Endocan in prediabetes, diabetes, and diabetes-related complications: a systematic review and meta-analysis

Fetuin-A levels in diabetic retinopathy: a systematic review and meta-analysis

Background

Diabetic retinopathy (DR) is one of the main microvascular complications of diabetes and one of the most common causes of vision loss worldwide. Fetuin-A is a glycoprotein correlated with insulin resistance and has been measured in DR patients. Herein, we aimed to investigate these studies through a systematic review and meta-analysis.

Methods

Four online databases, including PubMed, Embase, Scopus, and the Web of Science were searched comprehensively in order to retrieve relevant studies that compared blood fetuin-A levels in patients with DR vs. non-DR, DR vs. non-diabetic controls, non-DR vs. non-diabetic controls, and proliferative vs. non- proliferative DR. Random-effect meta-analysis was performed for the calculation of the standardized mean difference (SMD) and 95% confidence interval (CI).

Results

From the 186 found results through database search, after eligibility assessment, seven studies were included. A total of 1104 cases with a mean age of 57.24 ± 9.62 years were investigated. Meta-analysis showed that fetuin-A levels were significantly higher in patients with DR compared to both non-DR diabetic patients (SMD 0.41, 95% CI 0.10 to 0.72, P = 0.009), and non-diabetic healthy controls (SMD 0.77, 95% CI 0.47 to 1.07, P < 0.0001). Additionally, patients with proliferative DR had higher fetuin-A levels than those with non-proliferative DR (SMD 0.35, 95% CI 0.11 to 0.59, P = 0.004). However, no significant difference was found between diabetic patients without DR and healthy controls.

Conclusion

Based on our findings, fetuin-A was higher in patients with DR and could be potentially used for measurement in clinical settings if confirmed in future large-scale studies. Moreover, the fact that higher fetuin-A levels were associated with proliferative DR could have clinical implications.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-024-01533-0.

Endocan expression and correlation with other endothelial determinants in developing a score for early identification of diabetic peripheral neuropathy

Diabetic peripheral neuropathy is a common complication of diabetes mellitus that has dire outcomes, affecting the economic profile of a country. Despite the multifactorial background of the pathogenesis of this disease, the mechanism underlying peripheral neuropathy is still unclear. Endothelial damage is a new determinant of pathogenesis, with endocan as a potential biomarker for endothelial dysfunction in diabetic peripheral neuropathy patients. In this cross-sectional study, with 49 patients with diabetes with peripheral neuropathy and 48 patients with diabetes without neuropathy, endothelial biomarkers such as endocan, hs-CRP, vitamin D, and lipid profiles were measured and analyzed in both groups. The standardized scores for dyslipidemia, inflammation, vitamin D and endocan were calculated. All of these biomarkers were significantly altered in peripheral neuropathy patients. A strong correlation between endocan levels and lipid profiles and between hs-CRP and vitamin D levels was detected. The inflammatory score and a combined score including all the above biomarkers might help in the early stratification of diabetic patients who are at greater risk of developing peripheral neuropathy.

Association between serum endocan levels and organ failure in hospitalized patients with cirrhosis

BACKGROUND & AIMS

Acute-on-chronic liver failure is a syndrome characterized by organ failure and high short-term mortality. The lack of reliable biomarkers for the early detection of acute-on-chronic liver failure is a significant challenge. Endothelial dysfunction plays a key role in the development of organ failure. Serum endocan is a potential new biomarker for endothelial dysfunction. Therefore, this study aimed to assess the association between endocan and organ failure and 28-day mortality in patients with cirrhosis.

METHODS

Hospitalized patients with cirrhosis with and without organ failure were prospectively enrolled according to the criteria of the European Association for the Study of Liver-Chronic Liver Failure consortium. The comparative performances of serum endocan, procalcitonin, and interleukin-6 for diagnosing organ failure and predicting mortality were studied.

