Table.
Plasma concentrations (μmol/L) of total homocysteine and phosphatidylcholine in pre-menopausal women (n=43) stratified by phosphatidylethanolamine N-methyltransferase (PEMT) G5465A and G-744C genotypes as well as methylenetetrahydrofolate dehydrogenase (MTHFD1) G1958A genotype at baseline (Wk 0) and after 7-wk of folate restriction (Wk 7)a–c
| Metabolite | ||||||
|---|---|---|---|---|---|---|
| Homocysteine | Phosphatidylcholine | |||||
| Gene | Wk 0 | Wk 7 | Change | Wk 0 | Wk 7 | Change |
| PEMTG5465A | ||||||
| GG, n=3 | 5.1 ± 0.3 | 6.4 ± 0.5 | 1.3 ± 0.3yz | 1863 ± 89 | 1680 ± 137 | −183 ± 224 |
| GA, n=19 | 5.6 ± 0.2 | 6.9 ± 0.2 | 1.3 ± 0.1y** | 1866 ± 90 | 1712 ± 88 | −154 ± 38 |
| AA, n=21 | 5.5 ± 0.2 | 7.6 ± 0.3 | 2.1 ± 0.2z | 1821 ± 80 | 1703 ± 66 | −117 ± 50 |
| PEMTG-744C | ||||||
| GG, n=9 | 5.3 ± 0.3 | 7.3 ± 0.4 | 2.0 ± 0.3 | 1863 ± 133 | 1660 ± 103 | −203 ± 73y* |
| GC, n=17 | 5.8 ± 0.2 | 7.6 ± 0.3 | 1.8 ± 0.2 | 1783 ± 86 | 1620 ± 77 | −163 ± 59y+ |
| CC, n=17 | 5.4 ± 0.1 | 6.8 ± 0.3 | 1.4 ± 0.2 | 1895 ± 89 | 1814 ± 83 | −80 ± 40z |
| MTHFD1G1958A | ||||||
| GG, n=9 | 5.5 ± 0.2 | 7.0 ± 0.3 | 1.5 ± 0.2y+ | 1679 ± 104 | 1597 ± 102 | −82 ± 72 |
| GA, n=21 | 5.6 ± 0.2 | 7.1 ± 0.3 | 1.6 ± 0.2y* | 1930 ± 85 | 1756 ± 82 | −174 ± 51 |
| AA, n=13 | 5.5 ± 0.3 | 7.5 ± 0.4 | 2.0 ± 0.3z | 1818 ± 92 | 1699 ± 73 | −119 ± 45 |
Data are presented as mean ± standard error of the mean.
The women consumed 350 mg/d of choline throughout the study.
The data were analyzed using the general linear model procedure with the difference (ie, change) between wk 0 and wk 7 for folate restriction and wk 7 and 14 for folate treatment (data not shown) as the response variable. The independent variables included PEMT G5465A genotype, MTHFR C677T genotype and baseline measures (i.e., wk 0 for folate restriction). All possible interactions were included in the model and post-hoc analyses with multiple comparisons were employed for the purposes of mean separation. For the PEMT G5465A genotype, an additional analysis was performed after combining the carriers of the G allele. Values in a column with different superscript letters are indicative of differences,
for P<0.05,
for P<0.01; or trends,
P<0.1, relative to homozygous variant genotype. For PEMT G5465A, differences (P=0.001) were detected between carriers of the G allele and the AA genotype.