Sex Differences in Circulating Soluble Urokinase-Type Plasminogen Activator Receptor (suPAR) Levels and Adverse Outcomes in Coronary Artery Disease

suPAR in cardiovascular disease

Soluble urokinase plasminogen activator receptor (suPAR), the soluble counterpart of urokinase plasminogen activator receptor, is found in the circulation at various levels. suPAR and its parent molecule, cell surface uPAR, exhibit similar structure and extracellular functional roles facilitating fibrinolysis, cellular adhesion, and migration. Studies have assessed the correlation between suPAR in cardiovascular disease (CVD). It is postulated that suPAR may serve as an indicator of inflammatory activation and burden during CVD progression. Increased suPAR independently predicts poorer outcomes in acute coronary syndromes, in heart failure, as well as in coronary artery disease and atherosclerosis. To guide translation into clinical utization, suPAR has been assessed in numerous CVD settings for improved risk discrimination independently or in association with established traditional risk factors. Whilst the involvement of suPAR has been explored in other diseases such as kidney diseases and cancer, there is only emerging evidence of suPAR's mechanistic involvement in cardiovascular disease. In this review, we provide a background into suPAR and its potential role as a biomarker in CVD.

Soluble urokinase plasminogen activator receptor and cardiotoxicity in doxorubicin-treated breast cancer patients: a prospective exploratory study

BACKGROUND

Soluble urokinase plasminogen activator receptor is an inflammatory biomarker that may prognosticate cardiovascular outcomes. We sought to determine the associations between soluble urokinase plasminogen activator receptor and established markers of cardiotoxicity in breast cancer patients receiving doxorubicin.

METHODS

We conducted a prospective cohort study of women with newly diagnosed breast cancer receiving standard-dose doxorubicin (240 mg/m2) at Rush University Medical Center and Rush Oak Park Hospital (Chicago, IL) between January 2017 and May 2019. Left ventricular ejection fraction, global longitudinal strain, and cardiac biomarkers (N-terminal prohormone B-type natriuretic peptide, troponin-I, and high-sensitivity C-reactive protein) were measured at baseline and at intervals up to 12-month follow-up after end of treatment. The associations between soluble urokinase plasminogen activator receptor and these endpoints were evaluated using multivariable mixed effects linear regression.

RESULTS

Our study included 37 women (mean age 47.0 ± 9.3 years, 60% white) with a median baseline soluble urokinase plasminogen activator receptor level of 2.83 ng/dL. No participant developed cardiomyopathy based on serial echocardiography by one-year follow-up. The median percent change in left ventricular strain was -4.3% at 6-month follow-up and absolute changes in cardiac biomarkers were clinically insignificant. There were no significant associations between soluble urokinase plasminogen activator receptor and these markers of cardiotoxicity (all p > 0.05).

CONCLUSIONS

In this breast cancer cohort, doxorubicin treatment was associated with a very low risk for cardiotoxicity. Across this narrow range of clinical endpoints, soluble urokinase plasminogen activator receptor was not associated with markers of subclinical cardiotoxicity. Further studies are needed to clarify the prognostic utility of soluble urokinase plasminogen activator receptor in doxorubicin-associated cardiomyopathy and should include a larger cohort of leukemia and lymphoma patients who receive higher doses of doxorubicin.

Role of Soluble Urokinase-Type Plasminogen Activator Receptor in Cardiovascular Disease

PURPOSE OF REVIEW

Chronic inflammation is a major contributor to cardiovascular disease (CVD) risk. Soluble urokinase plasminogen activator receptor (suPAR) is an immune-derived glycoprotein that is strongly associated with atherosclerotic disease. This review summarizes evidence on suPAR's role in CVD pathogenesis and its potential as a prognostic indicator and therapeutic target.

RECENT FINDINGS

Clinical, genetic, and experimental evidence supports suPAR's role as a pathogenic factor in atherosclerosis. suPAR promotes atherosclerosis through modulation of monocyte activation and function. Clinically, elevated suPAR levels are linked to increased cardiovascular risk across diverse populations. Ongoing clinical trials are evaluating therapies targeting suPAR signaling. Current evidence positions suPAR as a regulator of myeloid cell function that contributes to vascular inflammation and subsequent cardiovascular events. Additional research is needed to determine whether suPAR measurement can improve CVD risk prediction and enable personalized management. Overall, suPAR is a promising immune-derived biomarker and target for reducing inflammation and cardiovascular risk.

