RBC Folate and Serum Folate, Vitamin B-12, and Homocysteine in Chinese Couples Prepregnancy in the Shanghai Preconception Cohort

Evaluating the association of depressive symptoms on serum folate and erythrocyte folate levels based on the 2017-2020 NHANES database

Objective

To improve further the management of the nutritional status and dietary habits of depressed patients.

Methods

This study investigated the effect of different severity states of depressive symptoms on serum and erythrocyte folate levels using the Nutrition Examination Survey (NHANES) database from 2017 to 2020. We comprised a sample of 4,872 cases from NHANES database. We developed 3 linear regression models to assess the effect of depressive symptoms on erythrocyte folate and serum folate by collating and analyzing the data. The relationship between depression severity and erythrocyte folate as well as serum folate was also mutually validated by the results of multiple logistic regression. Finally, we made restricted cubic spline plots using the glm function of R.

Results

Depression remained negatively correlated with serum folate levels with a OR value of -0.02, 95% CI of -0.05 ~ -0.00. Moderate depression was negatively correlated with folate, with a OR value of -0.03, 95% CI of -0.05 ~ -0.00. When exploring the association between different degrees of depressive symptoms and erythrocyte folate, it was unexpectedly found that major depression was negatively associated with erythrocyte folate with a OR value of -0.18, 95% CI of -0.31 ~ -0.04 after adjusting for all covariates.

Conclusion

Depression is associated with folate levels. The risk of serum folate insufficiency or erythrocyte folate insufficiency is higher after a positive depression. For different degrees of depressive symptoms, serum folate levels were significantly lower than normal in patients with moderate depression, while erythrocyte folate levels were lower than normal in patients with major depression. Therefore, attention should be paid to the dietary habits and nutritional status of patients with depression or depressive symptoms when they are undergoing long-term antidepressant treatment. Folic acid supplementation is recommended for patients with moderate or severe depression or for depressed patients who have developed unhealthy eating habits.

Maternal multivitamin supplementation mitigates the risk of fetal congenital heart disease associated with high indoor total volatile organic compounds exposure in east china: a case-control study

BACKGROUND

Congenital heart disease (CHD) is a common birth defect. Our previous studies suggest that indoor air pollution, especially total volatile organic compounds (TVOCs), may increase fetal CHD risk, whereas vitamin and folic acid (FA) supplements in early pregnancy might offer protection against CHD. However, limited research has explored whether FA or multivitamin supplementation can mitigate the effects of TVOCs exposure on CHD.

METHODS

We conducted a case-control study to investigate the association between maternal nutrient supplementation, household indoor air pollutant exposure during pregnancy, and CHD in offspring. Pregnant women with 22-30 gestational weeks were recruited from two hospitals in East China between January 2016 and March 2022. A comprehensive approach was used, incorporating questionnaires to collect nutrient supplement information, blood sample analysis to detect serum folate, vitamin B12, and homocysteine (HCY) concentrations, and field investigations to assess indoor benzene, toluene, xylene, formaldehyde, and TVOCs exposures. Logistic regression analysis was performed to identify CHD risk factors, and stratified analysis was used to evaluate the combined effects of nutrient supplementation and TVOCs on CHD.

RESULTS

The study included 53 cases and 77 controls. Logistic regression analysis identified high maternal serum HCY (> 6.125 µmol/L) and high household TVOCs exposure (> 0.0165 mg/m³) as risk factors for CHD in offspring, with adjusted odds ratios of 2.98 (95% CI: 1.31-6.36) and 9.23 (95% CI: 3.78-22.53), respectively. Regular multivitamin supplementation mitigated the risk of high TVOCs exposure on fetal CHD, while the adverse effect of high serum HCY-related CHD risk was attenuated in the group with regular FA supplementation.

CONCLUSION

Exposure to high indoor TVOCs concentrations increases the risk of fetal CHD. Regular multivitamin supplementation may reduce the adverse effects of high TVOCs exposure on fetal CHD.

Dietary folic acid intake, 13 genetic variants and other factors with red blood cell folate concentration in pregnancy-preparing population

PURPOSE

This study aims to evaluate a combined effect of dietary folic acid intake, multiple genetic polymorphisms in folate metabolism, and other environmental factors on red blood cell (RBC) folate concentration in pregnancy-preparing population.

METHODS

519 pregnancy-preparing subjects (260 couples) were investigated. Dietary intake was measured by 3-day dietary recalls. 13 Single Nucleotide polymorphisms (SNPs) reported in association with one-carbon metabolism including the methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C were genotyped. RBC folate concentration was measured using chemiluminescence assay. Hierarchical regression was applied for covariate selection. Factors showed significance(p < 0.0125) on RBC folate level was included for prediction model construction and R2 estimation. Validation cohort analysis was performed as post-hoc analysis if applicable.

RESULTS

The median RBC folate was 212.8 ng/ml. Only 10% took folic acid supplementation within three months. Based on hierarchical selection, folic acid supplementation, genetic polymorphism (especially TT genotype of MTHFR C677T), serum folate level were determinants of the variance of RBC folate concentrations, with adjusted R2 of 0.178-0.242. MTHFR A1298C polymorphism, sex difference with other socio-demographic and lifestyle factors (age, BMI, alcohol drinking, smoking, education, occupation) explained little to change in RBC folate level. Validation in another sub-cohort(n = 8105) had adjusted R2 of 0.273.