RESULTS

The study included 116 hospitalized patients with cirrhosis, 55 of whom had organ failure on admission. Patients with organ failure had significantly higher endocan, procalcitonin, and interleukin-6 levels than those without it. At a cut-off value of 15.8 ng/mL, endocan showed a sensitivity of 63.6% and specificity of 67.2% for the diagnosis of organ failure, with an area under the receiver operating characteristic curve of 0.65, which is comparable to procalcitonin and interleukin-6. Multivariate analysis identified serum endocan, creatinine, and total bilirubin as independent factors for organ failure in hospitalized patients with cirrhosis. Patients who died within 28 days had significantly higher baseline biomarker levels than those who survived. Liver failure, hospital-acquired infection, mechanical ventilator use, and interleukin-6 ≥37 pg/mL were independent predictors of 28-day mortality.

CONCLUSION

Serum endocan is associated with organ failure and is an independent risk factor of organ failure in hospitalized patients with cirrhosis.

Soluble Proteoglycans and Proteoglycan Fragments as Biomarkers of Pathological Extracellular Matrix Remodeling

Proteoglycans and their proteolytic fragments diffuse into biological fluids such as plasma, serum, urine, or synovial fluid, where they can be detected by antibodies or mass-spectrometry. Neopeptides generated by the proteolysis of proteoglycans are recognized by specific neoepitope antibodies and can act as a proxy for the activity of certain proteases. Proteoglycan and proteoglycan fragments can be potentially used as prognostic, diagnostic, or theragnostic biomarkers for several diseases characterized by dysregulated extracellular matrix remodeling such as osteoarthritis, rheumatoid arthritis, atherosclerosis, thoracic aortic aneurysms, central nervous system disorders, viral infections, and cancer. Here, we review the main mechanisms accounting for the presence of soluble proteoglycans and their fragments in biological fluids, their potential application as diagnostic, prognostic, or theragnostic biomarkers, and highlight challenges and opportunities ahead of their clinical translation.

Endocan as a biomarker for acute respiratory distress syndrome: A systematic review and meta-analysis

Background and Aims

Endocan is a marker of endothelial damage. Data regarding the association of this proteoglycan and acute respiratory distress syndrome (ARDS) is discrepant. Hence, this study sought to investigate the possible correlation between serum/plasma endocan concentration and ARDS.

Methods

A systematic review and meta-analysis of international online databases was conducted following PRISMA guidelines. PubMed, SCOPUS, Embase, and Web of Science were searched in March 2023, with the leading search terms being "ARDS" OR "respiratory distress" AND "endocan" and other associated terms. Studies that measured endocan levels in patients with ARDS and compared it with non-ARDS controls or within different severities of ARDS were included. We performed a random-effect meta-analysis for pooling the differences using standardized mean difference (SMD) and 95% confidence interval (CI).

Results

We included 14 studies involving 1,058 patients. Those developing ARDS had significantly higher levels of endocan compared to those without ARDS (SMD: 0.47, 95% CI: 0.10-0.84, p = 0.01). Our meta-analysis of three studies found that endocan levels in ARDS nonsurvivors were significantly higher than in survivors (SMD: 0.31, 95% CI: 0.02-0.60, p = 0.03). Three studies investigated endocan levels in different severities of ARDS. Only one of these studies reported significantly higher endocan levels in patients with worsening acute respiratory failure at Day 15. The other two reported no significant association between ARDS severity and circulating endocan levels.

Conclusion

Blood endocan levels were significantly higher in patients with ARDS than those without. Additionally, among patients with ARDS, blood endocan values were significantly elevated in nonsurvivors compared to survivors. These findings could help researchers design future studies and solidify these findings and finally, clinicians to take advantage of measuring endocan in clinical settings for assessment of patients with ARDS.

Correlation between omega-3 intake and the incidence of diabetic retinopathy based on NHANES from 2005 to 2008

AIMS

To identify correlations between omega-3 intake and incidence of diabetic retinopathy (DR).

METHODS

This was a cross-sectional study using data from participants over age 40 in the National Health and Nutrition Examination Survey (NHANES) 2005-2008. Metrics included participants' intake of omega-3 fatty acids, specifically three types of representative polyunsaturated fatty acids, DR prevalence, and demographic characteristics. Multiple logistic regression models were used to assess the relationship between omega-3 intake and DR.

