Exploring the role of osteoglycin in type 2 diabetes: implications for insulin resistance and vascular pathophysiology

Osteoglycin, a fundamental proteoglycan within the vascular extracellular matrix, is expressed in vascular smooth muscle cells (VSMCs). Type 2 diabetes (T2D) is associated with cardiovascular disease (CVD) but the role of osteoglycin in the development of CVD is controversial to date. Therefore, our aims are to determine and compare the level of osteoglycin in T2D patients with/without CVD versus control subjects both at serum and vascular tissue and to analyze in vitro role of osteoglycin in VSMCs under calcified conditions. For this, serum osteoglycin levels were determined by enzyme-linked immunosorbent assay (ELISA) in 117 controls and 129 patients with T2D (46 with CVD and 83 without CVD), revealing a significant increase in patients with T2D compared with controls. Osteoglycin level was not an estimator of CVD but correlated with markers of insulin resistance (triglycerides and triglycerides/high-density lipoprotein cholesterol index) in patients with T2D. At the vascular level, osteoglycin expression was assessed by RT-qPCR and immunohistochemistry, and no significant differences were observed between calcified arteries from patients with T2D and noncalcified arteries from controls. In vitro experiments using VSMCs (mock and overexpressing osteoglycin) under calcifying conditions were performed to analyze the osteoglycin function. The overexpression of osteoglycin in VMSCs under calcifying conditions revealed an increase of cell proliferation without effect on apoptosis and an upregulation of the expression of autotaxin (ATX) involved in inflammatory processes. In conclusion, osteoglycin could play a role in glycemic homeostasis, being a potential biomarker of insulin resistance in patients with T2D. Furthermore, osteoglycin could indirectly participate in the development of atherosclerosis through its regulatory effect on ATX and by proliferating VSMCs.NEW & NOTEWORTHY This study uncovers an increase of serum osteoglycin levels in patients with type 2 diabetes, which does not appear to be associated with the development of atherosclerosis, but rather with insulin resistance in this population. Overexpression of osteoglycin increased proliferation and upregulated the expression of autotaxin in vascular smooth muscle cells within calcified environments. Osteoglycin could be a biomarker of insulin resistance for type 2 diabetes and could be indirectly involved in the development of atherosclerosis.

Association between oxidative-stress-related markers and calcified femoral artery in type 2 diabetes patients

Currently, there are not many in-depth studies focusing on the protein analysis of antioxidants involved in the calcification of the femoral artery. In this context, this study aimed to increase the knowledge of the molecular redox mechanisms involved in this process. Samples from calcified femoral artery sections of seven patients diagnosed with type 2 diabetes (T2D) and critical ischemia were analyzed. The isolated proteins were identified using liquid chromatography and mass-mass spectrometry and were used to generate a protein-protein interaction (PPI) network. Subsequently, highly interconnected regions within the PPI network were identified to obtain a representative module linked to oxidative stress. The proteins of this module with a higher degree of centrality (hubs) were selected to validate them by datamining, transcriptomic and proteomic assays. The analysis of modules of the femoral PPI network showed a module with mainly antioxidant function in which superoxide dismutase 2 (SOD2) was reported as the most important hub. SOD2 was validated at transcriptomic and proteomic level and confirmed by datamining. These results indicate that SOD activity is highly linked to the atherosclerotic process. We suggest that SOD2 could be a potential therapeutic target to prevent the calcification of the femoral artery. The maintenance of optimal SOD2 levels and its cofactors could be used as a preventive strategy for vascular calcification and the related cardiovascular complications in T2D patients.

Influence of wound scores and microbiology on the outcome of the diabetic foot syndrome

AIMS

To establish if the microbiology and the TEXAS, PEDIS and Wagner wound classifications of the diabetic foot syndrome (DFS) predict amputation.

METHODS

Prospective cohort study of 250 patients with DFS from 2009 to 2013. Tissue samples for culture were obtained and wound classification scores were recorded at admission.

RESULTS

Infection was monomicrobial in 131 patients (52%). Staphylococcus aureus was the most frequent pathogen (76 patients, 30%); being methicillin-resistant S. aureus in 26% (20/76) Escherichia coli and Enterobacter faecalis were 2nd and 3rd most frequent pathogens. Two hundred nine patients (85%) needed amputation being major in 25 patients (10%). The three wound scales associated minor amputation but did not predict this outcome. Predictors of minor amputation in the multivariate analysis were the presence of osteomyelitis, the location of the wound in the forefoot and of major amputation elevated C reactive proteine (CRP) levels. A low ankle-brachial index (ABI) predicted major amputation in the follow-up. Overall, 74% of gram-positives were sensitive to quinolones and 98% to vancomycin and 90% of gram-negatives to cefotaxime and 95% to carbapenems.

CONCLUSIONS

The presence of osteomyelitis and the location of the wound in the forefoot predict minor amputation and elevated CRP levels predict major amputation. In the follow-up a low ABI predicts major amputation.

Clinical and health costs impact of progress in diagnosis and treatment in venous thromboembolic disease: evolution in 15 years

BACKGROUND

The therapeutic and diagnostic approach in deep vein thrombosis (DVT) has changed enormously in the last two decades with the introduction of ultrasound, low-molecular-weight heparin (LMWH), and premature motion. The aim of this study is to evaluate these changes and analyze their clinical and economic aspects.

METHODS

We registered all inpatients with a diagnosis of DVT during 1994 (n=110) and 2009 (n=75) and their sociodemographic and clinical features in a descriptive observational design. We performed a comparison of diagnostic techniques, length of stay, inpatient complications, and costs thus derived for both series, based on 2009 prices, so that we could get comparable results.

RESULTS

Ninety-one percent of inpatients in 1994 were diagnosed by venography, whereas, in 2009, the diagnosis was based on clinical features, D-dimer, and ultrasound in 100% of patients. Inpatient treatment went from 7% LMWH in 1994 to 96% in 2009, and as outpatient from 82% acenocumarol to 90.6% LMWH. Complications decreased by 13.3%. Length of stay was 2.7 higher in 1994. Globally, the cost per patient decreased by 63.39%, based primarily on reduced length of stay.

CONCLUSIONS

The current diagnostic and therapeutic approach in DVT allows for effective treatment, fewer complications, and a drastic reduction in inpatient costs.