Publications (12)94.32 Total impact
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Article: N-terminal pro-B-type natriuretic peptide in early and advanced phases of obesity.
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ABSTRACT: Increased plasma amino-terminal-cleavage-fragment of NP (NT-proBNP) is an established indicator for heart failure. Moreover, obese adults had low circulating NT-proBNP suggesting an obesity-related dysregulation (natriuretic handicap). Secretion and/or clearance of NT-proBNP were discussed to be impaired in obesity. As only older adults were investigated so far, it remains unclear when during the evolution of obesity the state of a natriuretic handicap develops, and whether NT-proBNP may still serve as a relevant cardiac marker in obese juveniles. We analysed NT-proBNP in juvenile (n=274, 10-18 years) and middle-aged (n=277, 18-50 years) normal weight (n=213) and obese (n=338) probands together with complex anthropometry, carotis sonography, clinical, and laboratory parameters. NT-proBNP showed a significant gender and age interaction. Adult females had significant higher NT-proBNP than adult males, and higher levels than juvenile females. Adult males had lower levels than juvenile males. Only a weak age and weight interaction was seen with obese juveniles which showed higher NT-proBNP than obese adults. Moreover, normal weight probands had higher NT-proBNP than overweight and obese. In a multiple regression including all probands, gender, creatinine and uric acid were the best predictors for NT-proBNP. In adults, female gender is the strongest driver for increased NT-proBNP. These results argue against an essential influence of obesity to B-type cardiac natriuretic hormone system regulation in the absence of heart failure, and suggest NT-proBNP as a useful cardiac marker irrespective of age and obesity.Clinical Chemistry and Laboratory Medicine 06/2011; 49(9):1539-45. · 2.15 Impact Factor -
Article: Glucose-transporter-mediated positive inotropic effects in human myocardium of diabetic and nondiabetic patients.
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ABSTRACT: Insulin causes inotropic effects via Ca(2+)-dependent and Ca(2+)-independent pathways. The latter one is potentially glucose dependent. We examined inotropic responses and signal transduction of insulin in human atrial myocardium of diabetic and nondiabetic patients to test for the role of glucose transporters. Experiments were performed in isolated atrial myocardium of 88 patients undergoing cardiac surgery and 28 ventricular muscle samples of explanted hearts. Influence of insulin (0.02 micromol/L) on isometric twitch force was examined with and without blocking glucose transporter (GLUT) 4 translocation (latrunculin), sodium-coupled glucose transporter (SGLT) 1 (phlorizin, T-1095A), or PI3-kinase (wortmannin). Experiments were performed in Tyrode solution containing glucose or pyruvate as energetic substrate. Messenger RNA expression of glucose transporters (GLUT1, GLUT4, SGLT1, SGLT2) was analyzed in atrial and ventricular myocardium of both diabetic and nondiabetic patients. Developed force increases after insulin (to 117.8% +/- 2.4% and 115.8% +/- 1.9%) in trabeculae from patients with and without diabetes. Inotropic effect was reduced after displacing glucose with pyruvate as well as after PI3-kinase inhibition (to 103% +/- 2%) or inhibition of glucose transporters GLUT4 (to 105% +/- 2%) and SGLT1 (phlorizin to 106% +/- 2%, T-1095A to 105% +/- 2%), without differences between the 2 groups. In glucose-free pyruvate-containing solution, only inhibition of PI3-kinase but not blocking glucose transporters resulted in further inhibitory effects. Messenger RNA expression did not show significant differences between patients with or without diabetes. Insulin exerts positive inotropic effects in human atrial myocardium. These effects are mediated via a PI3-kinase-sensitive and a glucose-transport-sensitive pathway. Differences in functional effects or messenger RNA expression of glucose transporters were not detectable between patients with and without diabetes.Metabolism: clinical and experimental 07/2010; 59(7):1020-8. · 2.59 Impact Factor -
