YKL-40 is elevated in patients with peripheral arterial disease and diabetes or pre-diabetes

YKL-40, cardiovascular events, and mortality in individuals recently diagnosed with type 2 diabetes: A Danish cohort study

AIMS

We investigated the association of the inflammatory biomarker YKL-40 with cardiovascular events (CVEs) and mortality in individuals with type 2 diabetes.

METHODS

We followed 11,346 individuals recently diagnosed with type 2 diabetes for up to 14 years. Baseline YKL-40 levels (measured in 9,010 individuals) were grouped into percentiles (0-33 %, 34-66 %, 67-90 %, and 91-100 %) and analyzed continuously (per 1 SD log increment), with comparisons to CRP (measured in 9,644 individuals). Cox regression assessed associations with atrial fibrillation (AF), ischemic stroke (IS), venous thromboembolism (VTE), myocardial infarction (MI), heart failure (HF), peripheral artery disease (PAD), and all-cause, cardiovascular, and cancer mortality.

RESULTS

Adjusted HRs (95% CIs) for the highest (91-100%) versus the lowest (0-33%) YKL-40 percentile category were 1.31 (1.04-1.66) for AF, 1.43 (0.98-2.07) for IS, 1.07 (0.65-1.76) VTE, 0.88 (0.52-1.48) for MI, 1.66 (1.19-2.31) for HF, 1.66 (1.12-2.48) for PAD, and 2.18 (1.85-2.56) for all-cause, 1.64 (1.07-2.50) for cardiovascular, and 2.73 (2.05-3.63) for cancer mortality. Each 1 SD log increase in YKL-40 and CRP levels similarly increased CVE risks, with CRP being superior for MI and cardiovascular mortality.

CONCLUSIONS

YKL-40 is a prognostic biomarker for most CVEs, and even more so for all-cause mortality, primarily driven by cancer-related causes.

Inflammatory Effects and Regulatory Mechanisms of Chitinase-3-like-1 in Multiple Human Body Systems: A Comprehensive Review

Chitinase-3-like-1 (Chi3l1), also known as YKL-40 or BRP-39, is a highly conserved mammalian chitinase with a chitin-binding ability but no chitinase enzymatic activity. Chi3l1 is secreted by various cell types and induced by several inflammatory cytokines. It can mediate a series of cell biological processes, such as proliferation, apoptosis, migration, differentiation, and polarization. Accumulating evidence has verified that Chi3l1 is involved in diverse inflammatory conditions; however, a systematic and comprehensive understanding of the roles and mechanisms of Chi3l1 in almost all human body system-related inflammatory diseases is still lacking. The human body consists of ten organ systems, which are combinations of multiple organs that perform one or more physiological functions. Abnormalities in these human systems can trigger a series of inflammatory environments, posing serious threats to the quality of life and lifespan of humans. Therefore, exploring novel and reliable biomarkers for these diseases is highly important, with Chi3l1 being one such parameter because of its physiological and pathophysiological roles in the development of multiple inflammatory diseases. Reportedly, Chi3l1 plays an important role in diagnosing and determining disease activity/severity/prognosis related to multiple human body system inflammation disorders. Additionally, many studies have revealed the influencing factors and regulatory mechanisms (e.g., the ERK and MAPK pathways) of Chi3l1 in these inflammatory conditions, identifying potential novel therapeutic targets for these diseases. In this review, we comprehensively summarize the potential roles and underlying mechanisms of Chi3l1 in inflammatory disorders of the respiratory, digestive, circulatory, nervous, urinary, endocrine, skeletal, muscular, and reproductive systems, which provides a more systematic understanding of Chi3l1 in multiple human body system-related inflammatory diseases. Moreover, this article summarizes potential therapeutic strategies for inflammatory diseases in these systems on the basis of the revealed roles and mechanisms mediated by Chi3l1.

Inhibition of Amyloid-β (Aβ)-Induced Cognitive Impairment and Neuroinflammation in CHI3L1 Knockout Mice through Downregulation of ERK-PTX3 Pathway

Several clinical studies reported that the elevated expression of Chitinase-3-like 1 (CHI3L1) was observed in patients suffering from a wide range of diseases: cancer, metabolic, and neurological diseases. However, the role of CHI3L1 in AD is still unclear. Our previous study demonstrated that 2-({3-[2-(1-Cyclohexen-1-yl)ethyl]-6,7-dimethoxy-4-oxo-3,4-dihydro-2-quinazolinyl}culfanyl)-N-(4-ethylphenyl)butanamide, a CHI3L1 inhibiting compound, alleviates memory and cognitive impairment and inhibits neuroinflammation in AD mouse models. In this study, we studied the detailed correlation of CHI3L1 and AD using serum from AD patients and using CHI3L1 knockout (KO) mice with Aβ infusion (300 pmol/day, 14 days). Serum levels of CHI3L1 were significantly elevated in patients with AD compared to normal subjects, and receiver operating characteristic (ROC) analysis data based on serum analysis suggested that CHI3L1 could be a significant diagnostic reference for AD. To reveal the role of CHI3L1 in AD, we investigated the CHI3L1 deficiency effect on memory impairment in Aβ-infused mice and microglial BV-2 cells. In CHI3L1 KO mice, Aβ infusion resulted in lower levels of memory dysfunction and neuroinflammation compared to that of WT mice. CHI3L1 deficiency selectively inhibited phosphorylation of ERK and IκB as well as inhibition of neuroinflammation-related factors in vivo and in vitro. On the other hand, treatment with recombinant CHI3L1 increased neuroinflammation-related factors and promoted phosphorylation of IκB except for ERK in vitro. Web-based gene network analysis and our results showed that CHI3L1 is closely correlated with PTX3. Moreover, in AD patients, we found that serum levels of PTX3 were correlated with serum levels of CHI3L1 by Spearman correlation analysis. These results suggest that CHI3L1 deficiency could inhibit AD development by blocking the ERK-dependent PTX3 pathway.

