Telomere length and procedural justice predict stress reactivity responses to unfair outcomes in African Americans

Salivary uric acid dynamics are associated with stress response hormones among African Americans in an urban sample

Acute physiological responses to psychosocial stressors are a potential pathway underlying racial disparities in stress-related illnesses. Uric acid (UA) is a potent antioxidant that has been linked to disparities in stress-related illnesses, and recent research has shown that UA is responsive to acute social stress. However, an examination of the relationships between the purinergic system and other commonly measured stress systems is lacking. Here, we measure and characterize associations of salivary uric acid (sUA) with markers of hypothalamic-pituitary-adrenal (HPA) axis activation, sympathetic-adreno-medullar (SAM) axis activation, and acute inflammation. A community sample of 103 African Americans (33 male, 70 female) completed the Trier Social Stress Test to induce social-evaluative threat. Passive drool collected before, during, and after the stressor task provided salivary reactivity measures of UA (sUA), cortisol, dehydroepiandrosterone sulfate (DHEAS), salivary alpha amylase (sAA - a surrogate marker of SAM activity) and C-reactive protein (sCRP). Multiple regressions revealed that total activation of cortisol, DHEAS, and sCRP were each positively associated with higher total activation of sUA. Additionally, DHEAS reactivity was positively associated with sUA reactivity. Relationships between HPA-axis markers and sUA were especially observed among younger and male participants. Overall, findings suggest potential coordination of stress systems with sUA in response to acute stress, which may further the contributions of biological stress processes to racial health disparities.

Lifetime discrimination in low to middle income mothers and cellular aging: A prospective analysis

BACKGROUND

Experiences of discrimination on the basis of race, ethnicity, and other characteristics are associated with adverse health outcomes, including elevated rates of morbidity in later life and earlier mortality. Acceleration of biological aging is a plausible pathway linking discrimination to disease risk. The objective of this study was to examine the relationship of self-reported lifetime and everyday discrimination to women's telomere length several years after birth of a child in a longitudinal cohort study.

METHODS

The Community Child Health Network (CCHN) conducted a community-based participatory research project focused on racial, ethnic, and socioeconomic disparities in maternal and child health. Data for the current substudy are from a longitudinal cohort study in 3 of the 5 project sites. This multi-site community-based longitudinal study was conducted in Lake County, IL north of Chicago, Washington, D.C., and rural North Carolina. Participants were low to middle-income mothers (N = 103) with a primary identity of Hispanic/Latina, Black, or non-Hispanic White who rated their experience of everyday and lifetime discrimination during an at-home interview one-month postpartum. Buccal samples were collected to assay buccal cell telomere length several years later when a consecutive child was 3-5 years of age. Telomere length derived from buccal cells was used as a biomarker indicating cellular aging and a risk factor for age-related disease.

RESULTS

Mothers (18-39 years old) who reported higher lifetime discrimination had shorter telomere length an average of 5.6 years later (B = -0.22 [SE = 0.04], p < 0.001). Mother's reports of everyday discrimination were not significantly related to telomere length (0.01[0.01], p = 0.15).

CONCLUSIONS

These findings suggest that lifetime exposure to discrimination, but not necessarily current reports of everyday discrimination, may increase biological aging as indicated by shorter buccal cell telomere length, providing evidence of a plausible route through which discrimination contributes to increased risk for earlier onset aging and age-related disease in women.

Coming up short: Comparing venous blood, dried blood spots & saliva samples for measuring telomere length in health equity research

BACKGROUND

Telomere length (TL) in peripheral blood mononuclear cells (PBMC) from fresh venous blood is increasingly used to estimate molecular impacts of accumulated social adversity on population health. Sometimes, TL extracted from saliva or dried blood spots (DBS) are substituted as less invasive and more scalable specimen collection methods; yet, are they interchangeable with fresh blood? Studies find TL is correlated across tissues, but have not addressed the critical question for social epidemiological applications: Do different specimen types show the same association between TL and social constructs?

