Michael Wolzt

University of Vienna, Wien, Vienna, Austria

Are you Michael Wolzt?

Claim your profile

Publications (388)1525.29 Total impact

  • Source

    Full-text · Article · Dec 2016 · Journal of Negative Results in BioMedicine
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background/aims: The use of antihypertensive medicines has been shown to reduce proteinuria, morbidity, and mortality in patients with chronic kidney disease (CKD). A specific recommendation for a class of antihypertensive drugs is not available in this population, despite the pharmacodynamic differences. We have therefore analysed the association between antihypertensive medicines and survival of patients with chronic kidney disease. Methods: Out of 2687 consecutive patients undergoing kidney biopsy a cohort of 606 subjects with retrievable medical therapy was included into the analysis. Kidney function was assessed by glomerular filtration rate (GFR) estimation at the time point of kidney biopsy. Main outcome variable was death. Results: Overall 114 (18.7%) patients died. In univariate regression analysis the use of alpha-blockers and calcium channel antagonists, progression of disease, diabetes mellitus (DM) type 1 and 2, arterial hypertension, coronary heart disease, peripheral vascular disease, male sex and age were associated with mortality (all p<0.05). In a multivariate Cox regression model the use of calcium channel blockers (HR 1.89), age (HR 1.04), DM type 1 (HR 8.43) and DM type 2 (HR 2.17) and chronic obstructive pulmonary disease (HR 1.66) were associated with mortality (all p < 0.05). Conclusion: The use of calcium channel blockers but not of other antihypertensive medicines is associated with mortality in primarily GN patients with CKD.
    No preview · Article · Dec 2015 · Kidney and Blood Pressure Research
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: Dual antiplatelet therapy (DAPT) with a P2Y12 inhibitor and aspirin is standard in acute coronary syndrome. DAPT causes more bleeding than single antiplatelet therapy (SAPT) with a P2Y12 inhibitor. Objectives: To compare effects of SAPT and DAPT on hemostatic system activation. Patients/methods: In a randomized, parallel-group, double-blind, placebo-controlled study 44 healthy volunteers received clopidogrel (600mg, then 150mg daily) and aspirin (100mg daily) or placebo for 7 days. 44 volunteers received single dose ticagrelor (180mg) and aspirin (300mg) or placebo. ß-thromboglobulin (ß-TG, IU/l) and prothrombin fragment 1.2 (f1.2, nmol/l) were measured in blood from bleeding time incision. Data are given as geometric mean ratio (GMR [95% confidence interval]) to describe the differences in the first 2 hours and as mean differences (Δ [95% confidence interval]) in AUC to discriminate differences in effects over the total observation time. Results: Clopidogrel/aspirin and clopidogrel/placebo reduced ß-TG by a GMR of 0.51 (0.42; 0.63) and 0.54 (0.46; 0.64) at 2 hours. Ticagrelor/aspirin and ticagrelor/placebo decreased ß-TG by a GMR of 0.38 (0.26; 0.57) and 0.47 (0.31; 0.72). Ticagrelor/aspirin and ticagrelor/placebo reduced f1.2 by a GMR of 0.58 (0.45; 0.75) and 0.55 (0.38; 0.80), clopidogrel did not. Over 24 hours a difference in ß-TG occurred neither between clopidogrel/aspirin and clopidogrel/placebo (ΔAUC=-2.9 [-9.9; 4.1]), nor between ticagrelor/aspirin and ticagrelor/placebo (ΔAUC=-3.5 [-11.8; 4.7]). No difference in f1.2 occurred between clopidogrel/aspirin and clopidogrel/placebo (ΔAUC=-4.2 [-10.2; 1.8]) and between ticagrelor/aspirin and ticagrelor/placebo (ΔAUC=-3.6 [-10.9; 3.7]). Conclusions: P2Y12 inhibitor mono-therapy and DAPT inhibit hemostatic system activation to a comparable extent. This article is protected by copyright. All rights reserved.
    No preview · Article · Dec 2015 · Journal of Thrombosis and Haemostasis
