Association Between Socioeconomic Status Mobility and Inflammation Markers Among White and Black Adults in the United States: A Latent Class Analysis

Influencing Factors of Healthy Aging Risk Assessed Using Biomarkers: A Life Course Perspective

Assessing individual risks of healthy aging using biomarkers and identifying associated factors have become important areas of research. In this study, we conducted a literature review of relevant publications between 2018 and 2023 in both Chinese and English databases. Previous studies have predominantly used single biomarkers, such as C-reactive protein, or focused on specific life course stages and factors such as socioeconomic status, mental health, educational levels, and unhealthy lifestyles. By summarizing the progress in this field, our study provides valuable insights and future directions for promoting healthy aging from a life course perspective.

Reflections on resilience

Resilience research has long sought to understand how factors at the child, family, school, community, and societal levels shape adaptation in the face of adversities such as poverty and war. In this article we reflect on three themes that may prove to be useful for future resilience research. First is the idea that mental and physical health can sometimes diverge, even in response to the same social process. A better understanding of explanations for this divergence will have both theoretical and public health implications when it comes to efforts to promote resilience. Second is that more recent models of stress suggest that stress can accelerate aging. Thus, we suggest that research on resilience may need to also consider how resilience strategies may need to be developed in an accelerated fashion to be effective. Third, we suggest that if psychological resilience interventions can be conducted in conjunction with efforts to enact system-level changes targeted at adversities, this may synergize the impact that any single intervention can have, creating a more coordinated and effective set of approaches for promoting resilience in young people who confront adversity in life.

Association between subjective social status and physical frailty in older adults in India: perceived discrimination and III-treatment as mediators and moderators

BACKGROUND

While extensive research exists on physical frailty, including in low- and middle-income countries like India, studies have yet to appraise whether perceived social standing is associated with physical frailty. As such, this study examines (1) the association between subjective social status (SSS) and physical frailty among older adults in India; and (2) whether this association is mediated and moderated by perceived discrimination and experiences of III-treatment.

METHODS

Data came from the Longitudinal Aging Study in India with a sample of 31,464 older adults aged 60 and above. Physical frailty was assessed using an adapted version of the frailty phenotype developed by Fried and colleagues. SSS was assessed using the Macarthur scale. Multivariable logistic regression models along with Karlson-Holm-Breen (KHB) methodology were employed to examine the direct association, mediational pathways, and the interactions.

RESULTS

The prevalence of frailty was 30.65% and those with lowest SSS reported higher prevalence of frailty (42.06%). After adjusting for several confounders, odds of frailty were lower among persons with high SSS relative to those with low SSS, and the variance explained by the SSS was higher than that explained by household consumption quintiles. Moreover, the association between SSS and frailty was mediated and moderated by perceived discrimination and III-treatment.

CONCLUSIONS

Our findings underscore that when examining the association between socioeconomic status (SES) and physical frailty, it is important to consider SSS given that perceived social status likely reflects the less apparent psychosocial components associated with SES, and that perceived discrimination and III-treatment both mediate and moderate the association between SSS and physical frailty is critical to identifying those older Indians most susceptible to the functional health implications of lower SSS.

Age and Sex Differences in the Associations Among Socioeconomic Status, Affective Reactivity to Daily Stressors, and Physical Health in the MIDUS Study

BACKGROUND

Low socioeconomic status (SES) is robustly associated with increased risks of morbidity and mortality. Affective reactivity to daily stressors has been proposed to be a mediator for this association. However, few longitudinal studies have empirically tested the indirect effect of SES on health through affective reactivity to daily stressors.

PURPOSE

This study aimed to test the indirect effect of SES on physical health via affective reactivity to daily stressors over a 10-year period and to explore age and sex differences in such indirect effect.

METHODS

Data were drawn from a subsample of 1,522 middle-aged and older adults (34-83 years of age, 57.2% female, 83.5% White) from the Midlife in the United States study. SES (i.e., education, household income, indicators of financial distress) was assessed in 2004-2006. Affective reactivity to daily stressors was computed using data collected during the 8-day daily stress assessment in 2004-2009. Self-reported physical health conditions were assessed in 2004-2006 and 2013-2014.

RESULTS

There was a significant indirect effect of lower SES on more physical health conditions via elevated negative affective reactivity to daily stressors among women but not men. The indirect effect of SES on physical health conditions via negative affective reactivity to daily stressors was consistent across the middle and older adulthood.

CONCLUSIONS

Our findings suggest that negative affective reactivity to daily stressors might be a key intermediate process contributing to persistent SES disparities in physical health, particularly among women.

