Status of plasma folate in the third trimester of pregnant women and newborn babies in the northern rural areas of China / 中华流行病学杂志

Objective To study the plasma folate concentrations in the third trimester of pregnant women and newborn babies so as to assess the association between them.Methods Pregnant women in Yuanshi and Laoting counties in Hebei province from May to June in 2009 were recruited with related information collected at enrollment.Those pregnant women being enrolled were followed up until delivery.Maternal blood was collected before delivery,and cord blood was collected after the expulsion of the placenta.Data from 437 pairs of women and newborns were analyzed.Plasma folate concentration was measured by Microbiological assay,with maternal plasma folate concentration ＜6.8 nmol/L defined as folate deficiency.Neonatal plasma folate concentration below 10％ was defined as relative deficiency.Student t-test and ANOVA were used to compare the plasma folate concentrations between the groups and x2 test was used to compare the situation of folate deficiency.In order to assess the association between maternal and newborn folate levels,logistic regression analysis was used to estimate the odds ratio of the neonatal plasma folate relative deficiency between the maternal folate deficient and normal groups after adjusting factors as age,BMI,region,career and education.Linear regression was used to test the trend by quintiles of maternal plasma folate concentration.Pearson' s test was used to test the relationship between the ratio of neonatal and maternal plasma folate level and the level of maternal plasma folate.Results The geometric mean of maternal plasma folate concentration was 8.0(95％CI:7.6-8.5) nmol/L and the deficiency was 29.3％,but in newborn babies,they were 24.0(95％CI:23.1-25.0) nmol/L and 0.9％ respectively.The plasma folate level in newborn babies was 3.0 times as high as in maternal (t=32.519,P＜0.01 )but the neonatal plasma folate deficiency status was higher than in matemal ( x2=137.2,P＜0.01 ).When compared with the normal plasma folate level group,the risk on neonatal plasma folate relative deficiency in the maternal folate deficiency group was significantly higher aiter adjusted for confounders (OR=1.96,95％CI:1.02-3.80).The neonatal plasma folate level significantly increased along with the maternal plasma folate level (Ptrend＜0.05).The ratio of neonatal and maternal plasma folate level was significantly inversely correlated with the maternal folate level (r=-0.810,P＜0.001 ).Conclusion Folate status in newborns was much better than in their mothers',in the northern rural areas of China.The maternal folate status was positively correlated with their offspring' s.Active placental transport for folate was significantly increasing when the maternal plasma folate level decreased.

Modulatory effect of plasma folate and polymorphisms in one-carbon metabolism on catecholamine methyltransferase (COMT) H108L associated oxidative DNA damage and breast cancer risk.

The present study was aimed to investigate the modulatory role of plasma folate and eight putatively functional polymorphisms of one-carbon metabolism on catecholamine methyltransferase (COMT)-mediated oxidative DNA damage and breast cancer risk. Plasma folate and 8-oxo-2’-deoxyguanosine (8-oxodG) were estimated by commercially available kits, while polymorphisms were screened by PCR-RFLP and PCR-AFLP methods. COMT H108L polymorphism showed independent association with breast cancer (OR: 1.73, 95% CI: 1.31-2.30). No significant interaction was observed between folate status and COMT genotype. Multifactor dimensionality reduction (MDR) analysis gave evidence for the significant epistatic (gene-gene) interactions (p<0.0001) of COMT H108L with reduced folate carrier 1 (RFC1) G80A, thymidylate synthase (TYMS) 5’-UTR 3R2R, TYMS 3’-UTR ins6/del6. Increased plasma 8-oxodG were observed in cases compared to controls (mean ± SE: 5.59 ± 0.60 vs. 3.50 ± 0.40 ng/ml, p<0.004). Plasma folate deficiency alone was not a significant predictor of 8-oxodG elevation. The genotype combinations namely, RFC1 G80A/methionine synthase reductase (MTRR) A66G, RFC1 G80A/SHMT C1420T/TYMS 3R2R and serine hydroxymethyltransferase (SHMT) C1420T/TYMS 3R2R/methionine synthase (MTR) A2756G/COMT H108L were strong predictors of 8-oxodG elevation in the order of risk. To conclude, the current study provides substantial evidence for a cross talk between one-carbon metabolism and COMT catalysis that might influence oxidative DNA damage and breast cancer risk.

Marginal folate inadequacy observed in a group of young children in Kwangju, Korea

Folate is important for multiple metabolic processes such as nucleic acid synthesis and interconversions, and cell division. Folate deficiency may be a risk factor for several pathologies, such as neural tube birth defects, dementia, and cardiovascular diseases. The objectives of this study were to estimate folate intakes and plasma concentrations of young children living in Kwangju, Korea. Three consecutive 24-h food recalls and fasting blood samples were obtained from 24 boys and 30 girls, aged 2-6 y, living in Kwangju, Korea. The daily folate intake (mean +/- SD) of the children was 146.7 +/- 73.6 microgram dietary folate equivalents. No differences in folate intakes were observed by gender (p> or =0.05). The mean folate intakes of the 2 and 3 y old groups were significantly lower (p or =0.05). No significant correlation was observed between folate intakes and plasma folate concentrations. One subject (1.9%) in this study had a plasma folate concentration <6.8 nmol/L, which is indicative of folate deficiency. Approximately 24% of subjects had plasma folate concentrations of 6.8-13.4 nmol/L, which is representative of marginal folate status. In conclusion, some young children may have less than adequate folate status in Korea.

COMPARISON STUDY OF PLASMA FOLATE IN CHINESE ADULTS IN GENDERS AND AGES / 营养学报

Objective: To describe the differences of plasma folate concentration and prevalence of folate deficiency in genders and ages in Chinese adults aged 35 to 64 years. Methods: By cross-sectional analysis, plasma folate concentration was measured in 2 545 adults including men and women by microbiological assay. Results: (1) Men tended to have lower plasma folate concentration and higher prevalence of folate deficiency(9.70 nmol/L, 31.0%) than did women(14.2 nmol/L, 12.5%, P=0.001). (2) Men in South have significantly higher plasma folate concentration and lower prevalence of folate deficiency than in North. The difference of plasma folate concentration was not evident between urban and rural area, but evident in North between in winter and spring. There were no significant differences of prevalence of folate deficiency for men between urban and rural areas in both regions. For women, the differences of plasma folate concentration in areas were significant, which were higher in South and urban, and lower in North and rural areas. (3) Plasma folate concentration increased with age in Southern men. A similar trend for others was not significant. Conclusion: Men have lower plasma folate concentration and higher prevalence of plasma folate deficiency than do women. The distribution of plasma folate concentrations in urban and rural areas seems different between men and women.