Analysis Of Serum Folic Acid,vitamin B₁₂ And Homocysteine Levels In Women Of Child-bearing Age And Early Pregnancy With Different Genetic Signs

Background and ObjectiveFolic acid,also known as pteroyl glutamate,is a B vitamin that can be converted into a variety of active coenzyme forms that participate in the transfer of a carbon unit within the body,the biosynthesis of purines,pyrimidines,nucleic acids and proteins,and cells.Splitting plays an important role.It is a necessary substance for maintaining the normal life processes of living organisms.Folic acid metabolism disorders cause folic acid to work in the body and cause a relative lack of folic acid,resulting in abnormal embryonic development.Commonly seen in Down syndrome^[1],neural tube defects^[2],cleft lip and palate^[3-4]and congenital Congenital malformations and vascular diseases such as heart disease^[5],mental disorders^[7],and cancer^[8].The key enzymes in folate metabolism,5,10-methylenetetrahydrofolate reductase?MTHFR?and methionine synthetase reductase?MTRR?,play an important role in DNA synthesis and the conversion of HCY to methionine.MTHFR C677C?T mutation?alanine?proline?,1298A?C mutation?glutamic acid?alanine?,MTRR66A?G?isoleucine?methionine?is a common major mutation site.The C?T mutation causes a significant decrease in the enzyme activity,which affects the normal metabolism of folic acid.Some studies have suggested that this site mutation directly leads to the accumulation of homocysteine?Hcy?in the body,among which homozygous mutants have higher levels of Hcy^[9,10].There are even studies that suggest that supplementation of folic acid and vitamin B₁₂ does not effectively control the level of Hcy even when given homozygous mutations^[11],but there are some studies that do not correlate between them^[12,13].Yang et al.^[14]showed that there was a significant difference in MTHFR C677T mutations among Chinese Han populations.A meta-analysis^[15]showed that the MTHFR C677T,A1298C,and MTRR A66G genes in the folate metabolic pathway in the Chinese population The frequency of polymorphism has significant geographical and ethnic differences.The genotype frequencies of the MTHFR C677T allele show an increasing trend from south to north.The genotype frequencies of the MTHFR A1298C and MTRR A66G alleles show a decreasing trend from south to north.In recent years,a large number of studies have confirmed that folic acid deficiency is the main cause of birth defects^[16],and the occurrence of birth defects is not only directly related to the lack of folic acid,and is associated with abnormal plasma HCY metabolism,resulting in close correlation between the accumulation of HCY in the plasma^[17].Folic acid supplementation has gradually become a global public health intervention.With the further development of the study,some malpractices caused by excessive folic acid supplementation by pregnant women have been reported one after another.The best supplement for folic acid has become a focus of attention for maternal and child care professionals..The purpose of this study was to analyze the polymorphisms of MTHFR and MTRR genes in healthy women of childbearing age and early pregnancy,and to detect their serum levels of folic acid,vitamin B₁₂,and HCY.The purpose of this study was to analyze the women's folic acid utilization and the influence of different genetic characteristics on serum folic acid,vitamin B12,and HCY levels,thus providing reference for women's targeted folic acid supplementation.Materials and methods1 Study populationFrom May 2015 to July 2017,1190 healthy women of child-bearing age in the outpatient department of the Third Affiliated Hospital of Zhengzhou University,20⁴5 years old,Han nationality,non pregnancy or lactation period,were excluded from pregnancy by color Doppler ultrasound and serum HCG,and folic acid preparations were not supplemented and included in the childbearing age group.Select 1530 women of early pregnancy(<13⁺⁶ weeks)from 2015.5 to 2017.7 in the outpatient department of the Third Affiliated Hospital of Zhengzhou University.The diagnostic criteria strictly follow the“Gynecology and Obstetrics Science”?by Xie Xing et al,People's Medical Publishing House,No.8?,20-45 years old,Han nationality,single child,naturally conceived,had no previous history of adverse pregnancy,according to whether or not to supplement folic acid 400 ug daily before pregnancy 3 months and during the first trimester,712 women without prophylactic folic acid were included In the unsupplemented group,818 women with preventive folic acid supplements were included in the supplemental group.The polymorphisms of MTHFR gene C677T,A1298C and MTRR gene A66G were detected at the same time,according to the conclusions of Colditz et al.