Transcriptomics analysis of long non-coding RNAs in smooth muscle cells from patients with peripheral artery disease and diabetes mellitus

Diabetes mellitus (DM) is a significant risk factor for peripheral arterial disease (PAD), and PAD is an independent predictor of cardiovascular disorders (CVDs). Growing evidence suggests that long non-coding RNAs (lncRNAs) significantly contribute to disease development and underlying complications, particularly affecting smooth muscle cells (SMCs). So far, no study has focused on transcriptome analysis of lncRNAs in PAD patients with and without DM. Tissue samples were obtained from our Vascular Biobank. Due to the sample's heterogeneity, expression analysis of lncRNAs in whole tissue detected only ACTA2-AS1 with a 4.9-fold increase in PAD patients with DM. In contrast, transcriptomics of SMCs revealed 28 lncRNAs significantly differentially expressed between PAD with and without DM (FDR < 0.1). Sixteen lncRNAs were of unknown function, six were described in cancer, one connected with macrophages polarisation, and four were associated with CVDs, mainly with SMC function and phenotypic switch (NEAT1, MIR100HG, HIF1A-AS3, and MRI29B2CHG). The enrichment analysis detected additional lncRNAs H19, CARMN, FTX, and MEG3 linked with DM. Our study revealed several lncRNAs in diabetic PAD patients associated with the physiological function of SMCs. These lncRNAs might serve as potential therapeutic targets to improve the function of SMCs within the diseased tissue and, thus, the clinical outcome.

Chitinase-3 like-protein-1, matrix metalloproteinase -9 and positive intracranial arterial remodelling

Introduction

Positive intracranial arterial remodelling is a dilated lesion of the large intracranial vessels; however, its pathogenesis is currently unknown. Some studies have identified chitinase-3 like-protein-1 (YKL-40) and matrix metalloproteinase (MMP)-9 as circulating inflammatory factors involved in positive vascular remodelling. Herein, we aimed to investigate the relationship between changes in serum YKL-40 and MMP-9 levels and positive intracranial arterial remodelling in patients with cerebral small vessel disease (CSVD).

Methods

A total of 110 patients with CSVD were selected. Patients with brain arterial remodelling (BAR) scores &gt;1 times the standard deviation were defined as the positive intracranial artery remodelling group (n = 21 cases), and those with BAR scores ≤1 times the standard deviation were defined as the non-positive intracranial artery remodelling group (n = 89 cases). Serum YKL-40 and MMP-9 levels were measured using an enzyme-linked immunosorbent assay kit. Factors influencing positive intracranial artery remodelling using binary logistic regression analysis and predictive value of YKL-40 and MMP-9 for positive intracranial arterial remodelling in patients with CSVD were assessed by a subject receiver operating characteristic curve.

Results

Statistically significant differences in serum YKL-40 and MMP-9 levels were observed between the positive and non-positive remodelling groups (p &lt; 0.05). The integrated indicator (OR = 9.410, 95% CI: 3.156 ~ 28.054, P&lt;0.01) of YKL-40 and MMP-9 levels were independent risk factors for positive intracranial arterial remodelling. The integrated indicator (OR = 3.763, 95% CI: 1.884 ~ 7.517, p &lt; 0.01) of YKL-40 and MMP-9 were independent risk factors for positive arterial remodelling in posterior circulation, but were not significantly associated with positive arterial remodelling in anterior circulation (p &gt; 0.05). The area under the curve for YKL-40 and MMP-9 diagnostic positive remodelling was 0.778 (95% CI: 0.692–0.865, p &lt; 0.01) and 0.736 (95% CI: 0.636–0.837, p &lt; 0.01), respectively.

Discussion

Elevated serum YKL-40 and MMP-9 levels are independent risk factors for positive intracranial arterial remodelling in patients with CSVD and may predict the presence of positive intracranial arterial remodelling, providing new ideas for the mechanism of its occurrence and development and the direction of treatment.

The Value of Serum YKL-40 and TNF-α in the Diagnosis of Acute ST-Segment Elevation Myocardial Infarction

Background

Acute ST-segment elevation myocardial infarction (STEMI) is a serious cardiovascular disease that poses a great threat to the life and health of patients. Therefore, early diagnosis is important for STEMI patient treatment and prognosis. The purpose of this study was to investigate the value of serum YKL-40 and TNF-α in the diagnosis of STEMI.

Methods

From October 2020 to February 2022, 120 patients with STEMI were admitted to the Chest Pain Center of the Second People's Hospital of Hefei, and 81 patients with negative coronary angiography were selected as the control group. Serum YKL-40 and TNF-α concentrations were measured by sandwich ELISA. Pearson correlation was used to analyze the correlation between serum YKL-40, TNF-α, and serum troponin I (cTnI) in STEMI patients; multivariate logistic regression analysis was used to screen independent risk factors for STEMI. Three diagnostic models were constructed: cTnI univariate model (model A), combined serum YKL-40 and TNF-α model other than cTnI (model B), and combined cTnI and serum YKL-40 and TNF-α model (model C). We assessed the clinical usefulness of the diagnostic model by comparing AUC with decision curve analysis (DCA).

Results

Serum YKL-40 and TNF-α in the STEMI group were significantly higher than those in the control group (P < 0.001). On Pearson correlation analysis, there was a significant positive correlation between serum YKL-40, TNF-α, and cTnI levels in STEMI patients. Multivariate logistic regression analysis showed that serum YKL-40 and TNF-α were independent risk factors for the development of STEMI. The results of ROC analysis showed that the area under the curve (AUC) of serum YKL-40 for predicting the occurrence of STEMI was 0.704. The AUC of serum TNF-α for predicting the occurrence of STEMI was 0.852. The AUC of cTnI as a traditional model, model A, for predicting the occurrence of STEMI was 0.875. Model B predicted STEMI with an AUC of 0.851. The addition of serum YKL-40 and serum TNF-α to the traditional diagnostic model composed of cTnI constituted a new diagnostic model; that is, the AUC of model C for predicting the occurrence of STEMI was 0.930. Model C had a better net benefit between a threshold probability of 70–95% for DCA.

Conclusion

In this study, we demonstrate the utility of serum YKL-40 and TNF-α as diagnostic markers for STEMI and the clinical utility of diagnostic models by combining serum YKL-40 and TNF-α with cTnI.

Expression-based Genome-wide Association Study Links OPN and IL1-RA With Newly Diagnosed Type 1 Diabetes in Children

CONTEXT

Islet autoantibodies (IAbs) are currently the most reliable indicators of islet autoimmunity. However, IAbs do not fully meet the need for the prediction and intervention of type 1 diabetes (T1D). Serological proteins should be great sources for biomarkers.

OBJECTIVE

This work aimed to identify new proteomic biomarkers with the technology of an expression-based genome-wide association study (eGWAS) in children newly diagnosed with T1D.

METHODS

In an attempt to identify additional biomarkers, we performed an eGWAS using microarray data from 169 arrays of the pancreatic islets of T1D rodents (78 T1D cases and 91 controls). We ranked all 16 099 protein-coding genes by the likelihood of differential expression in the pancreatic islets. Our top 20 secreted proteins were screened in 170 children including 100 newly diagnosed T1D, and 50 type 2 diabetes (T2D) and 20 age-matched healthy children. With 6 proteins showing significance, we further conducted a validation study using the second independent set of 400 samples from children including 200 newly diagnosed with T1D, 100 T2D, and 100 age-matched controls.

