Relationships Between Serum Cortisol, RAGE-Associated s100A8/A9 Levels, and Self-Reported Cancer-Related Distress in Women With Nonmetastatic Breast Cancer.

OBJECTIVE: Elevated inflammation and psychological distress in patients with breast cancer (BCa) have been related to poorer health outcomes. Regulation of the hypothalamic-pituitary-adrenal axis and signaling of the receptor for advanced glycation end products (RAGE) are important in the inflammatory response and have been associated with increased stress and poorer health outcomes in patients with cancer. This study examined relationships among circulating cortisol, a measure of hypothalamic-pituitary-adrenal axis activity and physiological stress; s100A8/A9, a RAGE ligand and emerging cancer-related biological measure; and self-reported cancer-related distress. METHODS: Patients with BCa ( N = 183, stages 0-IIIb) were recruited 2 to 10 weeks after surgery but before receiving adjuvant therapies. Participants provided blood samples, from which serum cortisol and s100A8/A9 levels were determined, and completed a psychosocial questionnaire. Regression analyses, adjusting for age, cancer stage, time since surgery, race, and menopausal status, were conducted examining the relationships between cortisol, s100A8/A9, and cancer-related distress (Impact of Event Scale [IES]-Revised). RESULTS: Cortisol and s100A8/A9 levels were positively related ( ß = 0.218, t (112) = 2.332, p = .021), although the overall model was not significant. Cortisol levels were also positively associated with IES-Intrusions ( ß = 0.192, t (163) = 2.659, p = .009) and IES-Hyperarousal subscale scores ( ß = 0.171, t (163) = 2.304, p = .022). CONCLUSIONS: Patients with higher cortisol levels also reported higher s100A8/A9 levels and more cancer-related distress. The relationship between cortisol and s100A8/A9 supports a link between the stress response and proinflammatory physiological processes known to predict a greater metastatic risk in BCa. Stress processes implicated in cancer biology are complex, and replication and extension of these initial findings are important.

Targeting RAGE Signaling in Inflammatory Disease.

The receptor for advanced glycation end-products (RAGE) is a multiligand pattern recognition receptor implicated in diverse chronic inflammatory states. RAGE binds and mediates the cellular response to a range of damage-associated molecular pattern molecules (DAMPs) including AGEs, HMGB1, S100s, and DNA. RAGE can also act as an innate immune sensor of microbial pathogen-associated molecular pattern molecules (PAMPs) including bacterial endotoxin, respiratory viruses, and microbial DNA. RAGE is expressed at low levels under normal physiology, but it is highly upregulated under chronic inflammation because of the accumulation of various RAGE ligands. Blocking RAGE signaling in cell and animal models has revealed that targeting RAGE impairs inflammation and progression of diabetic vascular complications, cardiovascular disease (CVD), and cancer progression and metastasis. The clinical relevance of RAGE in inflammatory disease is being demonstrated in emerging clinical trials of novel small-molecule RAGE inhibitors.

The effects of a randomized trial of brief forms of stress management on RAGE-associated S100A8/A9 in patients with breast cancer undergoing primary treatment.

BACKGROUND: Women with breast cancer (BCa) experience heightened distress, which is related to greater inflammation and poorer outcomes. The s100 protein family facilitates the inflammatory response by regulating myeloid cell function through the binding of Toll-like receptor 4 and the receptor for advanced glycation end products (RAGE). The heterodimer s100A8/A9 RAGE ligand is associated with hastened tumor development and metastasis. Previously, a 10-week stress-management intervention using cognitive behavioral therapy (CBT) and relaxation training (RT) was associated with less leukocyte inflammatory gene expression in patients with BCa; however, its impact on s100A8/A9 was not examined. Because a 10-week intervention may be impractical during primary treatment for BCa, the authors developed briefer forms of CBT and RT and demonstrated their efficacy in reducing distress over 12 months of primary treatment. Here, the effects of these briefer interventions were tested effects on s100A8/A9 levels over the initial 12 months of BCa treatment. METHODS: Postsurgical patients with BCa (stage 0-IIIB) were randomized to a 5-week, group-based condition: CBT, RT, or health education control (HE). At baseline and at 12 months, women provided sera from which s100A8/A9 levels were determined using any enzyme-linked immunosorbent assay. RESULTS: Participants (mean age ± standard deviation, 54.81 ± 9.63 years) who were assigned to either CBT (n = 41) or RT (n = 38) had significant s100A8/A9 decreases over 12 months compared with those who were assigned to HE (n = 44; F[1,114]  = 4.500; P = .036) controlling for age, stage, time since surgery, and receipt of chemotherapy or radiation. Greater increases in stress-management skills from preintervention to postintervention predicted greater reductions in s100A8/A9 levels over 12 months (ß = -0.379; t[101]  = -4.056; P < .001). CONCLUSIONS: Brief, postsurgical, group-based stress management reduces RAGE-associated s100A8/A9 ligand levels during primary treatment for BCa.