^[18]and the Chinese maternal and child health center's maternal and child genetic testing project's ability to use folic acid.Divided into:High-risk group,Moderate-risk group,Low-risk group,No-risk group.All the pregnant women were informed consent,and in line with the requirements of the Third Affiliated Hospital of Zhengzhou University ethics committee.2 MethodThe oral mucosal epithelial cells of the study subjects were collected,and the polymorphisms of MTHFR C677T and A1298C sites and MTRR gene A66G sites were detected by fluorescence quantitative PCR and DNA sequencing.The levels of serum folic acid,vitamin B₁₂ and HCY in the subjects'blood were measured by direct chemiluminescence and enzymatic cycling assay.3 Statistical analysisThe data were analysed using SPSS 21.0 software.The measurement datas of the normal distribution were represented asx±s.The comparison between the groups was performed using the t test or Kruskal Wallis test.The Bonferroni method was used to compare pairs of two groups and the calibration level was corrected,?,=?/m??<0.05 was the number of comparisons between groups?;Inspection level?=0.05.Results1 Folic acid use ability risk level resultIn the genetic testing of women's folate utilization capacity,the proportions of high-risk,moderate-risk,low-risk,and no-risk were:40.22%,25.96%,9.19%,and24.63%,respectively.2 Serum Folic Acid,Vitamin B₁₂,and HCY Levels of Childbearing AgeSerum folate levels:?15.65±6.56?ug/L,Serum vitamin B₁₂ levels:?411.85±155.16?ng/L,Serum HCY levels:?7.91±3.16?umol/L.Serum folic acid levels in the high-risk group were lower than those in the low-risk group and the no-risk group,serum folic acid levels in the moderate-risk group were lower than those in the low-risk group and no-risk group.The difference was statistically significant?P<0.008?.There was no significant difference between the other groups?P>0.008?.Serum HCY levels in the high-risk group were higher than those in the no-risk group,and the difference was statistically significant?P<0.008?.There was no significant difference between the other groups.There was no significant difference in serum vitamin B₁₂ levels between groups?P>0.008?.3 Serum folic acid,Vitamin B₁₂ and HCY levels in the unsupplemented group of the First TrimesterSerum folate levels:?14.63±6.72?ug/L,serum vitamin B₁₂ levels:?414.23±192.67?ng/L,serum HCY levels:?8.51±2.30?umol/L.Serum folic acid levels in the high-risk group were lower than those in the low-risk group and the no-risk group,serum folic acid levels in the moderate-risk group were lower than those in the low-risk group and no-risk group.The difference was statistically significant?P<0.008?.There was no significant difference between the other groups?P>0.008?.Serum HCY in the high-risk group was higher than in the moderate-risk group and no risk group.The difference was statistically significant?P<0.008?.There was no significant difference between the other groups.The serum vitamin B₁₂ levels in the high-risk group were lower than those in the no-risk group?P<0.008?.There was no significant difference in the other groups.4 Serum folic acid,Vitamin B₁₂ and HCY levels in the supplemental group of the First TrimesterSerum folate levels:?16.88±6.12?ug/L,serum vitamin B₁₂ levels:?396.22±194.63?ng/L,serum HCY levels:?6.77±2.73?umol/L.Serum folic acid levels in the no-risk group was higher than those in the high-risk group,moderate-risk group,and low-risk group.The difference was statistically significant?P<0.008?.There was no significant difference between the other groups?P>0.008?.Serum HCY in the high-risk group was higher than in the moderate-risk group and no-risk group.The difference was statistically significant?P<0.008?.There was no significant difference between the other groups.The serum vitamin B₁₂ level in the no-risk group was higher than that in the high-risk group.There was a statistically significant difference?P<0.008?.There was no significant difference between the other groups.5 Comparison of serum folic acid,vitamin B₁₂ and HCY levels between childbearing age group and unpregnant women of the First TrimesterThe serum folic acid level in the childbearing age group was higher than that in the unsupplemented group?P<0.05?.The serum HCY level in the childbearing age group was lower than that in the unsupplemented group?P<0.05?.There was no significant difference in serum vitamin B12 levels between groups.6 Comparison of serum folic acid,vitamin B₁₂ and HCY levels between unsupplemented group and supplemented group of the First TrimesterThe serum folic acid level in the unsupplemented group was lower than that in the supplemented group?P<0.05?.The serum HCY level in the unsupplemented group was higher than that in the supplemented group?P<0.05?.The levels of serum vitamin B₁₂ in the two groups was no significant difference.7 MTHFR,MTRR genotype and allele frequency distribution resultsWild-type CC accounted for 15.51%in MTHFR C677T loci and 37.69%inhomozygous mutants;wild-type AA accounted for 73.94%in MTHFR A1298C loci and 1.86%in homozygous mutants;MTRR A66G locus wild-type AA 57.23%,homozygous mutant GG accounted for 5.30%;MTHFR C677T site mutation gene T gene frequency was 61.08%:MTHFR A1298C site mutation gene C gene frequency was 13.97%:MTRR A66G sitemutation gene G gene frequency 24.03%.Conclusions1.Women in this region have poor folic acid utilization,accounting for 66.18%of the population with high and moderate risk;2.Preventive supplementation of folic acid can reduce serum HCY levels,and it is necessary to supplement folic acid according to different genetic characteristics.