Multi-proteomic Biomarker Risk Scores for Predicting Risk and Guiding Therapy in Patients with Coronary Artery Disease

PURPOSE OF REVIEW

Patients with established coronary artery disease (CAD) are at high residual risk for adverse events, despite guideline-based treatments. Herein, we aimed to determine whether risk scores based on multiple circulating biomarkers that represent activation of various pathophysiologically important pathways involved in atherosclerosis and myocardial dysfunction help identify those at greatest residual risk.

RECENT FINDINGS

Numerous circulating proteins, representing dysregulation of the pathways involved in the development and stability of coronary and myocardial diseases, have been identified. When aggregated together, biomarker risk scores (BRS) more accurately stratify patients with established CAD that may help target interventions in those individuals who are at elevated risk. Moreover, intensification of guideline-based therapies has been associated with parallel improvements in both BRS and outcomes, indicating that these risk scores may be employed clinically to target therapy. Multi-protein BRS are predictive of risk, independent of, and in addition to traditional risk factor assessments in patients with CAD. Those with elevated risk may benefit from optimization of therapies, and improvements in the BRS will identify those with improved outcomes.

The Association of suPAR with Cardiovascular Risk Factors in Young and Healthy Adults

The soluble urokinase plasminogen activator receptor (suPAR), as a correlate of chronic low-grade inflammation, may be used to predict individual cardiovascular risk. Since chronic low-grade inflammation is thought to be associated with the development of cardiovascular disease, this study aimed to evaluate if suPAR plasma levels are correlated with cardiovascular risk factors in young and healthy adults (aged 25-41 years). Consequently, data from the GAPP (genetic and phenotypic determinants of blood pressure and other cardiovascular risk factors) study were used to investigate suPAR plasma levels in relation to the following cardiovascular risk factors and laboratory parameters: BMI, physical activity, alcohol consumption, smoking status, blood pressure parameters, glucose status, and lipid levels. Additionally, suPAR was compared to the healthy lifestyle score and the Framingham score representing the overall cardiovascular risk profile. These associations were assessed using two different statistical approaches. Firstly, all cardiovascular risk factors and scores were compared amongst sex-specific suPAR plasma levels with ANOVA analysis. Secondly, sex-specific multivariable linear regressions were performed. Female participants had higher plasma suPAR levels than male participants (1.73 ng/mL versus 1.50 ng/mL; p < 0.001). A significant inverse correlation between suPAR plasma levels and HDL cholesterol was found in men (p = 0.001) and women (p < 0.001). Furthermore, male (p < 0.001) and female participants (p < 0.001) who smoked showed significantly higher plasma levels of suPAR (p < 0.001). For male participants, an inverse correlation of the healthy lifestyle score with suPAR plasma levels (p = 0.001) and a positive correlation of the Framingham score with suPAR plasma levels (p < 0.001) were detected. In women, no such correlation was found. The cholesterol levels (p = 0.001) and HbA1c (p = 0.008) correlated significantly with plasma suPAR levels in female participants. suPAR plasma levels were found to be strongly associated with certain cardiovascular risk factors; however, sex-specific differences were found. These sex-specific differences might be explained by the higher prevalence of cardiovascular risk factors in men resulting in a stronger correlation of suPAR as a marker of low-grade inflammation, since the existence of the risk factors already led to subclinical damage in men. Further research on suPAR levels in an older study population is needed.

Associations between plasma inflammatory markers and psychotic disorder, depressive disorder and generalised anxiety disorder in early adulthood: A nested case-control study

BACKGROUND

Low-grade inflammation may occur in association with several mental disorders of early adulthood, though associations with markers of chronic inflammation such as soluble urokinase plasminogen activator receptor (suPAR) are less well-established. We aimed to examine associations between acute and chronic inflammatory markers and mental disorders, as well as psychiatric co-morbidity, in young adults aged 24 years in the Avon Longitudinal Study of Parents and Children.

