Systemic chronic low-grade inflammation increases with aging and contributes to the risk or progression of a myriad of chronic diseases. Greater midlife inflammation has detrimental effects on future health outcomes. However, few studies have quantified inflammatory markers from midlife longitudinal measurements. Here, we measured cytokines, chemokines, and clinical biomarkers of inflammation at three different time points in a cohort of middle-aged (mean age 48) African American and White men and women. We analyzed longitudinal data for these inflammatory markers examining possible interactions across time, age, race, and sex. We report sex differences in the levels of CXCL10/IP-10, CXCL11/ITAC, and uric acid. Ferritin levels differed by sex and race; the highest levels were in White men and lowest in White women. MCP-1 and WBC count were higher in White participants than African American participants, and uric acid levels were lower for older White participants, but higher for older African American participants. In this longitudinal study, we found that IL-22 levels decreased over time while ferritin levels increased over time. For high sensitivity C-reactive protein (hsCRP), values changed differently over time across sex where men’s values increased and women’s values decreased over time. In addition, IL-10, CXCL11/ITAC, and hsCRP levels decreased over time in White participants, but not for African American participants. These data indicate that cytokine, chemokine, and clinical inflammatory biomarkers vary across time, age, sex, and race in a middle-aged cohort. Understanding inflammation at midlife may provide keys to reducing negative health outcomes later in life.

PURPOSE:Previous literature suggests that African American adults have higher levels of systemic oxidative stress than White adults. Mitochondrial DNA (mtDNA) variants can be traced to geographic origins of populations and classified into haplogroups. Emerging evidence indicates that mtDNA haplogroup may affect cellular stress responses such as the response to irradiation or oxidative stress. However, little is known about whether mtDNA haplogroup influences systemic baseline or induced levels of oxidative DNA damage. MATERIALS AND METHODS:We determined mtDNA haplogroup (African American or European) in 104 middle-aged adults living above and below poverty to investigate the association of mtDNA haplogroup and inflammatory markers with baseline and H2O2-induced DNA damage in peripheral blood mononuclear cells. DNA damage was measured using a high-throughput CometChip assay. Several inflammatory markers were measured in serum. Linear regression examined if variables were related to DNA damage in interactions or independently. RESULTS:mtDNA haplogroup alone did not influence levels of baseline or H2O2-induced DNA damage. However, baseline and H2O2-induced DNA damage were associated with poverty, sex, age, and markers of inflammation. Baseline DNA damage was related to IL-6 levels differentially based on poverty status. Baseline DNA damage was inversely associated with levels of IL-8. Men showed overall higher levels of H2O2-induced DNA damage. H2O2-induced DNA damage was also related to IL-6 levels but differentially based on age. mtDNA haplogroup did affect both baseline and H2O2-induced DNA damage through differential effects on two markers of inflammation. CONCLUSION:These data suggest that mtDNA haplogroup plays an indirect role in the cellular response to endogenous and exogenous oxidative stress. Sex and age may also contribute to levels of inflammation in the DNA damage response. Finally, the social determinant of health poverty status, appears to play a role in interactions with inflammatory markers for baseline DNA damage at mid-life.

Chronic psychological stress is an environmental factor associated with chronic disease risk and health disparities. Since environmental stressors alter gene expression and physiologic responses through epigenetic mechanisms, perceived discrimination (PD), or the subjective experience of receiving negative treatment related to personal characteristics may influence DNA methylation (DNAm) of CpGs within genes linked to chronic disease. Using the Illumina 850K EPIC chip and psychosocial stress-associated discrimination scales, including the lifetime, racial, and everyday discrimination scales, we identified novel CpGs and differentially methylated positions (DMPs) associated with PD in the context of age, sex, and poverty status among African American and White adults and ones that overlap previous findings of differentially methylated sites (or genes) with discrimination, inflammation, and chronic disease. Ingenuity Pathway Analysis identified several pathways associated with the DNAm patterns and PD with age, sex, and/or poverty status. With age, the white adipose tissue browning pathway was activated among African American participants. This was related to the differential methylation found in the CACNA1H, PRDM16, and BDNF genes. Among White participants, the opioid signaling pathway was activated and significantly enriched for the genes FGR, POMC, and RPS6KA2. Additionally, CpG sites associated with PD among White participants with poverty status revealed that the netrin signaling, opioid signaling, and calcium signaling pathways were activated and significantly enriched for differentially methylated genes, including NFATC1 and NFATC2. The identified novel DNAm genes associated with PD transduce effects through biological pathways related to inflammation and immune response, white adipose tissue browning, and calcium signaling.

