Daily Social Interactions and the Biological Stress Response: Are There Age Differences in Links Between Social Interactions and Alpha-Amylase?

Daily biofeedback to modulate heart rate oscillations affects structural volume in hippocampal subregions targeted by the locus coeruleus in older adults but not younger adults

Using data from a clinical trial, we tested the hypothesis that daily sessions modulating heart rate oscillations affect older adults' volume of a region-of-interest (ROI) comprised of adjacent hippocampal subregions with relatively strong locus coeruleus (LC) noradrenergic input. Younger and older adults were randomly assigned to one of two daily biofeedback practices for 5 weeks: (1) engage in slow-paced breathing to increase the amplitude of oscillations in heart rate at their breathing frequency (Osc+); (2) engage in self-selected strategies to decrease heart rate oscillations (Osc-). The interventions did not significantly affect younger adults' hippocampal volume. Among older adults, the two conditions affected volume in the LC-targeted hippocampal ROI differentially as reflected in a significant condition × time-point interaction on ROI volume. These condition differences were driven by opposing changes in the two conditions (increased volume in Osc+ and decreased volume in Osc-) and were mediated by the degree of heart rate oscillation during training sessions.

Effects of Linpan nature therapy on health benefits in older women with and without hypertension

Background

Nature therapy can significantly benefit the physiology and psychology of middle-aged and older people, but previous studies have focused on forest environments. The restoration potential of rural environments in urban fringe areas, which are more accessible to older people on a daily basis, has not been fully studied. This study assessed the effects of nature therapy on the physical and mental health of older women in a rural setting (locally known as Linpan) in the urban fringe area of Chengdu, China.

Methods

We recruited a total of 60 older women (65.3 ± 5.5 years old) living in cities for 3 days of nature therapy in the winter (30 subjects) and spring (30 subjects), including 20 hypertensive patients.

Results

The results showed that the overall blood pressure, pulse and sleep dysfunction rating scores of the participants were significantly lower than the pretest levels, and the finger blood oxygen saturation, mid-day salivary alpha-amylase and cortisol were increased post-treatment. Increases in these biomarker indicates and increase in stress. There were significant differences in the changes in systolic blood pressure between the hypertension group (HTN) and the normal group (normal) (HTN decreased by 8.8%, normal decreased by 5.4%), salivary alpha-amylase content (HTN decreased by 0.3%, normal increased by 16.9%), and sleep dysfunction rating scores (HTN decreased by 59.6%, normal decreased by 54%). The decreases in systolic blood pressure and pulse in the winter group were higher than those in the spring group by 1.8 and 4.4%, respectively, while the increases in salivary alpha-amylase content and salivary cortisol content were lower than those in the spring group by 11.7 and 11.2%, respectively, and the decrease in sleep dysfunction rating scores was lower than that in the spring group by 7.1%.

Conclusion

Our study concluded that nature therapy based on various health activities in the Linpan has significant health effects on older women. It can regulate blood pressure and pulse in older women, relieve cardiovascular disease, improve sleep quality. Meanwhile, older women with high blood pressure experienced a more significant effect than the healthy group.

Daily biofeedback to modulate heart rate oscillations affects structural volume in hippocampal subregions targeted by the locus coeruleus in older adults but not younger adults

Using data from a clinical trial, we tested the hypothesis that daily sessions modulating heart rate oscillations affect older adults' volume of a region-of-interest (ROI) comprised of adjacent hippocampal subregions with relatively strong locus coeruleus (LC) noradrenergic input. Younger and older adults were randomly assigned to one of two daily biofeedback practices for 5 weeks: 1) engage in slow-paced breathing to increase the amplitude of oscillations in heart rate at their breathing frequency (Osc+); 2) engage in self-selected strategies to decrease heart rate oscillations (Osc-). The interventions did not significantly affect younger adults' hippocampal volume. Among older adults, the two conditions affected volume in the LC-targeted hippocampal ROI differentially as reflected in a significant condition x time-point interaction on ROI volume. These condition differences were driven by opposing changes in the two conditions (increased volume in Osc+ and decreased volume in Osc-) and were mediated by the degree of heart rate oscillation during training sessions.

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

REGISTRATION

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

Everyday discrimination in later life: A social network approach

What factors shape everyday discrimination among older adults? Existing perspectives focus on individual identities and social group membership (e.g., race/ethnicity, age) as key determinants of perceived discrimination. This paper examines the idea that individuals' broader social contexts - including their personal social networks - also shape perceived discrimination, and in ways that may differ across racial groups. Using data from Round 3 of the National Social Life, Health, and Aging Project (N = 3312), I consider how properties of personal networks are associated with how frequently older adults report everyday discrimination. Results indicate that more kin-centric personal networks protect against more frequent everyday discrimination, but that this protective effect may be stronger among White older adults. I propose why more kin-centric networks may play a different role in the perceived discrimination of White and Black older adults, and close by suggesting that social network composition may be a source of heterogeneity in the link between everyday discrimination and inequality in later life outcomes such as health.

