Hiperhomocisteínemia ‐ Uma ameaça oculta da doença inflamatória intestinal?

Abstract

Introduction and objectives

Several recent studies have reported increased homocysteine levels in Inflammatory Bowel Disease (IBD). Hyperhomocysteinemia (hHcys) has been proved to be an independent risk factor for coronary artery disease, arterial and venous thrombosis, making it an interesting candidate as a pathogenic link in IBD. The aims of this study were to assess the prevalence of hHcys in patients with IBD and to investigate the relation between homocysteine levels and its main determinants.

Material and methods

Single‐center prospective study including 47 patients (29 patients with Crohn's disease and 18 patients with Ulcerative Colitis) consecutively observed in a consultation of Inflammatory Bowel Disease. Blood samples were obtained from all patients following fasting and these samples were used for determination of C reactive protein, folic acid, vitamin B₁₂ and homocysteine levels. Clinical data recorded from disease onset to the time of the homocysteine assay were analysed. Association between categorical variables and comparisons of means were tested by Fisher exact test and Student t test, respectively. To identify predictive factors of hHcys in patients with IBD, a linear regression analysis was applied. The statistical level of significance was established at 5%. Statistical analysis was performed with SPSS (version 18.0).

Results

In our series, 10.6% of IBD patients were found to have hHcys. Five patients (10.6%) had a previous history of thromboembolism. Compared to patients with normal homocysteine levels, those with hHcys were younger (p < 0.001), had lower levels of folic acid (p < 0.001), and had a lower illness duration (p < 0.001). In patients with hHcys there also were a statistically significant difference according to smoking status (p < 0.001). Linear regression analysis to predict homocysteine levels based on age, illness duration, vitamin B₁₂ and folic acid levels was significative (p = 0.001) and explain 37% of the variance found in homocysteine levels of this sample. The level of folic acid was a significant predictor (p = 0.01) of hHcys.

Conclusion

Hyperhomocysteinemia is a common phenomenon in patients with IBD. Preventive measures could focus on reversible risk factors correlated with hHcys, such as cessation of smoking and correction of vitamin deficiencies.