Table 2.
General characteristics and genotype distribution
| Variable | Case (n = 403) | Control (n = 342) | t/χ 2 | p |
|---|---|---|---|---|
| Ethnic | 0.43 | 0.805 | ||
| Han | 198 (49.1) | 160 (46.8) | ||
| Zhuang | 178 (44.2) | 159 (46.5) | ||
| Minority | 27 (6.7) | 23 (6.7) | ||
| Education level | 1.20 | 0.550 | ||
| ≤ 9 years of school | 157 (39.0) | 120 (35.1) | ||
| 10–12 years of school | 83 (20.6) | 74 (21.6) | ||
| ≥ 13 years of school | 163 (40.4) | 148 (43.3) | ||
| Gynecological surgery history | 1.09 | 0.298 | ||
| Yes | 42 (10.4) | 28 (8.2) | ||
| No | 361 (89.6) | 314 (91.8) | ||
| Current smoking | 0.10 | 0.756 | ||
| Yes | 7 (1.7) | 7 (2.0) | ||
| No | 396 (98.3) | 335 (98.0) | ||
| Passive smoking history | 0.003 | 0.960 | ||
| Yes | 89 (22.1) | 75 (21.9) | ||
| No | 314 (77.9) | 267 (78.1) | ||
| Drinking history | 0.04 | 0.847 | ||
| Yes | 43 (10.7) | 38 (11.1) | ||
| No | 360 (89.3) | 304 (88.9) | ||
| X-ray contact history | 0.52 | 0.596 | ||
| Yes | 1 (0.2) | 2 (0.6) | ||
| No | 402 (99.8) | 340 (99.4) | ||
| Chemical exposure history | 3.41 | 0.065 | ||
| Yes | 1 (0.2) | 5 (1.5) | ||
| No | 402 (99.8) | 337 (98.5) | ||
| Folic acid supplement | 3.91 | 0.048 | ||
| Yes | 131 (32.5) | 135 (39.5) | ||
| No | 272 (67.5) | 207 (60.5) | ||
| Multivitamin supplement | 1.38 | 0.240 | ||
| Yes | 17 (4.2) | 9 (2.6) | ||
| No | 386 (95.8) | 333 (97.4) | ||
| Age, year | 29.58 ± 5.48 | 29.88 ± 5.28 | 0.85 | 0.673 |
| Folic acid, nmol/L | 32.45 ± 8.86 | 34.35 ± 18.98 | −1.79 | 0.072 |
| Vitamin B12, pg/ml | 352.70 ± 124.01 | 347.48 ± 124.10 | 0.57 | 0.567 |
| Homocysteine, umol/L | 11.89 ± 4.62 | 11.20 ± 3.40 | 2.36 | 0.018 |
| Total protein, g/L | 72.17 ± 6.79 | 70.67 ± 9.47 | 2.52 | 0.012 |
| Total cholesterol, mmol/L | 5.43 ± 20.10 | 4.42 ± 1.91 | 0.92 | 0.359 |
| Triglyceride, mmol/L | 1.06 ± 0.69 | 1.03 ± 0.55 | 0.62 | 0.536 |
| High-density lipoprotein cholesterol, mmol/L | 1.66 ± 0.38 | 1.73 ± 0.38 | −2.38 | 0.018 |
| Low-density lipoprotein cholesterol, mmol/L | 2.61 ± 0.77 | 2.41 ± 0.68 | 3.62 | < 0.001 |
| Fasting glucose, mmol/L | 4.93 ± 0.38 | 4.92 ± 0.19 | 0.15 | 0.884 |
| Fasting insulin, pmol/L | 71.13 ± 14.82 | 67.60 ± 13.84 | 3.35 | 0.001 |
| HOMR-IR | 2.23 ± 0.45 | 2.12 ± 0.41 | 3.48 | 0.001 |
| IL6, pg/ml | 75.12 ± 311.20 | 40.58 ± 202.95 | 1.82 | 0.069 |
| TNFα, pg/ml | 28.40 ± 92.16 | 18.28 ± 31.02 | 2.08 | 0.038 |
| MTHFR C677T | ||||
| CC | 213 (52.9) | 253 (74.0) | 35.24 | < 0.001 |
| CT | 153 (38.0) | 78 (22.8) | 19.87 | < 0.001 |
| TT | 37 (9.2) | 11 (3.2) | 10.92 | 0.001 |
| C allele | 579 (71.8) | 584 (85.4) | – | – |
| T allele | 227 (28.2) | 100 (14.6) | 39.62 | < 0.001 |
| MTHFR A1298C | ||||
| AA | 231 (57.3) | 221 (64.6) | 4.13 | 0.042 |
| AC | 144 (35.7) | 102 (29.8) | 2.92 | 0.088 |
| CC | 28 (6.9) | 19 (5.6) | 0.61 | 0.436 |
| A allele | 606 (75.2) | 544 (79.5) | – | – |
| C allele | 200 (24.8) | 140 (20.5) | 3.97 | 0.046 |
| MTRR A66G | ||||
| AA | 225 (55.8) | 226 (66.1) | 8.14 | 0.004 |
| AG | 148 (36.7) | 100 (29.2) | 4.67 | 0.031 |
| GG | 30 (7.4) | 16 (4.7) | 2.44 | 0.118 |
| A allele | 598 (74.2) | 552 (80.7) | – | – |
| G allele | 208 (25.8) | 132 (19.3) | 8.90 | 0.003 |
HOMA-IR Homeostatic model assessment of insulin resistance, IL6 Interleukin 6, TNFα Tumor necrosis factor α