Daily Social Interactions and HPA Axis Activity Among Midlife and Older Adults

BACKGROUND AND OBJECTIVES

Older people experience fewer negative interactions and report less stress in response to interpersonal tensions. Less is known, however, about the implications of daily social interactions for biological stress responses. We evaluated links between daily positive and negative interactions and 2 key biomeasures of the hypothalamic-pituitary-adrenal axis: salivary cortisol and dehydroepiandrosterone sulfate (DHEA-S). We also considered the moderating effects of age.

RESEARCH DESIGN AND METHODS

Participants included a random sample of 93 individuals aged 40-95 who completed 14 days of daily diary interviews and provided saliva samples during 4 of those days.

RESULTS

Three-level piecewise models showed that individuals had higher sustained DHEA-S levels on days after reporting more positive interactions. Young-old adults (60-79) had lower overall DHEA-S on days when they had more negative interactions than oldest-old adults (80 and older). Oldest-old adults showed a flatter decline in DHEA-S on days after they reported more negative interactions compared to midlife adults (40-59). Daily social interactions were not significantly associated with cortisol.

DISCUSSION AND IMPLICATIONS

Strategies to increase positive interactions may help to build physiological resilience to stress, particularly among midlife and young-old adults.

Covariation of psychobiological stress regulation with valence and quantity of social interactions in everyday life: disentangling intra- and interindividual sources of variation

While the overall effects of social relationships on stress and health have extensively been described, it remains unclear how the experience of social interactions covaries with the activity of psychobiological stress in everyday life. We hypothesized that the valence as well as quantitative characteristics of social interactions in everyday life would attenuate psychobiological stress. Sixty healthy participants provided data for the analyses. Using an ecological momentary assessment design, participants received 6 prompts on their smartphone for 4 days. At each prompt, they reported on social interactions since the last prompt (any occurrence, frequency, duration, quality, and perceived social support), current subjective stress, and provided one saliva sample for the analyses of cortisol (sCort) and alpha-amylase (sAA). Experiencing any contact within days as well as higher daily levels of contact quality and perceived social support were associated with reduced levels of sCort. Furthermore, on a daily level, experiencing at least one contact in-between prompts more often as well as having more contacts on average attenuated the sAA output. Perceived social support and contact quality as well as higher daily contact durations were associated with lower subjective stress. For sCort, daily levels of stress moderated the effects of experiencing any contact within days while daily perceived social support moderated the effects of subjective stress. For sAA, experiencing at least one contact in-between prompts more often on a daily level moderated the effects of subjective stress. There were no between-person effects throughout all analyses. The results show ecologically valid evidence for direct attenuating effects of social interactions on psychobiological stress as well as for the stress-buffering hypothesis in everyday life. Increasing the quantity and improving the valence of social interactions on an intrapersonal level can possibly reduce psychobiological stress and prevent its consequences.

Salivary Biomarkers and Work-Related Stress in Night Shift Workers

Work organization, such as shifts and night work, can interfere with the perception of work-related stress and therefore on the development of pathological conditions. Night shift work, particularly, can have a negative impact on workers’ wellbeing by interfering with the biological sphere. The aim of this study is to evaluate the associations between work activities, shift work effects and stress-related responses in 106 dock workers enrolled in southeast Italy. Dock workers’ tasks consist of complex activities that seemed to affect more sleep quality than work-related stress. An analysis of salivary biomarkers such as cortisol, α-amylase, melatonin and lysozyme was performed along with validated psycho-diagnostic questionnaires. Alpha-amylase showed a significant negative correlation with the effort/reward imbalance score; thus, the measurement of salivary α-amylase is proposed as a sensitive and non-invasive biomarker of work-related stress. This study may provide new insights into developing strategies for the management of night shift work. Salivary biomarkers should be further investigated in the future in order to develop simple and effective tools for the early diagnosis of work-related stress or its outcomes.

Biopsychosocial Risk Profiles among African American and Non-Hispanic White Adults: Findings from The Health and Retirement Study

BACKGROUND

Compared to Whites, African Americans have elevated risk for earlier onset fatal and non-fatal chronic conditions and accelerated aging. Despite these persistent race disparities, the causes remain poorly understood. The purpose of this study was to define a biopsychosocial risk typology that might explain accelerated aging in African Americans.

METHODS

Analyses were based on the African American and White subsample of the Health and Retirement Study (N=8,269). Latent class analysis was used to identify risk types. Chronic health conditions, salivary telomere length (STL), emotional support from family, negative interaction with family, early life adversities, and discrimination were used as class indicators. Latent class multinomial logistic regression was used to identify racial and demographic differences in risk type membership.

RESULTS

Three distinct risk types were identified: high risk, health risk, and psychosocial risk. African Americans were more likely than Whites to be assigned to the high risk type characterized by chronic health conditions, shorter STL, strained social relationships and high psychosocial stress. African Americans were less likely than Whites to be assigned to the health risk type characterized by chronic health conditions, shorter STL, optimal social relationships and low psychosocial stress.

CONCLUSIONS

The biopsychosocial risk typology accounted for population heterogeneity, identified high-risk profiles and modifiable factors within risk types that can inform current clinical interventions. The risk types also revealed different patterns of risk and resilience factors and shed light on the interplay between telomere length, stress exposure, chronic disease and accelerated aging in African Americans.

