title: An increased risk of urinary tract infection precedes development of primary biliary cirrhosis.
abstract: BACKGROUND
  Primary Biliary Cirrhosis is known to be associated with Urinary Tract Infections (UTIs), but whether these precede or follow the liver disease is unclear. We have therefore attempted to determine whether UTIs are more common in people with Primary Biliary Cirrhosis (PBC) prior to their diagnosis.
  
  
  METHODS
  We conducted a case control study in the General Practice Research Database. All cases of PBC first recorded at least one year after entry to the dataset were selected along with up to 10 controls matched for age, sex. A second unmatched control group who had Chronic Liver Diseases but not PBC were chosen. The main exposures studied were the occurrence of Urinary tract infections and pyelonephritis at least one or at least five years before diagnosis. We also performed an analysis restricted to those younger than 55 at diagnosis, as we hypothesized the relationship to be stronger in the younger age group.
  
  
  RESULTS
  PBC is associated with UTI prior to diagnosis, OR 1.50 (CI 1.26-1.78), which was similar 5 years prior to diagnosis and after adjusting for smoking. The strongest relationships were observed in pyelonephritis exposures five years before diagnosis in cases under 55 years: adjusted odds ratios were 2.60 (1.02-6.63) in comparison with matched general population controls and adjusted odds ratios were OR 2.45 (1.02-5.59) in the comparison with chronic liver disease controls.
  
  
  CONCLUSIONS
  We found that the association between urosepsis and PBC is specific to this disease and precedes the diagnosis of PBC in a manner not previously observed in human data. This is consistent with a causal relationship.
authors.affiliation: Division of Epidemiology and Public Health, University of Nottingham, Clinical Sciences Building Phase 2, Hucknall Road, Nottingham, NG5 1PB, UK.
authors.forename: Fumi K
authors.initials: FK
authors.lastname: Varyani
authors.forename: Joe
authors.initials: J
authors.lastname: West
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Card
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008105:Liver Cirrhosis, Biliary / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011446:Prospective Studies; D012307:Risk Factors; D014552:Urinary Tract Infections / Q000150:complications*