CONCLUSION

In pregnancy-preparing subjects, folic acid supplementation, serum folate level and TT allele of MTHFR C677T polymorphism were determinants of the total variance of RBC folate level, which explained 19.8% variance in our subjects and 27.3% in the validation cohort. Food folate intake, sex and other environmental factors explained little to RBC folate level.

Genome-Wide Association Study Identifies Genetic Polymorphisms for Folate-Related Biomarkers in Chinese Preconception Women

BACKGROUND

Single-nucleotide polymorphism (SNP) allele frequencies, dietary habits, and folate status and their associations vary across ethnic populations. Little is known about the SNPs accounting for variations of folate-related biomarkers for Chinese preparing-for-pregnant females.

OBJECTIVES

We aimed to identify SNPs contributing to RBC and serum folate, vitamin B-12, and homocysteine concentrations in Chinese female preconception population.

METHODS

A genome-wide association study was conducted on 1000 randomly selected preconception Chinese women from the Shanghai Preconception Cohort. SNPs were genotyped using Illumina chips, and associations with biomarkers were assessed using simple linear regression models under the assumption of an additive genetic model. Genome-wide significance was considered at P < 10-7.

RESULTS

The MTHFR rs1801133 was the major genetic coding variant contributing to RBC folate, serum folate, and homocysteine concentrations (P = 2.28 × 10-16; P = 8.85 × 10-8, and P = 2.46 × 10-13, repsectively). It is associated with increased RBC folate (β: 0.154 per additional risk allele after log transform), decreased serum folate (β: -0.951 per additional risk allele), and increased serum homocysteine concentrations (β: 1.153 per additional risk allele). The predominant SNP associated with serum folate was rs147162222 in NTRK2 (P = 2.55 × 10-8), although that associated with homocysteine was rs77025184 located between PDE7B and LINC00271 (P = 4.91 × 10-17). For vitamin B-12, FUT2 rs1047781 was the dominant genetic variant (P = 1.59 × 10-10). The numbers of signals with a P value of <10-7 for RBC folate, serum folate, vitamin B-12, and homocysteine were 12, 18, 8, and 614, respectively.

CONCLUSIONS

This study represents the first genome-wide association study focusing on folate-related biomarkers in a Chinese preparing-for-pregnant female population. The contributions of dominent SNPs to each biomarker are partly different from other populations. The rs1801133 (C677T) in MTHFR is the predominant genetic variant contributing to RBC folate and rs1047781 (A385T) in FUT2 as the primary one explaining vitamin B-12. Notably, the intronic rs147162222 and noncoding rs77025184 are the predominant SNPs for serum folate and homocysteine, respectively.

Periconception Red Blood Cell Folate and Offspring Congenital Heart Disease : Nested Case-Control and Mendelian Randomization Studies

BACKGROUND

Periconception folic acid supplementation has been suggested to protect against congenital heart disease (CHD), but the association between maternal red blood cell (RBC) folate, the gold-standard biomarker of folate exposure, and subsequent offspring CHD risk is lacking.

OBJECTIVE

To quantify the association between periconception maternal RBC folate and offspring CHD risk.

DESIGN

Prospective, nested, case-control study and 1-sample Mendelian randomization. (ClinicalTrials.gov: NCT02737644).

SETTING

29 maternity institutions in 12 districts of Greater Shanghai, China.

PARTICIPANTS

All 197 mothers of offspring with CHD and 788 individually matched mothers of unaffected offspring from the SPCC (Shanghai Preconception Cohort).

MEASUREMENTS

Maternal RBC folate was measured before or at early pregnancy. Odds ratios [ORs] were estimated using conditional logistic regression after adjustment for covariates. Mendelian randomization was done using the methylenetetrahydrofolate reductase (MTHFR) C677T as the genetic instrument.

RESULTS

Case patients had lower median maternal RBC folate concentrations than control participants (714 nmol/L [interquartile range, 482 to 1008 nmol/L] vs. 788 nmol/L [557 to 1094 nmol/L]). Maternal RBC folate concentrations were inversely associated with offspring CHD (adjusted OR per 100 nmol/L, 0.93 [95% CI, 0.89 to 0.99]). The adjusted OR for mothers with periconception RBC folate of 906 nmol/L or more (vs. <906 nmol/L) was 0.61 (CI, 0.40 to 0.93). Mendelian randomization showed that each 100-nmol increase in maternal RBC folate concentrations was significantly associated with reduced offspring CHD risk (OR, 0.75 [CI, 0.61 to 0.92]).

LIMITATION

Potential confounding due to unmeasured covariates in the nested case-control study.

CONCLUSION

Higher maternal RBC folate is associated with reduced offspring CHD risk. For primary CHD prevention, higher target RBC folate levels than currently recommended for neural tube defect prevention may be needed and warrant further study.

PRIMARY FUNDING SOURCE

National Key Research and Development Program of China, National Natural Science Foundation of China, China Postdoctoral Science Foundation, and Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences.