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1.
MTHFR Gene and Serum Folate Interaction on Serum Homocysteine Lowering: Prospect for Precision Folic Acid Treatment.
Huang, X, Qin, X, Yang, W, Liu, L, Jiang, C, Zhang, X, Jiang, S, Bao, H, Su, H, Li, P, et al
Arteriosclerosis, thrombosis, and vascular biology. 2018;(3):679-685
Abstract
OBJECTIVE This post hoc analysis of the CSPPT (China Stroke Primary Prevention Trial) assessed the individual variation in total homocysteine (tHcy)-lowering response after an average 4.5 years of 0.8 mg daily folic acid therapy in Chinese hypertensive adults and evaluated effect modification by methylenetetrahydrofolate reductase (MTHFR) C677T genotypes and serum folate levels. APPROACH AND RESULTS This analysis included 16 413 participants from the CSPPT, who were randomly assigned to 2 double-blind treatment groups: either 10-mg enalapril+0.8-mg folic acid or 10-mg enalapril, daily and had individual measurements of serum folate and tHcy levels at baseline and exit visits and MTHFR C677T genotypes. Mean baseline tHcy levels were comparable between the 2 treatment groups (14.5±8.5 versus 14.4±8.1 μmol/L; P=0.561). After 4.5 years of treatment, mean tHcy levels were reduced to 12.7±6.1 μmol/L in the enalapril+folic acid group, but almost stayed the same in the enalapril group (14.4±7.9 μmol/L, group difference: 1.61 μmol/L; 11% reduction). More importantly, tHcy lowering varied by MTHFR genotypes and serum folate levels. Compared with CC and CT genotypes, participants with the TT genotype had a more prominent L-shaped curve between tHcy and serum folate levels and required higher folate levels (at least 15 ng/mL) to eliminate the differences in tHcy by genotypes. CONCLUSIONS Compared with CC or CT, tHcy in the TT group manifested a heightened L-shaped curve from low to high folate levels, but this difference in tHcy by genotype was eliminated when plasma folate levels reach ≈15 ng/mL or higher. Our data raised the prospect to tailor folic acid therapy according to individual MTHFR C677T genotype and folate status. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT00794885.
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Polymorphisms of the FTO and MTHFR genes and vascular, inflammatory and metabolic marker levels in postmenopausal women.
Chedraui, P, Pérez-López, FR, Escobar, GS, Espinoza-Caicedo, JA, Montt-Guevara, M, Genazzani, AR, Simoncini, T, ,
Journal of endocrinological investigation. 2016;(8):885-90
Abstract
OBJECTIVE To determine the prevalence of three single nucleotide polymorphisms (SNPs) in postmenopausal women with and without the metabolic syndrome (METS) and to explore levels of circulating biomarkers of inflammation, vascular and metabolic dysfunction according to SNP genotypes. METHODS DNA was extracted from the whole blood of 192 natural postmenopausal women (40 to 65 years) screened for the METS and tested for three gene SNPs related to obesity: the fat mass obesity (FTO: rs9939609) and the methylenetetrahydrofolate reductase (MTHFR C677T and A1298C). Blood levels of angiopoietin, IL-8, sFASL, IL-6, TNF-α, sCD40L, PAI-1, u-PA, leptin, adiponectin, resistin, ghrelin, visfatin, adipsin and insulin were measured in a subgroup, with and without the METS, using multiplex technology (n = 100) and compared according to SNP genotypes. RESULTS Genotype frequency of the three studied SNPs did not differ in relation to the presence of the METS. However, genotypes CT+TT (C677T) and AT (rs9939609) were more prevalent in women with high triglyceride levels. Pooled sub-analysis (n = 100) found that median sCD40L and visfatin levels were higher in women with genotypes AT+TT (rs9939609) as compared to AA (1178 vs. 937.0 pg/mL and 0.93 vs. 0.43 ng/mL, respectively, p < 0.05). CONCLUSION Two SNP genotypes related to obesity were more prevalent in women with abnormal triglyceride levels and two vascular and inflammatory serum markers were higher in relation to the rs9939609 SNP.
