Serum folate and homocysteine levels are associated with colon tumorigenesis in end-stage renal disease patients

The aim of this study was to evaluate the effect of folate and homocysteine on colon tumorigenesis by performing colonoscopy and examining serum folate and homocysteine levels in end-stage renal disease (ESRD) patients. We performed colonoscopy in 72 ESRD patients who were undergoing hemodialysis and also measured their serum folate and homocysteine levels. Serum folate and homocysteine concentrations of the 72 ESRD patients were 6.0 ± 3.9 μg/l and 37.3 ± 25.5 μmol/l, respectively. Colorectal neoplasia was detected in 47 (65%) of the patients. Compared to a control group, ESRD patients had significantly more and larger neoplasia (P = 0.002 and 0.001, respectively). Multivariate analysis revealed that ESRD patients with lower levels of serum homocysteine had significantly more and larger neoplasia than those with higher levels (P = 0.02 and 0.03, respectively). In addition, patients with a shorter duration of hemodialysis were likely to have larger neoplasia. ESRD patients had higher than normal serum homocysteine levels. Interestingly, patients with lower homocysteine levels were likely to carry more and larger colorectal neoplasia. These results suggest that suppression of folate metabolism and an elevated serum homocysteine concentration are inversely associated with colon tumorigenesis in ESRD patients.