Racial Differences in Elevated C-Reactive Protein Among US Older Adults

The mediating role of systemic inflammation and moderating role of racialization in disparities in incident dementia

BACKGROUND

Exposure to systemic racism is linked to increased dementia burden. To assess systemic inflammation as a potential pathway linking exposure to racism and dementia disparities, we investigated the mediating role of C-reactive protein (CRP), a systemic inflammation marker, and the moderating role of the racialization process in incident dementia.

METHODS

In the US Health and Retirement Study (n = 6,908), serum CRP was measured at baseline (2006, 2008 waves). Incident dementia was classified by cognitive tests over a six-year follow-up. Self-reported racialized categories were a proxy for exposure to the racialization process. We decomposed racialized disparities in dementia incidence (non-Hispanic Black and/or Hispanic vs. non-Hispanic white) into 1) the mediated effect of CRP, 2) the moderated portion attributable to the interaction between racialized group membership and CRP, and 3) the controlled direct effect (other pathways through which racism operates).

RESULTS

The 6-year cumulative incidence of dementia is 12%. Among minoritized participants (i.e., non-Hispanic Black and/or Hispanic), high CRP levels ( ≥ 75th percentile or 4.73μg/mL) are associated with 1.26 (95%CI: 0.98, 1.62) times greater risk of incident dementia than low CRP ( < 4.73μg/mL). Decomposition analysis comparing minoritized versus non-Hispanic white participants shows that the mediating effect of CRP accounts for 3% (95% CI: 0%, 6%) of the racial disparity, while the interaction effect between minoritized group status and high CRP accounts for 14% (95% CI: 1%, 27%) of the disparity. Findings are robust to potential violations of causal mediation assumptions.

CONCLUSIONS

Minoritized group membership modifies the relationship between systemic inflammation and incident dementia.

Racial/Ethnic differences in inflammation levels among older adults 56+: an examination of sociodemographic differences across inflammation measure

OBJECTIVE

Chronic inflammation is a key biological risk factor for many widespread adult health conditions. This study examines racial/ethnic differences in inflammation across several inflammatory markers, including selected cytokines that are identified as important for aging and age-related health outcomes.

METHODS

Data came from the 2016 Venous Blood Collection Subsample of the Health and Retirement Study. Using logistic regression models, we compared high-risk categories of C-reactive protein and cytokine markers (IL-6, IL-10, IL-1RA, TNFR1, and TGF-Beta), across race/ethnicity and whether these differences persisted among men and women.

RESULTS

The findings provided evidence of significant race/ethnic differences in inflammatory measures, but the patterns differed across marker types.

CONCLUSIONS

These findings emphasize that race/ethnic differences are not consistently captured across markers of inflammation and that researchers should proceed with caution when using individual markers of inflammation in an effort to not overlook potential racial/ethnic differences in biological risk.

White Blood Cell and C-Reactive Protein Levels Are Similar in Obese Hispanic White Women Reporting Adherence to a Healthy Plant, Unhealthy Plant, or Animal-Based Diet, unlike in Obese Non-Hispanic White Women

While modifying dietary patterns can reduce the effects of inflammation in obesity, less is known about the impact of dietary patterns on inflammation levels in women of different ethnicities. This study investigated the link between dietary patterns and mediators associated with inflammation, such as C-reactive protein (CRP) and white blood cells (WBCs), among obese Hispanic and Non-Hispanic White women. CRP and WBC counts were extracted from the National Health and Nutrition Examination Survey conducted between 2003 and 2010. Based on their recorded responses to two 24 h recall interviews, individuals were grouped into one of three dietary patterns: healthy plant-based, less healthy plant-based, or animal-based. Comparisons were run between obese Hispanic and Non-Hispanic women assigned to the same dietary pattern groups and between dietary pattern groups within ethnic groups. CRP and WBCs increased in obese Non-Hispanics as dietary patterns moved from healthy plant-based to animal-based (pCRP = 0.002 and pWBC = 0.017). Regardless of the dietary pattern, CRP and WBC expression were similar in Hispanic women. In addition, WBCs were higher in Hispanics compared to Non-Hispanics when both populations adhered to healthy plant and less healthy plant dietary patterns. The results indicate that dietary patterns may influence Hispanics' inflammation differently than Non-Hispanics.

