title: Overweight, obesity, and the risk of recurrent venous thromboembolism.
abstract: BACKGROUND
  Excess body weight is a risk factor for a first venous thromboembolism. The impact of excess body weight on risk of recurrent venous thrombosis is uncertain.
  
  
  METHODS
  We studied 1107 patients for an average of 46 months after a first unprovoked venous thromboembolism and withdrawal of anticoagulant therapy. Excluded were pregnant patients, those requiring long-term antithrombotic treatment, and those who had a previous or secondary thrombosis, natural coagulation inhibitor deficiency, lupus anticoagulant, or cancer. Our study end point was symptomatic recurrent venous thromboembolism.
  
  
  RESULTS
  A total of 168 patients had recurrent venous thromboembolism. Mean (SD) body mass index (BMI) (calculated as weight in kilograms divided by height in meters squared) was significantly higher among patients with recurrence than among those without recurrence: 28.5 (6.0) vs 26.9 (5.0) (P = .01). The relationship between excess body weight and recurrence was linear; the adjusted hazard ratio for each 1-point increase in BMI was 1.044 (95% confidence interval [CI], 1.013-1.076) (P < .001). Four years after discontinuation of anticoagulant therapy, the probability of recurrence was 9.3% (95% CI, 6.0%-12.7%) among patients of normal weight and 16.7% (95% CI, 11.0%-22.3%) and 17.5% (95% CI, 13.0%-22.0%) among overweight and obese patients, respectively. Compared with patients of normal weight, the hazard ratio of recurrence adjusted for age, sex, factor V Leiden, prothrombin G20210A mutation, high factor VIII levels, and type of initial venous thromboembolic event was 1.3 (95% CI, 0.9-1.9) (P = .20) among overweight patients and 1.6 (95% CI, 1.1-2.4) (P = .02) among obese individuals. The population attributable risk corresponding to excess body weight was 26.8% (95% CI, 5.3%-48.2%).
  
  
  CONCLUSIONS
  Excess body weight is a risk factor of recurrent venous thromboembolism.
authors.affiliation: Department of Internal Medicine I, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria. sabine.eichinger@meduniwien.ac.at
authors.forename: Sabine
authors.initials: S
authors.lastname: Eichinger
authors.forename: Gregor
authors.initials: G
authors.lastname: Hron
authors.forename: Christine
authors.initials: C
authors.lastname: Bialonczyk
authors.forename: Mirko
authors.initials: M
authors.lastname: Hirschl
authors.forename: Erich
authors.initials: E
authors.lastname: Minar
authors.forename: Oswald
authors.initials: O
authors.lastname: Wagner
authors.forename: Georg
authors.initials: G
authors.lastname: Heinze
authors.forename: Paul A
authors.initials: PA
authors.lastname: Kyrle
mesh_terms: D017677:Age Distribution; D000925:Anticoagulants / Q000627:therapeutic use; D001317:Austria / Q000453:epidemiology; D001779:Blood Coagulation Factors / Q000032:analysis; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000032:analysis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology*; D050177:Overweight / Q000453:epidemiology*; D012008:Recurrence; D012307:Risk Factors; D017678:Sex Distribution; D054556:Venous Thromboembolism / Q000188:drug therapy / Q000453:epidemiology*
chemical_list: D000925:Anticoagulants; D001779:Blood Coagulation Factors; D002097:C-Reactive Protein