METHODS

Included were 781 participants (of 4019 who attended at age 24 years) who completed psychiatric assessments and provided plasma samples. Of these, 377 met criteria for psychotic disorder, depressive disorder or generalised anxiety disorder and 404 did not. Plasma concentrations of IFN-γ, IL-6, IL-8, IL-10, TNF-α, CRP, sVCAM1, sICAM1, suPAR and alpha-2-macroglobulin were measured using immunoassays. Logistic regression compared standardised inflammatory marker levels in cases and controls. Negative binomial regression evaluated associations between inflammatory markers and co-morbidity (number of mental disorders). Models were adjusted for sex, body mass index, cigarette smoking, cannabis use and employment status, then additionally for childhood trauma.

RESULTS

For psychotic disorder, there was evidence for associations with IL-6 (odds ratio[OR] 1.68, 95 %CI 1.20-2.34) and suPAR (OR 1.74, 95 %CI 1.17-2.58). There was weaker evidence for an association between suPAR and depressive disorder (OR 1.31, 95 %CI 1.05-1.62). There was little evidence for associations between inflammatory markers and generalised anxiety disorder. There was weak evidence for an association between suPAR and co-morbidity (β 0.10, 95 %CI 0.01-0.19). There was little evidence for additional confounding by childhood trauma.

CONCLUSIONS

There was evidence that 24-year-olds with psychotic disorder had raised plasma IL-6 and suPAR concentrations compared to controls. These findings have implications regarding the role of inflammation in mental disorders in early adulthood.

The influence of age and sex on the prognostic importance of traditional cardiovascular risk factors, selected circulating biomarkers and other markers of subclinical cardiovascular damage

PURPOSE OF REVIEW

There is an increasing need for improved risk stratification to better individualize cardiovascular preventive measures. Although age and sex are strong and easily obtained cardiovascular risk factors (CVRFs), their influence on the prognostic importance of other CVRF, circulating biomarkers and other markers of subclinical cardiovascular damage has not previously been systematically and critically appraised. Therefore, we have revisited the European MORGAM and the Danish MONI10 cohorts.

RECENT FINDINGS

Theoretically, the relative risk of many CVRF is expected to be lower in older healthy individuals due to a combination of selection bias by disease, higher absolute risk primarily due to older age, and the fact that the CVRF and markers may primarily influence or reflect early parts of the cardiovascular disease process. This influence of age may vary between sexes, as the cardiovascular disease process is delayed and possibly different in women compared with men.

SUMMARY

Adjusted for the remaining Systematic COronary Risk Evaluation (SCORE) CVRF, higher SBP, serum cholesterol, soluble urokinase-type plasminogen activator receptor, left ventricular mass index and atherosclerotic plaques were more closely associated with outcomes in individuals younger than 52 years with some sex-specific differences, whereas higher N-terminal pro-brain natriuretic peptide and urine albumin/creatine ratio were more closely associated with outcomes in subjects aged 61 or 71 years.

Prognostic value of soluble urokinase-type plasminogen activator receptor in coronary artery disease: A meta-analysis

BACKGROUND

A potential inflammatory biomarker, soluble urokinase-type plasminogen activator receptor (suPAR) has been utilized to assist the prognostic assessment of coronary artery disease (CAD) patients; however, outcomes have been inconsistent. The prognostic relevance of suPAR as a predictor of CAD patient adverse outcomes was therefore examined.

METHODS

Research articles published as of 1 January 2022 were retrieved from PubMed, Embase, the Web of Science and the Cochrane Library. All-cause mortality, cardiovascular mortality and other major cardiovascular events (nonfatal myocardial infarction, heart failure or stroke) were analysed as a subset of relevant studies' results. We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) for each study. The broad EQUATOR guidelines were conformed. Risk of bias was assessed with ROBINS-I tool.

