Increased serum mannose binding lectin levels are associated with diabetic retinopathy

Circulating mannose-binding lectin in diabetic patients and risk of vascular complications: a systematic review and meta-analysis

Objectives

Recent studies have confirmed the involvement of mannose-binding lectin (MBL) in the pathogenesis of vascular complications in individuals with diabetes. Due to the discrepancy between the results of studies, a meta-analysis was conducted to evaluate MBL levels in patients with diabetes and its vascular complications.

Methods

We reviewed all observational studies published in PubMed/Medline, Scopus, EMBASE, and Web of Science Core Collection databases to identify relevant studies up to 1 April 2024. To account for describing heterogeneity among the studies, I2 and χ2 statistics were utilized. Also, a random-effects model was employed to combine the studies. The Newcastle Ottawa Scale (NOS) checklist was applied for quality assessment of each study.

Results

Twenty-eight papers were encompassed in this meta-analysis. The mean difference in MBL levels between patients with diabetic nephropathy and diabetic retinopathy differed significantly compared with the healthy control group and the diabetic group without vascular complications (P-value < 0.05). Moreover, the pooled results revealed a significant relationship between MBL levels and the incidence of vascular complications (pooled HR = 1.44, 95% CI: 1.07-1.95, P-value < 0.05) and disease-related mortality (pooled HR = 1.52, 95% CI: 1.07-2.16, P-value < 0.05) among diabetic patients. Also, there was a direct association between incidence of nephropathy in diabetics and higher levels of MBL (pooled HR = 2.16, 95% CI: 1.52-3.08, P-value < 0.05).

Conclusion

Diabetic patients with elevated MBL levels are potentially at increased risk of vascular complications such as nephropathy and retinopathy. Therefore, by determining MBL status in diabetic patients, it is possible to predict the progress and possible consequences of the disease.

The role of mannose-binding lectin (MBL) in diabetic retinopathy: A scoping review

Diabetes mellitus (DM) is a chronic systemic disease characterized by a multifactorial nature, which may lead to several macro and microvascular complications. Diabetic retinopathy (DR) is one of the most severe microvascular complications of DM, which can result in permanent blindness. The mechanisms involved in the pathogenesis of DR are multiple and still poorly understood. Factors such as dysregulation of vascular regeneration, oxidative and hyperosmolar stress in addition to inflammatory processes have been associated with the pathogenesis of DR. Furthermore, compelling evidence shows that components of the immune system, including the complement system, play a relevant role in the development of the disease. Studies suggest that high concentrations of mannose-binding lectin (MBL), an essential component of the complement lectin pathway, may contribute to the development of DR in patients with DM. This review provides an update on the possible role of the complement system, specifically the lectin pathway, in the pathogenesis of DR and discusses the potential of MBL as a non-invasive biomarker for both, the presence and severity of DR, in addition to its potential as a therapeutic target for intervention strategies.

iTRAQ plasma proteomics analysis for candidate biomarkers of type 2 incipient diabetic nephropathy

Background

Diabetic nephropathy is the most frequent cause of end-stage renal disease worldwide. Identification of biomarkers for diabetic nephropathy for early diagnosis may be the key to avoiding damage from this condition.

Methods

Proteomic iTRAQ technology was first used to identify differentially expressed plasma proteins in type 2 incipient diabetic nephropathy (IDN) using a Q-Exactive mass spectrometer.

Results

Compared with controls, 57 proteins (32 upregulated and 25 downregulated proteins) were identified. Furthermore, the gelsolin, collectin-11, PTPRJ, and AKAP-7 proteins were confirmed by Western blots as candidate biomarkers for type 2 IDN through ROC analysis.

Conclusions

These findings offer a theoretical basis for the early treatment of diabetic nephropathy.

Elevated plasma levels of copeptin linked to diabetic retinopathy in type 2 diabetes

BACKGROUND

The arginine vasopressin (AVP) system has been postulated to play a role in glucose homeostasis, insulin resistance, and diabetes mellitus in human and animal studies. The aim of this study was to evaluate the role of plasma copeptin in Chinese patients with type 2 diabetes mellitus (T2DM) with and without diabetic retinopathy (DR).

