Complications of Diabetes

MMP10 Promotes Efficient Thrombolysis After Ischemic Stroke in Mice with Induced Diabetes

Diabetes is an important risk factor for ischemic stroke (IS). Tissue-type plasminogen activator (tPA) has been associated with less successful revascularization and poor functional outcome in diabetes. We assessed whether a new thrombolytic strategy based on MMP10 was more effective than tPA in a murine IS model of streptozotocin (STZ)-induced diabetes. Wild-type mice were administered a single dose of streptozotocin (STZ) (180 mg/kg) to develop STZ-induced diabetes mellitus. Two weeks later, IS was induced by thrombin injection into the middle cerebral artery and the effect of recombinant MMP10 (6.5 μg/kg), tPA (10 mg/kg) or tPA/MMP10 on brain damage and functional outcome were analysed. Motor activity was assessed using the open field test. Additionally, we studied plasminogen activator inhibitor-1 (PAI-1) and thrombin-antithrombin complex levels (TAT) by ELISA and oxidative stress and blood-brain barrier (BBB) integrity by immunohistochemistry and western blot. MMP10 treatment was more effective at reducing infarct size and neurodegeneration than tPA 24 h and 3 days after IS in diabetic mice. Locomotor activity was impaired by hyperglycemia and ischemic injury, but not by the thrombolytic treatments. Additionally, TAT, oxidative stress and BBB permeability were reduced by MMP10 treatment, whereas brain bleeding or PAI-1 expression did not differ between treatments. Thrombolytic treatment with MMP10 was more effective than tPA at reducing stroke and neurodegeneration in a diabetic murine model of IS, without increasing haemorrhage. Thus, we propose MMP10 as a potential candidate for the clinical treatment of IS in diabetic patients.

Plasma soluble CD36, carotid intima-media thickness and cognitive function in patients with type 2 diabetes

INTRODUCTION

Diabetes and atherosclerosis are both risk factors of cognitive deficits. Scavenger receptor CD36 is associated with increasing risk of diabetes and atherosclerosis, and may play a role in cognitive deficits. The aim of this study is to determine the correlations of plasma soluble CD36 concentrations with carotid intima-media thickness (IMT) and cognitive function in patients with type 2 diabetes.

MATERIAL AND METHODS

We determined the levels of soluble CD36 (sCD36), blood lipids, fasting blood glucose, glycosylated hemoglobin, carotid atherosclerosis as IMT, cognitive function by the Montreal Cognitive Assessment (MoCA) scoring system, and other clinical characteristics in 357 patients with type 2 diabetes.

RESULTS

Diabetic patients with the lowest quartile of IMT (Q1) had lower sCD36 concentrations (ANOVA, p_trend < 0.05) and higher MoCA scores than upper ones (Q2-Q4) (p_trend < 0.05), and those with the highest quartile of sCD36(Q4) had higher FBG, LDL-C and carotid IMT than lower ones (Q1-Q3) (p_trend < 0.05 for all). Plasma log₁₀(sCD36) was significantly correlated with carotid IMT (r = 0.202, p < 0.001) after adjustment for age, gender, and education level. Carotid IMT was significantly associated with MoCA scores (r = 0.284, p < 0.001) after adjustment for, age, gender, education level, duration of DM and hypertension. There were no correlations between sCD36 and MoCA scores (r = -0.038, p = 0.470).

CONCLUSIONS

Our study shows that sCD36 is associated with carotid IMT, and carotid IMT is inversely correlated with cognitive function in type 2 diabetic patients. Nevertheless, no cross-sectional association between sCD36 and MoCA scores was detected in this study.

