TABLE 1.

Clinical and biochemical variables at the end of the controlled feeding study (week 12) in Mexican American men with the MTHFR 677CC or 677TT genotype who had choline intakes of 550 or 1100 mg/d¹

	Choline intake			P values
Variable	550 mg/d	1100 mg/d	All	Genotype	Choline	Interaction
Age (y)				0.038	0.927	0.604
677CC	28 (22–42)2	26 (19–35)	27 (19–42)3
677TT	21 (18–27)	22 (20–28)	22 (18–28)
Total	24 (18–42)	24 (19–35)	—
BMI (kg/m2)				0.652	0.317	0.179
677CC	24.5 (21–27)	28.8 (20–36)	26.6 (20–36)
677TT	26.1 (22–30)	25.5 (21–30)	25.8 (21–30)
Total	25.5 (21–30)	26.6 (20–36)	—
Serum folate (nmol/L)				0.003	0.676	0.915
677CC	12.3 ± 1.74	11.6 ± 2.7	11.9 ± 1.53
677TT	7.3 ± 0.9	6.9 ± 0.8	7.1 ± 0.6
Total	9.1 ± 1.1	8.5 ± 1.2	—
Plasma tHcy (μmol/L)				0.001	0.328	0.336
677CC	11.7 ± 0.7	11.8 ± 0.7	11.7 ± 0.53
677TT	28.5 ± 6.7	40.7 ± 5.7	35 ± 4.5
Total	22.4 ± 4.9	31.1 ± 5.6	—
Plasma choline (μmol/L)				0.655	0.052	0.841
677CC	7.0 ± 0.8	9.4 ± 2.2	8.2 ± 1.2
677TT	7.4 ± 0.7	10.2 ± 1.1	8.9 ± 0.8
Total	7.2 ± 0.5	10.0 ± 1.05	—
Plasma betaine (μmol/L)				0.418	0.014	0.755
677CC	46.0 ± 5.2	66.0 ± 14.0	56 ± 7.9
677TT	42.6 ± 3.1	58.3 ± 4.7	51 ± 3.5
Total	43.8 ± 2.6	60.9 ± 5.45	—
Plasma total PtdCho (d0+d3+d9) (μmol/L)				0.498	0.733	0.079
677CC	1784 ± 166	1532 ± 93	1658 ± 100
677TT	1492 ± 84	1665 ± 101	1585 ± 68
Total	1599 ± 88	1621 ± 74	—
Urinary choline (μmol/g Cr)				0.135	0.085	0.249
677CC	16.9 ± 6.3	22.7 ± 5.5	19.4 ± 4.1
677TT	20.3 ± 5.5	48.2 ± 10	35.3 ± 7.1
Total	19.0 ± 4.0	40.6 ± 8.2	—
Urinary betaine (μmol/g Cr)				0.290	0.853	0.925
677CC	80.2 ± 29	67.6 ± 18	74.8 ± 17
677TT	124.6 ± 55	120.5 ± 31	122.4 ± 29
Total	106.9 ± 34	104.7 ± 23	—
Urinary DMG (μmol/g Cr)				0.159	0.957	0.088
677CC	86.6 ± 23	35.7 ± 2	69.6 ± 18
677TT	76.7 ± 20	130.8 ± 26	105.8 ± 18
Total	80.7 ± 10	109.7 ± 9	—
Urinary sarcosine (μmol/g Cr)				0.909	0.123	0.627
677CC	12.1 ± 1.2	17.7 ± 5.3	14.5 ± 2.4
677TT	13.1 ± 2.5	16.1 ± 1.7	14.7 ± 1.5
Total	12.7 ± 1.6	16.5 ± 1.7	—
Urinary tHcy (μmol/g Cr)				0.012	0.041	0.057
677CC	4.5 ± 0.9	5.2 ± 0.4	4.8 ± 0.53
677TT	7.7 ± 3.4	25.8 ± 9.1	18.9 ± 5.2
Total	6.3 ± 2.1	18.9 ± 5.55	—
Urinary cystathionine (μmol/g Cr)				0.787	0.086	0.859
677CC	4.9 ± 1.2	7.2 ± 1.2	6.0 ± 0.9
677TT	5.4 ± 1.0	7.3 ± 1.1	6.4 ± 0.8
Total	5.2 ± 0.7	7.3 ± 0.85	—
Urinary cysteine (mmol/g Cr)				0.731	0.163	0.833
677CC	0.2 ± 0.03	0.3 ± 0.02	0.2 ± 0.02
677TT	0.2 ± 0.02	0.2 ± 0.02	0.2 ± 0.01
Total	0.2 ± 0.01	0.2 ± 0.01	—
Urinary methionine (μmol/g Cr)				0.356	0.135	0.673
677CC	6.3 ± 1.7	8.6 ± 1.9	7.4 ± 1.2
677TT	7.3 ± 2.3	11.4 ± 1.7	9.5 ± 1.5
Total	6.9 ± 1.5	10.4 ± 1.3	—
Urinary aminobutyric acid (μmol/g Cr)				0.944	0.517	0.713
677CC	5.7 ± 1.1	5.9 ± 1.4	5.8 ± 0.8
677TT	5.4 ± 0.6	6.4 ± 0.7	5.9 ± 0.5
Total	5.9 ± 0.5	6.2 ± 0.6	—
Urinary glycine (mmol/g Cr)				0.417	0.197	0.506
677CC	0.9 ± 0.2	0.8 ± 0.2	0.8 ± 0.1
677TT	1.1 ± 0.2	0.8 ± 0.1	0.9 ± 0.1
Total	1.0 ± 0.1	0.8 ± 0.1	—
Urinary serine (mmol/g Cr)				0.408	0.543	0.929
677CC	0.2 ± 0.04	0.2 ± 0.03	0.2 ± 0.02
677TT	0.3 ± 0.04	0.2 ± 0.04	0.2 ± 0.03
Total	0.2 ± 0.03	0.2 ± 0.03	—

¹n = 3–8 per group. Cr, creatinine; DMG, dimethylglycine; PtdCho, phosphatidylcholine; tHcy, total homocysteine.

²Mean; range in parentheses (all such values).

³Significantly different from the corresponding MTHFR 677TT genotype, P < 0.05 (2-factor ANOVA).

⁴Mean ± SEM (all such values).

⁵Significantly different from the corresponding 550 mg/d choline intake group, P < 0.05 (2-factor ANOVA).