METHOD

Plasma copeptin concentrations were determined in 281 patients with T2DM. At baseline, demographic and clinical information including presence of DR and vision-threatening DR (VTDR) was collected. The relationship between copeptin and DR or VTDR was investigated using logistic regression.

RESULTS

T2DM participants with DR or VTDR had significantly higher plasma copeptin concentrations on admission (P < 0.0001). Receiver operating characteristics to predict DR and VDTR demonstrated areas under the curve for copeptin of 0.784 (95% confidence interval [CI] 0.724-0.844) and 0.834 (95% CI 0.781-0.904), respectively, which were superior to those for the homeostasis model assessment of insulin resistance (DR AUC 0.736, 95% CI 0.676-0.797; VTDR AUC 0.754, 95% CI 0.703-0.828; P < 0.01). Multivariate logistic regression analysis adjusted for common DR risk factors showed plasma copeptin concentrations ≥28.6 pmol/L (>3rd quartile) to be an independent marker of DR (OR 3.68, 95% CI 2.04-6.79; P < 0.0001) and VTDR (OR 4.32, 95% CI 2.12-8.14; P < 0.0001).

CONCLUSIONS

We found that increased plasma copeptin concentrations were an independent marker of DR and VDTR in Chinese patients with T2DM, suggesting a possible role of copeptin in the pathogenesis of DR complications.

Plasma copeptin and functional outcome in patients with ischemic stroke and type 2 diabetes

BACKGROUND

The activation of the arginine vasopressin system may be involved in the pathology of stroke and diabetes. In this study, we therefore evaluated the short-term prognostic value of early measurement of plasma copeptin levels in Chinese patients with type 2 diabetes mellitus (T2DM) and acute ischemic stroke (AIS).

METHODS

From July 2014 to June 2015, all T2DM patients with first-ever AIS were included. Plasma levels of copeptin were tested at admission. The prognostic value of copeptin to predict the functional outcome and mortality 3months after stroke was compared with the National Institutes of Health Stroke Scale score and with other known outcome predictors.

RESULTS

We recorded 247 stroke patients with T2DM. The copeptin levels were obtained in those patients with a median value of 14.3pmol/L (IQR, 9.5-17.1pmol/L). At 3-month follow-up, a favorable functional outcome was found in 86 patients (34.8%). Plasma copeptin levels in patients with an unfavorable outcome were significantly greater than those in patients with a favorable outcome (16.2 [IQR, 12.2-20.3] vs. 12.4 [IQR, 8.6-15.2] pmol/L; Z=5.399; P<0.0001). In univariate logistic regression analysis, with an unadjusted OR of 1.123 (95% CI, 1.072-1.177, P<0.001), copeptin had a strong association with unfavorable functional outcome. In multivariate analyses, a copeptin level in the highest inter-quartile (>17.1pmol/L) was associated with a higher risk of unfavorable functional outcome (OR=4.62; 95% CI=2.63-9.21; P<0.001). After adjusting for other outcome predictors, a copeptin level in the highest inter-quartile (>17.1pmol/L) was associated with a higher risk of mortality (OR=5.12; 95% CI=2.20-11.38; P<0.001).

CONCLUSION

Our study suggested that copeptin levels may reliably predict short-term stroke prognosis at its onset in Chinese patients with T2DM and stroke.

Serum levels of copeptin are associated with type 2 diabetes and diabetic complications in Chinese population

PURPOSE

The aim of this study was to investigate copeptin levels in serum, and assess their associations with type 2 diabetes (T2DM) and diabetic complications.

METHODS

In this post hoc analysis, serum levels of copeptin were tested in 306 patients with T2DM. Clinical information including diabetic retinopathy (DR) and diabetic nephropathy (DN) were collected. The relation of serum copeptin with DR and DN were investigated with the use of logistic regression models according to equal quartiles of the distributions of serum copeptin.