Looking Upstream to Understand Race/Ethnicity as a Moderator for Poststroke Neuroinflammation and a Social Determinant for Poststroke Aphasia Outcomes

INTRODUCTION

Over the past decade, the stroke literature has begun to acknowledge and explore explanations for longstanding racial/ethnic differences in stroke outcomes. Poststroke cognitive impairment (PSCI) and poststroke aphasia are two such negative poststroke outcomes where racial/ethnic differences exist. Physiological differences, such as stroke type and lesion size, have been used to partially explain the variation in PSCI and aphasia. However, there is some evidence, although limited, that suggests neuroinflammatory processes as part of allostatic load may be a key contributor to the observed disparities.

METHOD

In this tutorial, we explore the influence of race differences in inflammation on poststroke cognitive outcomes. We suggest lifetime stress and other external determinants of health such as neighborhood environment and discriminatory practices through "weathering" explain differences in inflammation. While using an allostatic load framework, we explore the literature focusing specifically on the role of neuroinflammation on poststroke outcomes.

CONCLUSIONS

Examination of the immune response poststroke provides a foundation for understanding the mechanisms of PSCI and poststroke aphasia and the potential contributions of neuroinflammatory processes on poststroke cognitive outcomes. Furthermore, understanding of racial differences in those processes may contribute to a better understanding of racial disparities in general stroke outcomes as well as poststroke aphasia.

Particulate matter, traffic-related air pollutants, and circulating C-reactive protein levels: The Multiethnic Cohort Study

Inhaled particles and gases can harm health by promoting chronic inflammation in the body. Few studies have investigated the relationship between outdoor air pollution and inflammation by race and ethnicity, socioeconomic status, and lifestyle risk factors. We examined associations of particulate matter (PM) and other markers of traffic-related air pollution with circulating levels of C-reactive protein (CRP), a biomarker of systemic inflammation. CRP was measured from blood samples obtained in 1994-2016 from 7,860 California residents participating in the Multiethnic Cohort (MEC) Study. Exposure to PM (aerodynamic diameter ≤2.5 μm [PM2.5], ≤10 μm [PM10], and between 2.5 and 10 μm [PM10-2.5]), nitrogen oxides (NOx, including nitrogen dioxide [NO2]), carbon monoxide (CO), ground-level ozone (O3), and benzene averaged over one or twelve months before blood draw were estimated based on participants' addresses. Percent change in geometric mean CRP levels and 95% confidence intervals (CI) per standard concentration increase of each pollutant were estimated using multivariable generalized linear regression. Among 4,305 females (55%) and 3,555 males (45%) (mean age 68.1 [SD 7.5] years at blood draw), CRP levels increased with 12-month exposure to PM10 (11.0%, 95% CI: 4.2%, 18.2% per 10 μg/m3), PM10-2.5 (12.4%, 95% CI: 1.4%, 24.5% per 10 μg/m3), NOx (10.4%, 95% CI: 2.2%, 19.2% per 50 ppb), and benzene (2.9%, 95% CI: 1.1%, 4.6% per 1 ppb). In subgroup analyses, these associations were observed in Latino participants, those who lived in low socioeconomic neighborhoods, overweight or obese participants, and never or former smokers. No consistent patterns were found for 1-month pollutant exposures. This investigation identified associations of primarily traffic-related air pollutants, including PM, NOx, and benzene, with CRP in a multiethnic population. The diversity of the MEC across demographic, socioeconomic, and lifestyle factors allowed us to explore the generalizability of the effects of air pollution on inflammation across subgroups.

The association between socioeconomic status and C-reactive protein in Bayesian perspective

•This study analyzed the total health inequality on risks of chronic inflammation.•We used Bayesian multiple and distributional regression models.•Between-group posterior distributions show a robust educational gradient in health.•Within-group posterior distributions show polarized risks for individuals.

The Mediating Role of Systemic Inflammation and Moderating Role of Race/Ethnicity in Racialized Disparities in Incident Dementia: A Decomposition Analysis

Background

Exposure to systemic racism is linked to increased dementia burden. To assess systemic inflammation as a potential pathway linking exposure to racism and dementia disparities, we investigated the mediating role of C-reactive protein (CRP), a systemic inflammation marker, and the moderating role of race/ethnicity on racialized disparities in incident dementia.

Methods

In the US Health and Retirement Study (n=5,143), serum CRP was measured at baseline (2006, 2008 waves). Incident dementia was classified by cognitive tests over a six-year follow-up. Self-reported racialized categories were a proxy for exposure to the racialization process. We decomposed racialized disparities in dementia incidence (non-Hispanic Black and/or Hispanic vs. non-Hispanic White) into 1) the mediated effect of CRP, 2) the moderated portion attributable to the interaction between racialized group membership and CRP, and 3) the controlled direct effect (other pathways through which racism operates).

