Summary
Background and Aims. Why patients with inflammatory bowel disease are at increased
risk for thrombosis is unknown. Since they may have impaired absorption of vitamins
that regulate the metabolism of homocysteine, we tested the hypothesis that they have
hyper-homocysteinemia, an established risk factor for arterial and venous thrombosis.
Methods. The concentrations of total homocysteine (tHcy), folate and cobalamin were
measured in blood samples from 61 consecutive patients with inflammatory bowel disease
and 183 age- and sex-matched healthy controls. Results. The mean (± S.D.) concentration
of plasma tHcy was higher in patients (12.2 ± 7.7 μmol/l) than in controls (10.5 ±
4.6, p = 0.045). Eight patients (13%) had concentrations of tHcy higher than the 95th
percentile of distribution among controls, as compared with 9 healthy controls (5%,
p = 0.04). The prevalence of folate deficiency was higher in patients (15%) than in
controls (5%, p = 0.02). Oral administration of folate, cobalamin and pyridoxine to
15 patients for 30 days decreased their mean tHcy levels from 20.3 ± 9.9 to 9.5 ±
3.4 (p <0.001). Conclusions. In patients with inflammatory bowel disease there is
an increased prevalence of hyperhomocysteinemia, which can be corrected by the administration
of folate, cobalamin and pyridoxine. The high prevalence of hyperhomocysteinemia may
account for the thrombotic risk of IBD patients; whether or not its correction will
decrease the thrombotic risk should be tested in properly designed clinical trials.
Presented at the 39th Annual Meeting of the American Society of Hematology, San Diego (CA) December 5-9,
1997, and published in abstract form in Blood 1997; 90 (supplement 1): 398a.