Mistrust of the health care system is associated with underutilization of medical services and poor self-reported health, which itself is an important indicator for future morbidity and mortality. This study examines how several factors influence the association between medical mistrust and self-rated health in a middle-aged socioeconomically diverse cohort over 16 years. Participants (n = 1673) from the Health Aging in Neighborhoods of Diversity over the Life Span Study formed the sample. Information was gathered on race (African American/White), sex, poverty status, health literacy, and two measures of perceived discrimination. Linear mixed model regression was used for several models to examine the independent and combined influence of these factors on how medical mistrust is related to self-rated health over time. Poverty status exhibited the greatest influence on longitudinal self-rated health. Poverty status and health literacy did not influence the association between medical mistrust and self-rated health but perceived discrimination did. Stratified analyses by race found that White participants exhibited greater influence from medical mistrust and perceived discrimination on self-rated health than African American participants. Increasing trust, improving communication, and reducing unfair treatment across vulnerable groups is likely to improve health in middle-aged adults, but reducing overall poverty is likely to have the greatest effect.

A new DNA methylation biomarker, Dunedin Pace of Aging Calculated from the Epigenome (DunedinPACE), is associated with healthy lifespan in several European ancestry cohorts. Few studies have examined the relation between dietary quality and DunedinPACE in African American and White adults with longitudinal assessments. To assess the relationship between diet quality and DunedinPACE, we used longitudinal data from African American and White 30–64 year old adults living above and below poverty. Participants’ DunedinPACE scores and dietary assessments were calculated at two time points, approximately 5 years apart. Numbers of participants (n = 421; mean age 49 years) were balanced by race, sex, and poverty status. Diet quality was assessed using two different dietary indexes: Dietary Inflammatory Index (DII) and Healthy Eating Index-2010 (HEI). Linear mixed model regression examined the longitudinal association of DunedinPACE with DII and HEI adjusted by age, race, poverty status, BMI, and smoking status. Initial mean values of DII were 3.34 (SD = 2.16) and HEI was 40.67 (SD = 11.69), indicating a pro-inflammatory dietary pattern and low diet quality in this cohort. The initial mean DunedinPACE score was 1.07. We found that a higher DII score was associated with higher DunedinPACE score (β = 0.009; p < 0.001), higher HEI score was associated with lower DunedinPACE score (β = − 0.001; p = 0.032), and that these relationships were consistent over time. Overall, lower dietary quality was associated with a faster pace of aging captured by DunedinPACE score. Our findings demonstrate the independent contribution of diet quality to healthy aging-related epigenetic mechanisms.

Discrimination is a social adversity that is linked to several age-related outcomes. However, the molecular drivers of these observations are poorly understood. Social adverse factors are associated with proinflammatory and interferon gene expression, but little is known about whether additional genes are associated with discrimination among both African American and White adults. In this study, we examined how perceived discrimination in African American and White adults was associated with genome-wide transcriptome differences using RNA sequencing. Perceived discrimination was measured based on responses to self-reported lifetime discrimination and racial discrimination. Differential gene expression and pathway analysis were conducted in a cohort (N = 59) stratified by race, sex, and overall discrimination level. We found 28 significantly differentially expressed genes associated with race among those reporting high discrimination. Several of the upregulated genes for African American versus White adults reporting discrimination were related to immune function IGLV2-11, S100B, IGKV3-20, and IGKV4-1; the most significantly downregulated genes were associated with immune modulation and cancer, LUCAT1, THBS1, and ARPIN. The most enriched gene ontology biological process between African American and White men reporting high discrimination was the regulation of cytokine biosynthetic processes. The immune response biological process was significantly lower for African American women compared to White women reporting high discrimination. Discrimination was associated with the expression of small nucleolar RNAs, long noncoding RNAs, and microRNAs associated with energy homeostasis, cancer, and actin. Understanding the pathways through which adverse social factors like discrimination are associated with gene expression is crucial in advancing knowledge of age-related health disparities.