Regulation of Receptor for Advanced Glycation End Products (RAGE) Ectodomain Shedding and Its Role in Cell Function.

The receptor for advanced glycation end products (RAGE) is a multiligand transmembrane receptor that can undergo proteolysis at the cell surface to release a soluble ectodomain. Here we observed that ectodomain shedding of RAGE is critical for its role in regulating signaling and cellular function. Ectodomain shedding of both human and mouse RAGE was dependent on ADAM10 activity and induced with chemical activators of shedding (ionomycin, phorbol 12-myristate 13-acetate, and 4-aminophenylmercuric acetate) and endogenous stimuli (serum and RAGE ligands). Ectopic expression of the splice variant of RAGE (RAGE splice variant 4), which is resistant to ectodomain shedding, inhibited RAGE ligand dependent cell signaling, actin cytoskeleton reorganization, cell spreading, and cell migration. We found that blockade of RAGE ligand signaling with soluble RAGE or inhibitors of MAPK or PI3K blocked RAGE-dependent cell migration but did not affect RAGE splice variant 4 cell migration. We finally demonstrated that RAGE function is dependent on secretase activity as ADAM10 and γ-secretase inhibitors blocked RAGE ligand-mediated cell migration. Together, our data suggest that proteolysis of RAGE is critical to mediate signaling and cell function and may therefore emerge as a novel therapeutic target for RAGE-dependent disease states.

Subfractions of High-Density Lipoprotein-Cholesterol and Carotid Intima-Media Thickness: The Northern Manhattan Study.

BACKGROUND AND PURPOSE: Recent drug trials have challenged the high-density lipoprotein-cholesterol (HDL-C) antiatherosclerotic hypothesis, suggesting that total level of HDL-C may not be the best target for intervention. HDL-C subfractions may be better markers of vascular risk than total levels of HDL-C. The objective of this cross-sectional study was to investigate the relationship between HDL2-C and HDL3-C fractions and carotid intima-media thickness (cIMT) in the population-based Northern Manhattan Study. METHODS: We evaluated 988 stroke-free participants (mean age, 66±8 years; 60% women; 66% Hispanic, and 34% non-Hispanic) with available data on HDL-C subfractions using precipitation method and cIMT assessed by a high-resolution carotid ultrasound. The associations between HDL-C subfractions and cIMT were analyzed by multiple linear regression models. RESULTS: The mean HDL2-C was 14±8 mg/dL, HDL3-C 32±8 mg/dL, and the mean total HDL-C was 46±14 mg/dL. The mean cIMT was 0.90±0.08 mm. After controlling for demographics and vascular risk factors, HDL2-C and total HDL-C were inversely associated with cIMT (per 2 SDs, ß=-0.017, P=0.001 and ß=-0.012, P=0.03, respectively). The same inverse association was more pronounced among those with diabetes mellitus (per 2SDs, HDL2-C: ß=-0.043, P=0.003 and HDL-C: ß=-0.029, P=0.02). HDL3-C was not associated with cIMT. CONCLUSIONS: HDL2-C had greater effect on cIMT than HDL3-C in this large urban population. The effect of HDL2-C was especially pronounced among individuals with diabetes mellitus. More research is needed to determine antiatherosclerotic effects of HDL-C subfractions and their clinical relevance.

Fibroblast Growth Factor 23 Is Associated With Carotid Plaque Presence and Area: The Northern Manhattan Study.

