TABLE 1.
Characteristics of the study population1
| Baseline variables | Folate group (n = 96) | Placebo group (n = 98) |
|---|---|---|
| Men [n (%)] | 49 (51) | 47 (48) |
| As-induced skin lesions [n (%)] | 4 (4) | 6 (6) |
| Cigarette smoking [n (%)] | 41 (43) | 40 (41) |
| Use of betel nut [n (%)] | 38 (40) | 39 (40) |
| House type | ||
| Thatched or other [n (%)] | 5 (5) | 7 (7) |
| Corrugate [n (%)] | 86 (90) | 83 (85) |
| Semi-pakka [n (%)] | 5 (5) | 8 (8) |
| Number of children [n (%)] | ||
| 0 | 50 (52) | 53 (54) |
| 1–2 | 22 (23) | 14 (14) |
| ≥3 | 24 (25) | 31 (32) |
| Education | ||
| None [n (%)] | 41 (42.7) | 35 (35.7) |
| 1–5 y [n (%)] | 34 (35.4) | 40 (40.8) |
| >5 y [n (%)] | 21 (21.9) | 23 (23.5) |
| Age (y) | 40 ± 112 | 38 ± 10 |
| Education (y) | 3.3 ± 3.5 | 3.6 ± 3.5 |
| Weight (kg) | 49 ± 10 | 48 ± 8 |
| Height (cm) | 157 ± 8 | 155 ± 8.6 |
| BMI (kg/m2) | 20 ± 3.4 | 20 ± 2.7 |
| Children (n) | 1.4 ± 1.9 | 1.6 ± 2.1 |
| Urinary arsenic | ||
| (μg/L) | 147 ± 130 | 136 ± 129 |
| (μg/g Cr) | 296 ± 262 | 256 ± 217 |
| Urinary creatinine (mg/dL) | 58.4 ± 44.2 | 60.6 ± 42.1 |
| Urinary arsenic metabolites | ||
| %DMA | 71.9 ± 7.8 | 71.8 ± 8.7 |
| %MMA | 12.6 ± 3.9 | 13.2 ± 4.6 |
| %InAs | 15.5 ± 7.4 | 15.0 ± 6.1 |
| Plasma folate (nmol/L) | 8.3 ± 4.7 | 7.8 ± 3.0 |
| Plasma vitamin B-12 (pmol/L) | 289 ± 128 | 288 ± 126 |
| Plasma homocysteine (μmol/L) | 11.1 ± 4.0 | 11.4 ± 8.2 |
| Water arsenic (μg/L) | 106 ± 91 | 104 ± 113 |
1
%DMA, %bMMA, and %InAs, the proportion of total urinary arsenic excreted as dimethylarsinic acid, monomethylarsonic acid, and inorganic arsenic, respectively. Chi-square and Wilcoxon’s rank-sum tests were used for treatment group differences in categorical and quantitative variables, respectively. No significant group differences were found in any of the variables.
2
x̄ ± SD (all such values).