Chronic kidney disease (CKD) and obesity are major chronic diseases in the United States. Although obesity is a risk factor for CKD, little is known about how obesity contributes to CKD. Due to their role as intercellular communicators, extracellular vesicles (EVs) may be a factor connecting obesity and CKD. Circulating cell-free mitochondrial DNA (ccf-mtDNA), a damage-associated molecular pattern molecule associated with inflammation, is associated with renal disease and may be encapsulated within EVs. In this longitudinal study, we isolated plasma EVs and analysed EV mtDNA levels in a cohort of African American and White obese middle-aged individuals who at visit 1 did not have CKD but developed CKD by visit 2 (n = 19; CKD group) and matched this group to controls who did not develop CKD by visit 2 (n = 56; control group). In our cross-sectional analyses at visit 1, we found significant interactions for EV mtDNA levels between race and CKD status, poverty status and CKD status, and sex and CKD status. EV mtDNA levels were significantly lower in participants within the African haplogroup who developed CKD compared to participants within the European haplogroup who developed CKD and the African haplogroup control group. In our longitudinal analyses using data from both visit 1 and visit 2, individuals who developed CKD had lower EV mtDNA levels. Stratification by haplogroup showed that among participants within the African haplogroup, those who developed CKD had significantly lower EV mtDNA levels than those in the control group. In conclusion, EV mtDNA levels were lower in individuals who develop CKD. Our findings demonstrate that CKD status and mtDNA haplogroup influence EV cargo in obese individuals.

Perceived discrimination has been associated with poor age-related health outcomes, yet little is known about the molecular mechanisms. Previous data have indicated that exposure to acute psychological stress results in higher levels of circulating cell-free mitochondrial DNA (ccf-DNA) in blood. ccf-mtDNA is part of the damage-associated molecular pattern (DAMP) system where it can activate the innate immune system. The current study examined the relationship between perceived discrimination, race, and poverty with ccf-mtDNA in plasma and plasma-derived extracellular vesicles (EVs) in a cohort of African American and White men and women who experienced high or low perceived discrimination (N = 64). Ccf-mtDNA levels were quantified from plasma and plasma EVs. We found that among individuals living below poverty, those with higher perceived discrimination had lower ccf-mtDNA levels in both plasma and EVs than those with low perceived discrimination. With advancing age, ccf-mtDNA levels were higher in African American participants, while the opposite was observed in White participants. We also discovered that the EV inflammatory proteins IL-18 and Cystatin-D were associated with perceived discrimination and age, sex, or race. The presence of EV Caspase-8 and TNF were associated with perceived discrimination and poverty, while EV IL-8 and TNF and TWEAK were associated with perceived discrimination and sex. Our findings suggest that discrimination interacts with sex, race, and poverty to influence ccf-mtDNA levels in plasma and EVs and EV inflammatory proteins.

Geroscience may be the juggernaut that coalesces the pathways of biologic knowledge to expand our understanding beyond describing differences in rates of aging to feasible interventions for improving quality of life as we age. To accomplish this, geroscience must interdigitate with long-standing immutable factors about health. As early as the 17th century, physicians and early demographers like John Graunt, Percival Potts, Bernardino Ramazzini, and Rudolf Virchow identified the importance of differences in health trajectories and outcomes for individuals, and underlying aspects of health disparities. These differences in health status relate to numerous social determinants of health as they interact with biological risk factors and the environment. These populations and the psychosocial factors that influence health and longevity must be considered as an integral part of geroscience. Longitudinal studies that examine factors influencing the development of age-related health differences over time should be a key component of geroscience. The HANDLS study provides a useful demonstration project showing the value of studying aging in urban dwelling American adults, some of whom face significant social adversity based on race, socioeconomic status, and other factors.