Article: Insulin and Hippocampus Activation in Response to Images of High-Calorie Food in Normal Weight and Obese Adolescents
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ABSTRACT: Responsiveness to food cues, especially those associated with high-calorie nutrients may be a factor underlying obesity. An increased motivational potency of foods appears to be mediated in part by the hippocampus. To clarify this, we investigated by means of 3-T magnetic resonance imaging (MRI) the activation of the hippocampus and associated brain structures in response to pictures of high-calorie and low-calorie foods in 12 obese and 12 normal-weight adolescents. To investigate the relationship between neuronal activation patterns (e.g., hippocampus) to the caloric content of food images and plasma insulin levels, we performed a multiple regression analysis. Interestingly, a significant positive correlation between fasting plasma levels of insulin, waist circumference, and right hippocampal activation was seen after stimulation with high-caloric food images. BMI values did not correlate significantly with the hippocampal activation. On the other hand, we found a significant negative correlation in response to high-caloric food images and the plasma levels of insulin in the medial right gyrus frontalis superior and in the left thalamus. In summary, our data show that insulin is importantly involved in the central regulation of food intake. The significant positive relationship between hippocampal activation after stimulation with high-caloric food images, plasma insulin levels, and waist circumference suggests a permissive role of insulin signaling pathways in the hippocampal control of eating behavior. Interestingly, only the waist circumference, as a main indicator of abdominal obesity, correlated significantly with the hippocampal activation patterns, and not the BMI.Obesity 02/2010; 18(8):1552-1557. · 4.28 Impact Factor -
Article: Functional effects of glucose transporters in human ventricular myocardium.
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ABSTRACT: Insulin-dependent positive inotropic effects (PIE) are partially Ca(2+) independent. This mechanism is potentially glucose dependent. In contrast to most animal species, human myocardium expresses high levels of sodium-glucose-transporter-1 (SGLT-1) mRNA besides the common glucose-transporters-1 and -4 (GLUT1, GLUT4). We used ventricular myocardium from 61 end-stage failing human hearts (ischaemic cardiomyopathy, ICM and dilated cardiomyopathy, DCM) and 13 non-failing donor hearts. The effect of insulin on isometric twitch force was examined with or without blocking of PI3-kinase, GLUT4-translocation, or SGLT-1. Substrate-dependent (glucose vs. pyruvate vs. palmitoyl-carnitine) effects were tested in atrial myocardium. mRNA expression of glucose transporters was analysed. Insulin increased developed force by 122 + or - 7.4, 121.7 + or - 2.5, and 134.1 + or - 5.7% in non-failing, DCM, and ICM (P < 0.05 vs. DCM), respectively. Positive inotropic effect was partially blunted by inhibition of PI-3-kinase, GLUT4, or SGLT1. Combined inhibition of PI3-kinase and glucose-transport completely abolished PIE. Positive inotropic effect was significantly stronger in glucose-containing solution compared with pyruvate or palmitoyl-carnitine containing. mRNA expression showed only a tendency towards elevated GLUT4-expression in ICM. Positive inotropic effect of insulin is pronounced in ICM, but underlying mechanisms are unaltered. The Ca(2+)-independent PIE of insulin is mediated via glucose-transporters. Together with the Ca(2+)-dependent PI-3-kinase mediated pathway, it is responsible for the entire PIE. Substrate-dependency affirms a glucose-dependent part of the PIE.European Journal of Heart Failure 02/2010; 12(2):106-13. · 4.90 Impact Factor -
Article: Nuchal thickness of subcutaneous adipose tissue is tightly associated with an increased LMW/total adiponectin ratio in obese juveniles.
