were calculated using log-transformed cortisol values. We analyzed data from 26 (14 receiving CBT and 12 receiving GHE) caregivers who received at least one session of CBT or GHE (modified intention-to treat) using linear mixed models. Each model included time, study group, and time-by-study group interaction as fixed effects.

Results

Patients were older (66.94 ± 14.01 years) than caregivers (55.09 ± 15.24 years), and 54% of patients and 54% of caregivers were female. Most caregivers (58%) were spouses. A total of 14 (93%) CBT and 12 (80%) GHE participants received at least 1 session (p = .60), and 11 (73%) CBT and 11 (73%) GHE participants completed all 8 sessions (p = 1.00). There were no significant between-group differences in change for salivary cortisol or psychological outcomes. However, the CBT group had significant within-group improvements in perceived stress (p = .011), stress symptoms (p = .017), depression (p = .002), and anxiety (p = .006) from baseline to post-intervention, while the control group had no significant within-group change in the outcomes except for anxiety (p = .03). The significant improvements observed in the CBT group lasted for 6 months. No adverse effects were observed.

Conclusions

In this pilot trial, although between-group differences in change were not significant, CBT resulted in significant improvements in some psychological outcomes with no improvement in the control group. Our findings suggest the potential of the intervention to alleviate psychological distress in HF caregivers. Further examination in larger randomized trials is warranted.

Trial registration

ClinicalTrials.gov Identifier: NCT01937936 (Registered on 10/09/2013).

A Landscape of Subjective and Objective Stress in African-American Dementia Family Caregivers

Stress is a significant part of daily life, and systemic social inequities, such as racism and discrimination, are well-established contributors of chronic stress for African Americans. Added exposure to the stress of caregiving may exacerbate adverse health outcomes. This secondary analysis describes subjective and objective stress in African American family caregivers, and relationships of subjective and objective stress to health outcomes. Baseline data from 142 African American dementia family caregivers from the "Great Village" study were described using means and frequencies; regression models and Pearson's correlation were used to examine associations between demographics, social determinants of health, and health outcomes. Mixed models were used to examine change and change variation in cortisol. Most caregivers had moderate degrees of stress. Stress was associated with sleep disruption and depressive symptoms, and discrimination appeared to be an independent contributor to depressive symptoms. This work provides a foundation for interpreting subjective and objective indicators of stress to tailor existing multicomponent interventions.

Caregivers of patients with cancer: perceived stress, quality of life and immune function

OBJECTIVES

To examine the mediating effect of quality of life (QoL) on the relationship between perceived stress and immune function in Korean family caregivers of patients with cancer.

METHODS

In this cross-sectional study, 89 family caregivers of patients with cancer completed perceived stress and QoL questionnaires. Immune function was assessed using two proinflammatory biomarkers, IL-6 and tumour necrosis factor-alpha (TNF-α). Multiple parallel mediator regression was conducted using four mediators (burden, lifestyle disruption, positive adaptation and financial concern) representing the subscales of QoL related to caregiving.

RESULTS

Psychological (indirect effect (ab)=-0.52, 95% CI -1.25 to -0.01) and physical (ab=-0.44, 95% CI -1.07 to -0.05) stress had a significant indirect effect on IL-6 levels attributed to lifestyle disruption associated with caregiving. Psychological (ab=-0.97, 95% CI -2.37 to -0.11) and physical (ab=-1.10, 95% CI -2.87 to -0.08) stress also had a significant indirect effect on TNF-α as a result of financial concerns owing to caregiving. Other indirect effects of psychological/physical stress on inflammation were not significant.

CONCLUSION

This study demonstrated that the effects of perceived psychological and physical stress on IL-6 and TNF-α levels were mediated by the caregiver's QoL, especially lifestyle disruption and financial concerns. Stress management and improvement of caregivers' QoL related to lifestyle disruption and financial issues should be considered to reduce the negative effects of caregiving on immune function.

