title: A population-based cohort study suggests an increased risk of multiple sclerosis incidence in patients with type 2 diabetes mellitus.
abstract: BACKGROUND
  To prospectively investigate the incidence and relative risks of multiple sclerosis (MS) in patients with type 2 diabetes (T2DM).
  
  
  METHODS
  Patients with T2DM (n = 614,623) and age- and sex-matched controls (n = 614,021) were followed from 2000 to 2008 to identify cases of newly diagnosed MS (ICD-9-CM: 340). The person-year approach with Poisson assumption was used to evaluate the incidence density. We estimated the covariate-adjusted hazard ratio (HR) of MS incidence in relation to T2DM diabetes using a multiple Cox proportional hazard regression model.
  
  
  RESULTS
  Over 9 years of follow-up, 175 T2DM patients were newly diagnosed with MS, and 114 matched controls had the same first-ever diagnosis, representing a covariate-adjusted HR of 1.44 (95% confidence interval [CI], 1.08-1.94). The sex-specific adjusted HR for both men and women with T2DM was also elevated at 1.34 (95% CI, 0.81-2.23) and 1.51 (95% CI, 1.05-2.19), respectively. Women aged ≤50 years had the greatest risk of MS (HR 2.16; 95% CI, 1.02-4.59).
  
  
  CONCLUSIONS
  This study demonstrated a moderate but significant association of T2DM with MS incidence, and the association was not confounded by socio-demographic characteristics or certain MS-related co-morbidities.
authors.affiliation: Master Program in Long-Term Care, College of Nursing, Taipei Medical University, Taipei, Taiwan; School of Gerontology Health Management, College of Nursing, Taipei Medical University, Taipei, Taiwan; Department of Physical Medicine and Rehabilitation, Taipei Medical University Hospital, Taipei, Taiwan.
authors.forename: Wen-Hsuan
authors.initials: WH
authors.lastname: Hou
authors.affiliation: Department and Institute of Public Health, College of Medicine, National Cheng Kung University, Tainan City, Taiwan; Department of Public Health, College of Public Health, China Medical University, Taichung City, Taiwan.
authors.forename: Chung-Yi
authors.initials: CY
authors.lastname: Li
authors.affiliation: Department and Institute of Public Health, College of Medicine, National Cheng Kung University, Tainan City, Taiwan.
authors.forename: Hsin-Hui
authors.initials: HH
authors.lastname: Chang
authors.affiliation: Department of Neurology, En Chu Kong Hospital, Sanxia District, New Taipei City, Taiwan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Department of Surgery, Tainan Sin-Lau Hospital, Tainan, Taiwan; Department of Health Care Administration, Chang Jung Christian University, Tainan, Taiwan. Electronic address: d4233@sinlau.org.tw.
authors.forename: Chiang-Chin
authors.initials: CC
authors.lastname: Tsai
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D016022:Case-Control Studies; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D038801:International Classification of Diseases; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D011159:Population Surveillance; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D017678:Sex Distribution; D013624:Taiwan / Q000453:epidemiology
keywords: Cohort studies; Cox proportional hazard model; Diabetes mellitus; Multiple sclerosis