The mediating effect of allostatic load on the association between life course socioeconomic disadvantage and chronic pain: a prospective finding from the National Survey of Midlife Development in the United States

Background

Socioeconomic disadvantages (SEDs) are associated with chronic pain (CP) and allostatic load (AL). Few prospective population-based studies have examined the relationship between life course SED, CP interference, and CP widespreadness, and there is no prospective population-based study on whether AL mediates the association between SED and CP.

Objective

In this study, we investigated whether the prospective effect of SED on CP at Midlife in the United States (MIDUS) 3 is consistent with the accumulation of risk model and social mobility model, using the National Survey of MIDUS (n = 593). To prepare for the mediation analysis, we tested (1) whether SED would be prospectively associated with AL in the MIDUS 2 biomarker project, (2) whether AL would be prospectively associated with CP, and (3) whether childhood, as a critical period, moderated the association between AL and CP. In addition, the mediating effect of AL on the association between SED and CP was examined.

Method

SED was measured using cumulative scores and disadvantage trajectories derived from latent class trajectory modeling (LCTM). After multiple imputations, analyses were conducted using multinomial logistic regression for CP and negative binomial regression for AL, respectively. Finally, mediation analyses and moderated mediation analyses were performed.

Results

LCTM identified three SED trajectories, namely, constant low, high to low, and medium to high. The results showed that proximal cumulative SED was associated with high-interference CP. Furthermore, compared with the group with constant low SED, the group with medium-to-high SED was significantly associated with high-interference pain and experienced pain in at least three different sites. Cumulative SED and deteriorating SED trajectories were associated with higher AL, consistent with previous studies. Furthermore, childhood SED moderated the effect of AL on CP widespreadness and unexpectedly demonstrated a protective effect, while other associations between AL and CP were not significant. Subsequent mediation analysis did not yield statistically significant evidence.

Conclusions

People who experienced more recent SED or increasing disadvantage throughout their lives were more likely to suffer from CP, and this association was not mediated by physiological system dysregulation caused by chronic stress. Therefore, measures to alleviate AL may not be effective in protecting socioeconomically disadvantaged populations from CP.

Material circumstances, health care access, and self-reported health: A latent class analysis

Latent class analysis was used to explore intersections of material circumstances and health care access among 308 adults, and associations between classes with health outcomes. Good fit was found for a four-class model: Resource Stable (Class 1, 62.43%), Unbalanced Meals with Health Care (Class 2, 16.91%), Resource Insecurity with Delayed Health Care (Class 3, 14.75%), and Resource Stability without Access to Health Care (Class 4, 5.91%). Class 1 reported greater well-being and self-rated health than Class 2 and 3. Class 1 reported lower BMI than Class 2. Findings document intersections among economic marginalization indicators with varying health outcomes among classes.

Association of subjective social status with epigenetic aging among Black and White women

OBJECTIVE

Subjective social status (SSS), an individual's assessment of their own social status in relation to others, is associated with health and mortality independently of objective SES; however, no studies have tested whether SSS influences epigenetic aging. The current study examines if SSS is associated with epigenetic age acceleration in both Black and White women, independently of objective SES measured during both childhood and adulthood.

METHOD

For 9- and 10-year-old Black and White girls, parental education and annual household income was obtained. At ages 39-42, 361 participants (175 Black, 186 White) reported their current education, household income, and SSS, and provided saliva to assess age acceleration using the GrimAge epigenetic clock. Linear regression estimated the association of SSS with epigenetic age acceleration, controlling for objective SES (current education, current income, parents' education, income during childhood), smoking, and counts of cell types.

RESULTS

When all objective SES variables were included in the model, SSS remained significantly associated with epigenetic age acceleration, b = - 0.31, p = .003, ß = - 0.15. Black women had significantly greater age acceleration than White women, (t(359) = 5.20, p > .001, d = 0.55) but race did not moderate the association between SSS and epigenetic age acceleration.

CONCLUSIONS

Women who rated themselves lower in SSS had greater epigenetic age acceleration, regardless of income and education. There was no difference by race for this association.