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background: Clarithromycin, known as a potent inhibitor of the cytochrome P450 isoenzyme CYP3A, may increase the plasma concentration of statins metabolized by this pathway; therefore, increase the risk of interaction with statins in reference to pharmacokinetic studies. This study aimed to characterize whether the concomitant use of a statin with clarithromycin is associated with serious outcomes among adult persons. Methods: Health claims data of adult persons in the Regional Sickness Fund of Burgenland, Austria, who filled a prescription for clarithromycin between July 1, 2009 and June 30, 2012 were reviewed retrospectively. We assumed that the risk of hospitalisation increases acutely with the indication for taking an antibiotic, whereas statin use can be considered a chronic exposure with a low constant effect on hospitalisation. When defining the population as persons taking clarithromycin and the use of statins as the exposure we could achieve a comparable effect in both groups from the acute condition on hospitalisation. Therefore, we defined exposed patients as those who had overlapping treatment with a statin and unexposed controls as those who had filled a prescription for clarithromycin without concomitant statin therapy. Outcome was defined as a composite of hospital admission or death within 30 days after starting clarithromycin. We used generalised linear regression to model an association between outcome and exposure to statins. Results: Among 28,484 prescriptions of clarithromycin, 2317 persons were co-exposed to statins. Co-administration of CYP3A4 metabolized statins and clarithromycin was associated with a 2.11 fold increased risk of death or hospitalisation (95 % confidence interval [CI]: 1.79-2.48). This effect was explained by age, evidence of cardiovascular disease, diabetes mellitus and utilization of other antibiotics (multivariable adjusted risk ratio: 1.02, 95 % CI: 0.85-1.22). The sensitivity analyses did not change the significance of effect. Conclusions: The risk for hospitalisation or death in persons receiving clarithromycin increases with age and cardiovascular disease but is not causally associated with statin-clarithromycine co-administration.
    Full-text · Article · Oct 2015 · Lipids in Health and Disease
  • [Show abstract] [Hide abstract]
    ABSTRACT: Dietary trans-resveratrol (RES) is rapidly metabolized into sulfated and glucuronated conjugates in humans. This study focused on the in vitro determination of the antioxidant capacity of RES and its main physiological metabolites and on its relevance in vivo. In vitro, RES, RES-3-O-sulfate (R3S) and 3-O-glucuronide (R3G) showed antioxidant activities at a concentration of 1mM when compared to Trolox using an assay in which the antioxidant inhibits iron-induced linoleic acid oxidation: 0.87±0.08mM Trolox equivalents (TE) for RES, 0.52±0.01mM TE for R3S and 0.36±0.02mM TE for R3G. At a concentration of 1μM, compounds promoted linoleic acid peroxidation (RES -0.30±0.09mM TE, R3S -0.48±0.05mM TE and R3G -0.57±0.07mM TE). To elucidate whether these effects were reflected in vivo, total antioxidant capacity, reactive oxygen species (ROS), conjugated fatty acid dienes (CD), superoxide dismutase (SOD) and catalase (CAT) activities were determined in human plasma and erythrocytes over 24h, after oral intake of either 0.05g RES as piceid or 5g RES. Oral administration of RES did not show an impact on total antioxidant capacity, ROS or CD. However, enzymatic activities of ROS scavenging SOD and CAT were significantly lower after high-dose compared to low-dose administration of RES (P<.03 and P<.01). In conclusion, in healthy subjects, neither 0.05g nor 5g RES changed blood oxidative state, although our in vitro data point to a prooxidative activity of low concentrations of RES and its metabolites, which could be important in vivo for individuals with compromised antioxidant defense capacity.
    No preview · Article · Oct 2015 · The Journal of nutritional biochemistry