Results

The 6-year cumulative incidence of dementia was 15.5%. Among minoritized participants (i.e., non-Hispanic Black and/or Hispanic), high CRP levels (> 75th percentile or 4.57mcg/mL) was associated with 1.27 (95%CI: 1.01,1.59) times greater risk of incident dementia than low CRP (<4.57mcg/mL). Decomposition analysis comparing minoritized versus non-Hispanic White participants showed that the mediating effect of CRP accounted for 2% (95% CI: 0%, 6%) of the racial disparity, while the interaction effect between minoritized group status and high CRP accounted for 12% (95% CI: 2%, 22%) of the disparity. Findings were robust to potential violations of causal mediation assumptions.

Conclusions

Systemic inflammation mediates racialized disparities in incident dementia.

The Mediating Role of Systemic Inflammation and Moderating Role of Race/Ethnicity in Racialized Disparities in Incident Dementia: A Decomposition Analysis

Background

Exposure to systemic racism is linked to increased dementia burden. To assess systemic inflammation as a potential pathway linking exposure to racism and dementia disparities, we investigated the mediating role of C-reactive protein (CRP), a systemic inflammation marker, and the moderating role of race/ethnicity on racialized disparities in incident dementia.

Methods

In the US Health and Retirement Study (n=5,143), serum CRP was measured at baseline (2006, 2008 waves). Incident dementia was classified by cognitive tests over a six-year follow-up. Self-reported racialized categories were a proxy for exposure to the racialization process. We decomposed racialized disparities in dementia incidence (non-Hispanic Black and/or Hispanic vs. non-Hispanic White) into 1) the mediated effect of CRP, 2) the moderated portion attributable to the interaction between racialized group membership and CRP, and 3) the controlled direct effect (other pathways through which racism operates).

Results

The 6-year cumulative incidence of dementia was 15.5%. Among minoritized participants (i.e., non-Hispanic Black and/or Hispanic), high CRP levels (> 75th percentile or 4.57μg/mL) was associated with 1.27 (95%CI: 1.01,1.59) times greater risk of incident dementia than low CRP (≤4.57μg/mL). Decomposition analysis comparing minoritized versus non-Hispanic White participants showed that the mediating effect of CRP accounted for 2% (95% CI: 0%, 6%) of the racial disparity, while the interaction effect between minoritized group status and high CRP accounted for 12% (95% CI: 2%, 22%) of the disparity. Findings were robust to potential violations of causal mediation assumptions.

Conclusions

Systemic inflammation mediates racialized disparities in incident dementia.

C-reactive protein, but not neutrophil-lymphocyte ratio, is inversely associated with muscle strength only in older men: NHANES 1999-2002

To evaluate the association of inflammation (C-reactive protein (CRP) and neutrophil-lymphocyte ratio (NLR) levels) with muscle strength in older adults. We also aimed to evaluate whether these associations are sex-specific. A cross-sectional study was performed with data from the National Health and Nutrition Examination Survey (NHANES) 1999-2000 and 2001-2002. A total of 2387 individuals over 50 years of both sexes were evaluated, according to the eligibility criteria for the strength test. Muscle strength was measured by Kinetic Communicator isokinetic dynamometer; while the NLR was obtained by the ratio of the total neutrophil for lymphocyte count and CRP was quantified by latex nephelometry. Linear regression analyses, crude and adjusted for confounders, were used to estimate the coefficients and 95 % confidence intervals for peak strength (muscle strength) by tertiles of NLR and CRP. There was no association between NLR and peak strength for both sexes. CRP levels were inversely associated with peak force in men [2nd tertile β = -3.33 (-15.92; 9.25); 3rd tertile β = -24.69 (-41.18; -8.20), p for trend = 0.005], but not in women [2nd tertile β = -3.22 (-15.00; 8.56); 3rd tertile β = -9.23 (-28.40; -9.94), p for trend = 0.332]. In conclusion, NLR levels were not associated with muscle strength in both sexes. CRP levels were inversely associated with muscle strength in older men, but not in women, suggesting that the association between inflammation and muscle strength in older adults can be sex-specific.

