Table 1. Characteristics of cases and controls.
| Variables | Cases | Controls | ||
| n = 130 | % | n = 130 | % | |
| Sex | ||||
| Male | 71 | 54.6 | 71 | 54.6 |
| Female | 59 | 45.4 | 59 | 45.4 |
| Age (years) | ||||
| ≤40 | 26 | 20 | 24 | 18.5 |
| 41–50 | 28 | 21.5 | 28 | 21.5 |
| 51–60 | 44 | 33.9 | 44 | 33.8 |
| >60 | 32 | 24.6 | 34 | 26.2 |
| Mean (SD) | 51.9 (11.8) | 51.8 (11.9) | ||
| Median (min:max) | 53 (16:79) | 53 (18:76) | ||
| Marital status | ||||
| Single | 3 | 2.3 | 12 | 9.2 |
| Married | 113 | 86.9 | 99 | 76.2 |
| Separated, widowed | 14 | 10.8 | 19 | 14.6 |
| Occupation | ||||
| Agriculture, farmer | 88 | 68.2 | 79 | 61.7 |
| Office work, technical work | 14 | 10.9 | 15 | 11.7 |
| Professional work | 12 | 9.3 | 19 | 14.9 |
| Others | 15 | 11.6 | 15 | 11.7 |
| Education | ||||
| Illiterate | 4 | 3.1 | 4 | 3.1 |
| Primary school | 98 | 75.4 | 96 | 73.8 |
| Secondary school or higher | 28 | 21.5 | 30 | 23.1 |
| Household income per year (Baht) | ||||
| ≤20 000 | 39 | 30 | 39 | 30 |
| 20 001–40 000 | 39 | 30 | 37 | 28.5 |
| 40 001–60 000 | 12 | 9.2 | 13 | 10 |
| >60 000 | 40 | 30.8 | 41 | 31.5 |
| Median (min:max) | 36 000 (6000:720 000) | 36 000 (4992:960 000) | ||
| MTHFR C677T polymorphism | ||||
| C/C | 104 | 80 | 94 | 72.3 |
| C/T | 26 | 20 | 31 | 23.8 |
| T/T | 0 | 0 | 5 | 3.9 |
| MTHFR A1298C polymorphism | ||||
| A/A | 43 | 33.1 | 54 | 41.5 |
| A/C | 84 | 64.6 | 71 | 54.6 |
| C/C | 3 | 2.3 | 5 | 3.9 |