title: Type 1 diabetes mellitus and risk of incident epilepsy: a population-based, open-cohort study.
abstract: The aim of this research was to explore the relationship between incident epilepsy and type 1 diabetes in British participants.
  
  
  
  Using The Health Improvement Network database, we conducted a retrospective, open-cohort study. Patients who were newly diagnosed with type 1 diabetes mellitus at the age of ≤40 years were identified and followed-up from 1 January 1990 to 15 September 2015. These patients, identified as not suffering from epilepsy at the time of diagnosis, were randomly matched with up to four individuals without type 1 diabetes mellitus, based on age, sex and participating general practice. A Cox regression analysis was subsequently performed using Townsend deprivation index, cerebral palsy, head injury and learning disabilities as model covariates.
  
  
  
  The study population consisted of a total of 24,610 individuals (4922 with type 1 diabetes and 19,688 controls). These individuals were followed up for a mean of 5.4 years (approximately 132,000 person-years of follow up). Patients with type 1 diabetes were significantly more likely to be diagnosed with epilepsy during the observation period compared with controls (crude HR [95% CI]: 3.02 [1.95, 4.69]). The incidence rate was estimated to be 132 and 44 per 100,000 person-years in patients and controls, respectively. This finding persisted after adjusting for model covariates (adjusted HR [95% CI]: 3.01 [1.93, 4.68]) and was also robust to sensitivity analysis, excluding adult-onset type 1 diabetes mellitus.
  
  
  
  Patients with type 1 diabetes are at approximately three-times greater risk of developing epilepsy compared with matched controls without type 1 diabetes. This should be considered when investigating seizure-related disorders in patients with type 1 diabetes mellitus.
authors: Institute of Applied Health Research, University of Birmingham, Birmingham, UK.|First Department of Propaedeutic Internal Medicine, Diabetes Center, National and Kapodistrian University of Athens Medical School, Athens, Greece.
authors: George E
authors: GE
authors: Dafoulas
authors: Institute of Applied Health Research, University of Birmingham, Birmingham, UK.|Department of Endocrinology, 424 General Army Training Hospital, Thessaloniki, Greece.
authors: Konstantinos A
authors: KA
authors: Toulis
authors: Department of Neuroscience, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.
authors: Dougall
authors: D
authors: Mccorry
authors: Institute of Applied Health Research, University of Birmingham, Birmingham, UK.
authors: Balachadran
authors: B
authors: Kumarendran
authors: Institute of Applied Health Research, University of Birmingham, Birmingham, UK.
authors: G Neil
authors: GN
authors: Thomas
authors: Institute of Applied Health Research, University of Birmingham, Birmingham, UK.
authors: Brian H
authors: BH
authors: Willis
authors: Institute of Applied Health Research, University of Birmingham, Birmingham, UK.
authors: Krishna
authors: K
authors: Gokhale
authors: Centre for Computational Biology, University of Birmingham, Birmingham, UK.
authors: George
authors: G
authors: Gkoutos
authors: Centre for Endocrinology, Diabetes and Metabolism, Institute of Metabolism and Systems Research, University of Birmingham, Room 229, Medical School, College of Medical and Dental Sciences, Edgbaston, Birmingham, B15 2TT, UK. p.narendran@bham.ac.uk.|University of Birmingham, Birmingham, UK. p.narendran@bham.ac.uk.
authors: Parth
authors: P
authors: Narendran
authors: Institute of Applied Health Research, University of Birmingham, Birmingham, UK.|University of Birmingham, Birmingham, UK.
authors: Krishnarajah
authors: K
authors: Nirantharakumar
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000453:epidemiology*; D004827:Epilepsy / Q000097:blood / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007003:Hypoglycemia / Q000097:blood / Q000453:epidemiology; D007328:Insulin / Q000097:blood; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult
chemical_list: D007328:Insulin
keywords: Epilepsy; Hypoglycaemia; Insulin; Seizures; Type 1 diabetes mellitus