N. Ahmad Aziz

N. Ahmad Aziz
Deutsches Zentrum für Neurodegenerative Erkrankungen | DZNE · Department of Population Health Sciences

MD, PhD

About

131
Publications
14,788
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
2,569
Citations
Introduction
N. Ahmad Aziz currently works at the German Centre for Neurodegenerative Diseases (DZNE) and the Department of Neurology of the University Clinic Bonn, in Bonn, Germany. His research interests include Clinical Neurology, Neuropathology, Neuroendocrinology, Neuro-epidemiology and Genetics.
Education
October 2009 - September 2011
Leiden University
Field of study
January 2006 - March 2010
Leiden University
Field of study
September 2002 - December 2005
Leiden University
Field of study

Publications

Publications (131)
Preprint
Current concepts regarding the biology of aging are based on studies aimed at identifying factors regulating natural lifespan. However, lifespan as a sole proxy measure for aging can be of limited value because it may be restricted by specific sets of pathologies, rather than by general physiological decline. Here, we employed large-scale phenotypi...
Article
Full-text available
Spinocerebellar ataxia (SCA) type 7 (SCA7) is caused by a CAG trinucleotide repeat expansion in the ataxin 7 (ATXN7) gene, which results in polyglutamine expansion at the amino terminus of the ATXN7 protein. Although ATXN7 is expressed widely, the best characterized symptoms of SCA7 are remarkably tissue specific, including blindness and degenerati...
Article
Full-text available
Both retinal atrophy measured through optical coherence tomography and plasma neurofilament light chain (NfL) levels are markers of neurodegeneration, but their relationship is unknown. Therefore, we assessed their determinants and association in 4369 participants of a population‐based study. Both plasma NfL levels and inner retinal atrophy increas...
Article
Full-text available
Chronic kidney disease is a major public health burden. Elevated urinary albumin-to-creatinine ratio is a measure of kidney damage, and used to diagnose and stage chronic kidney disease. To extend the knowledge on regulatory mechanisms related to kidney function and disease, we conducted a blood-based epigenome-wide association study for estimated...
Article
Full-text available
Elevated serum urate levels, a complex trait and major risk factor for incident gout, are correlated with cardiometabolic traits via incompletely understood mechanisms. DNA methylation in whole blood captures genetic and environmental influences and is assessed in transethnic meta-analysis of epigenome-wide association studies (EWAS) of serum urate...
Conference Paper
Both plasma neurofilament light chain (NfL) levels and retinal layer volumes have emerged as biomarkers of central neurodegeneration, the former highlighting neuroaxonal damage, the latter as an extension of the brain susceptible to similar injuries. To date, the extent to which plasma NfL levels and retinal layer volumes could be used as complemen...
Article
Neurofilament light (NfL) protein level is considered a non‐specific marker of neurodegeneration. NfL levels have been associated with established, non‐blood based neurodegenerative markers, including cognitive performance and reduced brain volume. However, most studies were small (N<300), and compared levels in patients (MCI, Alzheimer’s disease)...
Conference Paper
Cortical thinning occurs with brain ageing and is a hallmark of neurodegenerative diseases, especially Alzheimer’s disease. While there is growing evidence that physical activity facilitates neuroplasticity and has neuroprotective effects, its influence on cortical thickness remains largely unexplored. We therefore aimed to elucidate 1) whether obj...
Article
Background: Decreased hippocampal volume has been associated with age-related memory decline as well as several neurodegenerative and neuropsychiatric disorders. However, the molecular determinants of hippocampal volume are still poorly understood. Epigenetic changes alter the expression of many neurotrophic genes and may mediate the effects of ge...
Article
Background. Schizophrenia is a heterogeneous disorder with substantial heritability. The use of endophenotypes may help clarify its aetiology. Measures from the smooth pursuit and anti-saccade eye movement tasks have been identified as endophenotypes for schizophrenia in twin and family studies. However, the genetic basis of the overlap between sch...
