35 research outputs found

    Subclinical cardiac dysfunction in obesity patients is linked to autonomic dysfunction: findings from the CARDIOBESE study

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    Aims: Obesity doubles the lifetime risk of developing heart failure. Current knowledge on the role of obesity in causing cardiac dysfunction is insufficient for optimal risk stratification. The aim of this study was first to estimate the prevalence of subclinical cardiac dysfunction in obesity patients and second to investigate the underlying pathophysiology. Methods and results: The CARDIOBESE study is a cross-sectional multicentre study of 100 obesity patients [body mass index (BMI) ≥ 35 kg/m2] without known cardiovascular disease and 50 age-matched and gender-matched non-obese controls (BMI ≤ 30 kg/m2). Echocardiography was performed, blood samples were collected, and a Holter monitor was affixed. Fifty-nine obesity patients [48 (42–50) years, 70% female] showed subclinical cardiac dysfunction: 57 patients had decreased global longitudinal strain (GLS), and two patients with normal GLS had either diastolic dysfunction or increased brain natriuretic peptide (BNP). Only one non-obese control had diastolic dysfunction, and none had another sign of cardiac dysfunction. Multivariable logistic analysis identified male gender and standard deviation of all NN intervals (SDNN) index, which is a measure of autonomic dysfunction, as independent significant risk factors for subclinical cardiac dysfunction in obesity patients. Conclusions: There was a high prevalence (61%) of subclinical cardiac dysfunction in obesity patients without known cardiovascular disease, which appeared to be best identified by GLS. Subclinical cardiac dysfunction in obesity was linked to autonomic dysfunction and male gender, and not to the presence of traditional cardiac risk factors, increased C-reactive protein, increased BNP, increased high-sensitivity troponin I, or increased left ventricular mass

    NP-hardness of Deciding Convexity of Quartic Polynomials and Related Problems

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    We show that unless P=NP, there exists no polynomial time (or even pseudo-polynomial time) algorithm that can decide whether a multivariate polynomial of degree four (or higher even degree) is globally convex. This solves a problem that has been open since 1992 when N. Z. Shor asked for the complexity of deciding convexity for quartic polynomials. We also prove that deciding strict convexity, strong convexity, quasiconvexity, and pseudoconvexity of polynomials of even degree four or higher is strongly NP-hard. By contrast, we show that quasiconvexity and pseudoconvexity of odd degree polynomials can be decided in polynomial time.Comment: 20 page

    Cross-sectional and prospective follow-up study to detect early signs of cardiac dysfunction in obesity: Protocol of the CARDIOBESE study

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    Introduction In view of the increasing occurrence of both obesity and heart failure, a growing overlap of these two clinical entities in the near future is expected. Significant advances in our understanding of the pathophysiological consequences of obesity for the cardiovascular system have been made over the past two decades. However, to optimise management and treatment of obesity patients, further research is required to improve early identification of cardiac dysfunction in obesity and to gain insight in the underlying pathophysiology. The CARdiac Dysfunction In OBesity - Early Signs Evaluation (CARDIOBESE) study has been designed to address these issues. Methods and analysis CARDIOBESE is a cross-sectional multicentre study of 100 obesity patients scheduled for bariatric surgery (body mass index (BMI) ≥35 kg/m 2) without known cardiovascular disease, and 50 age-matched and gender-matched non-obese controls (BMI <30 kg/m 2). Echocardiography, blood and urine biomarkers and Holter monitoring will be used to identify parameters that are able to show cardiac dysfunction at a very early stage in obesity patients (primary objective). Furthermore, a prospective follow-up study of obesity patients before and 1 year after bariatric surgery will be done to gain insight in the pathophysiology of obesity causing cardiac dysfunction (secondary objective). Ethics and dissemination The study was approved by the Medical Ethics Committee Toetsingscommissie Wetenschappelijk Onderzoek Rotterdam e.o. (TWOR). Inclusion of patients and controls is almost complete. Analyses of the investigations are currently being performed, and dissemination through peer-reviewed publications and conference presentations is expected from the first quarter of 2019. By identifying early markers of cardiac dysfunction in obesity, and by understanding the underlying pathophysiology of the abnormalities of these markers, the CARDIOBESE study may provide guidance for risk stratification, monitoring and treatment strategies for obesity patients