RESULTS

In total, this analysis included nine studies including 14,738 CAD patients. All included studies made a correction for certain potential confounders. However, risk of bias ranged from moderate to critical. When the ROBINS-I tool was used. Patients with CAD that exhibited increased suPAR levels had a substantially higher risk of all-cause mortality (HR = 2.24; 95% CI 1.97-2.55) or cardiovascular mortality (HR = 2.02; 95% CI 1.58-2.58), but not of developing other major cardiovascular events (HR = 1.63; 95% CI 0.86-3.11). Considerable heterogeneity across studies was observed in our meta-analyses, but no significant publication bias was detected.

CONCLUSION

In patients with coronary disease, suPAR may have prognostic value for both all-cause and cardiovascular mortality but not for other major cardiovascular events.

Soluble Urokinase Receptor and Mortality in Kidney Transplant Recipients

Main problem: Soluble urokinase plasminogen activator receptor (suPAR) is an immunological risk factor for kidney disease and a prognostic marker for cardiovascular events.

Methods: We measured serum suPAR levels in a total of 1,023 kidney transplant recipients either before (cohort 1, n = 474) or at year 1 after transplantation (cohort 2, n = 549). The association of suPAR levels and all-cause and cardiovascular mortality was evaluated by multivariable Cox regression analysis.

Results: The highest suPAR tertile compared to the two lower tertiles had a significantly higher risk of all-cause mortality in both cohorts separately (cohort 1: hazard ratio (HR) 1.92, 95% confidence interval (CI) 1.20–3.08, p = 0.007; cohort 2: HR = 2.78, 95% CI 1.51–5.13, p = 0.001) and combined (n = 1,023, combined HR = 2.14, 95% CI 1.48–3.08, p < 0.001). The association remained significant in the subgroup of patients with normal kidney function (cohort 2: HR = 5.40, 95% CI 1.42–20.5, p = 0.013). The increased mortality risk in patients with high suPAR levels was attributable mainly to an increased rate of cardiovascular death (n = 1,023, HR = 4.24, 95% CI 1.81–9.96, p < 0.001).

Conclusion: A high suPAR level prior to and at 1 year after kidney transplantation was associated with an increased risk of patient death independent of kidney function, predominantly from cardiovascular cause.

Soluble Urokinase Plasminogen Activator Receptor: Genetic Variation and Cardiovascular Disease Risk in Black Adults

BACKGROUND

suPAR (Soluble urokinase plasminogen activator receptor) has emerged as an important biomarker of coagulation, inflammation, and cardiovascular disease (CVD) risk. The contribution of suPAR to CVD risk and its genetic influence in Black populations have not been evaluated.

METHODS

We measured suPAR in 3492 Black adults from the prospective, community-based JHS (Jackson Heart Study). Cross-sectional associations of suPAR with lifestyle and CVD risk factors were assessed, whole-genome sequence data were used to evaluate genetic associations of suPAR, and relationships of suPAR with incident CVD outcomes and overall mortality were estimated over follow-up.

RESULTS

In Cox models adjusted for traditional CVD risk factors, estimated glomerular filtration rate, and CRP (C-reactive protein), each 1-SD higher suPAR was associated with a 21% to 31% increased risk of incident coronary heart disease, heart failure, stroke, and mortality. In the genome-wide association study, 2 missense (rs399145 encoding p.Thr86Ala, rs4760 encoding p.Phe272Leu) and 2 noncoding regulatory variants (rs73935023 within an enhancer element and rs4251805 within the promoter) of PLAUR on chromosome 19 were each independently associated with suPAR and together explained 14% of suPAR phenotypic variation. The allele frequencies of each of the four suPAR-associated genetic variants differ considerably across African and European populations. We further show that PLAUR rs73935023 can alter transcriptional activity in vitro. We did not find any association between genetically determined suPAR and CVD in JHS or a larger electronic medical record-based analyses of Blacks or Whites.

CONCLUSIONS

Our results demonstrate the importance of ancestry-differentiated genetic variation on suPAR levels and indicate suPAR is a CVD biomarker in Black adults.

Independent impact of periodontitis and cardiovascular disease on elevated soluble urokinase-type plasminogen activator receptor (suPAR) levels

BACKGROUND

Previous studies have demonstrated that a soluble urokinase-type plasminogen activator receptor (suPAR) plays an essential function in leukocytes and endothelial homeostasis and, therefore, in the development of coronary heart disease (CHD) and periodontitis. The aim of this study was to analyze the impact of gingival health, periodontitis, and CHD on suPAR levels in plasma and saliva and to evaluate suPAR as a biomarker of periodontitis and CHD.