Preprint
Full-text available
Objective: To assess whether severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection is associated with changes in plasma levels of neurofilament light chain (NfL), an extremely sensitive marker of neuroaxonal damage, in community-dwelling individuals. Setting: This study was embedded within the Rhineland Study, an ongoing community-...
Article
Importance Olfactory dysfunction is a prodromal manifestation of many neurodegenerative disorders, including Alzheimer and Parkinson disease. However, its neuroanatomical basis is largely unknown. Objective To assess the association between olfactory brain structures and olfactory function in adults 30 years or older and to examine the extent to w...
Article
Full-text available
Background Schizophrenia is a heterogeneous disorder with substantial heritability. The use of endophenotypes may help clarify its aetiology. Measures from the smooth pursuit and antisaccade eye movement tasks have been identified as endophenotypes for schizophrenia in twin and family studies. However, the genetic basis of the overlap between schiz...
Article
Full-text available
Objective Weight loss is associated with clinical progression in Huntington disease (HD), but whether body weight causally affects disease onset or progression is unknown. Therefore, we aimed to assess whether genetically determined variations in body weight are causally related to age at onset in HD. Methods Using data from different recent genom...
Article
Full-text available
Fast and reliable detection of patients with severe and heterogeneous illnesses is a major goal of precision medicine 1,2 . Patients with leukaemia can be identified using machine learning on the basis of their blood transcriptomes ³ . However, there is an increasing divide between what is technically possible and what is allowed, because of privac...
Article
Full-text available
To estimate the seroprevalence and temporal course of SARS-CoV-2 neutralizing antibodies, we embedded a multi-tiered seroprevalence survey within an ongoing community-based cohort study in Bonn, Germany. We first assessed anti-SARS-CoV-2 immunoglobulin G levels with an immunoassay, followed by confirmatory testing of borderline and positive test re...
Article
Full-text available
Metabolic syndrome (MetS) is a major public health burden worldwide and associated with brain abnormalities. Although insulin resistance is considered a pivotal feature of MetS, its role in the pathogenesis of MetS‐related brain alterations in the general population is unclear. Therefore, in 973 participants (mean age 52.5 years) of the population‐...
Article
Full-text available
Background The SARS-CoV-2 pandemic is currently leading to increasing numbers of COVID-19 patients all over the world. Clinical presentations range from asymptomatic, mild respiratory tract infection, to severe cases with acute respiratory distress syndrome, respiratory failure, and death. Reports on a dysregulated immune system in the severe cases...
Chapter
Huntington's disease (HD), an autosomal dominant hereditary disorder associated with the accumulation of mutant huntingtin, is classically associated with cognitive decline and motor symptoms, notably chorea. However, growing evidence suggests that nonmotor symptoms are equally prevalent and debilitating. Some of these symptoms may be linked to hyp...
Article
Fast and reliable detection of patients with severe and heterogeneous illnesses is a major goal of precision medicine1,2. Patients with leukaemia can be identified using machine learning on the basis of their blood transcriptomes3. However, there is an increasing divide between what is technically possible and what is allowed, because of privacy le...
Article
Metabolic syndrome (MetS) is a major public health burden worldwide and associated with brain abnormalities. Although insulin resistance is considered a pivotal feature of MetS, its role in the pathogenesis of MetS‐related brain alterations in the general population is unclear. Therefore, we aimed to 1) assess the relation of metabolic syndrome (Me...
Conference Paper
Physical activity is associated with a reduced risk of dementia. Although physical activity induces potent neuroprotective effects in animals, human studies assessing its effects on brain structure are sparse and inconclusive. The discrepancies in human studies may have been due to application of subjective physical activity measures, low spatial‐r...
Preprint
Full-text available
Background Accurate estimates of SARS-CoV-2 seroprevalence are crucial for the implementation of effective public health measures, but are currently largely lacking in regions with low infection rates. This is further complicated by inadequate test performance of many widely used serological assays. We therefore aimed to assess SARS-CoV-2 seropreva...