    Regional increase in P-glycoprotein function in the blood-brain barrier of patients with chronic schizophrenia: A PET study with [C-11]verapamil as a probe for P-glycoprotein function

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    P-glycoprotein (P-gp), a major efflux pump in the blood-brain barrier (BBB) has a profound effect on entry of drugs, peptides and other substances into the central nervous system (CNS). The brain's permeability can be negatively influenced by modulation of the transport function of P-gp. Inflammatory mediators play a role in schizophrenia, and may be able to influence the integrity of the BBB, via P-gp modulation. We hypothesized that P-gp function in the BBB is changed in patients with schizophrenia. Positron-emission tomography was used to measure brain uptake of [C-11]verapamil, which is normally extruded from the brain by P-gp. We found that patients with chronic schizophrenia under treatment with antipsychotic drugs compared with healthy controls showed a significant decrease in [C-11]verapamil uptake in the temporal cortex, the basal ganglia, and the amygdala, and amygdalae, and a trend towards a significant decrease was seen throughout the brain. The decrease of [C-11]verapamil uptake correlates with an increased activity of the P-gp pump. Increased P-gp activity may be a factor in drug resistance in schizophrenia, induced by the use of antipsychotic agents. (C) 2010 Elsevier Ireland Ltd. All rights reserved

    Tyrosine hydroxylase deficiency causes progressive encephalopathy and dopa-nonresponsive dystonia.

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    Tyrosine hydroxylase (TH) is the key enzyme in the biosynthesis of the catecholamines dopamine, epinephrine, and norepinephrine. Recessively inherited deficiency of TH was recently identified and incorporated into recent concepts of genetic dystonias as the cause of recessive Dopa-responsive dystonia or Segawa's syndrome in analogy to dominantly inherited GTP cyclohydrolase I deficiency. We report four patients with TH deficiency and two with GTP cyclohydrolase I deficiency. Patients with TH deficiency suffer from progressive infantile encephalopathy dominated by motor retardation similar to a primary neuromuscular disorder, fluctuating extrapyramidal, and ocular and vegetative symptoms. Intellectual functions are mostly compromised. Prenatally disturbed brain development and postnatal growth failure were observed. Treatment with levodopa ameliorates but usually does not normalize symptoms. Compared with patients with dominantly inherited GTP cyclohydrolase I deficiency, catecholaminergic neurotransmission is severely and constantly impaired in TH deficiency. In most patients, this results not in predominating dystonia, a largely nondegenerative condition, but in a progressive often lethal neurometabolic disorder, which can be improved but not cured by L-dopa. Investigations of neurotransmitter defects by specific cerebrospinal fluid determinations should be included in the diagnostic evaluation of children with progressive infantile encephalopathy

    Tyrosine hydroxylase deficiency causes progressive encephalopathy and dopa-nonresponsive dystonia.

    No full text
    Item does not contain fulltextTyrosine hydroxylase (TH) is the key enzyme in the biosynthesis of the catecholamines dopamine, epinephrine, and norepinephrine. Recessively inherited deficiency of TH was recently identified and incorporated into recent concepts of genetic dystonias as the cause of recessive Dopa-responsive dystonia or Segawa's syndrome in analogy to dominantly inherited GTP cyclohydrolase I deficiency. We report four patients with TH deficiency and two with GTP cyclohydrolase I deficiency. Patients with TH deficiency suffer from progressive infantile encephalopathy dominated by motor retardation similar to a primary neuromuscular disorder, fluctuating extrapyramidal, and ocular and vegetative symptoms. Intellectual functions are mostly compromised. Prenatally disturbed brain development and postnatal growth failure were observed. Treatment with levodopa ameliorates but usually does not normalize symptoms. Compared with patients with dominantly inherited GTP cyclohydrolase I deficiency, catecholaminergic neurotransmission is severely and constantly impaired in TH deficiency. In most patients, this results not in predominating dystonia, a largely nondegenerative condition, but in a progressive often lethal neurometabolic disorder, which can be improved but not cured by L-dopa. Investigations of neurotransmitter defects by specific cerebrospinal fluid determinations should be included in the diagnostic evaluation of children with progressive infantile encephalopathy
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