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Background: Obesity and Overweight which are globally increasing, are one of the main risk factors for the development of chronic, non communicable diseases. This is not only observed in the so called industrialized nations, but mainly targeting the population dense low and middle income countries. Obesity and overweight are not only associated with increased biochemical risk factors concerning e.g. lipid and glucose metabolism, but also with increased oxidative stress and DNA/chromosomal damage. Therefore, one of the main recommendations to reduce disease risk globally is weight reduction. Aim: In a pilot study we assessed the impact of a one year´s supervised weight reduction program on body weight, biochemical parameters and damage to the DNA in obese adults in Austria. Methods: 19 obese school teachers were enrolled in this pilot program. Over the period of one year they received a supervised program considering increased physical activity and a nutritional education. During this year body weight and composition was assessed as well as blood samples were taken. From the blood samples peripheral blood mononuclear cells (PBMC) were isolated and the comet assay (strand breaks, resistance to H2O2, FPG-sensitive sites) was performed. Results: First results show a highly significant decrease of all measured end points of the comet assay (p

The comet assay is the method of choice for measuring DNA damage. In human studies mostly peripheral blood mononuclear cells (PBMC) are used to conduct this single cell gel electrophoresis (Azqueta and Collins, 2013) and also a method for whole blood was described recently (Al-Salmani et al., 2013). However, oral viable leucocytes, obtained via mouth washes, might serve as a non-invasive alternative for the comet assay (Osswald et al., 2003). During a cross-sectional human study, comet assay of oral leucocytes in addition to PBMC and whole blood was performed. In total 146 female patients with diabetes mellitus type 2 donated oral leucocytes. Therefore, they rinsed their mouth with tap water which than was added to a sodium chloride solution. After washing the cells, the separation of oral leucocytes and buccal cells was performed with density gradient centrifugation. Oral leucocytes were counted and comet assay (strand breaks, resistance to H2O2, FPG-sensitive sites) was performed. Cell counts of oral leucocytes differed substantially and therefore are the limiting step. Only 110 patients (75 %) donated enough cells to perform the Comet assay. Resulting % Tail DNA (strand breaks, resistance to H2O2, FPG-sensitive sites) differed between PBMC vs. oral leucocytes and whole blood vs. oral leucocytes, but also between PBMC vs. whole blood. Nevertheless, values of % Tail DNA of all three matrices were in a biological comparable range. If sampling of oral leucocytes gets more reliable, it could be a fast alternative method to measure DNA damage in larger cohorts without any invasive needs.

Diabetes mellitus type 2 is very often associated with increased levels of reactive oxygen species. Previous studies also showed higher DNA damage in patients with diabetes mellitus type 2 compared to healthy controls (Tatsch et al., 2012; Blasiak et al., 2004). However, blood glucose concentration and level of glycated hemoglobin (HbA1c) can vary widely between diabetic patients and depends on country specific threshold levels. Therefore our aim was to analyze DNA damage in patients with lower glycated hemoglobin (HbA1c7.5%; n=72). In total 146 patients of the local diabetes outpatient clinic in Vienna were enrolled (age: 67.5±9,9years; BMI: 35.0±7.6kg/m²; diabetes duration: 14.4±8.0years).The Comet assay was performed in PBMCs (strand breaks, resistance to H2O2, FPG-sensitive sites) and whole blood (strand breaks, FPG-sensitive sites). No differences in DNA damage were found between the two groups of low vs. high HbA1c. In addition, neither diabetes duration nor medication (Insulin vs. oral antidiabetics) had an influence on DNA damage. Therefore we can conclude that female patients with diabetes mellitus type 2 in Austria are under optimal treatment to control blood sugar and other metabolic parameter, that no differences in DNA damage could be observed.