  • No preview · Article · Oct 2015 · Transplant International

  • No preview · Article · Sep 2015 · European Respiratory Journal
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objectives The aim of the trial was to assess the effect of self-evaluation and sexual diary keeping on female sexual function and depressive symptoms in women diagnosed with sexual dysfunction. Methods A single-arm non-randomised trial included 30 women (53 ± 7 years of age) with female sexual dysfunction (Female Sexual Function Index [FSFI] < 27) and a stable partnership duration of 5–40 years. Female sexual function was assessed by sexual, psychological and gynaecological history taking and validated questionnaires including the FSFI, Female Sexual Distress Scale (FSDS) and Hamilton Depression Scale (HDS), before and after 4 weeks of sexual diary keeping. Results A subjective improvement in communication of sexual problems was reported by 60% of participants; no participants reported any worsening of communication. FSFI and FSDS scores were, respectively, 18.0 ± 7.7 and 22.0 ± 10.0 at baseline and 20.2 ± 7.2 and 20.6 ± 11.5 after 4 weeks. HDS score decreased from 6.0 ± 4.0 at baseline to 4.4 ± 2.7 after 4 weeks (p = 0.042). Conclusions Self-evaluation and sexual diary keeping may improve aspects of sexual life, such as couple communication, without a direct effect on variables measured with validated questionnaires on different domains of sexual function.
    No preview · Article · Aug 2015 · The European Journal of Contraception and Reproductive Health Care
  • [Show abstract] [Hide abstract]
    ABSTRACT: A genome wide association study has identified a robust risk locus for cardiovascular disease on 3q22.3. However, the mechanisms by which the [C]/[T] polymorphism rs9818870 increases cardiovascular risk are unknown. This forearm blood flow (FBF) study addressed the question if the genetic association with cardiovascular disease in patients is preceded by incipient vasodilator impairment in young, healthy carriers of this new risk locus on chromosome 3. After a pre-screening of 74 subjects 17 male healthy volunteers homozygous/heterozygous for a the Single Nucleotide Polymorphism (SNP) risk allele on 3q22.3 and a control group of 17 healthy volunteers not carrying the allele were included into this case-control study. Forearm vascular endothelium-dependent and -independent vasodilator responses were in the normal range in both groups, although endothelium-dependent FBF reactivity to acetylcholine was significantly higher in SNP carriers of the risk allele. The augmented endothelium-dependent vasodilation of the forearm resistance vasculature does not support the presence of endothelial dysfunction in young SNP carriers and indicates that other mechanisms are responsible for the strong association between coronary artery diseases and the rs 9818870 polymorphism, located on 3q22.3. Copyright © 2015. Published by Elsevier Inc.
    No preview · Article · Aug 2015 · Microvascular Research
  • Source