RESULTS

We found that serum copeptin levels were significantly higher in diabetes as compared to normal controls [9.4(IQR, 7.4-12.5) pmol/L vs. 4.1(IQR, 2.5-6.2) pmol/L; P<0.0001]. In multivariate analysis, there was an increased risk of T2DM associated with copeptin levels (OR 1.312, 95% CI: 1.204-1.403; P<0.0001) after adjusting for possible confounders. After adjustment for possible confounders, serum copeptin levels were positively associated with the DR (odds ratio [OR], 1.117; 95% confidence interval [CI], 1.072-1.241; P<0.001) and DN (OR, 1.259; 95% CI, 1.198-1.323; P<0.001). Compared with the first quartile of serum copeptin levels, the ORs for DR and DN were as follows: second quartile, 1.19 (95% CI, 0.94-1.51, P=0.12) and 1.37 (95% CI, 0.78-2.37, P=0.28); third quartile, 1.61 (95% CI, 1.18-2.43, P=0.005) and 2.12 (95% CI, 1.32-3.27, P=0.003); fourth quartile, 2.83 (95% CI, 2.04-4.93; P<0.001) and 3.48 (95% CI, 1.77-7.03; P<0.001), respectively.

CONCLUSIONS

Using a post-hoc analysis our data show that elevated serum levels of copeptin are associated with type 2 diabetes and diabetic complications in Chinese population, suggesting a potential role of the AVP system (copeptin) in the pathophysiology of diabetes.

Reduced serum level of leukocyte cell-derived chemotaxin 2 is associated with the presence of diabetic retinopathy

BACKGROUND

Vascular endothelial growth factor (VEGF) signaling is an important pathway in the development of diabetic retinopathy (DR). A recent report showed that leukocyte cell-derived chemotaxin 2 (LECT2) suppresses the VEGF signaling in endothelial cells. However, the clinical relevance of LECT2 in DR is unknown. This study aimed to investigate serum LECT2 levels and the presence of DR.

METHODS

The study included 230 people with type 2 diabetes mellitus (DM), 95 with DR and 135 without DR. Serum LECT2 levels were measured using an enzyme-linked immunosorbent assay. Data were evaluated using Spearman's rank correlation, univariate and multivariate logistic regression.

RESULTS

Serum LECT2 levels were significantly lower in participants with DM having DR than in those not having DR (35.6±14.9ng/ml vs. 44.5±17.6ng/ml, P<0.001). Spearman's rank correlation analysis revealed a significant association between serum LECT2 levels and the presence of DR (P<0.001). Multiple regression analysis revealed that serum LECT2 levels were independently related to DR (P<0.001).

CONCLUSIONS

These findings indicated that serum LECT2 level is negatively associated with the presence of DR and suggest that low circulating LECT2 level is a risk factor for DR.

Serum Levels of Brain-Derived Neurotrophic Factor Are Associated with Diabetes Risk, Complications, and Obesity: a Cohort Study from Chinese Patients with Type 2 Diabetes

Brain-derived neurotrophic factor (BDNF) is associated with systemic inflammatory conditions, such as diabetes. The aim of this study was to assess the serum BDNF levels in Chinese patients with type 2 diabetes (T2DM). From the outpatient clinic at the endocrinology department of our hospital, all patients with long-standing T2DM were recruited for this study between August 2014 and December 2014. Serum levels of BDNF were assayed with solid-phase sandwich ELISA, and the demographical and clinical data were evaluated on admission. Median serum BDNF levels were significantly lower in patients with T2DM compared to control subjects (15.9 ng/mL (interquartile range (IQR), 12.6-19.8) VS. 24.6 ng/mL (IQR, 17.2-27.8); P < 0.0001). Serum BDNF levels were inversely correlated with fasting glucose (r = -0.394, P < 0.0001) and duration of illness (r = -0.272, P < 0.0001) in T2DM patients. Based on the receiver operating characteristic (ROC) curve, the optimal cutoff value of serum BDNF levels as an indicator for diagnosis of T2DM was projected to be 23.0 ng/mL, which yielded a sensitivity of 89.0 % and a specificity of 60.9 %, with the area under the curve at 0.794 (95 % confidence interval (CI), 0.747-0.841; P < 0.001). In multivariate logistic regression analysis, after adjusting for other significant factors, BDNF can be seen as an indicator of independent diabetes complications with an odds ratio (OR) of 0.84 (95 % CI, 0.75-0.89; P < 0.001) and obesity with an OR of 0.88 (95 % CI, 0.80-0.92; P < 0.001). Our study suggested that low levels of BDNF accompany impaired glucose metabolism. Importantly, we found that decreased BDNF were correlated with obesity and diabetes complications.