OBJECTIVE:This cross-sectional study explored the associations between spiritual transcendence (ST)-prayer/meditation fulfillment, connectedness, and universality- and the American Heart Association's Life's Simple 7 (LS7), and if variations across and within racial and socioeconomic groups emerged. METHODS:Data were taken from the Healthy Aging in Neighborhoods of Diversity across the Life Span study and included 1110 midlife and older African American and white adults [mean (SD) age=56.13 (8.91) y; 65.0% above poverty; 78.1% ≥high school education]. ST was self-reported. LS7 comprised physical activity, smoking, diet, body mass index, cholesterol, glucose, and blood pressure. Higher LS7 reflects better cardiovascular health (CVH). Multiple linear regression estimated associations between ST and LS7. A 3-way interaction term (ST, race, and either education or poverty status) was included in models adjusted for sex and age. RESULTS:A 3-way interaction was observed for ST, race, and poverty status ( b =1.29, SE=0.35, p <.001). Simple slopes showed a positive association for white adults living above poverty only ( b =0.54, SE=0.15, p <.001). Exploratory analyses found a nonlinear 3-way interactive effect including ST, race, and age (ie, U-shaped; b =0.04, SE=0.02, p =.048). Both lesser and greater ST were associated with higher LS7 for older African American adults exclusively ( b =0.03, SE=0.01, p =.024). CONCLUSIONS:Although spirituality was associated with overall CVH, it was not beneficial for everyone equally. If tailored appropriately, the integration of spirituality into care practices may promote better CVH. ABBREVIATIONS:AA: African American, AHA: American Heart Association, BMI: body mass index, BP: blood pressure, CVD(s): cardiovascular disease(s), CVH: cardiovascular health, HANDLS: Healthy Aging in Neighborhoods of Diversity across the Life Span, LS7: Life's Simple 7, M: mean, PTSD: posttraumatic stress disorder, SES: socioeconomic status, ST: spiritual transcendence.

Diet quality is a modifiable risk factor for frailty, but research on the association of frailty with dietary inflammatory potential is limited. The objective was to determine associations between diet quality assessed by the dietary inflammatory index (DII) with frailty status over time. Participants with both dietary and frailty data from the longitudinal Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study were used (n = 2901, 43.5% male, 43.8% African American, 48.5 y mean baseline age, with a mean 8.7 y of follow-up). Group-based trajectory modeling identified two frailty (remaining non-frail or being pre-frail/frail over time) and three diet quality trajectory groups (high or medium pro-inflammatory and anti-inflammatory potentials). Multiple logistic regression found both medium pro-inflammatory and anti-inflammatory DII trajectory groups, compared to the high pro-inflammatory group, were positively associated with being non-frail over time for the overall sample, both sexes and races. Kaplan–Meier curves and log-rank test revealed anti-inflammatory DII scores were associated with lower risk for being pre-frail or frail. No longitudinal relationship existed between frailty status at baseline and annualized DII change, a check on reverse causality. This study contributes to our current knowledge providing longitudinal evidence of the link between anti-inflammatory DII score with lower frailty risk.