RESULTS

Of the 1243 participants included in this study, omega-3 intake was lower in patients with DR relative to those without DR. Of the three polyunsaturated fatty acids within the omega-3 fatty acid family that we focused on, participants without DR consumed more docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) than those with DR. In contrast, there was no significant difference in the intake of eicosapentaenoic acid (EPA). Higher omega-3 intake was associated with a decreased risk of DR. In a crude model, the odds ratio (OR) was 0.548 (95% CI 0.315, 0.951; p = 0.033). In the fully adjusted model of omega-3 (model II), the adjusted OR was 0.525 (95% CI 0.306, 0.901; p = 0.021). DPA and DHA were also associated with a decreased risk of DR. In the full adjustment model (model II) of DPA and DHA, the adjusted ORs were 0.0002 (95% CI 0.000, 0.166; p = 0.014) and 0.293 (95% CI 0.105, 0.819; p = 0.020). Subgroup analysis showed that the protective effect of omega-3 against DR was more significant in younger patients (p value = 0.015).

CONCLUSIONS

In this cross-sectional study of the U.S. general population, we found that increased intake of omega-3 and its components, specifically DPA and DHA were negatively associated with DR incidence. This suggests that omega-3 may be a potential protective factor for DR and may help to prevent or delay the onset and progression of DR.

Relationship between angiogenesis biomarker endocan and apolipoproteins in patients with acute myocardial infarction

Aim: In the current study, serum levels of endocan in patients attended with ST-elevation myocardial infarction, as well as the possible correlation with apolipoprotein-A1 (APO-A1) and APO-B were investigated.Materials & methods: In 80 men, endocan, cTnI, APO-A1, and APO-B levels were measured. Finally, the correlation of endocan with APO-A1, APO-B, and APO-B/ APO-A1 ratio was assessed.Results: Significant changes in APO-A1, APO-B, endocan levels, and APO-B/APO-A1 ratio were found in acute myocardial infarction cases compared with the control arm (p < 0.05). In addition, our finding showed a significant correlation between APO-B and endocan levels, but not APO-A.Conclusion: High endocan level is an independent indicator of endothelial dysfunction and ischemic cardiovascular conditions, which could be related to APO-B.

Diagnostic Role of Circulating Endocan Levels in Obstructive Sleep Apnea: A Systematic Review and Meta-Analysis

Endocan, as an endothelial cell damage marker, plays role in several cardiovascular and non-cardiovascular diseases. This systematic review and meta-analysis evaluates the role of endocan as a potential diagnostic or prognostic biomarker for obstructive sleep apnea (OSA). International databases including PubMed, Embase, Web of Science, and Scopus were searched for relevant studies assessing endocan levels in OSA patients compared with healthy controls or within different severities or comorbidities of OSA. Random-effect meta-analysis was performed in order to calculate the standardized mean difference (SMD) and 95% confidence interval (CI) of serum/plasma endocan in all comparisons. A total of 10 studies were included in our systematic review, among which seven were used in meta-analysis. Meta-analysis showed that endocan levels were significantly higher in patients with OSA compared with healthy controls (SMD 1.29, 95% CI 0.64-1.93, P < .001) and this was not different between serum and plasma subgroups. However, there was no statistical difference between severe and non-severe OSA patients (SMD .64, 95% CI -.22 to 1.50, P = .147). Considerably, higher endocan levels in patients with OSA in comparison with non-OSA individuals might have clinical implications. This association warrants further research due to its potential use as a diagnostic and prognostic biomarker.

Exploring metabolically healthy obesity: prevalence, characteristics, and cardiovascular risk in the Iranian population based on the STEPS 2021

Background

Regarding the rapidly increasing prevalence of obesity throughout the globe, it remains a serious public health concern. A subgroup of obesity that does not meet metabolic syndrome criteria is called metabolically healthy obesity (MHO). However, whether the MHO phenotype increases cardiovascular disease (CVD) risk is controversial. This study aimed to evaluate the prevalence of MHO and its 10-year CVD risk in Iranian populations.

Methods

Based on the STEPS 2021 project in Iran, we collected data on 18119 Iranians 25 years and older from all 31 provinces after applying many statistical factors. Using the Framingham score, we evaluated the 10-year cardiovascular risk associated with the various MHO definition criteria for Iranian populations.