Caregiver subjective and physiological markers of stress and patient heart failure severity in family care dyads

Greater family caregiver exposure to uncontrolled patient symptoms is predictive of greater caregiver psychological and physiological stress in dementia and other chronic illnesses, but these phenomena have not been well-studied in heart failure (HF) - a disease with high symptom burden. The purpose of this study was to test the hypothesis that worse patient functional status (as reflected by increasing HF symptoms) would be associated with elevated psychological and physiological stress for the caregiver. This was a secondary analysis of data from 125 HF caregivers in the Caregiver Opportunities for Optimizing Lifestyle (COOL) study. Psychological stress was measured on four dimensions: care-related strain/burden (Oberst Caregiving Burden Scale), depression (Center for Epidemiological Studies Depression Scale), anxiety (State-Trait Anxiety Index), and general stress (Perceived Stress Scale). Physiological stress was measured by markers of HPA axis function (elevated cortisol awakening response [CAR]), endothelial dysfunction (increased PAI-1), and inflammation (increased IL-6, hsCRP). HF patient functional status was quantified by caregiver assessment of New York Heart Association (NYHA) Class. Generalized linear models were used to test associations between patient NYHA Class and stress (one model per indicator). NYHA Class (ordinal) was backwards difference coded in each model to examine caregiver stress in relation to increasing levels of HF severity. Caregivers were mostly female and in their mid-fifties, with a slight majority of the sample being African American and the patient's spouse. Overall, patient functional status was associated with greater caregiver psychological and physiological stress. In terms of psychological stress, higher NYHA Class was significantly associated with greater caregiver anxiety and general stress, but not with caregiver burden or depression. In terms of physiological stress, higher NYHA Class was associated with elevated markers in all models (elevated CAR and higher IL-6, hsCRP, and PAI-1). Across models, most associations between NYHA Class and stress were present at relatively early stages of functional limitation (i.e. Class II), while others emerged when functional limitations became more severe. To inform timing and mechanisms for much-needed caregiver interventions, research is needed to determine which aspects of HF symptomatology are most stressful for caregivers across the HF trajectory.

Caregiving and allostatic load predict future illness and disability: A population-based study

Background

Caring for sick or disabled relatives is a key model for understanding the effects of chronic stress on immunity/inflammation; biomarkers which are part of an index of allostatic load. Here, we examine whether caring and allostatic load are predictive of future illness/disability and if the association between caring and illness/disability is mediated by allostatic load.

Method

Using data from the Understanding Society Wave 2 (2011) and Wave 9 (2017–2019) datasets in the UK, a sample of 471 of caregivers and 2,151 non-caregivers (all initially healthy) were compared on allostatic load and future illness/disability.

Results

Caregivers had higher allostatic risk scores, for total as well as immune and non-immune biomarkers, and were more likely (23.3% vs 17.4%) to have an illness/disability in the future compared to non-caregivers. Moreover, caregiving was responsible for a 33% future illness/disability risk. Further, allostatic load was also predictive of excess risk (OR ​= ​1.18, 95% CI ​= ​1.08 – 1.26; p ​< ​.001); higher allostatic load was associated with increased risk of illness/disability in the future. In an unadjusted mediation model, allostatic load mediated the association between caregiving and future illness/disability. However, after controlling for confounding, the mediation became non-significant.

Conclusions

These results confirm that caregiving and allostatic load are damaging for future health. Results are also discussed in relation to public health aspects of caregiving.

•

Caregivers have a greater risk of future illness and disability relative to non-caregivers.

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Allostatic load is higher among caregivers.

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Risk of illness and disability continued beyond cessation of caring.

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Caregiving and allostatic load predicted future illness and disability.

Association between inflammatory cytokines and caregiving distress in family caregivers of cancer patients

PURPOSE

Caregivers of cancer patients experience distress that can manifest as caregiving burden, burnout, depression, and fatigue. Caregiving distress affects physical health in various ways such as causing the dysregulation of inflammatory functions. We examined the relationships between psychological distress experienced by and inflammatory cytokine levels of family caregivers of cancer patients.

METHODS

A descriptive, cross-sectional study involving 93 family caregivers of cancer patients was conducted. Self-report questionnaires were used to measure the distress variables, which included the caregiving burden, burnout, depression, and fatigue, and peripheral blood samples were collected to measure the IL-6, IL-10, and TNF-α levels. Multiple linear regression analyses were conducted to evaluate the impact of caregivers' distress on their inflammatory cytokine levels.