AbstractBackgroundRecent data indicate a decline in overall longevity in the United States. Even prior to the COVID‐19 pandemic, an increase in midlife mortality rates had been reported. Life expectancy disparities have persisted in the United States for racial and ethnic groups and for individuals living at low socioeconomic status. These continued trends in mortality indicate the importance of examining biomarkers of mortality at midlife in at‐risk populations. Circulating levels of cytokines and inflammatory markers reflect systemic chronic inflammation, which is a well‐known driver of many age‐related diseases.MethodsIn this study, we examined the relationship of nine different inflammatory proteins with mortality in a middle‐aged socioeconomically diverse cohort of African–American and White men and women (n = 1122; mean age = 47.8 years).ResultsWe found significant differences in inflammatory‐related protein serum levels between African–American and White middle‐aged adults. E‐selectin and fibrinogen were significantly higher in African–American adults. IFN‐γ, TNF‐α trimer, monocyte chemoattractant protein‐1 (MCP‐1), soluble receptor for advanced glycation end‐products (sRAGE) and P‐selectin were significantly higher in White participants compared to African–American participants. Higher levels of E‐selectin, MCP‐1 and P‐selectin were associated with a higher mortality risk. Furthermore, there was a significant interaction between sex and IL‐6 with mortality. IL‐6 levels were associated with an increased risk of mortality, an association that was significantly greater in women than men. In addition, White participants with high levels of sRAGE had significantly higher survival probability than White participants with low levels of sRAGE, while African–American participants had similar survival probabilities across sRAGE levels.ConclusionsThese results suggest that circulating inflammatory markers can be utilized as indicators of midlife mortality risk in a socioeconomically diverse cohort of African–American and White individuals.

Frailty is an age-related syndrome characterized by reduced recovery from stressors and increased risks of morbidity and mortality. Although frailty is usually studied in those over 65 years, our previous work showed that frailty is both present and a risk factor for premature mortality in midlife. We identified altered gene expression patterns and biological pathways associated with inflammation in frailty. Evidence suggests DNA oxidation damage related to inflammation accumulates with age, and that DNA repair capacity (DRC) declines with age and age-related conditions. We hypothesized that inter-individual differences in DNA oxidation damage and DRC are associated with frailty status and poverty level. Using the CometChip assay, we assessed baseline single-strand breaks and hydrogen peroxide (H2O2)-induced DNA oxidation damage and DRC in non-frail and frail middle-aged African American and White individuals with household incomes above and below poverty. Analysis of baseline single-strand breaks showed no associations with frailty, poverty, race, or sex. However, we identified an interaction between frailty and poverty in H2O2-induced DNA oxidation damage. We also identified interactions between sex and frailty as well as sex and poverty status with DRC. The social determinant of health, poverty, associates with DRC in men. Baseline DNA damage, H2O2-induced DNA damage as well as DRC were associated with serum cytokine levels. IL-10 levels were inversely associated with baseline DNA damage as well as H2O2-induced DNA damage, DRC was altered by IL-4 levels and sex, and by TNF-α levels in the context of sex and poverty status. This is the first evidence that DRC may be influenced by poverty status at midlife. Our data show that social determinants of health should be considered in examining biological pathways through which disparate age-related health outcomes become manifest.

Abstract Frailty is a major public health concern affecting the health and well-being of adults. Poor diet is among several modifiable risk factors for developing frailty. We examined associations of dietary quality assessed by the Healthy Eating Index with frailty status over mean 8.7y follow-up. The sample was comprised of African American (AA) and White participants enrolled in the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study (44% male, 44% AA, mean baseline age of 48.5y). Only participants from the baseline study and first 2 follow-up visits with dietary data, 2 recall days per visit, and frailty data were included (n=2901). Frailty was prospectively determined by the modified FRAIL scale. Group-based trajectory modeling identified 3 diet quality groups (high: g3 [5.2% of sample, HEI(X±SD): 57.4±4.1], medium (g2: 48.2%, 46.1±3.7), low (g1: 46.5%, 38.2±2.9) and 2 frailty groups (remaining non-frail [20.2% sample] or being pre-frail or frail over time). Multiple logistic and Cox proportional hazards regressions found high and medium HEI trajectory groups, compared to the low HEI group, were associated with reduced risk of being pre-frail or frail, with a clear dose-response relationship (g2 vs. g1: HR=0.77, 95% CI: 0.64-0.92, p=0.004; g3 vs. g1: HR=0.29, 95% CI: 0.18-0.49, P< 0.001), even after adjusting for sociodemographic factors, smoking, drug use, and allostatic load. These findings were corroborated with Kaplan-Meier curves and log-rank tests, providing longitudinal evidence of the link between better diet quality with lower frailty risk, and the importance of diet in successful aging during middle age.