High Mannose-Binding Lectin Serum Levels Are Associated with Diabetic Retinopathy in Chinese Patients with Type 2 Diabetes

OBJECTIVE

To investigate mannose-binding lectin (MBL) serum levels in type 2 diabetic patients with and without diabetic retinopathy (DR).

METHODS

Serum MBL levels were determined in type 2 diabetic patients (N=324) as well as in 300 healthy control Subjects. Multivariate analyses were performed using logistic regression models. Receiver operating characteristic curves (ROC) was used to test the overall predict accuracy of MBL and other markers.

RESULTS

Diabetic patients with DR and vision-threatening diabetic retinopathy (VTDR) had significantly higher MBL levels on admission (P<0.0001 and P<0.0001). MBL improved the area under the receiver operating characteristic curve of the diabetes duration for DRfrom 0.82(95% confidence interval [CI], 0.77-0.86) to 0.88(95% CI, 0.82-0.96; P<0.01) and for VDTR from 0.85(95% CI, 0.77-0.92) to 0.90(95% CI, 0.83-0.96; P<0.01). Multivariate logistic regression analysis adjusted for common risk factors showed that serum MBL levels(per log-unit increase) was an independent predictor of DR (OR=3.45; 95%CI: 1.42-7.05) and VTDR (OR=4.42; 95%CI: 1.51-8.18).

CONCLUSION

MBL is a novel, independent diagnostic marker of DR in type 2 diabetic patients, suggesting that MBL may be involved in the pathogenesis of DR in diabetic patients.

Serum 25-hydroxyvitamin D level and diabetic nephropathy in patients with type 2 diabetes mellitus

OBJECTIVE

Patients with chronic kidney disease have a very high prevalence of deficiency of 25-hydroxyvitamin D [25(OH)D]. We evaluate the association between 25(OH)D and diabetic nephropathy (DN) in a Chinese sample with type 2 diabetes mellitus.

METHOD

The subjects were patients with diabetes mellitus who were hospitalized at our hospital during the period from June 2012 to July 2014. Serum levels of 25(OH)D were tested at admission. DN was defined as a urinary albumin-to-creatinine ratio ≥30 mg/g in a random spot urine sample. Multivariate analyses were performed using logistic regression models.

RESULTS

We found that serum 25(OH)D levels were significantly lower in diabetes with DN as compared to without DN [8.5 (IQR 6.8-11.3) vs. 13.9 (IQR 11.2-18.2) ng/ml, P < 0.0001]. Based on the ROC curve, the optimal cutoff value of serum 25(OH)D levels as an indicator for diagnosis of DN was projected to be 10.5 ng/ml, which yielded a sensitivity of 82.6 % and a specificity of 72.7 %, with the area under the curve at 0.807 [95 % confidence interval (CI) 0.764-0.849]. Multivariate logistic regression analysis adjusted for common risk factors showed that with serum 25(OH)D level ≤10.5 ng/ml was an independent indicator of DN [odds ratio (OR) = 6.559; 95 % CI 2.864-11.368].

CONCLUSIONS

Our findings suggested that diabetes with DN had lower serum 25(OH)D levels and that determination of 25(OH)D statuses might be used to identify patients at increased risk of developing nephropathy complications.