Racial/ethnic variations in inflammatory markers: exploring the role of sleep duration and sleep efficiency

Individuals from minoritized racial/ethnic groups have higher levels of circulating inflammatory markers. However, the mechanisms underlying these differences remain understudied. The objective of this study was to examine racial/ethnic variations in multiple markers of inflammation and whether impaired sleep contributes to these racial/ethnic differences. Nurses from two regional hospitals in Texas (n = 377; 71.62% White; 6.90% Black; 11.14% Hispanic, 10.34% Asian; mean age = 39.46; 91.78% female) completed seven days of sleep diaries and actigraphy to assess mean and variability in total sleep time (TST) and sleep efficiency (SE). On day 7, blood was drawn to assess 4 inflammatory markers: C-reactive protein (CRP), Interleukin-6 (IL-6), Interleukin-1 beta (IL-1β), and tumor necrosis factor-alpha (TNF-α). Results from regression models showed differences in inflammatory markers by race/ethnicity, adjusting for age and gender. The associations between sleep parameters and inflammatory markers also varied by race/ethnicity. Among White nurses, lower mean and greater variability in actigraphy-determined TST and greater variability in diary-determined TST were associated with higher levels of IL-6. Among Black nurses, lower mean diary-determined SE was associated with higher levels of IL-6 and IL-1β. Among Hispanic nurses, greater diary-determined mean TST was associated with higher CRP. Among Asian nurses, greater intraindividual variability in actigraphy-determined SE was associated with lower CRP. Among nurses, we did not find racial/ethnic disparities in levels of inflammation. However, analyses revealed differential relationships between sleep and inflammatory markers by race/ethnicity. Results highlight the importance of using a within-group approach to understand predictors of inflammatory markers.

Inflammation and depression symptoms are most strongly associated for Black adults

Although race/ethnicity is associated with substantial differences in risk for depression and other diseases of aging in the United States, the processes underlying these health disparities remain poorly understood. We addressed this issue by examining how levels of a robust marker of inflammatory activity, C-reactive protein (CRP), and depression symptoms varied across racial/ethnic groups. Additionally, we tested whether the inflammation-depression association differed across groups. Data were drawn from the Chicago Community Adult Health Survey, an epidemiological survey examining biopsychosocial factors affecting health and well-being. Participants were 3105 Chicago community adults, of which 610 provided blood samples and were included in analyses. C-reactive protein was assayed from blood samples, and depression symptoms were assessed using the 11-item Center for Epidemiologic Studies-Depression scale. Race/ethnicity was self-reported and consisted of Black, Hispanic, White, and other racial/ethnic groups. Results revealed that these racial/ethnic groups differed in terms of both their CRP and depression levels. Specifically, Black Americans exhibited higher levels of CRP as compared to White and other race/ethnicity Americans. Moreover, Black Americans exhibited more depression symptoms than Hispanic Americans. Finally, we found that inflammatory levels were strongly related to depression symptoms but only for Black Americans, with CRP alone accounting for 8% of the variance in depression symptoms in this subgroup. These data thus point to a biological process that may help to explain disparities in mental health outcomes across race/ethnicity in the United States. At the same time, additional research is needed to understand the social and structural factors driving these effects.

Acute versus chronic inflammatory markers and cognition in older black adults: Results from the Minority Aging Research Study

Peripheral inflammation is elevated in older Black adults, an elevation which prior work has suggested may be due to chronic stress associated with systemic racism and related adverse cardiovascular health conditions. Inflammation is also involved in the pathogenic processes of dementia; however, limited (and mixed) results exist concerning inflammation and cognitive decline in Black adults. We characterized patterns of inflammation and their role in cognitive decline in 280 older Black adults (age = 72.99 ± 6.00 years; 69.6% female) from the Minority Aging Research Study (MARS) who were without dementia at baseline and followed between 2 and 15 years (mean = 9 years). Participants completed a blood draw at baseline and annual cognitive evaluations. Serum was assayed for 9 peripheral inflammatory markers; 19 neuropsychological test scores were used to create indices of global cognition and five cognitive domains. Principal component analysis with varimax rotation characterized patterns of inflammation with factor loadings > 0.6 per component contributing to two composite scores representing acute/upstream and chronic/downstream inflammation. These composites were used as separate predictors in linear mixed regression models to determine associations with level and change in cognition adjusting for relevant covariates. Higher baseline upstream/acute inflammation associated with lower baseline semantic memory (p = .040) and perceptual speed (p = .046); it was not related to cognitive decline. By contrast, higher baseline downstream/chronic inflammation associated with faster declines in global cognition (p = .010), episodic (p = .027) and working memory (p = .006); it was not related to baseline cognition. For older Black adults, chronic, but not acute, inflammation may be a risk factor for changes in cognition.