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Folic acid supplementation and methylenetetrahydrofolate reductase (MTHFR) gene variations in relation to in vitro fertilization pregnancy outcome.
Murto, T, Kallak, TK, Hoas, A, Altmäe, S, Salumets, A, Nilsson, TK, Skoog Svanberg, A, Wånggren, K, Yngve, A, Stavreus-Evers, A
Acta obstetricia et gynecologica Scandinavica. 2015;(1):65-71
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Abstract
OBJECTIVE To study folic acid intake, folate status and pregnancy outcome after infertility treatment in women with different infertility diagnoses in relation to methylenetetrahydrofolate reductase (MTHFR) 677C>T, 1298A>C and 1793G>A polymorphisms. Also the use of folic acid supplements, folate status and the frequency of different gene variations were studied in women undergoing infertility treatment and fertile women. DESIGN Observational study. SETTING University hospital. POPULATION Women undergoing infertility treatment and healthy, fertile, non-pregnant women. METHODS A questionnaire was used to assess general background data and use of dietary supplements. Blood samples were taken to determine plasma folate and homocysteine levels, and for genomic DNA extraction. A comparison of four studies was performed to assess pregnancy outcome in relation to MTHFR 677 TT vs. CC, and 1298 CC vs. AA polymorphisms. MAIN OUTCOME MEASURES Folic acid supplement intake, and plasma folate, homocysteine and genomic assays. RESULTS Women in the infertility group used significantly more folic acid supplements and had better folate status than fertile women, but pregnancy outcome after fertility treatment was not dependent on folic acid intake, folate status or MTHFR gene variations. CONCLUSION High folic acid intakes and MTHFR gene variations seem not to be associated with helping women to achieve pregnancy during or after fertility treatment.
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Effects of Italian Mediterranean organic diet vs. low-protein diet in nephropathic patients according to MTHFR genotypes.
Di Daniele, N, Di Renzo, L, Noce, A, Iacopino, L, Ferraro, PM, Rizzo, M, Sarlo, F, Domino, E, De Lorenzo, A
Journal of nephrology. 2014;(5):529-36
Abstract
BACKGROUND Several reports associate an Italian-style Mediterranean diet (IMD) with lower risk of cardiovascular disease and morbidity. The present study aimed to explore the effects of an Italian Mediterranean organic diet (IMOD) versus low-protein diet (LPD) in chronic kidney disease (CKD) patients, according to patients' carrier status for the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism. METHODS A total of 40 male patients with CKD and stable renal function (Kidney Disease Outcomes Quality Initiative stages 2 and 3) were classified according to MTHFR polymorphism as carrier T(+) or non carrier T(-). At the time of enrolment (T0) patients' diet consisted of LPD; they were then administered IMD for 14 days (T1), thereupon IMOD for 14 days (T2). Patients underwent a complete medical history, body composition assessment and biochemical analysis. RESULTS Baseline homocysteine levels were on average 8.24 mol/l higher (95 % confidence interval 6.47, 10.00) among T(+) than T(-) and the difference was statistically significant (p < 0.001). We found a significant interaction between MTHFR status and the effect of both the IMD and IMOD on homocysteine levels compared to LPD (p for interaction <0.001). Both the IMD and IMOD resulted in significant variations of anthropometric and laboratory measurements. CONCLUSIONS IMD and IMOD diets could represent a viable alternative to LPD in CKD patients on conservative therapy. The effect of these diets seems to be influenced by MTHFR genotypes.
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Homocysteine lowering by folate-rich diet or pharmacological supplementations in subjects with moderate hyperhomocysteinemia.