Assessing Screening Guidelines for Cardiovascular Disease Risk Factors using Routinely Collected Data

This study investigates if laboratory data can be used to assess whether physician-retesting patterns are in line with established guidelines, and if these guidelines identify deteriorating patients in a timely manner. A total of 7594 patients with high cholesterol were studied, along with 2764 patients with diabetes. More than 90% of borderline high cholesterol patients are retested within the 3 year recommended period, however less than 75% of pre-diabetic patients have repeated tests within the suggested 1-year time frame. Patients with borderline high cholesterol typically progress to full high cholesterol in 2-3 years, and pre-diabetic patients progress to full diabetes in 1-2 years. Data from routinely ordered laboratory tests can be used to monitor adherence to clinical guidelines. These data may also be useful in the design of adaptive testing strategies that reduce unnecessary testing, while ensuring that patient deterioration is identified in a timely manner. Established guidelines for testing of total serum cholesterol for hypercholesterolemia are appropriate and are well-adhered to, whereas guidelines for glycated hemoglobin A1c testing for type 2 diabetes mellitus could be improved to bring them in line with current practice and avoid unnecessary testing.

Transplantation of stromal-derived factor 1α and basic fibroblast growth factor primed insulin-producing cells reverses hyperglycaemia in diabetic rats

The defective insulin production is associated with severely reduced islet cell mass leading to diabetes. Growth factors preconditioned stem cells have arisen as an effective therapy to treat many diseases including diabetes. The current study was designed to assess the effect of pretreatment of ASCs derived IPCs with combination of stromal cell derived factor 1 alpha (SDF1α) and basic fibroblast growth factor (bFGF) in improving glucose tolerance in streptozotocin induced diabetic rats. The results showed maximally significant reduction in hyperglycaemia and fibrosis, while up-regulation of survival and pancreas-specific genes, insulin levels and homing of transplanted cells in SDF-1α + bFGF IPCs transplanted rats as compared with other groups. Moreover, increased expression of insulin, glucagon and Glut-2 in pancreas of the SDF-1α + bFGF IPCs transplanted group indicated more regeneration of pancreas. Hence, the use of IPCs preconditioned with SDF-1α + bFGF would be more effective for treating diabetes.

Hyperglycemia and diabetes have different impacts on outcome of ischemic and hemorrhagic stroke

INTRODUCTION

Stroke is the second leading cause of long-term disability and death worldwide. Diabetes and hyperglycemia may impact the outcome of stroke. We examined the impact of hyperglycemia and diabetes on in-hospital death among ischemic and hemorrhagic stroke patients.

MATERIAL AND METHODS

Data from 766 consecutive patients with ischemic (83.15%) and hemorrhagic stroke were analyzed. Patients were classified into four groups: ischemic and diabetic; ischemic and non-diabetic; hemorrhagic and diabetic; and hemorrhagic and non-diabetic. Serum glucose was measured on admission at the emergency department together with biochemical and clinical parameters.

RESULTS

Mean admission glucose in ischemic stroke patients with diabetes was higher than in non-diabetic ones (p < 0.001) and in hemorrhagic stroke patients with diabetes than in those without diabetes (p < 0.05). Mean admission glucose in all patients who died was significantly higher than in patients who survived. In multivariate analysis, the risk factors for outcome in patients with ischemic stroke and without diabetes were age, admission glucose level and estimated glomerular filtration rate (eGFR), while in diabetics they were female gender, admission glucose level, and eGFR; in patients with hemorrhagic stroke and without diabetes they were age and admission glucose levels. The cut-off value in predicting death in patients with ischemic stroke and without diabetes was above 113.5 mg/dl, while in diabetics it was above 210.5 mg/dl.

CONCLUSIONS

Hyperglycemia on admission is associated with worsened clinical outcome and increased risk of in-hospital death in ischemic and hemorrhagic stroke patients. Diabetes increased the risk of in-hospital death in hemorrhagic stroke patients, but not in ischemic ones.

Diabetes negatively affects cortical and striatal GABAergic neurons: an effect that is partially counteracted by exendin-4

Diabetes negatively affects specific subtypes of inhibitory neurons in brain areas that regulate sensory and motor functions. This impairment can be partially reversed by exendin-4 (Ex-4). The findings could contribute to the development of treatments against diabetic neurological complications.

