title: Comorbid diabetes and COPD: impact of corticosteroid use on diabetes complications.
abstract: OBJECTIVE
  To identify if there is a dose-dependent risk of diabetes complications in patients treated with corticosteroids who have both diabetes and chronic obstructive pulmonary disorder (COPD).
  
  
  METHODS
  A retrospective study of administrative claims data from the Australian Government Department of Veterans' Affairs, from 1 July 2001 to 30 June 2008, of diabetes patients newly initiated on metformin or sulfonylurea. COPD was identified by dispensings of tiotropium or ipratropium in the 6 months preceding study entry. Total corticosteroid use (inhaled and systemic) in the 12 months after study entry was determined. The outcome was time to hospitalization for a diabetes-related complication. Competing risks and Cox proportional hazard regression analyses were conducted with adjustment for a number of covariates.
  
  
  RESULTS
  A total of 18,226 subjects with diabetes were identified, of which 5.9% had COPD. Of those with COPD, 67.2% were dispensed corticosteroids in the 12 months from study entry. Stratification by dose of corticosteroids demonstrated a 94% increased likelihood of hospitalization for a diabetes complication for those who received a total defined daily dose (DDD) of corticosteroids≥0.83/day (subhazard ratio 1.94 [95% CI 1.14-3.28], P=0.014), by comparison with those who did not receive a corticosteroid. Lower doses of corticosteroid (<0.83 DDD/day) were not associated with an increased risk of diabetes-related hospitalization.
  
  
  CONCLUSIONS
  In patients with diabetes and COPD, an increased risk of diabetes-related hospitalizations was only evident with use of high doses of corticosteroids. This highlights the need for constant revision of corticosteroid dose in those with diabetes and COPD, to ensure that the minimally effective dose is used, together with review of appropriate response to therapy.
authors.affiliation: Corresponding author: Gillian E. Caughey, gillian.caughey@unisa.edu.au.
authors.forename: Gillian E
authors.initials: GE
authors.lastname: Caughey
authors.forename: Adrian K
authors.initials: AK
authors.lastname: Preiss
authors.forename: Agnes I
authors.initials: AI
authors.lastname: Vitry
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Gilbert
authors.forename: Elizabeth E
authors.initials: EE
authors.lastname: Roughead
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D000368:Aged; D000369:Aged, 80 and over; D048909:Diabetes Complications / Q000453:epidemiology*; D003920:Diabetes Mellitus / Q000188:drug therapy / Q000453:epidemiology; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology*; D012189:Retrospective Studies
chemical_list: D000305:Adrenal Cortex Hormones