title: Diabetes, glycemic control, and risk of hospitalization with pneumonia: a population-based case-control study.
abstract: OBJECTIVE
  To examine whether diabetes is a risk factor for hospitalization with pneumonia and to assess the impact of A1C level on such risk.
  
  
  METHODS
  In this population-based, case-control study we identified patients with a first-time pneumonia-related hospitalization between 1997 and 2005, using health care databases in northern Denmark. For each case, 10 sex- and age-matched population control subjects were selected from Denmark's Civil Registration System. We used conditional logistic regression to compute relative risk (RR) for pneumonia-related hospitalization among subjects with and without diabetes, controlling for potential confounding factors.
  
  
  RESULTS
  The study included 34,239 patients with a pneumonia-related hospitalization and 342,390 population control subjects. The adjusted RR for pneumonia-related hospitalization among subjects with diabetes was 1.26 (95% CI 1.21-1.31) compared with nondiabetic individuals. The adjusted RR was 4.43 (3.40-5.77) for subjects with type 1 diabetes and 1.23 (1.19-1.28) for subjects with type 2 diabetes. Diabetes duration >or=10 years increased the risk of a pneumonia-related hospitalization (1.37 [1.28-1.47]). Compared with subjects without diabetes, the adjusted RR was 1.22 (1.14-1.30) for diabetic subjects whose A1C level was <7% and 1.60 (1.44-1.76) for diabetic subjects whose A1C level was >or=9%.
  
  
  CONCLUSIONS
  Type 1 and type 2 diabetes are risk factors for a pneumonia-related hospitalization. Poor long-term glycemic control among patients with diabetes clearly increases the risk of hospitalization with pneumonia.
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Aalborg, Denmark. j.kornum@rn.dk
authors.forename: Jette B
authors.initials: JB
authors.lastname: Kornum
authors.forename: Reimar W
authors.initials: RW
authors.lastname: Thomsen
authors.forename: Anders
authors.initials: A
authors.lastname: Riis
authors.forename: Hans-Henrik
authors.initials: HH
authors.lastname: Lervang
authors.forename: Henrik C
authors.initials: HC
authors.lastname: Schønheyder
authors.forename: Henrik T
authors.initials: HT
authors.lastname: Sørensen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001786:Blood Glucose / Q000378:metabolism*; D016022:Case-Control Studies; D003718:Denmark / Q000453:epidemiology; D048909:Diabetes Complications / Q000453:epidemiology*; D003920:Diabetes Mellitus / Q000097:blood*; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000453:epidemiology*; D012306:Risk; D012307:Risk Factors
chemical_list: D001786:Blood Glucose