Social Integration, Daily Discrimination, and Biological Markers of Health in Mid- and Later Life: Does Self-Esteem Play an Intermediary Role?

Background and Objectives

This cross-sectional study examines associations of social integration and daily discrimination with 4 biological markers of inflammation and cardiovascular health and tests whether self-esteem may mediate any of these effects.

Research Design and Methods

Data came from 746 participants of the National Survey of Midlife Development in the United States (MIDUS) Refresher (2011–2014) and MIDUS Refresher Biomarker Project (2012–2016). Structural equation modeling estimated direct and indirect associations of social integration and daily discrimination with glycosylated hemoglobin (HbA1c), high-density lipoprotein (HDL), C-reactive protein, and interleukin-6.

Results

Social integration and daily discrimination were both significantly associated with self-esteem, which was in turn associated with HbA1c, HDL, and interleukin-6 levels. Social integration was indirectly associated with HbA1c, HDL, and interleukin-6 via self-esteem. Daily discrimination was directly associated with HbA1c, C-reactive protein, and interleukin-6 and was indirectly associated with HDL and interleukin-6 via self-esteem.

Discussion and Implications

Findings identify social correlates of inflammation and cardiovascular risk and suggest that self-esteem may serve as a pathway for effects. Overall, results were somewhat mixed: Daily discrimination was directly associated with both self-esteem and 3 of the 4 biological markers of health; however, although social integration was strongly associated with self-esteem, it was only weakly and indirectly associated with biological health markers. Moreover, the indirect effects of daily discrimination on the biomarker outcomes—while significant—were notably smaller than its direct effects. Implications for theory, practice, and future research are discussed, including the need for further study of self-esteem and physical health across mid- and later life.

Feasibility and Usability of Salivary Alpha-Amylase to Measure Stress Among Individuals With Dementia

Salivary alpha-amylase (sAA) is a noninvasive biomarker of the sympathetic-adrenal-medullary system and reflects stress. The purpose of the current study was to determine the feasibility and meaningfulness of the use of sAA levels for assisted living memory care (ALMC) residents. Participants were 10 ALMC and eight independent/assisted living (I/AL) residents. Saliva samples were collected eight times for each participant over a 12-hour period using a tongue swab collection technique with immediate sAA point-of-care analysis. Linear mixed effect modeling and case study analysis were conducted. Levels of sAA varied over a 12-hour period for each participant and between participants. Group membership (i.e., ALMC and I/AL) explained 9.3% of the variation of sAA throughout the day, whereas interpersonal differences explained 56.3%. Feasibility of saliva collection technique and measurement of sAA among an ALMC population was supported. Participants serving as their own controls when testing effects of interventions on sAA levels is warranted. [Research in Gerontological Nursing, 13(3), 120-124.].

Social Interaction in Walking Groups and Affective Responses Among Japanese Older Adults

This study examined whether satisfaction with social interactions and the number of people interacted with during walking groups is associated with affective responses among older adults. Twenty-six older adults were asked to participate in five walking group sessions. The participants walked together for 40-50 min. In every session, the participants reported their affective responses to walking (positive engagement, tranquility, and negative affect), their level of satisfaction with the social interactions experienced, and the number of people interacted with during the walk. The available data were from 107 person-sessions. Multilevel models revealed that, although a higher number of people interacted with was not significantly associated with improvements in any affective responses, higher satisfaction with the interactions was significantly associated with improvements in positive engagement at both the within- and between-person levels. This study found that higher satisfaction with the interactions was associated with desirable affective responses among older adults.

Isometric exercise facilitates attention to salient events in women via the noradrenergic system

The locus coeruleus (LC) regulates attention via the release of norepinephrine (NE), with levels of tonic LC activity constraining the intensity of phasic LC responses. In the current fMRI study, we used isometric handgrip to modulate tonic LC-NE activity in older women and in young women with different hormone statuses during the time period immediately after the handgrip. During this post-handgrip time, an oddball detection task was used to probe how changes in tonic arousal influenced functional coordination between the LC and a right frontoparietal network that supports attentional selectivity. As expected, the frontoparietal network responded more to infrequent target and novel sounds than to frequent sounds. Across participants, greater LC-frontoparietal functional connectivity, pupil dilation, and faster oddball detection were all positively associated with LC MRI structural contrast from a neuromelanin-sensitive scan. Thus, LC structure was related to LC functional dynamics and attentional performance during the oddball task. We also found that handgrip influenced pupil and attentional processing during a subsequent oddball task. Handgrip decreased subsequent tonic pupil size, increased phasic pupil responses to oddball sounds, speeded oddball detection speed, and increased frontoparietal network activation, suggesting that inducing strong LC activity benefits attentional performance in the next few minutes, potentially due to reduced tonic LC activity. In addition, older women showed a similar benefit of handgrip on frontoparietal network activation as younger women, despite showing lower frontoparietal network activation overall. Together these findings suggest that a simple exercise may improve selective attention in healthy aging, at least for several minutes afterwards.