METHODS

Healthy controls (n = 33), patients with periodontitis (n = 31), CHD (n = 29), and a combination of periodontitis + CHD (n = 29) were enrolled in the present study. All patients were clinically and periodontally evaluated and regularly assessed for socioeconomic status, serum lipids, high-sensitivity C-reactive protein (hs-CRP), and for plasma and salivary suPAR levels.

RESULTS

Patients with periodontitis (P <.001) and with periodontitis + CHD (P <.001) presented higher median plasma and salivary suPAR levels compared with CHD and healthy controls. Moreover, univariate regression analysis demonstrated that hs-CRP (P <.001) and periodontitis (P <.001) had a significant negative direct effect on both plasma and salivary suPAR levels. The multivariate regression analysis showed that periodontitis was the only significant predictor of plasma suPAR (P = .035) while hs-CRP was the only significant predictor of salivary suPAR (P <.001).

CONCLUSIONS

The results of the present study demonstrated that patients with periodontitis and periodontitis + CHD presented higher suPAR levels in both plasma and saliva in comparison with healthy controls and CHD. Moreover, periodontitis and hs-CRP were the only significant predictors of the augmented suPAR levels in plasma and saliva, respectively.

Soluble Urokinase Plasminogen Activator Receptor as a Diagnostic and Prognostic Biomarker in Cardiac Disease

This review summarizes the published literature referring to the use and validity of the biomarker soluble urokinase plasminogen activator receptor (suPAR) when used for the assessment of patients with cardiac diseases. It is measured by enzyme-linked immunosorbent assay (ELISA) in plasma samples. In cardiology a cut-off value range of 3.5 - 4.5 ng/mL has been commonly utilized. Different cut-off values may be applied based on the measuring kit used, the patient population and the clinical setting. A PubMed/Medline search was conducted aiming to identify all publications relevant to the use of suPAR in patients with cardiac diseases. A total of 39 studies were included in this review. suPAR as a marker of inflammation has been used more extensively in recent years, alone or in combination with other biomarkers of inflammation and cardiac pathology in the assessment of patients with acute and chronic cardiac diseases. suPAR is closely related to the pathophysiology of cardiac disease, and a number of publications encourages its use as a valuable biomarker in the assessment of patients presenting to the cardiology service. It may be most valuable in the risk assessment of patients with acute coronary syndromes and congestive heart failure, as suPAR elevation may be an independent predictor of mortality in these conditions. In conclusion, among several biomarkers used for clinical entities with underlying inflammatory pathophysiology including cardiac diseases, suPAR is a novel attractive index for the prognostic risk stratification of cardiac patients. More research is warranted to confirm its diagnostic and prognostic validity, alone or combined with other cardiac and inflammatory biomarkers.

Platelet Activation In Situ in Breasts at High Risk of Cancer: Relationship with Mammographic Density and Estradiol

CONTEXT

High mammographic density in postmenopausal women is an independent risk factor for breast cancer by undetermined mechanisms. No preventive therapy for this risk group is available. Activated platelets release growth factors that modulate the microenvironment into a protumorigenic state. Estrogens may affect the risk of breast cancer and platelet function. Whether platelets are activated in situ in breast cancer or in normal breast tissue at high risk of breast cancer and the association to estradiol remains elusive.

OBJECTIVE

To investigate whether platelets are activated in situ in breast cancers and in dense breast tissue of postmenopausal women and explore correlations between estradiol, released platelet factors, and inflammatory proteins.

SETTING AND DESIGN

Sampling of in vivo proteins was performed using microdialysis in a total of 71 women: 10 with breast cancer, 42 healthy postmenopausal women with different breast densities, and 19 premenopausal women.

