Homocysteine in inflammatory bowel disease: a risk factor for thromboembolic complications?

OBJECTIVE: Patients with inflammatory bowel disease (IBD) are at increased risk for thromboembolic events. Hyperhomocysteinemia, which is an established risk factor for arterial as well as venous thrombosis, may be more prevalent in IBD because of vitamin deficiencies.
METHODS: In this retrospective study, we studied the concentrations of total homocysteine (tHcy), cobalamin, folate, and pyridoxine in 231 consecutive patients with IBD, of whom 16 patients had a history of venous thrombosis, and nine a history of arterial thrombosis. Age- and gender-matched healthy volunteers served as controls (n = 102).
RESULTS: Homocysteine concentrations in patients were higher (12.3 micromol/L [range 4.6-51.3] vs 11.1 micromol/L [range 3.9-27.6], p = 0.001) and hyperhomocysteinemia tended to be more prevalent in patients than in the controls (11.1% vs 5%, p = 0.07). Folate, cobalamin, creatinine, and pyridoxine concentrations were correlated with tHcy. Folate deficiency was infrequently encountered in IBD patients (4.3%). The tHcy concentration in patients with a history of venous or arterial thrombosis was not higher than in patients without a history of thrombosis (12.7 micromol/L [range 4.6-40.1] and 15.2 micromol/L (range 10.5-26.8) vs 12.3 micromol/L [range 10.5-26.8], not significant). Hyperhomocysteinemia was found in 18.8% of the patients with venous thrombosis, 11.1% of the patients with arterial thrombosis, and 10.5% of the patients without thrombosis (not significant).
CONCLUSIONS: Hyperhomocysteinemia is a common phenomenon in IBD and correlates with serum folate, cobalamin, creatinine, and pyridoxine concentrations. No correlation between tHcy and a history of venous or arterial thromboembolic complications is found. Hyperhomocysteinemia does not seem to be a major contributory factor in the development of venous or arterial thrombosis in IBD patients.