RESULTS

We identified 2 serum proteins that were significantly changed in T1D vs both control and T2D, and 5 serum proteins were significantly changed both in T1D and T2D vs control. Serum osteopontin (OPN) levels were uniquely higher in T1D (T1D vs controls, P = 1.29E-13 ~ 9.38E-7, T1D vs T2D, P = 2.65E-8 ~ 1.58E-7) with no difference between T2D and healthy control individuals. Serum interleukin 1 receptor antagonist (IL-1RA) levels were lower in T1D compared both with T2D (P = 3.36E-9~0.0236) and healthy participants (P = 1.09E-79 ~ 2.00E-12).

CONCLUSION

Our results suggest that OPN and IL1-RA could be candidates for useful biomarkers for T1D in children.

Identification of Key Genes and Pathways in Peripheral Blood Mononuclear Cells of Type 1 Diabetes Mellitus by Integrated Bioinformatics Analysis

BACKGROUND

The onset and progression of type 1 diabetes mellitus (T1DM) is closely related to autoimmunity. Effective monitoring of the immune system and developing targeted therapies are frontier fields in T1DM treatment. Currently, the most available tissue that reflects the immune system is peripheral blood mononuclear cells (PBMCs). Thus, the aim of this study was to identify key PBMC biomarkers of T1DM.

METHODS

Common differentially expressed genes (DEGs) were screened from the Gene Expression Omnibus (GEO) datasets GSE9006, GSE72377, and GSE55098, and PBMC mRNA expression in T1DM patients was compared with that in healthy participants by GEO2R. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and protein-protein interaction (PPI) network analyses of DEGs were performed using the Cytoscape, DAVID, and STRING databases. The vital hub genes were validated by reverse transcription-polymerase chain reaction using clinical samples. The disease-gene-drug interaction network was built using the Comparative Toxicogenomics Database (CTD) and Drug Gene Interaction Database (DGIdb).

RESULTS

We found that various biological functions or pathways related to the immune system and glucose metabolism changed in PBMCs from T1DM patients. In the PPI network, the DEGs of module 1 were significantly enriched in processes including inflammatory and immune responses and in pathways of proteoglycans in cancer. Moreover, we focused on four vital hub genes, namely, chitinase-3-like protein 1 (CHI3L1), C-X-C motif chemokine ligand 1 (CXCL1), matrix metallopeptidase 9 (MMP9), and granzyme B (GZMB), and confirmed them in clinical PBMC samples. Furthermore, the disease-gene-drug interaction network revealed the potential of key genes as reference markers in T1DM.

CONCLUSION

These results provide new insight into T1DM pathogenesis and novel biomarkers that could be widely representative reference indicators or potential therapeutic targets for clinical applications.

Relationships between increased circulating YKL-40, IL-6 and TNF-α levels and phenotypes and disease activity of primary Sjögren's syndrome

BACKGROUND

There is now no single score or marker useful for evaluating disease activity of primary Sjögren's syndrome (pSS). This study was designed to explore the associations of circulating YKL-40, interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) with systemic activity and phenotypes of pSS.

METHODS

This study included 58 pSS patients and 30 healthy controls (HC). The sera were measured by multiplex immunoassay for YKL-40, IL-6 and TNF-α concentrations. The disease activity of pSS patients was evaluated by European league against rheumatism (EULAR) SS disease activity index (ESSDAI). Local severity was assessed in accordance with the Tarpley score.

RESULTS

Serum YKL-40, IL-6 and TNF-α levels significantly elevated in pSS patients compared with those in HC (all P < 0.001). These cytokines correlated with ESSDAI, ESR, CRP, and IgG (all P < 0.05). Serum YKL-40 level correlated markedly with age (r = 0.405, P = 0.002), neutrophil count (r = 0.399, P = 0.002) and neutrophil-to-lymphocyte ratio (NLR) (r = 0.401, P = 0.002), while IL-6 did weakly with NLR (r = 0.296, P = 0.024) and C3 (r = 0.288, 0.036). Serum levels of all three cytokines were substantially lower in patients with eye/mouth dryness vs. those without (all P < 0.05). Additionally, patients with pulmonary, renal involvement or anemia had remarkably higher concentrations of YKL-40 (all P < 0.05), while those with leukocytopenia had lower levels (P = 0.01). Fever or anemia patients showed higher serum concentrations of IL-6 (both P < 0.05), while serum levels of TNF-α were much higher in patients with presence of ANA, anti-SSA or anti-SSB antibodies (All P < 0.05). Serum IL-6 level correlated strongly with YKL-40 (r = 0.452, P < 0.001) and TNF-α (r = 0.743, P < 0.001) in pSS patients. A significant correlation was also found between YKL-40 and TNF-α (r = 0.308, P = 0.022) .

CONCLUSION

The circulating YKL-40, IL-6 and TNF-α levels increase in pSS, and all of them are significantly correlated with indicators (ESSDAI, ESR, CRP, and IgG) for systemic inflammation of pSS. Each cytokine is separately associated with specific pSS phenotype.

Lower extremity artery disease in patients with type 2 diabetes

Among all peripheral arterial diseases, lower extremity arterial disease is a serious condition in subjects with type 2 diabetes mellitus, associated with important disability, cardiovascular risk, and socio-economic burden. Patients with both conditions generally display poorer prognosis of affected limbs compared with non-diabetic subjects, leading to increased rates of adverse limb events including amputations. Nonetheless, awareness on lower extremity arterial disease remains somehow suboptimal in the diabetic population, partly related to an atypical clinical presentation in several cases. A regular and appropriate screening for lower extremity arterial disease in patients suffering from type 2 diabetes mellitus is therefore recommended. Affected subjects should receive optimal medical treatment including careful management of the different cardiovascular risk factors through a healthy lifestyle, a regular and structured physical activity, the administration of lipid-lowering, antidiabetic drugs, and (when indicated) antihypertensive and antithrombotic drugs. This review aims to outline current evidence about lower extremity arterial disease in patients with type 2 diabetes mellitus, in order to elucidate its epidemiology, pathophysiology, screening and diagnosis, and management options.