Poster
Many neurodegenerative disorders are characterised by changes in specific eye movement (EM) outcomes. Individuals with Alzheimer’s disease (AD) make more antisaccade errors and correct a lower proportion of those errors compared to controls. EM impairments occur at an early stage of neuropathological changes and have, therefore, been discussed as a...
Preprint
Full-text available
The SARS-CoV-2 pandemic is currently leading to increasing numbers of COVID-19 patients all over the world. Clinical presentations range from asymptomatic, mild respiratory tract infection, to severe cases with acute respiratory distress syndrome, respiratory failure, and death. Reports on a dysregulated immune system in the severe cases calls for...
Preprint
Full-text available
Identification of patients with life-threatening diseases including leukemias or infections such as tuberculosis and COVID-19 is an important goal of precision medicine. We recently illustrated that leukemia patients are identified by machine learning (ML) based on their blood transcriptomes. However, there is an increasing divide between what is t...
Article
Full-text available
Background: Heart failure and chronic obstructive pulmonary disease (COPD) are leading causes of disability and lead to substantial healthcare costs. The aim of this study was to evaluate the effectiveness of home telemonitoring in reducing healthcare usage and costs in patients with heart failure or COPD. Methods: The study was a retrospective obs...
Article
Full-text available
Although the heritability of cognitive function in old age is substantial, genome-wide association studies have had limited success in elucidating its genetic basis, leaving a considerable amount of "missing heritability." Aside from single nucleotide polymorphisms, genome-wide association studies are unable to assess other large sources of genetic...
Article
Full-text available
Huntington disease (HD) is an autosomal dominant, neurodegenerative disease caused by a CAG repeat expansion within the coding sequence of the HTT gene, resulting in a highly toxic protein with an expanded polyglutamine stretch that forms typical protein aggregates throughout the brain. We generated human induced pluripotent stem cells (hiPSCs) fro...
Article
Importance Nine hereditary neurodegenerative diseases are known as polyglutamine diseases, including Huntington disease, 6 spinocerebellar ataxias (SCAs) (SCA1, SCA2, SCA3, SCA6, SCA7, and SCA17), dentatorubral-pallidoluysion atrophy, and spinal bulbar muscular atrophy. Objective To determine the prevalence of carriers of intermediate and patholog...
Article
Full-text available
Background: The worldwide prevalence of obesity, a major risk factor for numerous debilitating chronic disorders, is increasing rapidly. Although a substantial amount of the variation in body mass index (BMI) is estimated to be heritable, the largest meta-analysis of genome-wide association studies (GWAS) to date explained only ~2.7% of the variat...
Article
Full-text available
Background Huntington's disease Like 2 (HDL2) is the most common Huntington's disease (HD) phenocopy in many countries and described as the phenocopy with the greatest resemblance to HD. The current clinical description of HDL2 is based on retrospective data. It is unknown whether HDL2 has clinical features which distinguish it from HD. Objective...
Article
The surge in the number of authors per article in the biomedical field makes it difficult to quantify the contribution of individual authors. Conventional citation metrics are typically based on the number of publications and the number of citations generated by a scientist, thereby disregarding the contribution of co-authors. Previously we develop...
Article
Background: Previous trials have shown that pridopidine might reduce motor impairment in patients with Huntington's disease. The aim of this study was to ascertain whether higher doses of pridopidine than previously tested reduce motor symptoms in a dose-dependent manner while maintaining acceptable safety and tolerability. Methods: PRIDE-HD was...
Article
Full-text available
Objective: We aimed to assess whether differences in energy metabolism in fibroblast cell lines derived from patients with Huntington disease were associated with age at onset independent of the cytosine-adenine-guanine (CAG) repeat number in the mutant allele. Methods: For this study, we selected 9 pairs of patients with Huntington disease matc...