Results

The prevalence of MHO was 6.42% (5.93-6.91) at the national level according to the AHA-NHLBI definition, and 23.29% of obese women and 24.55% of obese men were classified as MHOs. Moreover, the MHO group was younger than the metabolically unhealthy obesity (MUO) group based on all definitions (p < 0.001). The odds ratio of MUO individuals being classified as high-risk individuals by the Framingham criteria for CVD was significantly higher than that of MHO individuals by all definitions, with a crude odds ratio of 3.55:1 based on AHA-NHLBI definition.

Conclusion

This study reveals a significant prevalence of MHO in the Iranian population, with approximately 25% of obese individuals classified as MHO. While MHO is associated with a lower risk of cardiovascular disease compared to MUO, MHO carries the potential for transitioning to an unhealthy state.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01364-5.

Urinary and circulatory netrin-1 as biomarker in diabetes and its related complications: a systematic review and meta-analysis

BACKGROUND

Novel biomarkers have been suggested for the diagnosis and prognosis of diabetes mellitus. The biomarker utility of netrin-1 in diabetes as an extracellular protein has been investigated. In this systematic review and meta-analysis, we reviewed the role of netrin-1 as a biomarker in prediabetes, diabetes, and complications of diabetes.

METHODS

PubMed, Embase, Scopus, and Web of Science were systematically searched for studies that measured circulatory and/or urinary netrin-1 levels in diabetes and compared them with non-diabetic patients or evaluated the prognostic role of this marker. Standardized mean difference (SMD) and 95% confidence interval (CI) were calculated using random-effect meta-analysis to compare netrin-1 levels between groups. The impact of mean age, male sex percentage, sample size, mean body mass index, and publication year on the overall heterogeneity was assessed using meta-regression.

RESULTS

Among 413 records from international databases, 19 original studies were included with 2061 cases (1137 diabetics, 196 prediabetics, and 728 healthy controls). Meta-analysis of eight studies measuring netrin-1 in patients with diabetes and comparing it with healthy controls showed no significant difference between the two groups (SMD 0.69, 95% CI -0.78 to 2.16, I2 = 98%, p-value = 0.36). On the other hand, a meta-analysis of netrin-1 levels in patients with prediabetes in comparison with healthy controls revealed that they had lower levels (SMD -0.51, 95% CI -0.81 to -0.21, p-value < 0.01). Diabetic patients with microalbuminuria and macroalbuminuria had significantly higher circulatory netrin-1 levels compared to normoalbuminuric group SMD 1.18, 95% CI 0.83 to 1.53, p-value < 0.01 and SMD 1.67, 95% CI 0.76 to 2.58, p-value < 0.01, respectively). Moreover, no difference in urinary netrin-1 levels was found between micro-, macro-, and normoalbuminuric groups (p-value > 0.05).

CONCLUSION

Netrin-1 showed promising results as a biomarker in diabetes prognosis. However, more studies are required to confirm our findings, and higher sample size studies are needed to evaluate the diagnostic utility of this marker.

Correlation of Serum Endocan Level With Apoptosis Indicators and Severity of Atherosclerotic Lesions of Coronary Arteries in Patients With Coronary Heart Disease

