CDATA[The Effect of Oxidative Stress and Antioxidant Therapies on Pancreatic ß-cell Dysfunction: Results from in Vitro and in Vivo Studies.

BACKGROUND: Oxidative stress is a hallmark of many diseases. A growing body of evidence suggests that hyperglycemia-induced oxidative stress plays an important role in pancreatic ß-cells dysfunction and apoptosis, as well as in the development and progression of diabetic complications. Considering the vulnerability of pancreatic ß-cells to oxidative damage, the induction of endogenous antioxidant enzymes or exogenous antioxidant administration has been proposed to protect pancreatic ß-cells from damage. OBJECTIVES: The present review aims to provide evidence of the effect of oxidative stress and antioxidant therapies on pancreatic ß-cell function, based on in vitro and in vivo studies. METHODS: The MEDLINE and EMBASE databases were searched to retrieve available data. RESULTS: Due to poor endogenous antioxidant mechanisms, pancreatic ß-cells are extremely sensitive to Reactive Oxygen Species (ROS). Many natural extracts have been tested in vitro in pancreatic ß-cell lines in terms of their antioxidant and diabetes mellitus ameliorating effects, and the majority of them have shown a dose-dependent protective role. On the other hand, there is relatively limited evidence regarding the in vitro antioxidant effects of antidiabetic drugs on pancreatic ß -cells. Concerning in vivo studies, several natural extracts have shown beneficial effects in the setting of diabetes by decreasing blood glucose and lipid levels, increasing insulin sensitivity, and by up-regulating intrinsic antioxidant enzyme activity. However, there is limited evidence obtained from in vivo studies regarding antidiabetic drugs. CONCLUSION: Antioxidants hold promise for developing strategies aimed at the prevention or treatment of diabetes mellitus associated with pancreatic ß-cells dysfunction, as supported by in vitro and in vivo studies. However, more in vitro studies are required for drugs.

Plasma Irisin Levels in Subjects with Type 1 Diabetes: Comparison with Healthy Controls.

Irisin is a myokine that increases energy expenditure. In this cross-sectional study, we examined for differences in plasma irisin concentrations between subjects with type 1 diabetes mellitus and healthy individuals and searched for associations between plasma irisin levels and clinical and biochemical characteristics as well as self-reported physical activity. A total of 79 subjects with type 1 diabetes [age 38.2±12.5 years, men/women (n): 27/52], were consecutively recruited. Moreover, 53 healthy controls, matched for age and body mass index with those with diabetes were recruited. Plasma irisin was measured with ELISA. Participants were asked about their physical activity during the last week. We also measured trunk and visceral fat. Circulating irisin levels were lower in subjects with diabetes than in controls [median value (interquartile range): 53.0 (35.2, 106.3) vs. 178.1 (42.6, 641.6) ng/ml, respectively, p<0.001]. In the group of diabetes, univariate analysis showed that irisin levels were associated with waist circumference (beta=-0.283, p=0.023), serum triglycerides (beta=-0.282, p=0.031), and trunk fat (beta=-0.324, p=0.012). In multivariate analysis after adjustment for potential confounders, irisin levels were associated independently only with waist circumference (beta=-0.403, p=0.005). Among controls, multivariate analysis demonstrated that irisin levels were associated with pack-years of smoking (beta=-0.563, p=0.012) and fasting triglycerides (beta=-0.338, p=0.041). Circulating irisin levels were lower in subjects with diabetes in comparison with healthy-matched controls. In conclusion, plasma irisin concentrations in subjects with diabetes were associated with waist circumference, while in controls with serum triglycerides and pack-years of smoking.

Diabetic Foot Infections: Update on Management.

PURPOSE OF REVIEW: Diabetic foot infections (DFIs) are common in patients with diabetes mellitus complicated by foot ulcers and can be classified in different categories based on their severity. In this report, we present the diagnosis and management of DFIs according to their classification. RECENT FINDINGS: While appropriate antibiotic regiments and surgical techniques for the treatment of DFIs are well established, new technologies and techniques for example in medical imaging, wound care modalities, and supplementary therapy approaches show potentially promising results in preventing DFIs. As with every complex disease, fine tuning DFI management can be challenging as it requires careful evaluation of different parameters. It demands timely action, close collaboration of different specialties, and patient cooperation.