METHODS

We integrate expertise in social epidemiology, molecular biology, and the statistical impact of measurement error on parameter estimates. Recruiting a diverse sample of 132 Metro-Detroit women, we measure TL for each woman from fresh blood PBMC, DBS, and saliva. Using regression methods, we estimate associations between social characteristics and TL, comparing estimates across specimen types for each woman.

RESULTS

Associations between TL and social characteristics vary by specimen type collected from the same woman, sometimes qualitatively altering estimates of the magnitude or direction of a theorized relationship. Being Black is associated with shorter TL in PBMC, but longer TL in saliva or DBS. Education is positively associated with TL in fresh blood, but negatively associated with TL using DBS.

CONCLUSION

Findings raise concerns about the use of TL measures derived from different tissues in social epidemiological research. Investigators need to consider the possibility that associations between social variables and TL may be systematically related to specimen type, rather than be valid indicators of socially-patterned biopsychosocial processes.

Longer Leukocyte Telomere Length Predicts Stronger Response to a Workplace Sugar-Sweetened Beverage Sales Ban: An Exploratory Study

BACKGROUND

Shorter leukocyte telomere length (LTL) is associated with increased risk of a number of metabolic diseases including insulin resistance and the development of type 2 diabetes mellitus. Shorter LTL is also associated with stress reactivity suggestive of a possible role for LTL to predict response to behavioral interventions. However, few studies have evaluated how interventions, such as weight loss or dietary changes, are associated with LTL changes or whether LTL can predict behavioral responses to interventions.

OBJECTIVES

We evaluated metabolic changes in relation to LTL changes and LTL at baseline in a cohort of at-risk adults in response to a 10-mo workplace-based sugar-sweetened beverage (SSB) intervention.

METHODS

At baseline, metabolic health and LTL measurements were assessed through standard blood draws on 212 participants. Multivariable linear regression models were used to assess changes in anthropometrics, SSB consumption, and 13 blood-based metabolic risk factors, in relation to LTL at baseline and changes in LTL.

RESULTS

Longer LTL at baseline was associated with decreases in SSB consumption over the 6-mo follow-up period (B = -29.67; P = 0.04). Slower LTL attrition rates were associated with decreases in waist circumference (B = -0.27; P  = 0.03), HDL cholesterol (B = -0.20; P  = 0.05), and apoA1 (B = -0.09; P = 0.01).

CONCLUSIONS

Longer LTL at baseline predicted a favorable overall response to a behavioral intervention: decreases in SSB consumption. Abdominal adiposity losses paralleled slower declines in LTL suggestive of overall health benefits, but we found differences in the relations between metabolic changes and LTL at baseline compared with LTL attrition rates. Longer LTL may be a proxy marker of a positive behavioral response.This trial was registered at clinicaltrials.gov as NCT02585336.

A systematic review on the effects of social discrimination on telomere length

Discrimination is unfair treatment against a certain group based on race, age, gender, sexual orientation, or other social identities. Discrimination is pervasive in society, elevates psychosocial stress, and is associated with negative mental and physical health outcomes. However, more research is needed to understand the biological mechanisms underlying discrimination-related health disparities. Telomere science may contribute to elucidate some of these aspects. Telomeres are protein-DNA complexes that shorten after cell division and are valuable markers of cellular aging. Short telomeres have been associated with the onset of age-related diseases. Evidence shows that chronic psychological stress may accelerate telomere shortening. Since discrimination can lead to psychological strain with cumulative impact on general health, we hypothesized that groups that report more discrimination show reduced telomere length (TL) as a consequence of psychosocial stress elevation. Through a systematic review of the literature we found 12 articles that met our criteria. Eligible studies measured racial, gender, unfair policing, and multiple forms of discrimination in association with TL. Our review showed mixed results, suggesting that there is weak evidence of a main association between discrimination and TL. However, discrimination may interact with several variables (such as depressive symptoms, acculturation, higher socioeconomic status, internalization of negative racial bias, and not discussing discrimination experiences with others) and contribute to shorten telomeres. Discrimination is a complex social construct composed of a vast sum of experiences, impressions, and contexts that in combination with other sources of stress may have an impact on TL. Telomeres may be a plausible pathway to investigate health discrepancies in discriminated groups in society, but more evidence is needed to investigate the potential harm of discrimination on cells.