Chitinase-3 like-protein-1 function and its role in diseases

Non-enzymatic chitinase-3 like-protein-1 (CHI3L1) belongs to glycoside hydrolase family 18. It binds to chitin, heparin, and hyaluronic acid, and is regulated by extracellular matrix changes, cytokines, growth factors, drugs, and stress. CHI3L1 is synthesized and secreted by a multitude of cells including macrophages, neutrophils, synoviocytes, chondrocytes, fibroblast-like cells, smooth muscle cells, and tumor cells. It plays a major role in tissue injury, inflammation, tissue repair, and remodeling responses. CHI3L1 has been strongly associated with diseases including asthma, arthritis, sepsis, diabetes, liver fibrosis, and coronary artery disease. Moreover, following its initial identification in the culture supernatant of the MG63 osteosarcoma cell line, CHI3L1 has been shown to be overexpressed in a wealth of both human cancers and animal tumor models. To date, interleukin-13 receptor subunit alpha-2, transmembrane protein 219, galectin-3, chemo-attractant receptor-homologous 2, and CD44 have been identified as CHI3L1 receptors. CHI3L1 signaling plays a critical role in cancer cell growth, proliferation, invasion, metastasis, angiogenesis, activation of tumor-associated macrophages, and Th2 polarization of CD4⁺ T cells. Interestingly, CHI3L1-based targeted therapy has been increasingly applied to the treatment of tumors including glioma and colon cancer as well as rheumatoid arthritis. This review summarizes the potential roles and mechanisms of CHI3L1 in oncogenesis and disease pathogenesis, then posits investigational strategies for targeted therapies.

Predictive power of novel and established obesity indices for outcome in PAD during a five-year follow-up

BACKGROUND AND AIMS

Previous data show contradicting results regarding relevance of obesity on outcome in peripheral arterial disease (PAD). Thus, this study aims to evaluate the predictive power of obesity as measured by established and novel obesity indices (waist circumference WC, waist-hip ratio WHR, body-mass index BMI, body adiposity index BAI, visceral adiposity index VAI, weight-adjusted waist index WWI) in a PAD cohort.

METHODS AND RESULTS

In 367 patients with diagnosed PAD anthropometric parameters were assessed at study inclusion in an observational study. Mortality data was retrieved from the central death registry after five years. Outcome analyses were performed by multivariable Cox-regression models. 57 PAD patients (15.5%) died during the follow-up, of those 36 were categorized as cardiovascular origin. Patients from the all-cause mortality group were older, more often diabetics with a worse glucose control and had worse renal function. Obesity indices were not significantly different between the event and control group. None of the evaluated risk factors predicted cardiovascular or all-cause death after multivariable adjustment for age, gender, LDL-C, serum creatinine, systolic blood pressure, CRP, smoking habits, diabetes status and previous history of peripheral revascularisation (all-cause WC 1.007 (0.983-1.031), WHR 1.772 (0.106-29.595), BMI 1.006 (0.939-1.078), BAI 1.002 (0.945-1.063), VAI 1.019 (0.895-1.161), WWI 1.085 (0.831-1.416); cv-death WC 1.007 (0.978-1.036), WHR 0.382 (0.006-25.338), BMI 1.004 (0.918-1.098), BAI 1.034 (0.959-1.116), VAI 1.036 (0.885-1.213), WWI 1.061 (0.782-1.441)).

CONCLUSION

Obesity as risk marker estimated by indices both for general and visceral adiposity, does not predict mortality in a secondary prevention cohort of PAD patients.

Effects of vitamin D supplementation on circulatory YKL-40 and MCP-1 biomarkers associated with vascular diabetic complications: A randomized, placebo-controlled, double-blind clinical trial

AIM

Diabetic patients predispose to vascular diseases such as nephropathy, and retinopathy. Poor adherence to medical treatment and dietary recommendations in uncontrolled diabetes leads to vascular damages. Vitamin D has been extensively studied and found to be protective against diabetes mellitus. YKL-40 and Monocyte chemoattractant protein-1 (MCP-1) are considered to exert crucial role in diabetes and its complications. Therefore, this study was designed to investigate effects of vitamin D supplementation on serum levels of YKL-40 and MCP-1 involved in the development of diabetic complications.

METHODS

For 12 weeks, 48 type 2 diabetic patients enrolled in the trial and randomly were divided into two groups (n = 24 per group), receiving one of the following: 100 μg (4000 IU) vitamin D or placebo. Before and after intervention, serumYKL-40, MCP-1, insulin, IL-6, TNF-α, 25- (OH) vitamin D and HbA1c were measured.

RESULTS

Our results revealed that serum levels of 25 (OH) vitamin D significantly increased in vitamin D group (p < 0.001). Vitamin D supplementation also significantly reduced serum YKL-40 levels (-22.7 vs. -2.4 ng/ml; (p-value = 0.003)). There was a significant decline in MCP-1 concentration in intervention group at the end of the study (-45.7 vs. -0.9 pg/ml; (p = 0.001)). Furthermore, there was a significant decrease in IL-6, fasting insulin and HOMA-IR in intervention group after 3 months supplementation.

CONCLUSIONS

Daily vitamin D supplementation effectively reduced circulatory YKL-40 and MCP-1 levels in patients with type-2 diabetes and vitamin D deficiency. Vitamin D might contribute in reducing diabetic complications via modulating YKL-40 and MCP-1 signaling pathways.

An association between YKL-40 and type 2 diabetes in psychotic disorders

OBJECTIVE

This study examines if YKL-40 is increased in individuals with psychotic disorders and if elevated YKL-40 levels at baseline is associated with subsequent development of type 2 diabetes.

METHOD

A total of 1383 patients with a diagnosis of schizophrenia or affective psychosis and 799 healthy controls were recruited in the period 2002-2015. Plasma YKL-40 and metabolic risk factors were measured and medication was recorded. Using national registry data, association between baseline risk factors and later development of type 2 diabetes was assessed using Cox proportional hazards models.

RESULTS

Plasma YKL-40 was higher in patients vs. healthy controls also after adjusting for metabolic risk factors, with no difference between the schizophrenia and affective psychosis groups. Patients were diagnosed with type 2 diabetes at a significantly younger age. Multivariate Cox regression analyses showed that elevated YKL-40 (hazard ratio (HR) = 5.6, P = 0.001), elevated glucose (HR = 3.6, P = 0.001), and schizophrenia diagnosis (HR = 3.0, P = 0.014) at baseline were associated with subsequent development of type 2 diabetes.

CONCLUSIONS

Patients with psychotic disorders have at baseline increased levels of YKL-40 beyond the effect of comorbid type 2 diabetes and metabolic risk factors. Elevated YKL-40 level at baseline is associated with later development of type 2 diabetes.