OBJECTIVE: Elevated fibroblast growth factor 23 (FGF23), a hormone that regulates phosphate homeostasis, has been associated with mortality, cardiovascular events, and stroke, and to arterial calcification in chronic kidney disease, but its role in atherosclerosis is unclear and population-based studies are lacking. We hypothesized that elevated FGF23 would associate with carotid plaque presence, area, and echogenicity in the race/ethnically diverse community-based Northern Manhattan Study (NOMAS) sample. APPROACH AND RESULTS: There were 1512 stroke-free NOMAS participants with FGF23 and 2-dimensional carotid ultrasound data (mean age, 68±9 years; 61% women; 62% Hispanic, 18% black, and 18% white). We used multivariable linear and logistic regression to evaluate FGF23, continuously and by quintiles, as a correlate of carotid plaque, plaque area (cubic root transformed), and echogenicity adjusting for sociodemographic and vascular risk factors. Participants with FGF23 levels in the top quintile were more likely to have carotid plaque (odds ratio, 1.49; 95% confidence interval, 1.02-2.19; P=0.04) and larger plaque area (ß=0.32 mm(2), 95% confidence interval, 0.10-0.53 mm(2); P=0.004) than those in the lowest quintile, adjusting for estimated glomerular filtration rate, demographics, and vascular risk factors. Linear regression models also showed that log transformed FGF23 (LnFGF23) associated with greater odds of plaque presence (odds ratio, 1.26 per LnFGF23; 95% confidence interval, 1.01-1.58; P=0.04), and plaque area (ß=0.19 mm(2) per LnFGF23; 95% confidence interval, 0.07-0.31 mm(2); P=0.002). CONCLUSIONS: Higher FGF23 associated with greater likelihood and burden of carotid atherosclerosis independent of CKD. Atherosclerosis may be a mechanism through which FGF23 increases cardiovascular events and stroke.

A low-glucose eating pattern is associated with improvements in glycemic variability among women at risk for postmenopausal breast cancer: an exploratory analysis.

Background: High glycemic variability (GV) is a biomarker of cancer risk, even in the absence of diabetes. The emerging concept of chrononutrition suggests that modifying meal timing can favorably impact metabolic risk factors linked to diet-related chronic disease, including breast cancer. Here, we examined the potential of eating when glucose levels are near personalized fasting thresholds (low-glucose eating, LGE), a novel form of timed-eating, to reduce GV in women without diabetes, who are at risk for postmenopausal breast cancer. Methods: In this exploratory analysis of our 16-week weight loss randomized controlled trial, we included 17 non-Hispanic, white, postmenopausal women (average age = 60.7 ± 5.8 years, BMI = 34.5 ± 6.1 kg/m2, HbA1c = 5.7 ± 0.3%). Participants were those who, as part of the parent study, provided 3-7 days of blinded, continuous glucose monitoring data and image-assisted, timestamped food records at weeks 0 and 16. Pearson's correlation and multivariate regression were used to assess associations between LGE and GV, controlling for concurrent weight changes. Results: Increases in LGE were associated with multiple unfavorable measures of GV including reductions in CGM glucose mean, CONGA, LI, J-Index, HBGI, ADDR, and time spent in a severe GV pattern (r = -0.81 to -0.49; ps < 0.044) and with increases in favorable measures of GV including M-value and LBGI (r = 0.59, 0.62; ps < 0.013). These associations remained significant after adjusting for weight changes. Conclusion: Low-glucose eating is associated with improvements in glycemic variability, independent of concurrent weight reductions, suggesting it may be beneficial for GV-related disease prevention. Further research in a larger, more diverse sample with poor metabolic health is warranted.Clinical trial registration: ClinicalTrials.gov, NCT03546972.

RAGE inhibitor TTP488 (Azeliragon) suppresses metastasis in triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is a highly aggressive and metastatic cancer subtype, which is generally untreatable once it metastasizes. We hypothesized that interfering with the Receptor for Advanced Glycation End-products (RAGE) signaling with the small molecule RAGE inhibitors (TTP488/Azeliragon and FPS-ZM1) would impair TNBC metastasis and impair fundamental mechanisms underlying tumor progression and metastasis. Both TTP488 and FPS-ZM1 impaired spontaneous and experimental metastasis of TNBC models, with TTP488 reducing metastasis to a greater degree than FPS-ZM1. Transcriptomic analysis of primary xenograft tumor and metastatic tissue revealed high concordance in gene and protein changes with both drugs, with TTP488 showing greater potency against metastatic driver pathways. Phenotypic validation of transcriptomic analysis by functional cell assays revealed that RAGE inhibition impaired TNBC cell adhesion to multiple extracellular matrix proteins (including collagens, laminins, and fibronectin), migration, and invasion. Neither RAGE inhibitor impaired cellular viability, proliferation, or cell cycle in vitro. Proteomic analysis of serum from tumor-bearing mice revealed RAGE inhibition affected metastatic driver mechanisms, including multiple cytokines and growth factors. Further mechanistic studies by phospho-proteomic analysis of tumors revealed RAGE inhibition led to decreased signaling through critical BC metastatic driver mechanisms, including Pyk2, STAT3, and Akt. These results show that TTP488 impairs metastasis of TNBC and further clarifies the signaling and cellular mechanisms through which RAGE mediates metastasis. Importantly, as TTP488 displays a favorable safety profile in human studies, our study provides the rationale for evaluating TTP488 in clinical trials to treat or prevent metastatic TNBC.