Key Points Question As a biomarker of biological aging, does DNA methylation (DNAm) adequately assess the rate of change in aging over time among socioeconomically diverse middle-aged African American and White adults? Findings In this cohort study of 470 socioeconomically diverse middle-aged African American and White adults, household income below poverty level and African American race were associated with a higher DNAm-based pace of aging. Meaning These findings suggest that the DNAm-based pace of aging may provide insight into how social constructs such as race play a role in healthy aging.

Circulating cell-free mitochondrial DNA (ccf-mtDNA) acts as a damage-associated molecular pattern molecule and may be cargo within extracellular vesicles (EVs). ccf-mtDNA and select mitochondrial DNA (mtDNA) haplogroups are associated with cardiovascular disease. We hypothesized that ccf-mtDNA and plasma EV mtDNA would be associated with hypertension, sex, self-identified race, and mtDNA haplogroup ancestry. Participants were normotensive (n = 107) and hypertensive (n = 108) African American and White adults from the Healthy Aging in Neighborhoods of Diversity across the Life Span study. ccf-mtDNA levels were higher in African American participants compared with White participants in both plasma and EVs, but ccf-mtDNA levels were not related to hypertension. EV mtDNA levels were highest in African American participants with African mtDNA haplogroup. Circulating inflammatory protein levels were altered with mtDNA haplogroup, race, and EV mtDNA. Our findings highlight that race is a social construct and that ancestry is crucial when examining health and biomarker differences between groups.

Background Frailty, a clinical syndrome commencing at midlife, is a risk for morbidity and mortality. Little is known about the factors that contribute to the chronic inflammatory state associated with frailty. Extracellular vesicles (EVs) are small, membrane-bound vesicles that are released into the circulation and are mediators of intercellular communication. We examined whether mitochondrial DNA (mtDNA) and inflammatory proteins in EVs may act as damage-associated molecular pattern (DAMP) molecules in frailty. Results To address whether EVs and their associated mtDNA and inflammatory protein cargo are altered with frailty, EVs were isolated from non-frail ( n = 90) and frail ( n = 87) middle-aged (45–55 years) participants from the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study. EV concentration was highest in frail White participants. EV mtDNA levels were significantly higher in frail individuals compared to non-frail individuals. The presence of six inflammatory proteins in EVs (FGF-21, HGF, IL-12B, PD-L1, PRDX3, and STAMBP) were significantly associated with frailty. EV inflammatory proteins were significantly altered by frailty status, race, sex, and poverty status. Notably, frail White participants had higher levels of EV-associated CD5, CD8A, CD244, CXCL1, CXCL6, CXCL11, LAP-TGF-beta-1 and MCP-4 compared to frail and non-frail African American participants. Frail White participants living below poverty had higher levels of EV-associated uPA. EV-associated CCL28 levels were highest in non-frail women and CXCL1 were highest in non-frail men. Men living below poverty had higher levels of CD5, CD8A, CXCL1, LAP-TGF-beta-1, and uPA. CXCL6 levels were significantly higher in individuals living above poverty. There was a significant correlation between EV mtDNA levels and the presence of inflammatory proteins. Conclusions These data suggest that mtDNA within EVs may act as a DAMP molecule in frailty. Its association with chemokines and other inflammatory EV cargo proteins, may contribute to the frailty phenotype. In addition, the social determinant of health, poverty, influences the inflammatory cargo of EVs in midlife.