YKL-40 levels increase with declining ankle-brachial index and are associated with long-term cardiovascular mortality in peripheral arterial disease patients

BACKGROUND AND AIMS

YKL-40 is an inflammatory marker secreted by macrophages and is expressed in atherosclerotic plaques. YKL-40 increases in coronary artery disease (CAD) with poor coronary collateral vessel development. Higher levels are linked to reduced survival in CAD patients. Studies evaluating YKL-40 in patients with peripheral arterial disease (PAD) are scarce. This study aims to elucidate a possible link between YKL-40 and PAD severity as well as cardiovascular long-term mortality.

METHODS

YKL-40 was measured at baseline in 365 elderly PAD patients (age 69 ± 10.4, 33.7% women, Fontaine stage I-II) by bead-based multiplex assay. Patients were followed for seven years to assess long-term cardiovascular and all-cause survival by Kaplan-Meier and Cox regression.

RESULTS

YKL-40 levels were associated with declining ankle-brachial index (ABI) in PAD patients without Moenckeberg's mediasclerosis (R = -0.189, p=0.002). PAD patients with mediasclerosis exhibited higher YKL-40 levels (p=0.002). Baseline YKL-40 levels were significantly associated with cardiovascular mortality (HR 1.52 (1.21-1.91), p < 0.001) and all-cause mortality (HR 1.45 (1.20-1.75), p < 0.001) over a seven-year observation period. After multivariable adjustment for gender, patient age, known carotid artery disease, known coronary artery disease, smoking status, systolic blood pressure, HbA_1c, low density lipoprotein cholesterol, estimated glomerular filtration rate, aspartate aminotransferase, and C-reactive protein, YKL-40 remained significantly associated with cardiovascular (HR 1.34 (1.02-1.75), p=0.033) and all-cause mortality (HR 1.25 (1.01-1.55), p=0.039).

CONCLUSIONS

Increased YKL-40 levels are independently associated with poor long-term cardiovascular survival in peripheral arterial disease patients. Furthermore, YKL-40 correlates with patients' ABI in PAD in the absence of mediasclerosis.

Insulin treatment corrects hepcidin but not YKL-40 levels in persons with type 2 diabetes mellitus matched by body mass index, waist-to-height ratio, C-reactive protein and Creatinine

BACKGROUND

It has been shown that hepcidin and YKL-40 levels change in persons with insulin resistance in different circumstances. However, variations of the levels of these parameters through the stages of prediabetes and type 2 diabetes mellitus are unclear. We hypothesized that hepcidin levels will decrease in persons with prediabetes, while these levels will tend to correct when persons with diabetes are treated with insulin. Finally we sought to determine the levels of YKL-40 in all groups of participants included in the study.

METHODS

Serum hepcidin levels and YKL-40 levels were measured in control group (n = 20), persons with prediabetes (n = 30) and persons with diabetes on insulin therapy (n = 30) using ELISA method. Patients in all three groups were matched by Body Mass Index, Waist-to-Height Ratio, C-Reactive Protein and creatinine levels.

RESULTS

Hepcidin levels were lower in persons with prediabetes compared to control, while persons with diabetes on insulin therapy had higher values than those with prediabetes (p = 0,00001). YKL-40 levels showed no significant changes.

CONCLUSIONS

Serum hepcidin levels in matched persons with prediabetes are a stronger marker of early changes in glucose metabolism compared to YKL-40 levels. Also, treatment with insulin corrects hepcidin levels, but not YKL-40 levels. Correcting levels of hepcidin is important for reducing iron-overload, which is a risk factor for diabetes.

Crossroads between peripheral atherosclerosis, western-type diet and skeletal muscle pathophysiology: emphasis on apolipoprotein E deficiency and peripheral arterial disease

Atherosclerosis is a chronic inflammatory process that, in the presence of hyperlipidaemia, promotes the formation of atheromatous plaques in large vessels of the cardiovascular system. It also affects peripheral arteries with major implications for a number of other non-vascular tissues such as the skeletal muscle, the liver and the kidney. The aim of this review is to critically discuss and assimilate current knowledge on the impact of peripheral atherosclerosis and its implications on skeletal muscle homeostasis. Accumulating data suggests that manifestations of peripheral atherosclerosis in skeletal muscle originates in a combination of increased i)-oxidative stress, ii)-inflammation, iii)-mitochondrial deficits, iv)-altered myofibre morphology and fibrosis, v)-chronic ischemia followed by impaired oxygen supply, vi)-reduced capillary density, vii)- proteolysis and viii)-apoptosis. These structural, biochemical and pathophysiological alterations impact on skeletal muscle metabolic and physiologic homeostasis and its capacity to generate force, which further affects the individual's quality of life. Particular emphasis is given on two major areas representing basic and applied science respectively: a)-the abundant evidence from a well-recognised atherogenic model; the Apolipoprotein E deficient mouse and the role of a western-type diet and b)-on skeletal myopathy and oxidative stress-induced myofibre damage from human studies on peripheral arterial disease. A significant source of reactive oxygen species production and oxidative stress in cardiovascular disease is the family of NADPH oxidases that contribute to several pathologies. Finally, strategies targeting NADPH oxidases in skeletal muscle in an attempt to attenuate cellular oxidative stress are highlighted, providing a better understanding of the crossroads between peripheral atherosclerosis and skeletal muscle pathophysiology.

Pathophysiology of peripheral arterial disease in diabetes mellitus

Peripheral arterial disease (PAD) increases the risk of lower extremity amputation. It is also an independent predictor of cardiovascular and cerebrovascular ischemic events, affecting both the quality and expectancy of life. Many studies have demonstrated that the prevalence of PAD in patients with diabetes mellitus (DM) is higher than in non-diabetic patients. In diabetic patients, PAD occurs early with rapid progression, and is frequently asymptomatic. Multiple metabolic aberrations in DM, such as advanced glycation end-products, low-density lipoprotein cholesterol, and abnormal oxidative stress, have been shown to worsen PAD. However, the role of DM in PAD is not completely understood. The purpose of the present article is to review and discuss the pathophysiology of PAD in DM.

High serum YKL-40 level positively correlates with coronary artery disease

AIM

We investigated the predictive value of chitinase-like protein YKL-40 in coronary artery disease (CAD).

PATIENTS

Serum YKL-40 levels in 116 CAD patients and 82 healthy controls were analyzed. Severity of CAD was evaluated using Gensini scores. Spearman's correlation was used to evaluate the correlation between Gensini scores and YKL-40 levels. The predictive value of YKL-40 was determined by receivers operating characteristic curve analysis.

