Inflammatory bowel disease promotes venous thrombosis earlier in life

Background: Patients with inflammatory bowel disease (IBD) may be at increa sed risk of having venous thromboembolism. Methods: Medical records from 12 53 IBD patients attending hospital care during the years 1987-97 were studi ed. These patients were recruited from a population of 340,000 inhabitants. Patients with verified venous thrombosis were characterized clinically, an d blood samples were examined for coagulopathy including analyses of antith rombin, plasminogen, protein C, protein S, factor V, and prothrombin mutati ons. As control groups we used 99 patients with verified venous thrombosis and no history of IBD and 288 volunteers with no history of thrombosis. Res ults: The incidence of venous thrombosis was 1.5/1000 IBD patients per year , which is comparable to the background population. The mean age was signif icantly lower in IBD patients than in non-IBD patients (53 versus 64 years, P = 0.0225). We found one patient with antithrombin deficiency but none wi th protein C, protein S, or plasminogen deficiency. Factor V mutation was a s prevalent in IBD patients with thrombosis as in thrombotic non-LED patien ts (27% versus 28%) and 3.0 times (95% confidence interval, 0.8-11.9) more frequent in IBD patients with thrombosis than in healthy controls. Prothrom bin mutation was not detected in IBD patients with venous thrombosis. Concl usion: We found no increased incidence of venous thrombosis in IBD patients compared with a background population. However, IBD patients had venous th rombosis earlier in life than non-IBD patients. Although factor V mutation may contribute to thrombosis, IBD acts as a trigger through mechanisms that still remain unexplained.