RESULTS

Inflammatory cytokine levels were negatively correlated with caregiving distress. High fatigue levels (B =  - 0.047, p = 0.026) and additional days of care provided per week (B =  - 0.048, p = 0.009) was associated with low IL-6 levels. High depression levels (B =  - 0.250, p = 0.007), high fatigue levels (B =  - 0.054, p = 0.027), and more days of care provided per week (B =  - 0.048, p = 0.033) were associated with low TNF-α levels. The age of the caregiver (B =  - 0.011, p = 0.020) and days of care provided per week (B =  - 0.138, p = 0.031) were associated factors for IL-10 levels.

CONCLUSION

The inflammatory responses were associated with the distress in family caregiving for cancer patients. Thus, interventions are needed to support caregivers and manage their caregiving distress.

Glucocorticoid resistance and β2-adrenergic receptor signaling pathways promote peripheral pro-inflammatory conditions associated with chronic psychological stress: A systematic review across species

Activation of the HPA-axis and SNS are widely accepted to link chronic stress with elevated levels of peripheral pro-inflammatory markers in blood. Yet, empirical evidence showing that peripheral levels of glucocorticoids and/or catecholamines mediate this effect is equivocal. Recent attention has turned to the possibility that cellular sensitivity to these ligands may contribute to inflammatory mediators that accompany chronic stress. We review current evidence for the association of chronic stress with glucocorticoid receptor (GR) and β-adrenergic receptor (β-AR) signaling sensitivity. Across 15 mouse, 7 primate, and 19 human studies, we found that chronic stress reliably associates with downregulation in cellular GR sensitivity, alterations in intracellular β-AR signaling, and upregulation in pro-inflammatory biomarkers in peripheral blood. We also present evidence that alterations in GR and β-AR signaling may be specific to myeloid progenitor cells such that stress-related signaling promotes release of cells that are inherently less sensitive to glucocorticoids and differentially sensitive to catecholamines. Our findings have broad implications for understanding mechanisms by which chronic stress may contribute to pro-inflammatory phenotypes.

Potential mechanisms linking psychological stress to bone health

Chronic psychological stress affects many body systems, including the skeleton, through various mechanisms. This review aims to provide an overview of the factors mediating the relationship between psychological stress and bone health. These factors can be divided into physiological and behavioural changes induced by psychological stress. The physiological factors involve endocrinological changes, such as increased glucocorticoids, prolactin, leptin and parathyroid hormone levels and reduced gonadal hormones. Low-grade inflammation and hyperactivation of the sympathetic nervous system during psychological stress are also physiological changes detrimental to bone health. The behavioural changes during mental stress, such as altered dietary pattern, cigarette smoking, alcoholism and physical inactivity, also threaten the skeletal system. Psychological stress may be partly responsible for epigenetic regulation of skeletal development. It may also mediate the relationship between socioeconomic status and bone health. However, more direct evidence is required to prove these hypotheses. In conclusion, chronic psychological stress should be recognised as a risk factor of osteoporosis and stress-coping methods should be incorporated as part of the comprehensive osteoporosis-preventing strategy.

Spousal bereavement after dementia caregiving: A turning point for immune health

Losing a spouse can increase the risk for premature mortality, and declines in immune health are thought to play a role. Most of the supporting data have come from cross-sectional studies comparing already-bereaved individuals to matched controls, which provides valuable information about health disparities between groups but does not reveal health changes over time. Moreover, the health consequences of bereavement may be unique for dementia family caregivers, a large and growing segment of the population. The current study sought to evaluate the course of health around 52 dementia spousal caregivers' bereavement by capturing lymphocyte proliferation to Con A and PHA and self-rated health before and after spousal loss. To investigate the moderating role of the social environment, we examined associations between social ties and health trajectories before and after spousal loss. Using piecewise linear mixed models to allow for turning points in caregivers' trajectories, we found that, for the average caregiver, lymphocyte proliferation to both mitogens weakened as bereavement neared and continued to decline after the loss, but at a slower pace. In tandem, perceived health degraded as bereavement approached but rebounded thereafter. Further, we found that socially isolated caregivers showed marked declines in immune responses to Con A and PHA over time both before and after bereavement, whereas their socially connected counterparts had shallower declines to PHA and maintained a level immune response to Con A. In addition, socially isolated caregivers reported poorer health before and after bereavement compared to their counterparts, whose self-rated health declined as the loss neared but later recovered to exceed prior levels. These findings shed new light on the dynamics of immune function in response to spousal bereavement after dementia caregiving: longitudinal data reveal a pattern of health recovery following caregivers' loss, particularly among those with more robust social networks prior to bereavement.

