title: Risk of bladder cancer in patients with diabetes: a retrospective cohort study.
abstract: OBJECTIVE
  The objective of this study was to examine the association between diabetes, and both urinary bladder cancer (UBC) risk and mortality.
  
  
  METHODS
  We conducted a retrospective cohort study using data from the UK Clinical Practice Research Datalink (CPRD) linked to the Office of National Statistics (ONS). Patients diagnosed with diabetes mellitus type 1 or 2, or using antidiabetic drugs (ADDs), were compared to matched non-diabetic controls. Cox proportional hazards models were used to estimate the risk and mortality of UBC. We adjusted for age, sex, smoking status and body mass index.
  
  
  RESULTS
  The cohort included 329,168 patients using ADD, and 307,315 controls with 1295 and 1071 patients, respectively, diagnosed as having UBC during follow-up. The adjusted HRs of UBC were 0.77 (95% CI 0.57 to 1.05) and 1.04 (95% CI 0.96 to 1.14) for type 1 and 2 diabetes, respectively. These results were similar if we restricted our analysis to an inception cohort. We noticed a small increased risk during the first year after diagnosis (HR=1.26 (95% CI 1.05 to 1.52)), which could be explained by detection bias. There was no influence of the severity of diabetes as measured by the glycated haemoglobin. Mortality of UBC was not increased for patients with either type 1 (HR=0.95 (95% CI 0.39 to 2.34)) or type 2 diabetes (HR=1.16 (95% CI 0.91 to 1.46)).
  
  
  CONCLUSIONS
  Neither the risk of UBC nor the mortality from UBC was increased in patients with type 1 and patients with type 2 diabetes in the CPRD data.
authors.affiliation: Department of General Practice, KU Leuven, Leuven, Belgium.
authors.forename: Maria E
authors.identifier: http://orcid.org/0000-0001-7128-1354
authors.initials: ME
authors.lastname: Goossens
authors.affiliation: Department of Complex Genetics, University of Maastricht, NUTRIM School of Nutrition, Translational Research in Metabolism, Maastricht, The Netherlands.
authors.forename: Maurice P
authors.initials: MP
authors.lastname: Zeegers
authors.affiliation: Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht University, Utrecht Institute of Pharmaceutical Sciences, The Netherlands.
authors.forename: Marloes T
authors.initials: MT
authors.lastname: Bazelier
authors.affiliation: Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht University, Utrecht Institute of Pharmaceutical Sciences, The Netherlands.
authors.forename: Marie L
authors.initials: ML
authors.lastname: De Bruin
authors.affiliation: Department of General Practice, KU Leuven, Leuven, Belgium Department of General Practice, University of Maastricht, CAPHRI, School for Primary Care and Public Health, Maastricht, The Netherlands.
authors.forename: Frank
authors.initials: F
authors.lastname: Buntinx
authors.affiliation: Division of Pharmacoepidemiology and Clinical Pharmacology, Utrecht University, Utrecht Institute of Pharmaceutical Sciences, The Netherlands Department of Clinical Pharmacy and Toxicology, Maastricht University Medical Centre, Maastricht, The Netherlands Research Institute CAPHRI, University of Maastricht, The Netherlands MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK.
authors.forename: Frank
authors.initials: F
authors.lastname: de Vries
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003922:Diabetes Mellitus, Type 1 / Q000150:complications* / Q000401:mortality; D003924:Diabetes Mellitus, Type 2 / Q000150:complications* / Q000401:mortality; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D006113:United Kingdom / Q000453:epidemiology; D001749:Urinary Bladder Neoplasms / Q000209:etiology* / Q000401:mortality; D055815:Young Adult
keywords: EPIDEMIOLOGY; mortality