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ABSTRACT: Subcutaneous adipose tissue (SAT) topography contributes significantly to metabolic risk profiles and atherosclerotic vascular burden in obese adults. However, little information exists concerning individual risk profiles in early phases of obesity found in childhood and adolescence. Thus, the rationale of this study was to evaluate possible impacts of SAT topography in obese juveniles on adiponectin subfractions, with special emphasis on low molecular weight (LMW) adiponectin. To address this, we analysed associations between lipometry, early metabolic and preatherosclerotic symptoms and adiponectin subfractions in 71 obese juveniles and 75 normal weight controls of similar age and gender distribution. Compared to the controls, obese juveniles had a significantly decreased ratio between high molecular weight (HMW) and total adiponectin whereas the LMW/total adiponectin ratio was increased. The LMW/total adiponectin ratio correlated significantly positively with the SAT thickness of trunk-located lipometer measure points neck, biceps, upper back, lower back, body mass index (BMI), and waist circumference. Further significant positive correlations were seen with systolic blood pressure, intima media thickness (IMT) of common carotid arteries, and metabolic parameters such as HOMA-index, leptin, oxidized LDL (oxLDL), liver transaminases, and HDL-triglycerides. This remained stable after controlling for gender. A stepwise multiple regression analysis encompassing all these variables revealed a robust positive association between LMW/total adiponectin ratio and nuchal SAT thickness defined by the lipometer measure point neck. Taken together, our data provide the first evidence that nuchal SAT thickness is tightly positively associated with an increased LMW/total adiponectin ratio.Atherosclerosis 03/2009; 203(1):277-83. · 3.79 Impact Factor -
Article: Preatherosclerosis and Adiponectin Subfractions in Obese Adolescents
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ABSTRACT: We evaluated total adiponectin, high-molecular weight (HMW), medium-molecular weight (MMW), low-molecular weight (LMW) adiponectin subfractions, clinical parameters, routine lab parameters, lipids, metabolic, inflammatory biomarkers, and intima-media thickness (IMT) of common carotid arteries in 70 obese juveniles and adolescents with preatherosclerosis and 55 normal weight controls of similar age and gender distribution. Compared with the controls, the obese probands had a significantly increased IMT (P < 0.001) and elevated ultra-sensitive C-reactive protein (P < 0.001) indicating early vascular burden. Total and HMW adiponectin were significantly decreased in the obese cohort. The ratio between HMW and total adiponectin was significantly decreased in obese probands whereas the LMW/total adiponectin ratio was increased. Overall, total-, HMW, and MMW adiponectin were significantly negatively correlated with carotid IMT. The HMW/total adiponectin ratio correlated significantly negatively, and the LMW/total adiponectin ratio significantly positively with the IMT. Furthermore, HMW adiponectin was significantly positively correlated with high-density lipoprotein (HDL)-cholesterol and serum apolipoprotein A1, and negatively with BMI, triglycerides, homeostatic model assessment (HOMA)-index, leptin, liver transaminases, and uric acid. This remained stable after controlling for gender. Multiple regression analysis of body measures and all other lab parameters showed the strongest correlation between HMW adiponectin and carotid IMT ( = -0.35, P < 0.001). Taken together, our study provides the first evidence that preatherosclerosis in obese juveniles and adolescents is associated with altered subfractions of adiponectin, whereas after multiple testing the HMW subfraction showed a better correlation to IMT compared with total adiponectin.Obesity 10/2008; 16(12):2578-2584. · 4.28 Impact Factor -
Article: Preatherosclerosis and adiponectin subfractions in obese adolescents.
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ABSTRACT: We evaluated total adiponectin, high-molecular weight (HMW), medium-molecular weight (MMW), low-molecular weight (LMW) adiponectin subfractions, clinical parameters, routine lab parameters, lipids, metabolic, inflammatory biomarkers, and intima-media thickness (IMT) of common carotid arteries in 70 obese juveniles and adolescents with preatherosclerosis and 55 normal weight controls of similar age and gender distribution. Compared with the controls, the obese probands had a significantly increased IMT (P < 0.001) and elevated ultra-sensitive C-reactive protein (P < 0.001) indicating early vascular burden. Total and HMW adiponectin were significantly decreased in the obese cohort. The ratio between HMW and total adiponectin was significantly decreased in obese probands whereas the LMW/total adiponectin ratio was increased. Overall, total-, HMW, and MMW adiponectin were significantly negatively correlated with carotid IMT. The HMW/total adiponectin ratio correlated significantly negatively, and the LMW/total adiponectin ratio significantly positively with the IMT. Furthermore, HMW adiponectin was significantly positively correlated with high-density lipoprotein (HDL)-cholesterol and serum apolipoprotein A1, and negatively with BMI, triglycerides, homeostatic model assessment (HOMA)-index, leptin, liver transaminases, and uric acid. This remained stable after controlling for gender. Multiple regression analysis of body measures and all other lab parameters showed the strongest correlation between HMW adiponectin and carotid IMT (beta = -0.35, P < 0.001). Taken together, our study provides the first evidence that preatherosclerosis in obese juveniles and adolescents is associated with altered subfractions of adiponectin, whereas after multiple testing the HMW subfraction showed a better correlation to IMT compared with total adiponectin.Obesity 10/2008; 16(12):2578-84. · 4.28 Impact Factor -
Article: Periodontal treatment improves endothelial dysfunction in patients with severe periodontitis.