Socioeconomic Classes among Oldest-Old Women in South Korea: A Latent Class Analysis

Oldest-old women are known to live at the intersection of multiple socioeconomic disadvantages in South Korean society. This study classified oldest-old Korean women into several socioeconomically homogeneous classes based on various socioeconomic status (SES) risks and compared health characteristics among the identified classes. This cross-sectional study utilized the 2019 Korean Community Health Survey, including data from 11,053 women (≥80 years). Latent class analysis determined the number of underlying socioeconomic classes based on nine selected SES variables. Four distinct socioeconomic classes were identified: “Urban, living alone, recipient of NBLSS, moderate education, leisure activity” (Class 1), “Rural, traditional house, living with others, not financially deprived, low education, employed” (Class 2), “Urban, living with family, financially affluent, not employed, no barriers to healthcare” (Class 3), “Rural, traditional house, living alone, financially deprived, uneducated, employed, barriers to healthcare” (Class 4). Depressive symptoms, subjective stress, and the prevalence of sleep disorder and diabetes were higher in Class 1 compared to other classes. Health-related quality of life, perceived health, and self-rated oral health were the poorest in Class 4. Class 3 reported the best health status. Understanding the intersecting SES risk factors in this group can aid in developing targeted interventions.

The contribution of racism-related stress and adversity to disparities in birth outcomes: evidence and research recommendations

Currently, racial and ethnic differences in adverse birth outcomes and infant mortality are some of the largest and most persistent health disparities in the United States. This narrative review article synthesizes existing literature to present a conceptual model of how racism-related stress and adversity are critical determinants of such disparities. We describe how historical and ongoing racism has created conditions wherein women of color are disproportionately exposed to chronic, multilayered stress and adversity and how the biological consequences of exposure to these stressors confers risk for adverse birth outcomes. Next, we identify important priorities and considerations for future research, including the heterogeneity of racism-related stressors, biomarkers and mechanisms, chronicity and sensitive periods of exposure, developmental programming of lifespan health, resilience, and community-engaged research methodologies.

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Historical and ongoing racism has created conditions wherein women of color are disproportionately exposed to stress and adversity.

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The consequences of exposure to racism-related stress and adversity can confer risk for health conditions implicated in adverse birth outcomes and alter maternal physiology associated with fetal development and timing of parturition.

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Conjointly studying racism-related stress, biologic profiles, and birth outcomes is a priority for future research.

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It is important to identify factors that mitigate the impact of racism-related stress and adversity on birth outcomes.

Life course pathways from parental education to age-related decrements in kidney function among Black and white American adults

OBJECTIVE

Using cross-sectional data on Black and white adults, this analysis examined whether age-related decrements in kidney function across adulthood were associated with parental education, and whether the association was differentially influenced by race. Further, this study assessed racial differences in life course pathways from parental education to age-related decrements in kidney function, through current SES and health-related risk factors.

METHOD

Data from the main survey and the Biomarker Project of the Midlife in the United States (MIDUS) Wave 2 and Refresher samples were combined, resulting in 1861 adults (54.5% female; age 25-84, Mage = 53.37) who self-identified as non-Hispanic Black (n = 326) and non-Hispanic white (n = 1535). Estimated glomerular filtration rate (eGFR) was based on serum creatinine, calculated using the CKD-EPI formula. Adults SES was based on education, income, and financial strains. Health-related risk factors included obesity, elevated blood pressure (BP), and insulin resistance. Hypotheses were tested by utilizing multiple linear regression and regression-based moderated mediation analysis.

RESULTS

Lower parental education was associated with steeper age-related decrements in eGFR (B = 0.38, SE = 0.15, p = .013, 95%CI = 0.08, 0.68), due to higher eGFR among younger participants and lower eGFR among older participants. In addition, age-related decrements in kidney function were steeper among Black relative to white adults (B = 0.41, SE = 0.13, p < .01, 95%CI = 0.16, 0.66), driven by higher proportion of younger Black adults that met criterion for renal hyperfiltration. Furthermore, parental education and race were associated with age-related decrements in kidney function in an additive rather than interactive way. There were some racial differences in the life course pathways from parental education to age-related differences in eGFR, glucoregulation, and hypertension. Among Black adults, lower parental education was associated with elevated eGFR among younger participants through insulin resistance. Among white adults, lower parental education was linked to higher eGFR among younger adults and lower eGFR among older adults, and the association was mediated by current SES, elevated BP, and insulin resistance.

DISCUSSION

Early life SES can have a long-lasting influence on the preclinical renal senescence that is associated with the normal biology of aging for both Black and white adults.