Zappacosta, B, Mastroiacovo, P, Persichilli, S, Pounis, G, Ruggeri, S, Minucci, A, Carnovale, E, Andria, G, Ricci, R, Scala, I, et al
Nutrients. 2013;(5):1531-43
Abstract
BACKGROUND/OBJECTIVES To compare the efficacy of a diet rich in natural folate and of two different folic acid supplementation protocols in subjects with "moderate" hyperhomocysteinemia, also taking into account C677T polymorphism of 5,10-methylenetetrahydrofolate reductase (MTHFR) gene. SUBJECTS/METHODS We performed a 13 week open, randomized, double blind clinical trial on 149 free living persons with mild hyperhomocyteinemia, with daily 200 μg from a natural folate-rich diet, 200 μg [6S]5-methyltetrahydrofolate (5-MTHF), 200 μg folic acid or placebo. Participants were stratified according to their MTHFR genotype. RESULTS Homocysteine (Hcy) levels were reduced after folate enriched diet, 5-MTHF or folic acid supplementation respectively by 20.1% (p < 0.002), 19.4% (p < 0.001) and 21.9% (p < 0.001), as compared to baseline levels and significantly as compared to placebo (p < 0.001, p < 0.002 and p < 0.001, respectively for enriched diet, 5-MTHF and folic acid). After this enriched diet and the folic acid supplementation, Hcy in both genotype groups decreased approximately to the same level, with higher percentage decreases observed for the TT group because of their higher pre-treatment value. Similar results were not seen by genotype for 5-MTHF. A significant increase in RBC folate concentration was observed after folic acid and natural folate-rich food supplementations, as compared to placebo. CONCLUSIONS Supplementation with natural folate-rich foods, folic acid and 5-MTHF reached a similar reduction in Hcy concentrations.
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5,10-Methylenetetrahydrofolate reductase (MTHFR), methionine synthase (MTRR), and methionine synthase reductase (MTR) gene polymorphisms and adult meningioma risk.
Zhang, J, Zhou, YW, Shi, HP, Wang, YZ, Li, GL, Yu, HT, Xie, XY
Journal of neuro-oncology. 2013;(2):233-9
Abstract
The causes of meningiomas are not well understood. Folate metabolism gene polymorphisms have been shown to be associated with various human cancers. It is still controversial and ambiguous between the functional polymorphisms of folate metabolism genes 5,10-methylenetetrahydrofolate reductase (MTHFR), methionine synthase (MTRR), and methionine synthase reductase (MTR) and risk of adult meningioma. A population-based case–control study involving 600 meningioma patients (World Health Organization [WHO] Grade I, 391 cases; WHO Grade II, 167 cases; WHO Grade III, 42 cases) and 600 controls was done for the MTHFR C677T and A1298C, MTRR A66G, and MTR A2756G variants in Chinese Han population. The folate metabolism gene polymorphisms were determined by using a polymerase chain reaction–restriction fragment length polymorphism assay. Meningioma cases had a significantly lower frequency of MTHFR 677 TT genotype [odds ratio (OR) = 0.49, 95 % confidence interval (CI) 0.33–0.74; P = 0.001] and T allele (OR = 0.80, 95 % CI 0.67–0.95; P = 0.01) than controls. A significant association between risk of meningioma and MTRR 66 GG (OR = 1.41, 95 % CI 1.02–1.96; P = 0.04) was also observed. When stratifying by the WHO grade of meningioma, no association was found. Our study suggested that MTHFR C677T and MTRR A66G variants may affect the risk of adult meningioma in Chinese Han population.
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Effect of the MTHFR C677T and A1298C polymorphisms on survival in patients with advanced CKD and ESRD: a prospective study.
