title: Increased risk of urinary tract calculi among patients with diabetes mellitus--a population-based cohort study.
abstract: OBJECTIVE
  To investigate the inter-relationship among diabetes, urinary tract infection (UTI), and urinary tract calculi (UTC).
  
  
  METHODS
  This study used Taiwan's National Health Insurance claims data of ambulatory care visits and hospitalizations. A total of 12,257 newly diagnosed diabetes cases in 2000-2002 and 96,781 controls were followed to the end of 2007. The person-year approach with Poisson assumption was used to estimate the incidence density (ID) of UTC by diabetic status. Relative risk of UTC in relation to diabetes and UTI were estimated from Cox proportional hazard model with adjustment for sociodemographic variables and comorbidities.
  
  
  RESULTS
  Over nearly 8 years of follow-up, 8.9% of diabetes and 7.2% of control subjects sought ambulatory care or were hospitalized for UTC, representing the ID of 14.4 and 11.4 per 1000 person-years, respectively. The multivariate analysis indicated that UTC risk was independently associated with diabetes (hazard ratio 1.18, 95% CI 1.10-1.27) and UTI (HR 1.68, 95% CI 1.60-1.76). The hazard ratio of UTC in relation to diabetes in men and women without UTI was 1.24 and 1.26, respectively. Diabetes may further increase the rate of UTC in women with UTI, with an hazard ratio increased from 1.79-2.12. Such additive effect by diabetes in men with UTI was only marginal (HR 1.68 vs 1.67).
  
  
  CONCLUSIONS
  This cohort study provides epidemiologic support for the causal association between diabetes and UTC, which is independent of UTI. In addition, female patients with UTI accompanied by diabetes tended to be associated with a greater rate of UTC.
authors: Department of Physical Medicine and Rehabilitation, China Medical University, Bei-Gang Hospital, Yun-Lin, Taiwan.
authors: Hsin-Shui
authors: HS
authors: Chen
authors: Li-Ting
authors: LT
authors: Su
authors: Shinn-Zong
authors: SZ
authors: Lin
authors: Fung-Chang
authors: FC
authors: Sung
authors: Ming-Chung
authors: MC
authors: Ko
authors: Chung-Yi
authors: CY
authors: Li
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D016009:Chi-Square Distribution; D015331:Cohort Studies; D015897:Comorbidity; D016208:Databases, Factual; D003920:Diabetes Mellitus / Q000175:diagnosis / Q000453:epidemiology*; D003922:Diabetes Mellitus, Type 1 / Q000175:diagnosis / Q000453:epidemiology; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016012:Poisson Distribution; D015995:Prevalence; D011379:Prognosis; D016016:Proportional Hazards Models; D012720:Severity of Illness Index; D017678:Sex Distribution; D013624:Taiwan / Q000453:epidemiology; D014552:Urinary Tract Infections / Q000175:diagnosis / Q000453:epidemiology*; D052878:Urolithiasis / Q000175:diagnosis / Q000453:epidemiology*; D055815:Young Adult