RESULTS

Serum YKL-40 levels were significantly elevated in CAD group as compared with control group. A positive correlation was found between the serum YKL-40 level and Gensini score. The optimum cut-off value of YKL-40 concentration was 127.7 ng/ml for distinguishing CAD patients from healthy controls with a 75.9% sensitivity and 57.3% specificity.

CONCLUSION

A positive correlation exists between YKL-40 levels and CAD, and YKL-40 might be a useful adjunct in the diagnosis of CAD.

Serum YKL-40 and gestational diabetes - an observational cohort study

To examine serum YKL-40 in women developing gestational diabetes mellitus (GDM). In the present large observational cohort study of 1179 pregnant women, we determined serum YKL-40 four times during pregnancy (at gestational age 12, 20, 25, and 32 weeks). Pregnancy outcome was obtained from medical records. Sixty-eight women (5.8%) developed GDM. Serum YKL-40 increased from gestational age (GA) 12 weeks and the following weeks in the women who developed GDM and was independent of BMI, parity, and maternal age (OR = 2.69, 95% CI: 1.45-5.00, p = 0.002). No association was found between serum YKL-40 and the oral glucose tolerance test results. In conclusion, YKL-40 significantly increased in pregnant women with GDM compared with women without GDM, probably reflecting the low-grade inflammation of GDM. However, we did not find an association between serum concentrations of YKL-40 in early pregnancy and the development of GDM and thus we conclude that YKL-40 alone is not usable as a biomarker for early prediction of GDM.

Increased serum YKL-40 level is associated with the presence and severity of metabolic syndrome

Objective:

Metabolic syndrome (MS) is defined by a cluster of interdependent physiological, biochemical, and clinical risk factors and linked to a state of chronic inflammation. YKL-40 is known as an inflammatory glycoprotein, which is secreted by various cell lines during inflammation. Thus, we aimed to assess the association of serum YKL-40 levels with the presence and severity of MS.

Methods:

In this prospective cross-sectional study, a total of 177 consecutive patients [n=114 MS present and n=63 MS absent] were enrolled. MS was defined according to National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) criteria. Serum YKL-40 and hs-CRP levels were measured for all participants.

Results:

Serum YKL-40, hs-CRP and white blood cell count (WBC) were significantly higher in the MS present group (p<0.05). There was a graded relationship between increasing number of MS components and serum YKL-40 level (p<0.05). In addition, serum YKL-40 level was positively correlated with hs-CRP level (r=0.467, p<0.001) and WBC count (r=0.251, p=0.001). In multivariable regression analysis, serum YKL-40 [1.022 (1.011–1.033), p<0.001] and hs-CRP [1.346 (1.111–1.632), p=0.002] were remained as independent predictors for the presence of MS. In the ROC curve analysis, using a cut-off level of 147.0, YKL-40 well predicted the presence of MS with a sensitivity of 73.7% and specificity of 69.8% (AUC: 0.785; 95% CI: 0.718–0.853, p<0.001).

Conclusion:

In this study, we demonstrated that serum YKL-40 level was significantly associated with the presence of MS. According to these findings, we concluded that serum YKL-40 may be a novel and useful indicator for MS. (Anatol J Cardiol 2016; 16: 953-8)

Chitinase 3 Like-1: An Emerging Molecule Involved in Diabetes and Diabetic Complications

Chitinase 3 like-1 (CHI3L1) is a chitinase-like protein member of family 18 chitinases, expressed in innate immune cells and involved in endothelial dysfunction and tissue remodelling. Since CHI3L1 is highly expressed in a variety of inflammatory diseases of infectious and non-infectious aetiology, it is recognised as a non-invasive prognostic biomarker for inflammation. A variety of studies revealing the increase in CHI3L1 levels in obesity, insulin resistance and in pathological conditions, such as atherosclerosis, coronary artery disease, acute ischaemic stroke, nephropathy, diabetic retinopathy and osteolytic processes, have suggested that CHI3L1 may also play a critical role in the evolution and complication of diabetes mellitus (DM). In this review we highlight the impact of CHI3L1 expression in DM and its contribution to the complication of this disease.

Levels of the inflammation marker YKL-40 in young adults exposed to intrauterine hyperglycemia

Plasma levels of the inflammatory marker YKL-40 were investigated in 597 adult offspring born to women with and without diabetes during pregnancy. No association between fetal exposure to maternal hyperglycemia and levels of YKL-40 was found. However, female sex and increasing BMI in the offspring were associated to YKL-40.

Perspectives for Monocyte/Macrophage-Based Diagnostics of Chronic Inflammation

Low-grade chronic inflammation underlies the development of the most dangerous cardiometabolic disorders including type 2 diabetes and its vascular complications. In contrast to acute inflammation induced by bacteria and viruses, chronic inflammation can be driven by abnormal reaction to endogenous factors, including Th2 cytokines, metabolic factors like advanced glycation end products (AGEs), modified lipoproteins, or hyperglycemia. The key innate immune cells that recognize these factors in blood circulation are monocytes. Inflammatory programming of monocytes which migrate into tissues can, in turn, result into generation of tissue macrophages with pathological functions. Therefore, determination of the molecular and functional phenotype of circulating monocytes is a very promising diagnostic tool for the identification of hidden inflammation, which can precede the development of the pathology. Here we propose a new test system for the identification of inflammatory programming of monocytes: surface biomarkers and ex vivo functional system. We summarize the current knowledge about surface biomarkers for monocyte subsets, including CD16, CCR2, CX3CR1, CD64, stabilin-1 and CD36, and their association with inflammatory human disorders. Furthermore, we present the design of an ex vivo monocyte-based test system with minimal set of parameters as a potential diagnostic tool for the identification of personalized inflammatory responses.

Relationship of YKL-40 and adiponectin and subclinical atherosclerosis in asymptomatic patients with type 1 diabetes mellitus from a European Mediterranean population

Background

The glycoprotein YKL-40 is a new marker of early inflammation and endothelial dysfunction. Adiponectin is a collagen-like protein with anti-atherogenic and anti-inflammatory effects. Increased concentrations of both markers have been reported in patients with type 1 diabetes (T1D).

Aim

To assess the possible role of YKL-40 and adiponectin as a marker of subclinical cardiovascular disease in asymptomatic patients with type 1 diabetes with no history of ischemic or macrovascular heart disease and its relationship with other classic inflammatory biomarkers.

Methods

Concentrations of YKL-40, adiponectin, IL-6, IL-1β, TNF- α, hsCRP and homocysteine were determined in 150 T1D patients (58 % men, age: 38.6 ± 8.1 years, 20.4 ± 8.1 years of evolution, BMI: 25.1 ± 3.6 kg/m²; HbA_1c 8.1 ± 2.3 %, 48 % smokers; 26 % retinopathy, microalbuminuria 9 %) and 50 controls age, sex and smoke condition matched. Subclinical atherosclerosis was assessed by a carotid ultrasonography and a computed tomography for evaluation of calcium artery calcification score (CACS).

Results

82 % of T1D patients and 92 % of controls had a calcium score of 0. T1D patients showed a significantly higher mean common carotid artery intima media thickness (CIMT) compared to controls (0.55 ± 0.14 vs 0.48 ± 0.14 mm, p = 0.01). Concentrations of YKL-40 and adiponectin were significantly higher in T1D [42.6 (10.4–195.0) vs ±28.7 (11.0–51.2) ng/ml, p = 0.001 and 15.8 ± 9.1 vs. 12.4 ± 5.3 mg/ml, p = 0.008], with no differences when compared to other inflammatory parameters. In T1D patients no association was found between YKL-40 and adiponectin and screening test for subclinical arterial disease (neither CACS nor CIMT). A positive correlation was found between levels of YKL-40 and age and duration of disease (r = 0.28, p = 0.003; r = 0.35, p = 0.001). There were no differences in the YKL-40 in relation to the presence or absence of retinopathy or nephropathy. Levels of adiponectin were higher in patients with nephropathy (21.84 ± 8.15 vs. 14.88 ± 8.27 mg/ml, p = 0.008).

Conclusions

Type 1 diabetes patients from a Mediterranean area with a longer disease evolution, although a lower degree of subclinical disease, showed significatively higher concentrations of YKL-40 and adiponectin compared with the controls. Therefore, we conclude that YKL-40 and adiponectin are early inflammatory markers in diabetic subjects even in the presence of a low atherosclerotic background.

A review of the pathophysiology and potential biomarkers for peripheral artery disease

Peripheral artery disease (PAD) is due to the blockage of the arteries supplying blood to the lower limbs usually secondary to atherosclerosis. The most severe clinical manifestation of PAD is critical limb ischemia (CLI), which is associated with a risk of limb loss and mortality due to cardiovascular events. Currently CLI is mainly treated by surgical or endovascular revascularization, with few other treatments in routine clinical practice. There are a number of problems with current PAD management strategies, such as the difficulty in selecting the appropriate treatments for individual patients. Many patients undergo repeated attempts at revascularization surgery, but ultimately require an amputation. There is great interest in developing new methods to identify patients who are unlikely to benefit from revascularization and to improve management of patients unsuitable for surgery. Circulating biomarkers that predict the progression of PAD and the response to therapies could assist in the management of patients. This review provides an overview of the pathophysiology of PAD and examines the association between circulating biomarkers and PAD presence, severity and prognosis. While some currently identified circulating markers show promise, further larger studies focused on the clinical value of the biomarkers over existing risk predictors are needed.

Circulating YKL-40 level, but not CHI3L1 gene variants, is associated with atherosclerosis-related quantitative traits and the risk of peripheral artery disease

YKL-40, a pleotropic cytokine, is emerging as a risk factor and a prognostic predictor of atherosclerotic cardiovascular disease. We attempted to elucidate the genetic, clinical and biochemical correlates of circulating YKL-40 level and, by combining it with CHI3L1 gene variants, with the risk and long-term mortality of peripheral artery disease (PAD). Plasma YKL-40 concentrations were measured in 612 Taiwanese individuals who had no clinically overt systemic disease. Clinical parameters, CHI3L1 gene promoter variants and 18 biomarker levels were analyzed. Eighty-six PAD patients were further enrolled for analysis. Significant associations were found between CHI3L1 genotypes/haplotypes and YKL-40 levels for the health examination subjects (smallest p = 8.36 × 10-7 for rs4950928 and smallest p = 1.72 × 10-10 for haplotype TGG) and also for PAD patients. For the health examination subjects, circulating YKL-40 level, but not CHI3L1 gene variants, were positively associated with age, smoking, and circulating levels of triglyceride, lipocalin 2 and multiple inflammatory biomarkers and negatively associated with low-density-lipoprotein cholesterol levels. Circulating YKL-40 level is also significantly associated with the risk of PAD (p = 3.3 × 10-23). Circulating YKL40 level, but not CHI3L1 gene promoter variants, is associated with the risk of PAD in Taiwanese. The association of YKL-40 levels with multiple quantitative traits relating to the risk of PAD may provide a molecular basis linking YKL-40 to atherosclerotic cardiovascular disease.

Increased expression of chitinase 3-like 1 in aorta of patients with atherosclerosis and suppression of atherosclerosis in apolipoprotein E-knockout mice by chitinase 3-like 1 gene silencing

INTRODUCTION

The purpose of this study was to investigate the changes of chitinase 3-like 1 (CHI3L1) in the aorta of patients with coronary atherosclerosis and to determine whether inhibition of CHI3L1 by lentivirus-mediated RNA interference could stabilize atherosclerotic plaques in apolipoprotein E-knockout (ApoE(-/-)) mice.

METHODS

We collected discarded aortic specimens from patients undergoing coronary artery bypass graft surgery and renal arterial tissues from kidney donors. A lentivirus carrying small interfering RNA targeting the expression of CHI3L1 was constructed. Fifty ApoE(-/-) mice were divided into control group and CHI3L1 gene silenced group. A constrictive collar was placed around carotid artery to induce plaques formation. Then lentivirus was transfected into carotid plaques.

RESULTS

We found that CHI3L1 was overexpressed in aorta of patients with atherosclerosis and its expression was correlated with the atherosclerotic risk factors. After lentivirus transduction, mRNA and protein expression of CHI3L1 were attenuated in carotid plaques, leading to reduced plaque content of lipids and macrophages, and increased plaque content of collagen and smooth muscle cells. Moreover, CHI3L1 gene silencing downregulated the expression of local proinflammatory mediators.

CONCLUSIONS

CHI3L1 is overexpressed in aorta from patients with atherosclerosis and the lentivirus-mediated CHI3L1 gene silencing could represent a new strategy to inhibit plaques progression.

Serum biomarkers in elderly asthma

OBJECTIVE

Asthma is usually misdiagnosed and under-treated in the elderly population, resulting in complications and increased severity to the patient. In this review, we describe some of the most important serum markers of asthma studied so far, reporting their outcomes and possible prediction of asthma in the elderly population.

METHODS

The PubMed electronic database was used to search for promising serum biomarkers of asthma studied in original articles published in peer-reviewed journals from 2000 to January 2013.