Jamison, RL, Shih, MC, Humphries, DE, Guarino, PD, Kaufman, JS, Goldfarb, DS, Warren, SR, Gaziano, JM, Lavori, P, ,
American journal of kidney diseases : the official journal of the National Kidney Foundation. 2009;(5):779-89
Abstract
BACKGROUND Abnormalities in the gene regulating methylenetetrahydrofolate reductase (MTHFR) are associated with increased homocysteine levels and increased mortality in normal and chronic kidney disease (CKD) populations. STUDY DESIGN Gene association study. SETTING & PARTICIPANTS This was a substudy of 677 patients from 21 Veterans Affairs medical centers participating in a randomized clinical trial (Homocysteinemia in Kidney and End-Stage Renal Disease [HOST]) of the effect on all-cause mortality of vitamin-induced lowering of plasma homocysteine levels. Of 677 patients, 213 (31%) were treated by using dialysis (end-stage renal disease [ESRD]) and 464 (69%) had a Cockcroft-Gault estimated creatinine clearance less than 30 mL/min (advanced CKD). PREDICTOR Polymorphisms C677T (rs1801133) and A1298C (rs1801131) of the MTHFR gene. OUTCOMES Unadjusted and adjusted all-cause mortality. MEASUREMENTS DNA was extracted from blood samples and amplified by means of polymerase chain reaction. RESULTS The adjusted hazard ratio in a recessive model of the relationship between the C677T polymorphism and all-cause mortality in all patients was 1.47 (95% confidence interval, 1.00 to 2.16; P = 0.05). In patients with ESRD with the mutant TT genotype, the adjusted hazard ratio for mortality in all patients was 2.27 (95% confidence interval, 1.07 to 4.84; P = 0.03); patients with advanced CKD showed a similar, although not significant, trend. The risk of myocardial infarction (P = 0.05) and composite risk of myocardial infarction, stroke, lower-extremity amputation, and mortality (P = 0.02) were greater in patients with ESRD with the mutant T allele at nucleotide 677. The overall relationship between the A1298C polymorphism and mortality was not significant (P = 0.6). LIMITATIONS Participants were 98% men; DNA samples were not obtained at enrollment in HOST; linkage disequilibrium with another causal polymorphism is a potential confounding factor; and power was reduced by the limited number of participants. CONCLUSIONS These findings provide additional support for the hypothesis that the mutant TT genotype at nucleotide 677 of the gene regulating MTHFR activity may increase the mortality risk in patients with ESRD.
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The relationship between C677T methylenetetrahydrofolate reductase gene polymorphism and retinopathy in type 2 diabetes: a meta-analysis.
Zintzaras, E, Chatzoulis, DZ, Karabatsas, CH, Stefanidis, I
Journal of human genetics. 2005;(6):267-275
Abstract
The association between retinopathy in type 2 diabetes [diabetic retinopathy (DR)] and the C677T polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene has been investigated in several case-control studies. These studies rendered contradictory results, some indicating that the polymorphism is associated with the risk of developing DR whereas others concluded there is no association. To shed light on these inconclusive findings, a meta-analysis of all available studies relating the C677T polymorphism to the risk of developing DR was conducted. Four out of five identified studies included populations of East Asian descent, and only one involved samples from European descent (Caucasians). Overall, the meta-analysis suggested large heterogeneity between studies (p = 0.08, I(2) = 52%) and marginal association between C677T transition and the risk of developing DR: random effects odds ratio (OR) = 1.39 [95% CI (1.05, 1.83)]. The sensitivity analysis [exclusion of one East Asian study with the controls not in Hardy-Weinberg equilibrium (HWE)] showed no heterogeneity (p = 0.25, I(2) = 27%) and no significant association: fixed effects OR = 1.22 [95% CI (0.99, 1.51)] and random effects OR = 1.24 [95% CI (0.96, 1.60)]. The sub-group analysis for the East Asian population produced a significant association: fixed effects OR = 1.48 [95% CI (1.20, 1.83)] and random effects OR = 1.52 [95% CI (1.14, 2.03)]. However, sensitivity analysis in East Asians revealed that the association is marginal: fixed effects OR = 1.33 [95% CI (1.04, 1.70)] and random effects OR = 1.36 [95% CI (1.01, 1.83)]. There is a source of bias in the selected studies: the largest studies failed to show association while the smallest study claimed an association. The above findings reinforce the need for larger and more rigourous studies in this area.