Aim    To study the relationship of blood serum concentration of endocan with indexes of apoptosis and clinical and instrumental characteristics of patients with ischemic heart disease (IHD).Material and methods    The study included 176 subjects (105 men and 71 women). 150 of them were diagnosed with IHD and 26 were healthy volunteers. Anthropometric measurements, coronary angiography, echocardiography, duplex ultrasound scanning of extracranial parts of the brachiocephalic arteries were performed for all patients. Concentrations of endocan (ng / ml), glucose (mmol / l), and apoptotic markers Bcl-2 (ng / ml), Bax (ng / ml), Bcl-2 / Bax, TRAIL (pg / ml), and p53 (ng / ml) were measured in blood serum. Patients were divided into groups based on their SYNTAX scores: group 1 with moderate atherosclerotic lesions of the coronary arteries (CA) (score < 22, 78 patients); group 2 with severe CA atherosclerosis (score 23-32, 37 patients); and group 3 with extremely severe CA lesions (score >33, 35 patients). The control group consisted of healthy volunteers (26 subjects). All groups were age- and sex-matched. Differences were considered statistically significant at p<0.05.Results    A correlation was found between endocan concentration and IHD severity (r=0.32, p<0.001). In group 1, the median endocan concentration was 14.57 ng / ml [8.21; 23.66], in group 2, 19.34 ng / ml [8.425; 26.645], in group 3, 32.13 ng / ml [18.2; 39.12], and in the control group, 6.92 ng / ml [4.62; 9.18]. Correlations of varying strength and significance were observed between the endocan concentration and a number of clinical and instrumental characteristics. Endocan concentrations significantly differed in groups of patients with multifocal atherosclerosis (p<0.01), angina pectoris (p<0.01), a history of myocardial infarction (p<0.001), and obesity (p<0.05) from patients without these signs. Also, a correlation was found between serum endocan concentration and apoptotic markers: TRAIL (r= -0.448, p<0.001); BCL-2 (r= -0.552, p<0.001), Bax (r= -0.519, p<0.001), Bcl-2 / Bax (r= -0.576, p<0.001) and p53 (r= -0.520, p <0.001).Conclusion    The study demonstrated a potential role of endocan as a promising biomarker for risk stratification, prognosis and therapeutic monitoring of IHD patients.

Serum Endocan Levels in Postmenopausal Women with Metabolic Syndrome

Aim: Studies that explored endocan (as a novel marker of endothelial dysfunction) in relation to metabolic syndrome (MetS) are scarce and show discordant results. Importantly, no study has yet examined serum endocan levels in exclusively postmenopausal women with MetS and free of diabetes. Oxidative stress and inflammation are the key features of MetS and consequently cardiovascular diseases. Hence, we aimed to explore the potential relationship between endocan, oxidative stress [i.e., determined by total antioxidant status, total oxidant status, and pro-oxidant/antioxidant balance (PAB)], inflammation, and MetS in a cohort of postmenopausal women. Methods: A total of 126 postmenopausal women were included consecutively. MetS was diagnosed following the International Diabetes Federation criteria. Results: Higher serum endocan levels were found in MetS group as compared with MetS-free counterparts [6.03 (3.47-10.37) pg/mL vs. 2.27 (1.49-3.50) pg/mL, P < 0.001]. Endocan showed good discriminatory ability toward MetS [area under the curve (AUC) = 0.809]. Besides age, the inclusion of oxidative stress and inflammation biomarkers, such as PAB and high-sensitivity C-reactive protein (hsCRP), the AUC for discrimination postmenopausal women with MetS from MetS-free women was 0.845. Conclusion: Postmenopausal women with MetS exhibited almost 2.7 times higher serum endocan level as compared with MetS-free middle-aged women. Endocan showed good discriminatory ability toward MetS and could be a diagnostic marker in MetS. Similar results were confirmed when added an age, oxidative stress, and inflammation biomarkers (i.e., PAB and hsCRP) were included for the discrimination of postmenopausal with MetS from MetS-free women.

Endocan as a marker of endothelial dysfunction in hypertension: a systematic review and meta-analysis

Hypertension is one of the foremost risk factors for cardiovascular disease and a significant cause of death worldwide. Importantly, endothelial dysfunction (ED) is one of the primary manifestations that may precede the development of hypertension. Endocan is a novel endothelial dysfunction and inflammation biomarker secreted from endothelial cells. Whether endocan may serve as a biomarker of hypertension is currently debated. This systematic review and meta-analysis aimed at linking endocan to ED in hypertensive patients. International databases, including PubMed, Scopus, Embase, and Web of Science, were systematically searched for studies investigating Endocan serum or plasma levels in hypertensive patients and healthy controls. Random effect meta-analysis was performed to calculate the standardized mean difference (SMD) and 95% confidence interval (CI). A total of 20 studies assessing the association between endocan levels and hypertension were included in which 3130 individuals with a mean age of 50.48 ± 8.45 years were assessed. Hypertensive patients presented with higher circulating endocan levels (SMD 0.91, 95% CI 0.44-1.38, p-value < 0.01) compared with healthy controls. Interestingly, our data demonstrated that removing three studies assessing endocan levels in hypertensive patients with different comorbidities or special populations resulted in the same statistically higher endocan levels (SMD 1.16, 95% CI 0.66-1.65, p-value < 0.01). Overall, this systematic review and meta-analysis indicated that in hypertensive patients circulating endocan levels are significantly elevated. Thus, suggesting endocan as an easy-to-use biomarker to detect ED in hypertension. Despite this, more research is warranted to address this potential ability specifically.