    Full-text · Dataset · Aug 2015
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background: Phosphate imbalances or disorders have a high risk of morbidity and mortality in patients with chronic kidney disease. It is unknown if this finding extends to mortality in patients presenting at an emergency room with or without normal kidney function. Methods and patients: This cross sectional analysis included all emergency room patients between 2010 and 2011 at the Inselspital Bern, Switzerland. A multivariable cox regression model was applied to assess the association between phosphate levels and in-hospital mortality up to 28 days. Results: 22,239 subjects were screened for the study. Plasma phosphate concentrations were measured in 2,390 patients on hospital admission and were included in the analysis. 3.5% of the 480 patients with hypophosphatemia and 10.7% of the 215 patients with hyperphosphatemia died. In univariate analysis, phosphate levels were associated with mortality, age, diuretic therapy and kidney function (all p<0.001). In a multivariate Cox regression model, hyperphosphatemia (OR 3.29, p<0.001) was a strong independent risk factor for mortality. Hypophosphatemia was not associated with mortality (p>0.05). Conclusion: Hyperphosphatemia is associated with 28-day in-hospital mortality in an unselected cohort of patients presenting in an emergency room.
    Full-text · Article · Aug 2015 · PLoS ONE
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To assess the effect of on-demand intranasal oxytocin administration on female sexual function and activity. Randomized, prospective, double-blind, placebo-controlled, crossover trial with duration of 22 weeks. Academic medical center. Thirty pre-and postmenopausal women with sexual dysfunction. Over 8 weeks, intranasal oxytocin (32 IU) or placebo self-administered by women within 50 minutes before sexual intercourse; after a washout period of 2 weeks, crossover with patients switched to the alternate group for another 8 weeks. Primary outcome parameter: Female Sexual Function Index (FSFI); secondary outcome parameters: Female Sexual Distress Scale (FSDS), Sexual Quality of Life-Female (SQOL-F), Sexual Interest and Desire Inventory-Female (SIDI-F), and Hamilton depression scale (HDS). After oxytocin and placebo, the FSFI score increased by 26% and 31%, SQOL-F score by 144% and 125%, and SIDI-F score by 29% and 23%, respectively (repeated measures analysis of variance between groups). After oxytocin and placebo, the FSDS score decreased by 36% and 45%, respectively (repeated measures analysis of variance between groups). There was no statistically significant treatment, sequence (placebo first/second), or interaction effect. Long-term intranasal oxytocin and placebo administration both improved sexual function and symptoms of depression in women over time with no treatment, sequence (placebo first/second), or interaction effect. NCT02229721. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.
    Full-text · Article · Jul 2015 · Fertility and sterility
  • [Show abstract] [Hide abstract]
    ABSTRACT: Simultaneous acquisition of spatially resolved (31) P-MRI data for evaluation of muscle specific energy metabolism, i.e., PCr and pH kinetics. A three-dimensional (3D) gradient-echo sequence for multiple frequency-selective excitations of the PCr and Pi signals in an interleaved sampling scheme was developed and tested at 7 Tesla (T). The pH values were derived from the chemical shift-induced phase difference between the resonances. The achieved spatial resolution was ∼2 mL with image acquisition time below 6 s. Ten healthy volunteers were studied performing plantar flexions during the delay between (31) P-MRI acquisitions, yielding a temporal resolution of 9-10 s. Signal from anatomically matched regions of interest had sufficient signal-to-noise ratio to allow single-acquisition PCr and pH quantification. The Pi signal was clearly detected in voxels of actively exercising muscles. The PCr depletions were in gastrocnemius 42 ± 14% (medialis), 48 ± 17% (lateralis) and in soleus 20 ± 11%. The end exercise pH values were 6.74 ± 0.18 and 6.65 ± 0.27 for gastrocnemius medialis and lateralis, respectively, and 6.96 ± 0.12 for soleus muscle. Simultaneous acquisition of PCr and Pi images with high temporal resolution, suitable for measuring PCr and pH kinetics in exercise-recovery experiments, was demonstrated at 7T. This study presents a fast alternative to MRS for quantifying energy metabolism of posterior muscle groups of the lower leg. Magn Reson Med, 2015. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.
    No preview · Article · Jun 2015 · Magnetic Resonance in Medicine