RAGE binds C1q and enhances C1q-mediated phagocytosis.

RAGE, the multiligand receptor of the immunoglobulin superfamily of cell surface molecules, is implicated in innate and adaptive immunity. Complement component C1q serves roles in complement activation and antibody-independent opsonization. Using soluble forms of RAGE (sRAGE) and RAGE-expressing cells, we determined that RAGE is a native C1q globular domain receptor. Direct C1q-sRAGE interaction was demonstrated with surface plasmon resonance (SPR), with minimum K(d) 5.6 µM, and stronger binding affinity seen in ELISA-like experiments involving multivalent binding. Pull-down experiments suggested formation of a receptor complex of RAGE and Mac-1 to further enhance affinity for C1q. C1q induced U937 cell adhesion and phagocytosis was inhibited by antibodies to RAGE or Mac-1. These data link C1q and RAGE to the recruitment of leukocytes and phagocytosis of C1q-coated material.

Vascular and inflammatory stresses mediate atherosclerosis via RAGE and its ligands in apoE-/- mice.

Endothelial dysfunction is a key triggering event in atherosclerosis. Following the entry of lipoproteins into the vessel wall, their rapid modification results in the generation of advanced glycation endproduct epitopes and subsequent infiltration of inflammatory cells. These inflammatory cells release receptor for advanced glycation endproduct (RAGE) ligands, specifically S100/calgranulins and high-mobility group box 1, which sustain vascular injury. Here, we demonstrate critical roles for RAGE and its ligands in vascular inflammation, endothelial dysfunction, and atherosclerotic plaque development in a mouse model of atherosclerosis, apoE-/- mice. Experiments in primary aortic endothelial cells isolated from mice and in cultured human aortic endothelial cells revealed the central role of JNK signaling in transducing the impact of RAGE ligands on inflammation. These data highlight unifying mechanisms whereby endothelial RAGE and its ligands mediate vascular and inflammatory stresses that culminate in atherosclerosis in the vulnerable vessel wall.

Alternative splicing of the murine receptor for advanced glycation end-products (RAGE) gene.

The alternative splicing of pre-mRNAs is a critical mechanism in genomic complexity, disease, and development. Studies of the receptor for advanced glycation end-products (RAGE) indicate that this gene undergoes a variety of splice events in humans. However, no studies have extensively analyzed the tissue distribution in other species or compared evolutionary differences of RAGE isoforms. Because the majority of studies probing RAGE function have been performed in murine models, we therefore performed studies to identify and characterize the splice variants of the murine RAGE gene, and we compared these to human isoforms. Here, using mouse tissues, we identified numerous splice variants including changes in the extracellular domain or the removal of the transmembrane and cytoplasmic domains, which produce soluble splice isoforms. Comparison of splice variants between humans and mice revealed homologous regions in the RAGE gene that undergo splicing as well as key species-specific mechanisms of splicing. Further analysis of tissue splice variant distribution in mice revealed major differences between lung, kidney, heart, and brain. To probe the potential impact of disease-like pathological states, we studied diabetic mice and report that RAGE splice variation changed dramatically, resulting in an increase in production of soluble RAGE (sRAGE) splice variants, which were not associated with detectable levels of sRAGE in murine plasma. In conclusion, we have determined that the murine RAGE gene undergoes extensive splicing with distinct splice isoforms being uniquely distributed in different tissues. These differences in RAGE splicing in both physiological and pathogenic states further expand our understanding of the biological repertoire of this receptor in health and disease.

Kansuinine A and Kansuinine B from Euphorbia kansui L. inhibit IL-6-induced Stat3 activation.