Efficacy of a Stress Management Intervention for Mothers of Children with Cancer

OBJECTIVE

Mothers of children with cancer confront life stress that can impact their psychological and physical health and, in turn, the health of the family. Recommendations advocate preemptive stress-management interventions; however, few studies have investigated their efficacy. Here, we report results of a parallel randomized pilot trial examining health benefits of a stress management intervention designed to teach coping skills.

METHODS

One hundred twenty mothers (age 36 ± 8 years) of children newly diagnosed with cancer were randomized to a 12-session stress management intervention (n = 60) or usual care (n = 60). Sessions took place in the inpatient or outpatient setting of a children's hospital. Primary outcome variables included psychological function and physical health assessed preintervention and postintervention and at 6-month follow-up (∼12 months postdiagnosis).

RESULTS

Enrollment, retention, and satisfaction data supported feasibility and acceptability. Latent change score models showed the intervention reduced perceived stress (d = -0.37, p = 0.03), anxiety symptoms (ds = -0.38 and -0.56, ps < .03) and, a nonsignificant effect for depressive symptoms (d = -0.29, p = .11) across the 6 months following diagnosis. Intervention participants also endorsed fewer depressive symptoms than controls ∼12 months after diagnosis. The intervention improved stress management skills, which associated with the psychological benefits of participation. There were no intervention-related changes in perceived health or markers of inflammation.

CONCLUSION

Intervention-related improvements in stress management skills may result in better psychological health in the face of caring for a child with cancer.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02022449.

The transition to family caregiving and its effect on biomarkers of inflammation

Chronic stress has been widely proposed to increase systemic inflammation, a pathway that may link stress with a heightened risk for many diseases. The chronic stress-inflammation relationship has been challenging to study in humans, however, and family caregiving has been identified as one type of stressful situation that might lead to increased inflammation. Previous studies of caregiving and inflammation have generally used small convenience samples, compared caregivers with poorly characterized control participants, and assessed inflammation only after caregivers provided care for extended periods of time. In the current project, changes over a 9-y period were examined on six circulating biomarkers of inflammation for 480 participants from a large population-based study. All participants reported no involvement in caregiving prior to the first biomarker assessment, and 239 participants then took on extensive and prolonged family caregiving responsibilities at some point prior to the second biomarker assessment. Incident caregivers were individually matched on multiple demographic and health history variables with participants who reported no caregiving responsibilities. Of the six biomarkers examined, only tumor necrosis factor alpha receptor 1 showed a significantly greater increase in caregivers compared with controls. This effect was small (d = 0.14), and no effects were found for a subset of 45 caregivers who were living with a spouse with dementia. These results are consistent with recent meta-analytic findings and challenge the widespread belief that caregiving is a substantial risk factor for increased inflammation. Future research is warranted on factors that may account for stress resilience in family caregivers.

Trajectory of Psychosocial Measures amongst Informal Caregivers: Case-Controlled Study of 1375 Informal Caregivers from the English Longitudinal Study of Ageing

Informal caregivers provide vital support for older adults living in the community with chronic illnesses. The purpose of this study was to assess the psychosocial status of informal caregivers of community-dwelling adults over an eight-year period. Informal caregivers of adult care-recipients were identified from Wave 1 of the English Longitudinal Study of Ageing (ELSA) cohort. Multivariate regression analysis models were constructed to assess the association between participant's psychosocial characteristics and informal caregiving. Multilevel modelling explored the psychosocial changes between caregivers and non-caregivers over eight years. 1375 informal caregivers and 2750 age-matched non-caregivers were analyzed. Self-reported loneliness (Odd Ratio (OR): 0.26; 95% confidence intervals (CI): 0.01-0.51) and relationship status (OR: 0.36; 95% CI: 0.16-0.46) were independently associated with caregiving. Caregivers were more socially isolated with less holidaying abroad (OR: 0.51; 95% CI: 0.35-0.66), attendance to church (OR: 0.30; 95% CI: 0.11-0.49), or charity groups (OR: 0.35; 95% CI: 0.14-0.55). On multilevel analysis, over time (eight-years), caregivers reported greater loneliness (p < 0.01), change in relationship status (p = 0.01) and reduced control, autonomy, and pleasure (p ≤ 0.01) compared to non-caregivers. Given the deleterious effects caregiving can place on health and wellbeing, further interventions are required to improve these psychosocial factors.