Socioeconomic position, social mobility, and health selection effects on allostatic load in the United States

The contemporaneous association between higher socioeconomic position and better health is well established. Life course research has also demonstrated a lasting effect of childhood socioeconomic conditions on adult health and well-being. Yet, little is known about the separate health effects of intergenerational mobility-moving into a different socioeconomic position than one's parents-among early adults in the United States. Most studies on the health implications of mobility rely on cross-sectional datasets, which makes it impossible to differentiate between health selection and social causation effects. In addition, understanding the effects of social mobility on health at a relatively young age has been hampered by the paucity of health measures that reliably predict disease onset. Analysing 4,713 respondents aged 25 to 32 from the National Longitudinal Study of Adolescent Health's Waves I and IV, we use diagonal reference models to separately identify the effects of socioeconomic origin and destination, as well as social mobility on allostatic load among individuals in the United States. Using a combined measure of educational and occupational attainment, and accounting for individuals' initial health, we demonstrate that in addition to health gradient among the socially immobile, individuals' socioeconomic origin and destination are equally important for multi-system physiological dysregulation. Short-range upward mobility also has a positive and significant association with health. After mitigating health selection concerns in our observational data, this effect is observed only among those reporting poor health before experiencing social mobility. Our findings move towards the reconciliation of two theoretical perspectives, confirming the positive effect of upward mobility as predicted by the "rags to riches" perspective, while not contradicting potential costs associated with more extensive upward mobility experiences as predicted by the dissociative thesis.

Socioeconomic status trajectories across the life course, daily discrimination, and inflammation among Black and white adults

OBJECTIVE

This study replicates and expands Surachman et al.'s (2020) findings documenting socioeconomic status (SES) trajectories across the life course in an independent sample of Black (majority recruited from Milwaukee, WI) and white adults in the United States. We extend this work by examining whether SES trajectories and daily discrimination are independently associated with markers of inflammation.

METHOD

Data were from 215 Black adults (188 recruited from Milwaukee, WI; 27 recruited from across the continental US) and 985 white adults (7 recruited from Milwaukee, WI; 978 recruited from across the continental US) who completed the baseline interview and biomarker assessment during the second wave of the Midlife in the United States (MIDUS) Study (ages = 34-84). SES life course trajectories were examined using latent class analysis based on objective (e.g., income and education) and subjective (e.g., social status and financial strain) indicators of SES. The association between life course SES trajectories and daily discrimination with markers of inflammation (IL-6, CRP, fibrinogen) were examined using multiple linear regression analyses, controlling for demographic, psychological, behavioral, and health-related covariates.

RESULTS

Black and white participants showed different patterns of life course SES trajectories. Among Black participants, the trajectories were Objectively Stable Low (45.16%), Downwardly Mobile (18.05%), and Upwardly Mobile (36.79%). Compared to the Upwardly Mobile, the Objectively Stable Low class showed elevated IL-6 after controlling for all covariates. Further, daily discrimination, but not SES trajectories, was significantly associated with CRP and fibrinogen after controlling for demographic, psychological, and behavioral covariates. White participants' experiences of life course SES trajectories were characterized as Objectively Stable Low (7.02%), Subjectively Downward (12.48%), Upwardly Mobile (39.99%), and Stable High (40.51%). Among white participants, SES trajectories, but not daily discrimination, were associated with all markers of inflammation (controlling for age and sex).

DISCUSSION

Consistent with the fundamental cause theory, multiple independent pathways link SES trajectories across the life course and daily discrimination to racial disparities in IL-6, CRP, and fibrinogen.

Four weeks of vitamin D supplementation improves nitric oxide-mediated microvascular function in college-aged African Americans

Reduced nitric oxide (NO)-mediated cutaneous vasodilation, secondary to increased oxidative stress, presents in young African American (AA) compared with European American (EA) adults and may be modulated by vitamin D status. We assessed cutaneous microvascular function in 18 young, healthy (21 ± 2 yr; 9 men, 9 women) subjects before (pre, 8 AA, 10 EA) 4 wk of 2,000 IU/day oral vitamin D supplementation and in 13 subjects after (post, 7 AA, 6 EA) 4 wk of 2,000 IU/day oral vitamin D supplementation. Serum vitamin D concentrations [25(OH)D] were measured at each visit. Three intradermal microdialysis fibers placed in the ventral forearm were randomized for treatment with 10 μM Tempol, 100 μM apocynin, or lactated Ringer's solution (control). Local heating (39°C) induced cutaneous vasodilation; red cell flux was measured at each site (laser-Doppler flowmetry), and cutaneous vascular conductance (CVC = flux/MAP) was expressed as a percentage of maximum (28 mM sodium nitroprusside, +43°C) for each phase of local heating. After stable elevated blood flow was attained, 15 mM N^G-nitro-l-arginine methyl ester (l-NAME; NO synthase inhibitor) was perfused at all sites to quantify the NO contribution to cutaneous vasodilation (%NO), calculated as the difference between local heating and l-NAME plateaus. Serum [25(OH)D], the magnitude of the local heating response, and %NO were all lower in AAs versus EAs (P < 0.01). Tempol (P = 0.01), but not apocynin (P ≥ 0.19), improved the local heating response and %NO. Four weeks of supplementation improved serum [25(OH)D], the local heating response, and %NO in AAs (P ≤ 0.04) but not in EAs (P ≥ 0.41). Vitamin D supplementation mitigated endothelial dysfunction, an antecedent to overt cardiovascular disease (CVD), in otherwise healthy, young AA adults.NEW & NOTEWORTHY Endothelial dysfunction, an antecedent to overt cardiovascular disease (CVD), is observed earlier and more frequently in otherwise healthy African Americans (AAs) when compared with other ethnic groups. Vitamin D may modulate endothelial function, and darkened skin pigmentation increases risk of vitamin D deficiency. We show that 4 wk of 2,000 IU/day vitamin D supplementation improves microvascular responses to local heating in AAs. Ensuring adequate vitamin D status may mitigate development of cardiovascular dysfunction in this at-risk population.