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ABSTRACT: Because epidemiological studies provide evidence that periodontal infections are associated with an increased risk of progression of cardiovascular and cerebrovascular disease, we postulated that endothelial dysfunction, a critical element in the pathogenesis of atherosclerosis, would be present in patients with periodontal disease. We tested endothelial function in 30 patients with severe periodontitis and 31 control subjects using flow-mediated dilation (FMD) of the brachial artery. The groups were matched for age, sex, and cardiovascular risk factors. Three months after periodontal treatment, including both mechanical and pharmacological therapy, endothelial function was reassessed by brachial artery FMD. Markers of systemic inflammation were measured at baseline and at follow up. Flow-mediated dilation was significantly lower in patients with periodontitis than in control subjects (6.1% +/- 4.4% vs 8.5% +/- 3.4%, P = .002). Successful periodontal treatment resulted in a significant improvement in FMD (9.8% +/- 5.7%; P = .003 compared to baseline) accompanied by a significant decrease in C-reactive protein concentrations (1.1 +/- 1.9 vs 0.8 +/- 0.8 at baseline, P = .026). Endothelium-independent nitro-induced vasodilation did not differ between the study groups at baseline or after periodontal therapy. These results indicate that treatment of severe periodontitis reverses endothelial dysfunction. Whether improved endothelial function will translate into a beneficial effect on atherogenesis and cardiovascular events needs further investigation.American heart journal 07/2005; 149(6):1050-4. · 4.65 Impact Factor -
Article: [Dihydropyridines for treatment of arterial hypertension].
Pharmazie in unserer Zeit 02/2005; 34(5):388-91. -
Article: Hemochromatosis gene (HFE) polymorphisms are not associated with peripheral arterial disease.
Thrombosis and Haemostasis 07/2004; 91(6):1258-9. · 5.04 Impact Factor -
Article: The angiotensin-converting-enzyme insertion/deletion polymorphism is not related to venous thrombosis.
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ABSTRACT: The insertion/deletion (I/D) polymorphism of the gene for angiotensin-converting-enzyme (ACE) is associated with ACE plasma levels and activity. Conflicting results have been reported about the relevance of this polymorphism for venous thrombosis. The aim of the present study was to analyze the role of this polymorphism for deep venous thrombosis. The study was designed as a case-control study, including 330 patients with documented deep venous thrombosis and 354 controls. ACE genotype was determined by size-analysis of polymerase chain reaction products. Results showed that, ACE genotype frequencies were similar between patients (II: 24.8%; ID: 43.3%; DD: 31.8%) and controls (II: 22.9%; ID: 50.6%; DD: 26.6%, P = 0.15). The adjusted odds ratio of carriers of the DD geno-type for venous thrombosis was 1.24 (95% confidence interval 0.90-1.80). The polymorphism was furthermore not associated with age at first thromboembolic event or the occurrence of pulmonary embolism. From these results, we can conclude that the ACE I/D polymorphism is not a significant risk factor for deep venous thrombosis.Thrombosis and Haemostasis 02/2004; 91(1):76-9. · 5.04 Impact Factor -
Article: Images in clinical medicine. Fistula connecting the left main coronary artery with the right atrium in a marathon runner.
New England Journal of Medicine 04/2002; 346(12):904. · 53.30 Impact Factor
Top co-authors
Top Journals
Institutions
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2008–2009
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Medical University of Graz
- Klinisches Institut für Medizinische und Chemische Labordiagnostik
Graz, Styria, Austria
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2002
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Karl-Franzens-Universität Graz
Graz, Styria, Austria
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