Periodontal disease, sleep duration, and white blood cell markers in the 2009 to 2014 National Health and Nutrition Examination Surveys

BACKGROUND

Elevated levels of inflammatory biomarkers are consistently associated with chronic conditions, for which periodontitis and sleep are established risk factors. We examined the relationships between periodontitis, hours of sleep and white blood cell (WBC) markers among a nationally representative sample of US adults.

METHODS

Cross-sectional study using existing demographic, examination, laboratory and questionnaire data on 11,813 participants (5,814 men and 5,999 women, mean age ± SE; range: 52.74 ± 0.24; 30 to 80 years) from the 2009 to 2014 National Health and Nutrition Examination Surveys. Unadjusted, sex- and age-adjusted, as well as fully adjusted linear and logistic regression models were conducted in addition to generalized structural equations models, while considering sampling design complexity. β, odds ratios with their 95% confidence intervals, indirect effects and mediation proportions were estimated.

RESULTS

The weighted mean WBC count was 7,130 cells/µL, with the WBC 5-part differential estimated in terms of percentages of lymphocytes (29.50%), monocytes (7.99%), neutrophils (59.03%), eosinophils (2.84%), and basophils (71.88%). Furthermore, 36.2% of participants reported <7 hours of sleep and 49.8% had periodontitis. In fully adjusted models controlling for sociodemographic, lifestyle, and health characteristics, neither WBC markers nor periodontitis were related to hours of sleep. By contrast, periodontitis was directly related to WBC count and %neutrophils and inversely related to %lymphocytes, especially among men. However, the relationship of periodontitis with %neutrophils and %lymphocytes may be modified by hours of sleep, as it was specific to individuals reporting ≥7 hours of sleep.

CONCLUSION

Periodontitis may be directly related to WBC count and %neutrophils and inversely related to %lymphocytes, especially among men and individuals reporting ≥7 hours of sleep, with implications for primary and secondary prevention.

Transitions to family caregiving: enrolling incident caregivers and matched non-caregiving controls from a population-based study

BACKGROUND AND AIM

Providing care to an older adult with a disability has been associated with increased risk to the caregiver's health, but most previous studies of caregiving and health compare persons who are already caregivers with poorly matched non-caregiving controls and are often based on convenience samples. In this report, we describe the enrollment of persons who transitioned into a family caregiving role while participating in a national epidemiological study.

METHODS

Participants in the REasons for Geographic And Racial Differences in Stroke (REGARDS) study were asked on two occasions 9-14 years apart if they were providing care on an ongoing basis to a family member with a chronic illness or disability. Those who answered "no" and "yes", respectively, to this caregiving question and reported sufficient caregiving responsibilities after their transitions were enrolled in the present study as incident caregivers (N = 251). Participants matched on multiple demographic and health history variables and who reported no history of caregiving were enrolled as non-caregiving controls (N = 251).

RESULTS

Among eligible participants, 84% agreed to participate, and 47% of caregivers reported caring for a person with dementia. Descriptive analyses confirmed the success of the matching procedures for balancing the groups on multiple demographic and pre-caregiving health variables. Depressive symptoms and perceived stress increased significantly after the transition to caregiving.

CONCLUSION

Comparable, population-based samples of incident caregivers and matched non-caregivers have been enrolled. Future analyses will examine within-person changes in health and circulating biomarkers as a function of the transition to caregiving.

Is Family Caregiving Associated With Inflammation or Compromised Immunity? A Meta-Analysis

BACKGROUND AND OBJECTIVES

Family caregiving stress has been widely reported to have negative effects on circulating biomarkers of immune system function and inflammation. Our goals were to systematically review this literature and conduct a meta-analysis on the extracted effects.

RESEARCH DESIGN AND METHODS

A systematic search of published studies comparing caregivers and noncaregivers on biomarkers measured from blood samples was conducted in the PubMed, Embase, and Cochrane databases. This search identified 2,582 articles and abstracts. After removing duplicative papers and studies not meeting inclusion criteria, 30 articles were identified that reported analyses on 86 relevant biomarkers from 1,848 caregivers and 3,640 noncaregivers.