The current study was performed to examine the mechanisms underlying the potential effects of E. KANSUI on IL-6-induced cellular signaling in human hepatoma cells. We found that two diterpenoids, kansuinine A and B, from E. KANSUI have an inhibitory effect on IL-6-induced Stat3 activation by activating ERK1/2. Inhibition of MEK significantly blocked the effects of kansuinine A and B on IL-6-induced Stat3 activation and tyrosine phosphorylation. These results suggest that blocking of IL-6-induced signal transduction is partially due to the sustained activation of ERK1/2 by kansuinine A and B, which in turn results in an increase of Stat3 serine phosphorylation and SOCS-3 expression. Treatment with kansuinine A and B represents a novel method to block these IL-6-induced effects.

Soluble receptor for advanced glycation end products: a new biomarker in diagnosis and prognosis of chronic inflammatory diseases.

The formation of advanced glycation end products (AGEs) is a result of the non-enzymatic reaction between sugars and free amino groups of proteins. AGEs, through interacting with their specific receptor for AGEs (RAGE), result in activation of pro-inflammatory states and are involved in numerous pathologic situations. The soluble form of RAGE (sRAGE) is able to act as a decoy to avoid interaction of RAGE with its pro-inflammatory ligands (AGEs, HMGB1, S100 proteins). sRAGE levels have been found to be decreased in chronic inflammatory diseases including atherosclerosis, diabetes, renal failure and the aging process. The use of measuring circulating sRAGEs may prove to be a valuable vascular biomarker and in this review, we describe the implications of sRAGE in inflammation and propose that this molecule may represent a future therapeutic target in chronic inflammatory diseases.

RAGE: a novel biological and genetic marker for vascular disease.

RAGE [receptor for AGEs (advanced glycation end-products)] plays an important role in the development and progression of vascular disease. Studies in cultured cells and small animal models of disease have clearly demonstrated that RAGE is central to the pathogenesis of vascular disease of the macro- and micro-vessels in both the diabetic and non-diabetic state. Emerging results from human clinical studies have revealed that levels of circulating soluble RAGE in the plasma may reflect the presence and/or extent of vascular disease state. Additionally, genetic variants of the RAGE gene (AGER in HUGO nomenclature) have been associated with vascular disease risk. Combining RAGE circulating protein levels and the presence of particular RAGE polymorphisms may be a useful clinical tool for the prediction of individuals at risk for vascular disease. Therapeutic intervention targeted at the RAGE gene may therefore be a useful means of treating pathologies of the vasculature.

Identification, classification, and expression of RAGE gene splice variants.

The receptor for advanced glycation end-products (RAGE) is a single-transmembrane, multiligand receptor of the immunoglobulin superfamily. RAGE up-regulation is implicated in numerous pathological states including vascular disease, diabetes, cancer, and neurodegeneration. The understanding of the regulation of RAGE is important in both disease pathogenesis and normal homeostasis. Here, we demonstrate the characterization and identification of human RAGE splice variants by analysis of RAGE cDNA from tissue and cells. We identified a vast range of splice forms that lead to changes in the protein coding region of RAGE, which we have classified according to the Human Gene Nomenclature Committee (HGNC). These resulted in protein changes in the ligand-binding domain of RAGE or the removal of the transmembrane domain and cytosolic tail. Analysis of splice variants for premature termination codons reveals approximately 50% of identified variants are targeted to the nonsense-mediated mRNA decay pathway. Expression analysis revealed the RAGE_v1 variant to be the primary secreted soluble isoform of RAGE. Taken together, identification of functional splice variants of RAGE underscores the biological diversity of the RAGE gene and will aid in the understanding of the gene in the normal and pathological state.

Percutaneous cell delivery into the heart using hydrogels polymerizing in situ.

Heart disease is the leading cause of death in the US. Following an acute myocardial infarction, a fibrous, noncontractile scar develops, and results in congestive heart failure in more than 500,000 patients in the US each year. Muscle regeneration and the induction of new vascular growth to treat ischemic disorders of the heart can have significant therapeutic implications. Early studies in patients with chronic ischemic systolic left ventricular dysfunction (SLVD) using skeletal myoblasts or bone marrow-derived cells report improvement in left ventricular ejection function (LVEF) and clinical status, without notable safety issues. Nonetheless, the efficacy of cell transfer for cardiovascular disease is not established, in part due to a lack of control over cell retention, survival, and function following delivery. We studied the use of biocompatible hydrogels polymerizable in situ as a cell delivery vehicle, to improve cell retention, survival, and function following delivery into the ischemic myocardium. The study was conducted using human bone marrow-derived mesenchymal stem cells and fibrin glue, but the methods are applicable to any human stem cells (adult or embryonic) and a wide range of hydrogels. We first evaluated the utility of several commercially available percutaneous catheters for delivery of viscous cell/hydrogel suspensions. Next we characterized the polymerization kinetics of fibrin glue solutions to define the ranges of concentrations compatible with catheter delivery. We then demonstrate the in vivo effectiveness of this preparation and its ability to increase cell retention and survival in a nude rat model of myocardial infarction.

