Table 2.
Blood metabolite data at sampling1
| Characteristic | Anencephaly (n 25)2 | Spina Bifida only (n 34) | Others (n 5)3 | Total Cases (n 64) | Control (n 207) | P4 |
|---|---|---|---|---|---|---|
| Hemogobin (g/dL) | 12.6 (11.9,13.2) | 12.2 (11.5,13.1) | 13.0 (11.8,13.5) | 12.4 (11.5,13.2) | 12.3 (11.7,13.1) | 0.74 |
| Plasma Ferritin (μg/L) | 10.4 (6.7,32.5) | 17.5 (9.7,33.1) | 30.7 (16.3,36.3) | 16.9 (8.8,32.6) | 15.4 (9.1,25.7) | 0.84 |
| Plasma Ferritin<12 μg/L | 13 (52%)5 | 9 (26%)5 | 0 (0%)5 | 22 (34%) | 76 (37%) | 0.77 |
| Red cell folate (nmol/l) | 624 (454,786) | 540 (460,817) | 354 (310,497) | 566 (428,778) | 734 (531,895) | <0.001 |
| Plasma folate (nmol/l) | 8.1 (4.6,12.6) | 7.9 (5.5,12.1) | 4.1 (2.8,11.1) | 7.9 (5.0,12.2) | 10.2 (5.9,15.6) | 0.016 |
| Vitamin B12 (pmol/L) | 211 (164,250) | 185 (161,247) | 152 (145,168) | 191 (158,243) | 222 (182,273) | 0.023 |
| Homocysteine (μmol/l) | 9.4 (7.8,11.2) | 9.5 (8.3,11.7) | 10.1 (9.5,16.0) | 9.5 (8.1,11.4) | 8.6 (7.3,10.7) | 0.063 |
| Creatinine (μmol/l) | 40.5 (38.6,44.2) | 40.1 (36.3,45.8) | 40.3 (38.2,43.2) | 40.3 (37.6,44.2) | 43.4 (38.3,47.7) | 0.10 |
1
Values are medians (inter-quartile range);
2
Anencephaly only or anencephaly + spina bifida;
3
Encephalocele only or iniencephaly only or iniencephaly + spina bifida or iniencephaly + spina bifida + anencephaly;
4
Differences between total cases and controls were assessed using Student’s t-test on log transformed data for continuous variables and Fisher’s Exact test for ferritin categories;
5
Fisher’s Exact p values for individual NTD types against controls are p=0.12 for anencephaly, p=0.33 for spina bifida and p=0.16 for others.