RESULTS

Random-effects models revealed an overall effect size across all biomarkers of 0.164 SD units (d). A slightly larger overall effect (d = 0.188) was found for dementia caregivers only. Immune system comparisons yielded somewhat larger differences than inflammation comparisons. Most studies used small convenience samples, and effect sizes were larger for studies with moderate or high bias ratings than for studies with low bias ratings. No significant associations were found in studies that used population-based samples.

DISCUSSION AND IMPLICATIONS

Caregivers had small but significantly reduced immune system functioning and greater inflammation than noncaregivers, but associations were generally weak and of questionable clinical significance. The absence of clear associations from low bias studies and population-based studies underscores concerns with possible selection biases in many of the convenience samples. Population-based studies that assess biomarkers before and after the onset of caregiving might add much clarity to this literature.

Stress and inflammation - The need to address the gap in the transition between acute and chronic stress effects

Stress responses help us navigate our environment and respond appropriately to threats. Stress systems communicate threats to the entire organism, and as such, also stimulate inflammatory mechanisms. This modulation might serve protective functions in the short term, but sustained low-grade inflammation has severe long-term health consequences. While we have reached a reasonable level of understanding of acute, as well as chronic stress effects on inflammatory mechanisms, there is a significant gap in our understanding of the transitional phase between acute and chronic stress. The purpose of this review is to first summarize current knowledge of our understanding of acute stress effects on inflammation, as well as of chronic stress effects on inflammation, and to then analyze the state of knowledge about the transitional phase between acute and chronic stress. Research discussed here shows that we are beginning to understand the early phase of repeated acute stress, but lack information on longer term exposure to repeated acute stress experiences. More research is needed to bridge this important gap und our conceptualization and understanding of the stress and health relationship.

Biomedical health profiles of unpaid family carers in an urban population in South Australia

OBJECTIVES

To compare the biomedical health profile and morbidity of adult carers with non-carers.

METHODS

The North West Adelaide Health Study (NWAHS) is a representative population-based longitudinal biomedical cohort study of 4056 participants aged 18 years and over at Stage One. Informal (unpaid) carers were identified in Stage 3 of the project (2008-2010). Risk factors, chronic medical conditions and biomedical, health and demographic characteristics using self-report and blood measured variables were assessed. Data were collected through clinic visits, telephone interviews and self-completed questionnaires. Risk factors included blood pressure, cholesterol/lipids, body mass index (BMI), smoking and alcohol intake. Chronic medical conditions included cardiovascular and respiratory diseases, diabetes, and musculoskeletal conditions. Blood measured variables were routine haematology, biochemistry, Vitamin D, and the inflammatory biomarkers high sensitivity C-Reactive Protein (hs-CRP), Tumor Necrosis Factor alpha (TNFα) and Interleukin-6 (Il-6).

RESULTS

The prevalence of carers aged 40 years and over was 10.7%, n = 191. Carers aged 40 years and over were more likely to assess their health status as fair/poor and report having diabetes, arthritis, anxiety and depression. They also reported insufficient exercise and were found to have higher BMI compared with non-carers. Significant findings from blood measured variables were lower serum Vitamin D and haemoglobin. Male carers had raised diastolic blood pressure, higher blood glucose, lower haemoglobin and albumin levels and slightly elevated levels of the inflammatory biomarkers TNFα and hs-CRP.

DISCUSSION AND CONCLUSIONS

This study confirms informal carers had different biomedical profiles to non-carers that included some chronic physical illnesses. It identifies that both female and male carers showed a number of risk factors which need to be considered in future caregiver research, clinical guidelines and policy development regarding carer morbidity.

Stress and Immunological Aging

Immunological aging, which encompasses age-associated declines in the immune system (immunosenescence) and increases in inflammation (inflammaging), is associated with morbidity and mortality. A growing body of research suggests stress is one factor that may accelerate immunological aging. This article provides a brief overview of immunological aging, describes key biological pathways acting at multiple lifespan stages linking stress and immunological aging, and reviews recent innovative work characterizing associations between stress in several domains and immunological aging, as well as potential protective and risk factors. Important directions for future research include careful characterizations of the complexities of stress and rigorous measurement of immunological aging processes. Advancing knowledge of stress resilience and healthy immune aging may ultimately slow disease onset and extend healthspan.