How social/environmental determinants and inflammation affect salivary telomere length among middle-older adults in the health and retirement study

Social epidemiology posits that chronic stress from social determinants will lead to a prolonged inflammatory response that may induce accelerated aging as measured, for example, through telomere length (TL). In this paper, we hypothesize variables across demographic, health-related, and contextual/environmental domains influence the body’s stress response, increase inflammation (as measured through high-sensitivity C-reactive protein (hs-CRP)), and thereby lead to shortening of telomeres. This population-based research uses data from the 2008 Health and Retirement Study on participants ages ≤ 54–95 + years, estimating logistic regression and Cox proportional hazards models of variables (with and without confounders) across the domains on shortened TL. A mediation analysis is also conducted. Contrary to expectations, hs-CRP is not associated with risk of shortened TL. Rather, factors related to accessing health care, underlying conditions of frailty, and social inequality appear to predict risk of shorter TL, and models demonstrate considerable confounding. Further, hs-CRP is not a mediator for TL. Therefore, the social determinants of health examined do not appear to follow an inflammatory pathway for shortened TL. The finding of a relationship to social determinants affecting access to health care and medical conditions underscores the need to address social determinants alongside primary care when examining health inequities.

Differences in Inflammation, Treatment, and Outcomes Between Black and Non-Black Patients Hospitalized for COVID-19: A Prospective Cohort Study

PURPOSE

Racial disparities in coronavirus disease 2019 (COVID-19) outcomes have been described. We sought to determine whether differences in inflammatory markers, use of COVID-19 therapies, enrollment in clinical trials, and in-hospital outcomes contribute to racial disparities between Black and non-Black patients hospitalized for COVID-19.

METHODS

We leveraged a prospective cohort study that enrolled 1325 consecutive patients hospitalized for COVID-19, of whom 341 (25.7%) were Black. We measured biomarkers of inflammation and collected data on the use COVID-19-directed therapies, enrollment in COVID-19 clinical trials, mortality, need for renal replacement therapy, and need for mechanical ventilation.

RESULTS

Compared to non-Black patients, Black patients had a higher prevalence of COVID-19 risk factors including obesity, hypertension, and diabetes mellitus and were more likely to require renal replacement therapy (15.8% vs 7.1%, P < .001) and mechanical ventilation (37.2% vs 26.6%, P < .001) during their hospitalization. Mortality was similar between both groups (15.5% for Blacks vs 14.0% for non-Blacks, P = .49). Black patients were less likely to receive corticosteroids (44.9% vs 63.8%, P< .001) or remdesivir (23.8% vs 57.8%, P < .001) and were less likely to be enrolled in COVID-19 clinical trials (15.3% vs 28.2%, P < .001). In adjusted analyses, Black race was associated with lower levels of C-reactive protein and soluble urokinase receptor and higher odds of death, mechanical ventilation, and renal replacement therapy. Differences in outcomes were not significant after adjusting for use of remdesivir and corticosteroids.

CONCLUSIONS

Racial differences in outcomes of patients with COVID-19 may be related to differences in inflammatory response and differential use of therapies.

Correlates of Elevated C-Reactive Protein Among Black Older Adults: Evidence From the Health and Retirement Study

OBJECTIVES

Substantial evidence documents gender and racial disparities in C-reactive protein (CRP), a measure of systemic inflammation, among older adults. Yet, the comparative approaches of these studies may obscure distinct risk and protective factors associated with elevated CRP among older Black Americans. To pinpoint opportunities for intervention, this study utilizes a "within-group approach" to identify the sociodemographic, psychosocial, behavioral, and health-related correlates of elevated CRP among older Black women and men.

METHOD

The sample consisted of 2,420 Black respondents aged 51 and older in the Health and Retirement Study (2006-2016). Gender-stratified, random effects logistic regression models were used to examine correlates of elevated CRP (>3.0 mg/L).

RESULTS

More than 50% of Black women had elevated CRP, and younger age, Medicaid, lower mastery, religiosity, overweight/obesity, physical inactivity, and activities of daily living (ADLs) contributed to elevated CRP among this group. In contrast, elevated CRP was reported among only 37.25% of Black men, for whom financial distress was associated with lower odds of elevated CRP; religiosity, less neighborhood cohesion, current smoking, overweight/obesity, ADLs, and more chronic conditions were associated with greater odds of elevated CRP among this group.