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Assessment of tailor-made prevention of atherosclerosis with folic acid supplementation: randomized, double-blind, placebo-controlled trials in each MTHFR C677T genotype.
Miyaki, K, Murata, M, Kikuchi, H, Takei, I, Nakayama, T, Watanabe, K, Omae, K
Journal of human genetics. 2005;(5):241-248
Abstract
This study aimed at assessing the effect of folic acid supplementation quantitatively in each MTHFR C677T genotype and considered the efficiency of tailor-made prevention of atherosclerosis. Study design was genotype-stratified, randomized, double-blind, placebo-controlled trials. The setting was a Japanese company in the chemical industry. Subjects were 203 healthy men after exclusion of those who took folic acid or drugs known to effect folic acid metabolism. Intervention was folic acid 1 mg/day p.o. for 3 months. The primary endpoint was plasma total homocysteine level (tHcy). In all three genotypes, there were significant tHcy decreases. The greatest decrease was in the TT homozygote [6.61 (3.47-9.76) micromol/l] compared with other genotypes [CC: 2.59 (1.81-3.36), CT: 2.64 (2.16-3.13)], and there was a significant trend between the mutated allele number and the decrease. The tHcy were significantly lowered in all the genotypes, but the amount of the decrease differed significantly in each genotype, which was observed at both 1 and 3 months. Using these time-series data, the largest benefit obtained by the TT homozygote was appraised as 2.4 times compared with the CC homozygote. Taking into account the high allele frequency of this SNP, this quantitative assessment should be useful when considering tailor-made prevention of atherosclerosis with folic acid.
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Are effects of MTHFR (C677T) genotype on BMD confined to women with low folate and riboflavin intake? Analysis of food records from the Danish osteoporosis prevention study.
Abrahamsen, B, Madsen, JS, Tofteng, CL, Stilgren, L, Bladbjerg, EM, Kristensen, SR, Brixen, K, Mosekilde, L
Bone. 2005;(3):577-83
Abstract
We have previously found BMD and fracture risk to be significantly associated with the MTHFR (C677T) polymorphism in healthy postmenopausal women in the first years after menopause. Since then, other cohort studies have suggested that sufficient intake of riboflavin and/or folate may have the potential to prevent development of low BMD in women with the TT genotype. This could to some extent explain why this polymorphism is associated with low BMD or fracture in some study populations and not in others. It would also indicate that fractures associated with the TT genotype could be preventable by vitamin B supplementation. We have, therefore, reviewed baseline food record data from our original study to determine if BMD and fracture associations with the MTHFR genotype depended on the intake of folate, riboflavin, or other members of the vitamin B complex, associated with homocysteine metabolism. We analyzed genotype, BMD, and dietary records from 1700 healthy postmenopausal women who participated in the DOPS study. For the assessment of fracture risk, we used longitudinal observations from 854 women in the control group who remained compliant with their initial allocation of no treatment. Riboflavin intake was significantly correlated with femoral neck (FN) BMD in women with the TT genotype (r = 0.24, P < 0.01). FN and lumbar spine (LS) BMD were only associated with the MTHFR genotype in the lowest quartile of riboflavin intake. At the FN, similar threshold effects were shown for folate, vitamin B12, and vitamin B6. Among these vitamin B complex members, stepwise regression analysis identified riboflavin as the only significant predictor of FN BMD in the TT genotype. In conclusion, we confirm reports that BMD in the MTHFR TT genotype is only significantly reduced in the lowest quartile of riboflavin, B12, B6, and folate intake, at least at the time of menopause. Vitamin B supplementation would only be expected to benefit BMD in about 2% of the population, i.e., those with the TT genotype and low vitamin B intake.