Article
Genomewide association studies (GWASs) have contributed greatly to unraveling the genetic basis of Alzheimer's disease (AD). However, a large amount of “missing heritability” remains. In this exploratory study, we investigated the effect of cytosine-adenine-guanine (CAG) repeats in polyglutamine disease–associated genes (PDAGs) on the risk of AD an...
Conference Paper
Introduction Disrupted gating of motor control through striatal pathways is thought to drive the development of motor symptoms in Huntington’s disease (HD). The range of motor symptoms, from chorea to bradykinesia, is thought to be driven by disruption in different striatal pathways. Aside from motor control, striatal pathways are also thought to p...
Conference Paper
Background Mutant CAG repeat size is the lead determinant of age of onset in Huntington disease. Nevertheless, a substantial proportion of variation in age of onset in Huntington disease remains unexplained. Accumulating evidence suggests that bioenergetic defects play a central role in Huntington disease pathology, but to what extent these impairm...
Preprint
Full-text available
UNSTRUCTURED Objective The aim of this study was to evaluate the effectiveness of home telemonitoring in reducing healthcare usage and costs in patients with heart failure or chronic obstructive pulmonary disease (COPD). Design The study was a retrospective observational study with a pre-post research design and a follow-up duration of up to 3 year...
Article
Full-text available
Objective: A fundamental but still unresolved issue regarding Huntington disease (HD) pathogenesis is whether the factors that determine age at onset are the same as those that govern disease progression. Because elucidation of this issue is crucial for the development as well as optimal timing of administration of novel disease-modifying therapie...
Article
Objective: Our aim was to determine the prognostic significance of the systemic-immune-inflammation index (SIII) in patients with resectable pancreatic cancer, using cancer-specific survival as the primary outcome. Background: Pancreatic cancer is associated with a dysfunctional immune system and poor prognosis. We examined the prognostic signif...
Article
Full-text available
Huntington disease (HD) is a severe neuropsychiatric disorder caused by a cytosine-adenine-guanine (CAG) repeat expansion in the HTT gene. Although HD is frequently complicated by depression, it is still unknown to what extent common HTT CAG repeat size variations in the normal range could affect depression risk in the general population. Using bin...
Article
Full-text available
CAG Repeat expansions in the coding regions of nine polyglutamine (polyQ) genes (HTT, ATXN1, ATXN2, ATXN3, CACNA1A, ATXN7, ATN1, AR, and TBP) are the cause of several neurodegenerative diseases including Huntington's disease (HD), six different spinocerebellar ataxias (SCAs), dentatorubral-pallidoluysian atrophy and spinobulbar muscular atrophy. Th...
Article
Polyglutamine diseases are a group of nine hereditary neurodegenerative disorders and include Huntington disease (HD), the most prevalent spinocerebellar ataxias (SCAs type 1, 2, 3, 6, 7 and 17), dentatorubral-pallidoluysian atrophy and spinal and bulbar muscular atrophy (also known as Kennedy disease). Apart from the latter, these disorders are ch...
Article
Unintended weight loss is a hallmark of Huntington disease (HD), but it is unknown to what extent weight loss impacts the rate of disease progression. Therefore, using longitudinal data from the Enroll-HD study, we assessed the association between baseline body mass index (BMI) and the rate of clinical progression in 5821 HD mutation carriers. We f...
Article
Full-text available
Recently Wiener's causality theorem, which states that one variable could be regarded as the cause of another if the ability to predict the future of the second variable is enhanced by implementing information about the preceding values of the first variable, was linked to information theory through the development of a novel metric called 'transfe...
Article
Full-text available
Depression is one of the most prevalent and debilitating psychiatric disorders worldwide. Recently, we showed that both relatively short and relatively long cytosine-adenine-guanine (CAG) repeats in the huntingtin gene (HTT) are associated with an increased risk of lifetime depression. However, to what extent the variations in CAG repeat length in...