DISCUSSION

Sociodemographic factors had a limited association with elevated CRP among older Black Americans. Rather, a range of psychosocial, behavioral, and health-related factors were more influential determinants of elevated CRP among older Black Americans. Most notably, findings demonstrate distinct correlates of CRP among Black women and men, underscoring the critical need to further evaluate the risk and protective mechanisms undergirding disparities among this aging population.

Assessing the roles of demographic, social, economic, environmental, health-related, and political factors on risk of osteoporosis diagnosis among older adults

Chronic stress from social/environmental pressures has been proposed to affect bone health through increased inflammation. We demonstrate that inflammation from prolonged stress does not cause changes to bone health through inflammation but instead impacts access to health care, social inequalities, and overall health, which in turn impact bone health.

PURPOSE

The study provides a comprehensive assessment of how determinants of health across demographic, psychological, mobility-related, health, environmental, and economic domains are associated with the diagnosis of osteoporosis and tests three hypotheses: (1) a diverse set of variables across domains will predict osteoporosis, (2) chronic inflammation as a result of stress (represented by high-sensitivity C-reactive protein) will not be associated with osteoporosis, and (3) the model developed will have high accuracy in predicting osteoporosis.

METHODS

Logistic regression and Cox proportional hazards models of osteoporosis diagnosis were estimated using data from 14,792 and 13,169 participants (depending on model) in the 2012-2016 waves of the Health and Retirement Study, including the Biomarker Study, the Contextual Data Resource, and validated measures of childhood socioeconomic status. Predictive accuracy was assessed using k-Nearest Neighbors Discriminant Analysis.

RESULTS

Demographic, environmental, and health-related factors were associated with osteoporosis diagnosis, and predictive accuracy of the models was good. High-sensitivity C-reactive protein was not associated with osteoporosis diagnosis.

CONCLUSION

Social determinants identified indicate access to health care, inequalities in the greater social environment (e.g., access to resources), and overall health (i.e., underlying medical conditions) are key components for developing osteoporosis and indicate underlying health inequities in this sample. There is a need to further address the interplay between primary health care and social determinants of health.

Race, Gender, and Socioeconomic Variations in C-Reactive Protein Using the Health and Retirement Study

OBJECTIVES

To clarify the relationships among race, gender, and socioeconomic status (SES) with C-reactive protein (CRP).

METHOD

The present study analyzed data from 6,521 Black and White respondents aged 51 and older in the Health and Retirement Study, a nationally representative sample of midlife and older adults, to address two aims. We sought to (i) assess the independent associations between race, gender, and SES with CRP concentrations and (ii) test whether race, gender, and SES interacted to produce unequal CRP concentrations cross-sectionally and over a 4-year follow-up.

RESULTS

The results demonstrated that race, gender, and SES were each independently associated with baseline CRP, but only SES was associated with CRP at follow-up. Furthermore, race, gender, and education interacted to produce differential CRP levels at baseline. There were incremental benefits for each additional level of education for White men and women, but the relationship between education and CRP was more complicated for Black men and women. Compared with other race/gender groups with less than high school, Black women had the highest and Black men had the lowest levels of CRP. There were no apparent benefits to CRP for Black women with college compared with Black women with high school, while Black men with less than high school and college had similar concentrations of CRP.

DISCUSSION

In clarifying the complexity inherent in CRP disparities, this work contributes to a greater understanding of the biological mechanisms underlying racial disparities in leading causes of morbidity and mortality in the United States.

Concurrent and Longitudinal Associations of Sex and Race with Inflammatory Biomarkers during Adolescence

Chronic, systemic inflammation is implicated in physical and mental health; little is known about whether sex and racial differences detected in adulthood are observed during adolescence or about normative changes occurring during adolescence. This longitudinal, United States-based study examined four biomarkers of systemic inflammation [C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and IL-8) in 315 adolescents (51% female; 58% black; baseline age = 16.49 years (SD = 1.56; range: 12.14-21.28)] at three timepoints. Notable results included: general decline in inflammatory biomarkers in older adolescents, lower levels of TNF-α/IL-8 in black adolescents, elevated CRP/IL-6 in females, and especially higher levels of IL-6 in black, female adolescents. Implications are discussed, particularly the potential health implications of elevated IL-6 in black females.