RESULTS

Our data demonstrate increased levels of coagulation factors in dense breast tissue similar to that found in breast cancers, indicating excessive platelet activation. Premenopausal breasts exhibited similar levels of coagulation factors as postmenopausal dense breasts. Out of 13 coagulations factors that were upregulated in dense breasts, 5 exhibited significant correlations with estradiol, both locally in the breast and systemically. In breast tissue, positive correlations between coagulation factors and key inflammatory proteins and matrix metalloproteinases were detected.

CONCLUSIONS

Breast density, not estradiol, is the major determinant of local platelet activation. Inactivation of platelets may be a therapeutic strategy for cancer prevention in postmenopausal women with dense breasts.

Sex- and age-related differences in the predictive capability of circulating biomarkers: from the MONICA 10 cohort

OBJECTIVES

The purpose of this study was to assess whether high-sensitivity C-reactive protein (hs-CRP), N-terminal pro-brain natriuretic peptide (NT-proBNP), and soluble urokinase plasminogen activator receptor (suPAR) differed in their ability to predict cardiovascular outcomes beyond traditional risk factors in younger and older men and women without known cardiovascular disease. Design. Prospective population-based cohort study of 1951 individuals from the MONItoring of trends and determinants in Cardiovascular disease (MONICA) study, examined 1993-1994. Participants were stratified into four groups based on sex and age. Subjects aged 41 or 51 years were classified as younger; those aged 61 or 71 years were classified as older. The principal endpoint was death from cardiovascular causes. Predictive capabilities of biomarkers were tested using Cox proportional-hazards regression, Harrell's concordance-index, net reclassification improvement, and classification and regression tree (CART) analysis. Results. Median follow-up was 18.5 years, during which 19/597 younger men, 100/380 older men, 12/607 younger women, and 46/367 older women had died from a cardiovascular cause. NT-proBNP was independently associated with death from cardiovascular causes among all participants (p ≤ .02) except younger women (p = .70), whereas hs-CRP was associated with this endpoint in men (p ≤ .007), and suPAR in older men only (p < .001). None of the biomarkers improved discrimination ability beyond traditional risk factors (p ≥ .07). However, NT-proBNP enhanced reclassification in men and older women. CART-analysis showed that NT-proBNP was generally of greater value among men, and suPAR among women. Conclusions. Hs-CRP, NT-proBNP, and suPAR displayed different associations with cardiovascular death among apparently healthy younger and older men and women.

Sex Differences in Circulating Soluble Urokinase-Type Plasminogen Activator Receptor (suPAR) Levels and Adverse Outcomes in Coronary Artery Disease

Background

Women have higher circulating levels of soluble urokinase‐type plasminogen activator receptor (suPAR), and elevated suPAR is associated with cardiovascular risk. The independent association of sex with suPAR and the impact of sex on its association with cardiovascular risk are unknown.

Methods and Results

Plasma suPAR was measured using ELISA in 2 cohorts of 666 asymptomatic individuals (49 years, 65% women) and 4184 patients with coronary artery disease (63 years, 37% women). Independent association of sex with suPAR was studied using linear regression models adjusted for demographics, risk factors, and visceral adiposity in asymptomatic participants. Impact of sex on association of suPAR with all‐cause mortality was studied in patients with coronary artery disease using multivariable‐adjusted Cox models. Sex‐specific suPAR cutoffs for predicting all‐cause mortality were calculated. Asymptomatic women had 10% higher suPAR compared with men after adjusting for confounders, and visceral adiposity partly accounted for this association. Over a median follow‐up of 5.2 years, 795 deaths were recorded in patients with coronary artery disease. Log₂‐transformed suPAR was independently associated with mortality (hazard ratio per 1‐SD 1.72, 95% CI 1.60–1.85) and an interaction with sex was noted (P=0.005). Association of suPAR with mortality was slightly weaker in women (hazard ratio 1.61, 95% CI 1.41–1.83) compared with men (hazard ratio 1.83, 95% CI 1.67–2.00). However, using sex‐specific suPAR cut‐offs (4392 pg/mL for women and 3187 pg/mL for men), a similar mortality incidence was observed for both sexes (38.5% and 35.5%, respectively, P=0.3).

Conclusions

Women have 10% higher plasma suPAR levels compared with men. Elevated sex‐specific plasma suPAR levels are equally predictive of risk of adverse events in both sexes.