Reactivity of salivary uric acid in response to social evaluative stress in African Americans

High uric acid (UA) is associated with hypertension and cardiovascular disease (CVD), both of which occur disproportionately among African Americans. High UA also predicts greater blood pressure reactivity responses to acute social stress. However, whether UA itself shows reactivity in response to stress is unknown. We evaluated salivary uric acid (sUA) and blood pressure reactivity in response to acute social stress. Healthy African Americans (N = 103; 32 % male; M age = 31.36 years), completed the Trier Social Stress Test. sUA and blood pressure measurements were taken before, during and after the stressor task. sUA showed significant reactivity and recovery, especially among older African Americans. Total sUA activation was also associated with systolic and diastolic blood pressure total activation. Findings illuminate that acute stress may be a way in which UA is implicated in hypertension and CVD, suggesting a critical need to explore UA reactivity as a novel parameter of the acute stress response.

Salivary uric acid: Associations with resting and reactive blood pressure response to social evaluative stress in healthy African Americans

High levels of uric acid are associated with greater risk of stress-related cardiovascular illnesses that occur disproportionately among African Americans. Whether hyperuricemia affects biological response to acute stress remains largely unknown, suggesting a need to clarify this potential connection. The current study examined how salivary uric acid (sUA) is associated with resting and reactive blood pressure - two robust predictors of hypertension and related cardiovascular disease and disparity. Healthy African Americans (N = 107; 32% male; M age = 31.74 years), completed the Trier Social Stress Test to induce social-evaluative stress. Systolic and diastolic blood pressure readings were recorded before, during, and after the task to assess resting and reactive change in blood pressure. Participants also provided a saliva sample at baseline that was assayed for sUA. At rest, and controlling for age, sUA was modestly associated with higher systolic (r = .201, p =  .044), but not diastolic (r = .100, p =  .319) blood pressure. In response to the stressor task, and once again controlling for age, sUA was also associated with higher total activation of both systolic (r = .219, p =  .025) and diastolic blood pressure (r = .198, p <  .044). A subsequent moderation analysis showed that associations between sUA and BP measures were significant for females, but not for males. Findings suggest that uric acid may be implicated in hypertension and cardiovascular health disparities through associations with elevated blood pressure responses to acute social stress, and that low levels of uric acid might be protective, particularly for females.

Acute salivary cortisol response among Mexican American adolescents in immigrant families

OBJECTIVES

Though previous research has indicated that language brokering can be stressful, the findings are mixed, pointing to potential moderators of the association. Guided by an ecological perspective, we examined the role of individual, family, and environmental factors in Mexican American adolescents' acute cortisol responses to language brokering.

METHOD

The study consisted of 46 Mexican American adolescents recruited around a metropolitan city in Central Texas. Participants translated a difficult medical document from English to Spanish for their parents, followed by an arithmetic task (modeled after the Trier Social Stress Test [TSST]). Participants' perceptions (perceived efficacy and parental dependence), parental hostility, and discrimination experiences were assessed via self-report and were examined as moderators of adolescents' responses to the task.

RESULTS

Results revealed differential responses to the task based on individual, family, and environmental factors. High efficacy and low dependence-parental hostility-discrimination related to stress responses characterized by low baselines, steeper reactivity, and faster recovery. Low efficacy and high dependence related to greater baseline stress and a slower recovery. High levels of parental hostility related to a slower recovery. High levels of discrimination related to greater baseline stress.

CONCLUSIONS

The study demonstrates that the modified TSST task can elicit an acute hypothalamic-pituitary-adrenal axis response, but the nature of this response is dependent upon participants' perceptions of language brokering (parental dependence and efficacy), parental hostility, and discrimination experiences. Adolescents' individual characteristics and contextual demands remain important considerations in understanding their acute stress responses. (PsycINFO Database Record (c) 2018 APA, all rights reserved).