RAGE ligand upregulation of VEGF secretion in ARPE-19 cells.

PURPOSE: The importance of VEGF in stimulating neovascular age-related macular degeneration (AMD) is well-recognized, but the initiating factors that induce local upregulation of VEGF remain unclear. The current study was conducted to test the hypothesis that activation of RAGE (receptor for advanced glycation end products [AGEs]) by its ligands, including AGEs, amyloid-beta peptide (Abeta), and S100B/calgranulins, some of which are known components of drusen and Bruch's membrane deposits, modulate secretion of VEGF by retinal pigment epithelial (RPE) cells. METHODS: ARPE-19 cells were used for all experiments. The cells were transfected with constructs encoding a signal transduction mutant of human RAGE to assess the RAGE-dependence of intracellular signaling. VEGF secretion and gene expression were assessed by ELISA and quantitative real-time PCR. SDS-PAGE and size exclusion chromatography were performed to analyze the structural changes of S100B after oxidation of its thiol groups under denaturing and nondenaturing conditions, respectively. NF-kappaB activation was assessed via electrophoretic mobility shift assay (EMSA). The impact of the NF-kappaB inhibition was assessed by using parthenolide. RESULTS: ARPE-19 cells basally secreted VEGF under normal cell culture conditions. Immobilized ligands of RAGE increased VEGF secretion in a RAGE-dependent manner. In contrast, soluble AGE-BSA, fresh Abeta, and S100B were less effective in increasing VEGF secretion. Studies with Abeta demonstrated that oligomeric and surface-immobilized forms of Abeta, but not soluble monomeric forms of Abeta, were effective upregulators of VEGF secretion via RAGE. Oxidation of S100B's thiol groups resulted in the formation of oligomers that displayed distinct RAGE biological activity compared with the simple dimeric form. RAGE-mediated upregulation of VEGF secretion by ARPE-19 cells was largely dependent on NF-kappaB, as indicated by studies with parthenolide. CONCLUSIONS: Immobilized or oligomerized ligands for RAGE induce RPE cells to increase VEGF secretion. NF-kappaB plays a central role in RAGE-dependent RPE secretion of VEGF. In AMD, activation of the RAGE axis in RPE cells may contribute to upregulation of VEGF, potentially inciting or propagating neovascular macular disease.

Associations of hyperglycemia and insulin resistance with biomarkers of endothelial dysfunction in Hispanic/Latino youths: Results from the Hispanic Community Children's Health Study/Study of Latino Youth (SOL Youth).

AIMS: We hypothesized that Hispanic/Latino youth at high risk for diabetes would have elevated biomarkers of endothelial dysfunction. METHODS: Among 1316 children 8-16years old from the Study of Latino Youth (SOL Youth), we used Poisson regression to obtain prevalence ratios (PRs) and 95% CIs for the cross-sectional association of quartiles of fasting glucose, HbA1c, and insulin resistance with E-selectin and plasminogen activator inhibitor-1 (PAI-1) levels above the median (≥48.1 and ≥2.02ng/mL, respectively). RESULTS: Levels of E-selectin and PAI-1 were higher in children who were obese or had higher levels of hs-CRP (p<0.05). Insulin resistance was independently associated with higher levels of PAI-1 (adjusted PR and 95% CI for the highest versus lowest quartile (Q4 vs Q1): 2.25 [1.64, 3.09]). We found stronger evidence of associations of insulin resistance with higher levels of PAI-1 among boys as compared with girls (p-interaction = 0.10). CONCLUSIONS: Insulin resistance was associated with endothelial dysfunction, as measured by higher levels of PAI-1, in Hispanic/Latino youth. These biomarkers may be useful in risk stratification and prediction of diabetes and cardiovascular disease in high-risk youth.