RESULTS

A total of 13 relevant serum biomarkers were selected, including IgE, CRP, high sensitive CRP, IL-6, IL-8, IL-17, TNF-α, neopterin, serum amyloid A, eosinophil cationic protein, leukolysin, YKL-40 and soluble CD86.

CONCLUSIONS

Although the major focus of treatment and research has been on allergic asthma, several forms of the disease are recognized, such as neutrophilic asthma, which is characteristic of older patients. Different phenotypes imply different treatments and so it becomes important to correctly determine which type of asthma the patient is suffering from. Serum markers capable of supporting a diagnosis of asthma are needed in order to counter mistreatment and misdiagnosis with other obstructive airways disease (OAD) in elderly patients. As convenient as serum markers may seem to be, a marker capable of accurately identifying asthma with sufficient specificity is yet to be found.

The expression of chitinase 3-like 1: a novel prognostic predictor for hepatocellular carcinoma

OBJECTIVES

Chitinase 3-like 1 (CHI3L1) is associated with poor prognosis of various human cancers. However, the clinical and prognostic significance of CHI3L1 in hepatocellular carcinoma (HCC) is largely unknown. The aim of the present study is to investigate the expression of CHI3L1 in human HCC cell lines, clinical HCC specimens and its association with expressions of phosphorylated-Akt (p-Akt), E-cadherin and prognostic significance.

METHODS

The protein level of CHI3L1 in HCC cell lines was evaluated by western blot. The mRNA and protein levels of CHI3L1 in 19 self-paired HCC specimens were assessed by RT-PCR and western blot assays. The clinical and prognostic significance of CHI3L1 in 70 cases of HCC patients was determined by immunohistochemistry. In addition, expressions of p-Akt and E-cadherin were also assessed.

RESULTS

The protein level of CHI3L1 paralleled with increased malignant potential of HCC cell lines (P < 0.05). The mRNA and protein levels of CHI3L1 in HCC tissues were up-regulated compared with those in adjacent peritumoral tissues and further increased in tumors with metastasis (P < 0.05). Clinicopathological analysis showed that positive CHI3L1 expression was significantly associated with larger tumor size, capsular invasion, advanced TNM stages and status of metastasis (P = 0.035, 0.003, 0.023 and 0.003, respectively). Furthermore, CHI3L1 expression was positively correlated with high level of p-Akt (r = 0.293, P = 0.014), but inversely correlated with expression of E-cadherin (r = -0.267, P = 0.026). Additionally, Kaplan-Meier survival analysis showed that HCC patients with positive CHI3L1 expression had a worse overall survival and disease-free survival compared with those with negative CHI3L1 expression (P < 0.001, respectively). Multivariate analysis identified CHI3L1 as an independent prognostic predictor for overall survival and disease-free survival of HCC patients (P = 0.044 and 0.031, respectively).

CONCLUSIONS

CHI3L1 plays an essential role in HCC malignancies and may be served as a valuable prognostic biomarker for HCC patients.

Association of CHI3L1 in African-Americans with prior history of asthma exacerbations and stress

RATIONALE

Asthma exacerbations are influenced by multiple factors including environmental exposures, psychosocial interactions, and genetic variations.

AIM

To better understand the correlation between clinical, physiologic, genetic, and psychological dimensions in asthma phenotypes and exacerbations.

METHODS

Supervised cluster analysis of a previously conducted clinical trial of asthma was used to identify subpopulations with differing exacerbation rates in an African-American study population (n = 475). The clusters were characterized by their clinical characteristics and genetic variations. The genetic analysis (n = 322) compared subgroups across 40 different polymorphisms of 10 genes associated with asthma exacerbations.

RESULTS

Four clusters were identified with varying annualized rates of exacerbations. Cluster 1 (n = 272) was represented by subjects with a mean age of 25 years and 52% females. In contrast, cluster 4, most divergent from cluster 1, was represented by subjects with the highest rate of asthma exacerbations (1.18 events per year), was mostly female (>80%), with a mean body mass index of 34, and was distinguished by the report of stress and emotions as the cause for prior exacerbations. Lower lung function and increased rescue medication use was also reported in cluster 4. Additionally, genetic analysis revealed a significant difference in distribution of genotypes among the four clusters for rs4950928, a single nucleotide polymorphism (SNP) located in the promoter region of the CHI3L1, the chitinase 3-like 1 gene encoding YKL-40.

CONCLUSIONS

African-Americans who reported stress and emotions as a primary historical cause of exacerbations had the highest annualized rate of exacerbation. Further, a significant correlation with the genotypes in CHI3L1/YKL-40 was observed in the context of stress and asthma severity.

Potential association between coronary artery disease and the inflammatory biomarker YKL-40 in asymptomatic patients with type 2 diabetes mellitus

Background

Inflammation plays an important role in coronary artery disease from the initiation of endothelial dysfunction to plaque formation to final rupture of the plaque. In this study, we investigated the potential pathophysiological and clinical relevance of novel cytokines secreted from various cells including adipocytes, endothelial cells, and inflammatory cells, in predicting coronary artery disease (CAD) in asymptomatic subjects with type 2 diabetes mellitus.

Methods

We enrolled a total of 70 asymptomatic type 2 diabetic patients without a documented history of cardiovascular disease, and determined serum levels of chemerin, omentin-1, YKL-40, and sCD26. We performed coronary computed tomographic angiography (cCTA) in all subjects, and defined coronary artery stenosis ≥ 50 % as significant CAD in this study.

Results

Subjects were classified into two groups: patients with suspected coronary artery stenosis on cCTA (group I, n = 41) and patients without any evidence of stenosis on cCTA (group II, n = 29). Group I showed significantly higher YLK-40 levels and lower HDL-C levels than group II (p = 0.038, 0.036, respectively). Levels of chemerin, omentin-1, and sCD26 were not significantly different between the two groups. Serum YKL-40 levels were positively correlated with systolic/diastolic BP, fasting/postprandial triglyceride levels, and Framingham risk score. Furthermore, YKL-40 levels showed moderate correlation with the degree of coronary artery stenosis and the coronary artery calcium score determined from cCTA. In multivariate logistic analysis, after adjusting for age, gender, smoking history, hypertension, and LDL-cholesterol, YLK-40 levels showed only borderline significance.

Conclusions

YKL-40, which is secreted primarily from inflammatory cells, was associated with several CVD risk factors and was elevated in type 2 diabetic patients with suspected coronary artery stensosis on cCTA. These results suggest the possibility that the inflammatory biomarker YKL-40 might be associated with coronary artery disease in asymptomatic patients with type 2 diabetes mellitus.