Health and frailty among older spousal caregivers: an observational cohort study in Belgium

Background

Among older couples, spouses are first in line to provide care, and they are key elements in the home support of dependent older persons. In this context, ensuring the health of these older spousal caregivers should be an important issue for all of the providers who care for older adults. The aim of this study was to longitudinally assess the health of older spousal caregivers considering frailty, nutrition, cognition, physical performance and mood disorders.

Methods

In this longitudinal, observational cohort study, participants were assessed at home in Wallonia, Belgium. At baseline, 82 community-dwelling spouses of older patients with cognitive deficits or functional impairment were assessed; 78 caregivers were assessed at follow-up (16 months). The clinical instruments used included Frailty Phenotype (Fried), the Mini Nutritional Assessment-short form (MNA-SF), Short Physical Performance Battery (SPPB), Geriatric Depression Scale (GDS-15), clock drawing test, medications, Zarit Burden Index (ZBI), and Caregiver Reaction Assessment (CRA). Biological assessments included plasma interleukin-6 (IL-6), ultrasensitive C-reactive protein (CRP), cortisol, albumin and insulin growth factor-1 (IGF-1).

Results

Among caregivers, 54% were women, and the mean age was 80 years. Among care-receivers, 83% had cognitive impairment. Caregivers were more likely to be in a pre-frail stage. In one-third of the caregivers, the frailty status worsened. Transitions were observed between each of the states, except from frail to robust. In contrast to frailty, items including nutrition, cognitive status, SPPB and mood assessments were stable over time, with approximately 70% of the caregivers not experiencing significant change at follow-up. Caregiver experiences assessed with the Zarit Burden Interview and CRA were relatively stable over 16 months.

Conclusion

Many caregivers of geriatric patients are spouses who are old themselves. A failure in the health of the caregiver may anticipate an undesired care breakdown. Caregiver health and its determinants should be explored in future longitudinal studies that cover a longer time period.

Electronic supplementary material

The online version of this article (10.1186/s12877-018-0980-3) contains supplementary material, which is available to authorized users.

[Biopsychosocial approach to caregiving burden: Why should we care about caregivers' health?]

There are 11 million family caregivers in France and some estimates indicate that there will be 17 million in 2020. Caregiving is a source of chronic stress that requires adaptation and coping strategies. Caregiving may benefit the health of a caregiver with a positive coping style and altruistic goals. However, the caregiver's burden is frequently associated with negative effects in terms of biopsychosocial imbalance and medical conditions, with frequent anxiety and depression. The management of the caregiving burden starts with the recognition of health professionals - caregivers may benefit from consultation-liaison psychiatry and multidisciplinary medico-social strategies, in addition to constant support from their GPs.

Development of glucocorticoid resistance over one year among mothers of children newly diagnosed with cancer

Chronic distress associates with peripheral release of cortisol and a parallel upregulation of innate inflammation. Typically, cortisol functions to down-regulate inflammatory processes. However, in the context of chronic stress, it is hypothesized that glucocorticoid receptors within immune cells become less sensitive to the anti-inflammatory effects of cortisol, resulting in increased systemic inflammation. Caring for a child newly diagnosed with cancer is a particularly provocative chronic stressor. Here, we examine evidence for the development of cellular resistance to glucocorticoids among 120 mothers (Aged 18-56 years; 86% Caucasian) across the 12 months following their child's new diagnosis with cancer. Measures of psychological distress, interleukin (IL)-6, and glucocorticoid resistance (GCR) were assessed 1, 6, and 12 months after the diagnosis. A latent factor for distress was derived from the covariation among symptoms of anxiety, depression, and post-traumatic stress. Latent change score models revealed a significant positive association between change in distress and change in GCR from 0 to 6 months, and 6 months-1 year. This finding provides initial evidence for a longitudinal association between change in maternal distress and change in GCR from the onset of a chronic stressor through one year. Although levels of IL-6 increased during the first six months after the child's diagnosis, the magnitude of this change was not related to change in distress or change in GCR. Given the possible health consequences of reduced immune sensitivity to glucocorticoids, future work should further explore this stress response and its clinical significance.