We also found that the RBC folate level was

We also found that the RBC folate level was significantly increased in individuals with the TT Nitidine chloride Supplier compared to individuals with the CC genotype. The plasma folate concentration fluctuates in relation to diet, and is thus a useful dynamic measure that reflects recent nutritional uptake. Therefore, serum folate is commonly used as a marker for the short-term folate status, whereas RBC folate is used as a marker for long-term folate status because it reflects the folate status during erythropoiesis. The reduced stability and activity of the MTHFR enzyme associated with the MTHFR C677T polymorphism may diminish the utilization of folate, thereby leading to its accumulation. Fohr et al showed that individuals with the TT genotype had a greater increase in RBC folate after supplementation with a folate derivative, compared to individuals with the CT or CC genotype. Previous intervention studies in humans taking folate and/or vitamin B12 supplements showed that DNA hypomethylation, chromosome breaks, uracil misincorporation, and micronucleus formation were minimized when the plasma concentration of vitamin B12 was >300pM, the plasma folate concentration was >34nM, the RBC folate concentration was >700 M, and the plasma Hcy concentration was <7.5μM. Therefore, these levels served as our criteria for defining low vitamin levels, and a cutoff level below 7.5μM was considered a reasonable fasting tHcy concentration. To our knowledge, this is the first study to report the relative contribution of the MTHFR C677T gene polymorphism and folate and vitamin B12 deficiency on serum tHcy levels. Our data suggest no significant correlation between the mean serum levels of tHcy and the C677T polymorphism when the folate level is high (>34nM); however, at a low folate level (≤34 nM), individuals with the TT genotype had significantly higher tHcy levels. Thus, the C677T polymorphism is associated with increased serum Hcy levels when combined with a low folate status. This finding is consistent with previous work showing that most T-homozygous individuals with low serum folate levels had increased tHcy levels, whereas T-homozygous individuals with high serum folate levels had normal tHcy levels, and that dietary folate is a key risk modifier that can negate the risk associated with the MTHFR C677T polymorphism by directly controlling tHcy levels. Riboflavin and folate levels are significant predictors of Hcy levels in individuals homozygous for the MTHFR T677 allele, which suggests that T-homozygous individuals require a higher riboflavin and folate intake to maintain low Hcy levels. Therefore, the impact of folate on tHcy levels is greater than the impact of the MTHFR C677T gene polymorphism. In conclusion, the MTHFR C677T polymorphism and folate and vitamin B12 deficiency were all associated with elevated serum tHcy levels in healthy individuals in Yunnan Province, China. Among these three factors, folate deficiency appears to be much more important than the MTHFR C677T polymorphism for elevating the tHcy concentration, whereas B12 deficiency was the weakest factor. These results suggest that appropriate doses of folic acid and vitamin B12 supplementation could help to normalize the blood tHcy level, especially in individuals with the MTHFR 677TT genotype. These results may provide new strategies for preventing diseases related to Hcy accumulation, particularly cardiovascular disease.
Acknowledgments This research was supported by the National Natural Science Foundation of China (Beijing, China; Project #31260268 and #31560307). We are grateful to all volunteers who participated in the study.
Introduction Colonoscopy is an endoscopic examination of the large bowel and the distal part of the small bowel that is used to diagnose pathological lesions, such as ulceration, polyps, inflammation, and even cancer, via gross inspection or biopsy and as a therapeutic approach to remove suspected malignant lesions. In recent years, colonoscopy has been considered the gold standard for colon cancer screening and surveillance.