Triglyceride-glucose index and heart failure: a systematic review and meta-analysis

BACKGROUND

Insulin resistance (IR) is a major metabolic disorder observed in heart failure (HF) and is tightly associated with patients' poor prognosis. The triglyceride-glucose index (TyG) has been proposed as a surrogate marker of IR in HF. Yet, whether TyG is a reliable clinical marker is still under debate. Hence, we aimed to respond to this relevant question via a systematic review and meta-analysis of existing studies.

METHODS

A systematic search was conducted in PubMed, Embase, Scopus, and Web of Science to find studies investigating the TyG index in patients with HF or its association with the incidence of HF. Adjusted hazard ratios (HR) and 95% confidence intervals (CI) were pooled through random-effect meta-analysis. HRs were calculated using TyG as a continuous variable (1 unit increase) and by comparing the group with the highest TyG to the lowest TyG group.

RESULTS

Thirty studies, involving 772,809 participants, were included in this systematic review. Meta-analysis of seven studies comparing the highest-TyG to the lowest-TyG group showed a significantly increased risk of HF in the former group (HR 1.21, 95% CI 1.14 to 1.29, P < 0.01). The same result was found when pooling the HRs for a one-unit increase in the TyG index (HR 1.17, 95% CI 1.08 to 1.26). Similarly, a more elevated TyG index was associated with a higher incidence of HF in patients with type 2 diabetes or coronary artery disease. Additionally, the incidence of adverse events (readmission and mortality) in patients with HF was associated with TyG.

CONCLUSION

Our findings support the TyG index as a valuable marker to assess the risk of HF incidence in different populations and as a prognostic marker in patients with HF. Further studies should be conducted to confirm these associations and investigate the clinical utility of the TyG index.

High circulating endocan in chronic kidney disease? A systematic review and meta-analysis

BACKGROUND

Chronic kidney disease (CKD) is one of the leading causes of morbidity and mortality worldwide. Endothelial dysfunction has been suggested to be involved in the pathophysiology of CKD. Endocan, as an endothelial factor, has been shown to increase in several diseases. The current systematic review and meta-analysis was performed with the aim of determining the association between endocan levels and CKD.

METHODS

Four international databases, including PubMed, Embase, Scopus, and Web of Science were searched for relevant studies. Afterward, screening and extraction of data were performed. We conducted a random-effect meta-analysis to calculate the standardized mean difference (SMD) and 95% confidence interval (CI) to compare circulating endocan levels between patients with CKD (including patients undergoing hemodialysis) and healthy controls. Subgroup analysis based on the specimen in which endocan was measured (serum or plasma) was also performed.

RESULTS

After screening by title/abstract and full-text review by the authors, 20 studies were included. Meta-analysis revealed that serum endocan is higher in CKD patients compared to healthy controls (SMD 1.34, 95% CI 0.20 to 2.48, p-value<0.01). This higher endocan level was also observed in the subgroup of studies that measured plasma endocan while this was not the case for the subgroup of studies assessing serum endocan. Meta-analysis was also performed for comparison of CKD patients without other comorbidities and healthy controls, which resulted in the same conclusion of higher endocan levels in patients with CKD (SMD 0.74, 95% CI 0.52 to 0.95, p-value<0.01). Moreover, endocan was associated with cardiovascular diseases in CKD.

CONCLUSION

Our study demonstrated that endocan is significantly increased in patients with CKD. This can have clinical implications as well as highlight the need for future research investigating the diagnostic and prognostic role of endocan in CKD.