Limited investigation has been done on diet quality trajectories over adulthood. The main study objectives were to determine the diet quality group trajectories (GTs) over time and to detect changes in a socio-economically and racially diverse middle-aged cohort. Data from three waves of the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study were used to determine diet quality with group-based trajectory modeling (GBTM). Three quality indices-the Healthy Eating Index (HEI), the Dietary Inflammatory Index (DII), and the Mean Adequacy Ratio (MAR)-were explored. The rate of change in quality over time was determined by mixed-effects regression analysis. Three diet quality GTs, low, middle, and high quality, were identified for each index and confirmed with spaghetti plots. Within each GT, only small changes in diet quality scores were observed, with improvements for the HEI and DII indices and a slight decline in MAR scores. Weighted kappa values revealed that the DII had better agreement with the HEI-2010 and MAR indices compared with the agreement between the HEI-2010 and MAR. Bayesian estimates revealed that the annualized rate of change in diet quality per person across the GTs was similar. There was minimal change in diet quality over time, regardless of the diet quality index used.

Background The growing epidemic of the inflammation-related metabolic disease, type 2 diabetes mellitus, presents a challenge to improve our understanding of potential mechanisms or biomarkers to prevent or better control this age-associated disease. A gelsolin isoform is secreted into the plasma as part of the extracellular actin scavenger system which serves a protective role by digesting and removing actin filaments released from damaged cells. Recent data indicate a role for decreased plasma gelsolin (pGSN) levels as a biomarker of inflammatory conditions. Extracellular vesicles (EVs), a heterogeneous group of cell-derived membranous structures involved in intercellular signaling, have been implicated in metabolic and inflammatory diseases including type 2 diabetes mellitus. We examined whether pGSN levels were associated with EV concentration and inflammatory plasma proteins in individuals with or without diabetes. Methods We quantified pGSN longitudinally (n = 104) in a socioeconomically diverse cohort of middle-aged African American and White study participants with and without diabetes mellitus. Plasma gelsolin levels were assayed by ELISA. EV concentration (sub-cohort n = 40) was measured using nanoparticle tracking analysis. Inflammatory plasma proteins were assayed on the SomaScan® v4 proteomic platform. Results pGSN levels were lower in men than women. White individuals with diabetes had significantly lower levels of pGSN compared to White individuals without diabetes and to African American individuals either with or without diabetes. For adults living below poverty, those with diabetes had lower pGSN levels than those without diabetes. Adults living above poverty had similar pGSN levels regardless of diabetes status. No correlation between EV concentrations and pGSN levels was identified (r = − 0.03; p = 0.85). Large-scale exploratory plasma protein proteomics revealed 47 proteins that significantly differed by diabetes status, 19 of which significantly correlated with pGSN levels, including adiponectin. Conclusions In this cohort of racially diverse individuals with and without diabetes, we found differences in pGSN levels with diabetes status, sex, race, and poverty. We also report significant associations of pGSN with the adipokine, adiponectin, and other inflammation- and diabetes-related proteins. These data provide mechanistic insights into the relationship of pGSN and diabetes.

Even before the COVID-19 pandemic declines in life expectancy in the United States were attributed to increased mortality rates in midlife adults across racial and ethnic groups, indicating a need for markers to identify individuals at risk for early mortality. Extracellular vesicles (EVs) are small, lipid-bound vesicles capable of shuttling functional proteins, nucleic acids, and lipids. Given their role as intercellular communicators and potential biomarkers of disease, we explored whether circulating EVs may be markers of mortality in a prospective, racially, and socioeconomically diverse middle-aged cohort. We isolated plasma EVs from 76 individuals (mean age = 59.6 years) who died within a 5 year period and 76 surviving individuals matched by age, race, and poverty status. There were no significant differences in EV concentration, size, or EV-associated mitochondrial DNA levels associated with mortality. We found that several EV-associated inflammatory proteins including CCL23, CSF-1, CXCL9, GDNF, MCP-1, STAMBP, and 4E-BP1 were significantly associated with mortality. IL-10RB and CDCP1 were more likely to be present in plasma EVs from deceased individuals than in their alive counterparts. We also report differences in EV-associated inflammatory proteins with poverty status, race, and sex. Our results suggest that plasma EV-associated inflammatory proteins are promising potential clinical biomarkers of mortality.