Childhood socioeconomic status, comorbidity of chronic kidney disease risk factors, and kidney function among adults in the midlife in the United States (MIDUS) study

Background

There is a lack of empirical effort that systematically investigates the clustering of comorbidity among known risk factors (obesity, hypertension, diabetes, hypercholesterolemia, and elevated inflammation) of chronic kidney disease (CKD) and how different types of comorbidity may link differently to kidney function among healthy adult samples. This study modeled the clustering of comorbidity among risk factors, examined the association between the clustering of risk factors and kidney function, and tested whether the clustering of risk factors was associated with childhood SES.

Methods

The data were from 2118 participants (ages 25–84) in the Midlife in the United States (MIDUS) Study. Risk factors included obesity, elevated blood pressure (BP), high total cholesterol levels, poor glucose control, and increased inflammatory activity. Glomerular filtration rate (eGFR) was estimated from serum creatinine, calculated with the CKD-EPI formula. The clustering of comorbidity among risk factors and its association with kidney function and childhood SES were examined using latent class analysis (LCA).

Results

A five-class model was optimal: (1) Low Risk (class size = 36.40%; low probability of all risk factors), (2) Obese (16.42%; high probability of large BMI and abdominally obese), (3) Obese and Elevated BP (13.37%; high probability of being obese and having elevated BP), (4) Non-Obese but Elevated BP (14.95%; high probability of having elevated BP, hypercholesterolemia, and elevated inflammation), and (5) High Risk (18.86%; high probability for all risk factors). Obesity was associated with kidney hyperfiltration, while comorbidity between obesity and hypertension was linked to compromised kidney filtration. As expected, the High Risk class showed the highest probability of having eGFR < 60 ml/min/1.73 m² (P = .12; 95%CI = .09–.17). Finally, higher childhood SES was associated with reduced probability of being in the High Risk rather than Low Risk class (β = − 0.20, SE = 0.07, OR [95%CI] = 0.82 [0.71–0.95]).

Conclusion

These results highlight the importance of considering the impact of childhood SES on risk factors known to be associated with CKD.

The Wildman Programme. A Nature-Based Rehabilitation Programme Enhancing Quality of Life for Men on Long-Term Sick Leave: Study Protocol for a Matched Controlled Study In Denmark

Many men have poor mental health and need help to recover. However, designing a rehabilitation intervention that appeals to men is challenging. This study protocol aims to describe the ‘Wildman Programme’, which will be a nature-based rehabilitation programme for men on long-term sick leave due to health problems such as stress, anxiety, depression, post-cancer and chronic cancer, chronic obstructive pulmonary disease (COPD), cardiovascular disease, or diabetes type II. The programme will be a nature-based rehabilitation initiative combining nature experiences, attention training, body awareness training, and supporting community spirit. The aim of the study will be to examine whether the ‘Wildman Programme’ can help to increase quality of life and reduce stress among men with health problems compared to treatment as usual. The study will be a matched control study where an intervention group (number of respondents, N = 52) participating in a 12-week nature-based intervention will be compared to a control group (N = 52) receiving treatment as usual. Outcomes are measured at baseline (T1), post-treatment (T2), and at follow up 6 months post-intervention (T3). The results of this study will be important to state whether the method in the ‘Wildman Programme’ can be implemented as a rehabilitation offer in the Danish Healthcare System to help men with different health problems.