title: Association between small intestinal bacterial overgrowth and deep vein thrombosis.
abstract: OBJECTIVE
  Small intestinal bacterial overgrowth (SIBO) has been associated with several diseases. The association between SIBO and deep vein thrombosis (DVT) has not been investigated. This study was aimed to investigate the frequency and risk factors for the development of DVT in patients tested for SIBO.
  
  
  METHODS
  All 321 eligible patients were included from the Cleveland Clinic Gastrointestinal Motility Lab databank from January 2008 to January 2014. Patients who were evaluated with glucose hydrogen/methane breath test as well as Doppler ultrasonography for suspected DVT were included. Patients with catheter-related DVT were excluded. The primary outcomes were the frequency and risk factors (including SIBO) for DVT in this patient population.
  
  
  RESULTS
  Of the 321-case cohort, 144 patients (44.9%) tested positive for SIBO, and 53 (16.5%) had ultrasonographic findings of DVT. SIBO evaluation before the evaluation of DVT occurred in 201 patients (median time from the breath test to ultrasonography: 27 months; interquartile range [IQR]: 11.0-45.0 months), and SIBO evaluation after evaluation for DVT occurred in 120 patients (median time from ultrasonography to the breath test: 30 months; IQR: 11.8-54.3 months). In the univariate analysis, DVT was associated with family history of thromboembolic events (35.8% vs 16.0%, P=0.001), chronic kidney diseases (CKD; 26.4% vs 13.4%, P=0.019) and the presence of SIBO (69.8% vs 39.9%, P<0.001). In the multivariate analysis, family history of thromboembolic events (odds ratio [OR]: 3.39; 95% confidence interval [CI]: 1.67-6.87; P<0.001), CKD (OR: 2.23; 95%CI: 1.04-4.74; P = 0.037), and the presence of SIBO (OR: 3.27; 95% CI: 1.70-6.32; P < 0.001) remained independently associated with DVT.
  
  
  CONCLUSIONS
  SIBO was found to be associated with DVT. The nature of this association warrants further investigation.
authors.affiliation: Department of Internal Medicine, The Cleveland Clinic Foundation, Cleveland, OH, USA and.
authors.forename: Andre
authors.initials: A
authors.lastname: Fialho
authors.affiliation: Department of Internal Medicine, The Cleveland Clinic Foundation, Cleveland, OH, USA and.
authors.forename: Andrea
authors.initials: A
authors.lastname: Fialho
authors.affiliation: Department of Internal Medicine, The Cleveland Clinic Foundation, Cleveland, OH, USA and.
authors.forename: Aldo
authors.initials: A
authors.lastname: Schenone
authors.affiliation: Department of Gastroenterology and Hepatology, The Cleveland Clinic Foundation, Cleveland, OH, USA.
authors.forename: Prashanthi
authors.initials: P
authors.lastname: Thota
authors.affiliation: Department of Gastroenterology and Hepatology, The Cleveland Clinic Foundation, Cleveland, OH, USA.
authors.forename: Arthur
authors.initials: A
authors.lastname: McCullough
authors.affiliation: Department of Gastroenterology and Hepatology, The Cleveland Clinic Foundation, Cleveland, OH, USA shenb@ccf.org.
authors.forename: Bo
authors.initials: B
authors.lastname: Shen
keywords: deep vein thrombosis; risk factors; small intestine bacterial overgrowth