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Patients with electrolyte imbalances or disorders have a high risk of mortality. It is unknown if this finding from sodium or potassium disorders extends to alterations of magnesium levels. In this cross-sectional analysis, all emergency room patients between 2010 and 2011 at the Inselspital Bern, Switzerland, were included. A multivariable logistic regression model was performed to assess the association between magnesium levels and in-hospital mortality up to 28days. A total of 22,239 subjects were screened for the study. A total of 5339 patients had plasma magnesium concentrations measured at hospital admission and were included into the analysis. A total of 6.3% of the 352 patients with hypomagnesemia and 36.9% of the 151 patients with hypermagnesemia died. In a multivariate Cox regression model hypermagnesemia (HR 11.6, p<0.001) was a strong independent risk factor for mortality. In these patients diuretic therapy revealed to be protective (HR 0.5, p=0.007). Hypomagnesemia was not associated with mortality (p>0.05). Age was an independent risk factor for mortality (both p<0.001). The study does demonstrate a possible association between hypermagnesemia measured upon admission in the emergency department, and early in-hospital mortality. Copyright © 2015 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.
    Full-text · Article · Jun 2015 · European Journal of Internal Medicine
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Purpose: The objective of this study was to identify hospitalisations in Austria caused by adverse drug reactions (ADR) and to analyse preceding medication for the risk of drug-drug interactions (DDI) based on healthcare billing databases. Methods: A retrospective study was performed using the billing data of the Austrian health system. The research database of the Main Association of Austrian Social Security Organisations was used, which contains hospital discharge diagnoses and all medications reimbursed from prescriptions for 5,046,325 adult Austrian patients in 2006 and 2007. Results: 0.4% of the population was discharged with at least one diagnosis indicating an ADR during the observation period. 1.5% of hospitalised patients had a diagnosis related to an ADR. Of these, a DDI was identified in 68% (13,511 subjects) and a severe interaction in 12% (2,412 subjects), respectively. Conclusions: Billing data provide important information to complement reporting systems for drug safety. These database searches may contribute to signal and hypothesis generation. Citation: M. Wolzt et al., (2015) Relationship of Drug-Drug Interactions with Hospital Diagnoses Associated to Adverse Drug Reactions: A Retrospective Study of Billing Data In Austria. Int J Clin Pharmacol Toxicol, S1:001, 1-6.
    Full-text · Article · May 2015
  • [Show abstract] [Hide abstract]
    ABSTRACT: Guideline-recommended therapy has been proven beneficial in heart failure (HF), but general implementation remains poor. The aim of this study was to evaluate the adherence to drug therapy, quality of primary non-drug medical care (NDMC) and its impact on HF outcome. From 13 Austrian health insurance funds, we identified 36 829 patients (77.1 ± 10.8 years, 44.8% men) hospitalised for HF who survived more than 90 days after discharge in the period between April 2006 and June 2010. Drug adherence was analysed from prescriptions filled and NDMC from numbers of physician consultations and diagnostic tests relevant for HF per quarter of a year (medical care index (MedCI)) claimed from the insurance funds. Kaplan-Meier and multivariate Cox regression analyses were performed to identify the association of outcome (survival and death without further admission for HF, readmission for HF) with drug adherence and NDMC. Readmission due to HF or death without prior readmission for HF occurred in 19.7% and 22.5%, respectively. Adherence to angiotensin-converting-enzyme inhibitors or angiotensin receptor blockers, beta-blockers and aldosterone antagonists was 49.3%, 40.4% and 16.1%, respectively, and was associated with better survival by Kaplan-Meier analysis. NDMC was consumed less frequently by deceased (76.0%; MedCI 2.55 ± 3.04) than surviving (79.3%; 3.60 ± 3.81) or readmitted (78.4%; 3.80 ± 4.13) patients (p < 0.001 for deceased vs both other). Drug adherence and NDMC were independent factors associated with better survival by multivariate regression analysis. Guideline-recommended drug therapy remains underutilised in Austria. Drug adherence and quality of NDMC are associated with better outcome in HF patients. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.
    No preview · Article · May 2015 · Pharmacoepidemiology and Drug Safety