Type 2 diabetic (T2D) patients often develop early cognitive and sensorimotor impairments. The pathophysiological mechanisms behind these problems are largely unknown. Recent studies demonstrate that dysfunctional γ-aminobutyric acid (GABAergic) neurons are involved in age-related cognitive decline. We hypothesized that similar, but earlier dysfunction is taking place under T2D in the neocortex and striatum (two brain areas important for cognition and sensorimotor functions). We also hypothesized that the T2D-induced effects are pharmacologically reversible by anti-diabetic drugs targeting the glucagon-like peptide-1 receptor (GLP-1R). We determined the effect of T2D on cortical and striatal GABAergic neurons positive for glutamic acid decarboxylase-67 (GAD67), calbindin (CB), parvalbumin (PV) and calretinin (CR) by using immunohistochemistry and quantitative microscopy. Young and middle-aged T2D Goto-Kakizaki (GK) (a model of spontaneous T2D) and Wistar rats were used. Furthermore, we determined the therapeutic potential of the GLP1-R agonist exendin-4 (Ex-4) by treating middle-aged GK rats for 6 weeks with 0.1 μg/kg Ex-4 twice daily. We show that T2D reduced the density of GAD67-positive neurons in the striatum and of CB-positive neurons in both striatum and neocortex. T2D also increased the average volume of PV-positive interneurons in the striatum. Ex-4 treatment increased the density of CB-positive neurons in the striatum of GK rats. Our data demonstrate that T2D negatively affects GAD67 and CB-positive GABAergic neurons in the brain during aging, potentially identifying some of the pathophysiological mechanisms to explain the increased prevalence of neurological complications in T2D. We also show a specific, positive effect of Ex-4 on striatal CB-positive neurons, which could be exploited in therapeutic perspective.

Statin-associated myopathy and the quest for biomarkers: can we effectively predict statin-associated muscle symptoms?

Over the past three decades, statins have become the cornerstone of prevention and treatment of atherosclerotic cardiovascular and metabolic diseases. Albeit generally well tolerated, these drugs can elicit a variety of muscle-associated symptoms that represent the most important reason for treatment discontinuation. Statin-associated myopathy has been systematically underestimated by randomized controlled trials as compared with the incidence observed in clinical practice and obtained from patient registries. There are several reasons for this discrepancy, among which the lack of reliable diagnostic tests and a validated questionnaire to assess muscle symptoms are recognized as unmet needs. Here, we review the cellular and molecular mechanisms underlying statin-associated myopathy and discuss the experimental and clinical data on various biomarkers to diagnose and predict muscle-related complaints.

Association between Serum Cystatin C and Diabetic Foot Ulceration in Patients with Type 2 Diabetes: A Cross-Sectional Study

Serum cystatin C (CysC) has been identified as a possible potential biomarker in a variety of diabetic complications, including diabetic peripheral neuropathy and peripheral artery disease. We aimed to examine the association between CysC and diabetic foot ulceration (DFU) in patients with type 2 diabetes (T2D). 411 patients with T2D were enrolled in this cross-sectional study at a university hospital. Clinical manifestations and biochemical parameters were compared between DFU group and non-DFU group. The association between serum CysC and DFU was explored by binary logistic regression analysis. The cut point of CysC for DFU was also evaluated by receiver operating characteristic (ROC) curve. The prevalence of coronary artery disease, diabetic nephropathy (DN), and DFU dramatically increased with CysC (P < 0.01) in CysC quartiles. Multivariate logistic regression analysis indicated that the significant risk factors for DFU were serum CysC, coronary artery disease, hypertension, insulin use, the differences between supine and sitting TcPO₂, and hypertension. ROC curve analysis revealed that the cut point of CysC for DFU was 0.735 mg/L. Serum CysC levels correlated with DFU and severity of tissue loss. Our study results indicated that serum CysC was associated with a high prevalence of DFU in Chinese T2D subjects.