Higher Plasma Homocysteine Is Associated with Increased Risk of Developing Colorectal Polyps

Colorectal adenomas are considered to be precursors of colorectal cancer. B-vitamins (i.e., folate, vitamin B₆ and B₁₂) are involved in homocysteine metabolism and play an important role as coenzymes in 1-carbon metabolism, which is thought to have a critical role in the progression of colorectal polyps. The purpose of this study was to examine the effects of B-vitamins and homocysteine on the risk of developing colorectal polyps. Forty-eight participants with colorectal polyps [29 adenomatous polyps (AP), 19 hyperplastic polyps (HP)], and 96 age- and sex-matched healthy controls were recruited. Fasting blood was drawn from each participant to measure hematological parameters, plasma pyridoxal 5′-phosphate (PLP), serum folate and vitamin B₁₂, and plasma homocysteine. Participants with AP and HP had significantly higher plasma homocysteine levels than did healthy controls. There was no significant difference in serum folate and vitamin B₁₂ and plasma PLP among the 3 groups. B-vitamins had no significant effect on the risk of colorectal polyps. However, participants with higher plasma homocysteine [odds ratio (OR) = 1.87, 95% confidence interval (CI) = 1.13, 3.08) level exhibited significantly increased risk of colorectal polyps after adjusting for potential confounders. Plasma homocysteine was a strong predictor of the risk of colorectal polyps in participants with adequate B-vitamins status.