  • No preview · Article · May 2015 · Journal of Sexual Medicine

  • No preview · Article · May 2015 · Journal of Sexual Medicine
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This study demonstrates the applicability of semi-LASER localized dynamic (31)P MRS to deeper lying areas of the exercising human soleus muscle (SOL). The effect of accurate localization and high temporal resolution on data specificity is investigated. To achieve high signal-to-noise ratio (SNR) at a temporal resolution of 6 s, a custom-built human calf coil array was used at 7T. The kinetics of phosphocreatine (PCr) and intracellular pH were quantified separately in SOL and gastrocnemius medialis (GM) muscle of nine volunteers, during rest, plantar flexion exercise, and recovery. The average SNR of PCr at rest was [Formula: see text] in SOL ([Formula: see text] in GM). End exercise PCr depletion in SOL ([Formula: see text] %) was far lower than in GM ([Formula: see text] %). The pH in SOL increased rapidly and, in contrast to GM, remained elevated until the end of exercise. (31)P MRS in single-shots every 6 s localized in the deeper-lying SOL enabled quantification of PCr recovery times at low depletions and of fast pH changes, like the initial rise. Both high temporal resolution and accurate spatial localization improve specificity of Pi and, thus, pH quantification by avoiding multiple, and potentially indistinguishable sources for changing the Pi peak shape.
    Full-text · Article · Apr 2015 · MAGMA Magnetic Resonance Materials in Physics Biology and Medicine
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: Hypoglycemia, a major side effect of intensive glucose lowering therapy, was recently linked to increased cardiovascular risk in patients with diabetes. Whether increased circulating free fatty acids (FFA) owing to catecholamine-induced lipolysis affect myocardial energy metabolism and thus link hypoglycemia to cardiac vulnerability is unclear. Therefore, the study investigated the impact of hypoglycemia counter-regulation (+/- inhibition of lipolysis) on myocardial lipid content (MYCL) and left-ventricular function in healthy subjects. Research Design and Methods: Nine healthy men were studied in randomized order: (i) insulin-hypoglycemia-test (IHT;ins+/aci-), (ii) IHT during inhibition of adipose tissue lipolysis by acipimox (ins+/aci+), (iii) normoglycemia with acipimox (ins-/aci+) and (iv) normoglycemia with placebo (ins-/aci-). MYCL and cardiac function were assessed employing magnetic resonance spectroscopy/imaging at baseline and at 2 and 6 hours. Results: In response to acute hypoglycemia (i), plasma free fatty acids (FFA, p<.0001) and ejection fraction (EF, from 63.2±5.5 to 69.6±6.3%,p=.0001) significantly increased and were tightly correlated with each other (R=0.68, p=0.0002); this response was completely blunted by inhibition of adipose tissue lipolysis (ii). In the presence of normoglycemia (iii), inhibition of lipolysis was associated with a drop in EF (from 59.2±5.5 to 53.9±6.9%,p=0.005) and a significant decrease in plasma FFA, triglycerides and MYCL (by 48.5%, p=.0001). Conclusiones: The present data indicate that an intact inter-organ-crosstalk between adipose tissue and the heart is prerequisite for catecholamine-mediated myocardial contractility and preservation of myocardial lipid stores in response to acute hypoglycemia. Copyright © 2015, American Journal of Physiology - Endocrinology and Metabolism.
    No preview · Article · Feb 2015 · AJP Endocrinology and Metabolism

Publication Stats

8k Citations
1,525.29 Total Impact Points


  • 1995-2015
    • University of Vienna
      • • Department of Internal Medicine III
      • • Department of Nuclear Medicine
      Wien, Vienna, Austria
  • 1991-2015
    • Medical University of Vienna
      • Department of Clinical Pharmacology
      Wien, Vienna, Austria
    • IST Austria
      Klosterneuberg, Lower Austria, Austria
  • 2012
    • Arbor Research Collaborative for Health
      Ann Arbor, Michigan, United States
  • 2002-2011
    • Vienna General Hospital
      Wien, Vienna, Austria
  • 2008
    • Clinical pharmacology of Miami
      Miami, Florida, United States
  • 2004
    • Università Telematica San Raffaele
      Milano, Lombardy, Italy
  • 1999
    • University College London
      • Centre for Clinical Pharmacology and Theraputics
      Londinium, England, United Kingdom
  • 1994
    • Karl-Franzens-Universität Graz
      Gratz, Styria, Austria