Table 2.
Associations [OR (95% CI)] between baseline arsenic exposure variables and QTc prolongation measured during follow-up.
| Variable | Arsenic exposure in quartilesa | Continuous arsenicb | pTrend | |||
|---|---|---|---|---|---|---|
| Q1 | Q2 | Q3 | Q4 | |||
| All | ||||||
| Well-water arsenic (µg/L) | ||||||
| n (cases/noncases) | 57/371 | 63/369 | 49/374 | 68/353 | ||
| Model 1c | 1.00 | 1.11 (0.75, 1.64) | 0.86 (0.57, 1.30) | 1.24 (0.84, 1.82) | 1.12 (0.98, 1.27) | 0.10 |
| Model 2d | 1.00 | 1.08 (0.73, 1.59) | 0.85 (0.56, 1.28) | 1.24 (0.84, 1.83) | 1.13 (0.99, 1.29) | 0.08 |
| Model 3e | 1.00 | 1.10 (0.74, 1.63) | 0.87 (0.57, 1.31) | 1.31 (0.87, 1.96) | 1.17 (1.01, 1.35) | 0.04 |
| Urinary arsenic (µg/g creatinine) | ||||||
| n (cases/noncases) | 51/359 | 56/354 | 58/355 | 64/349 | ||
| Model 1c | 1.00 | 1.09 (0.73, 1.65) | 1.13 (0.75, 1.70) | 1.22 (0.82, 1.81) | 1.04 (0.91, 1.19) | 0.53 |
| Model 2d | 1.00 | 1.13 (0.75, 1.70) | 1.19 (0.79, 1.79) | 1.30 (0.86, 1.97) | 1.07 (0.93, 1.22) | 0.35 |
| Model 3e | 1.00 | 1.14 (0.75, 1.72) | 1.22 (0.81, 1.85) | 1.42 (0.91, 2.21) | 1.18 (0.97, 1.43) | 0.10 |
| Men | ||||||
| Well-water arsenic (µg/L) | ||||||
| n (cases/noncases) | 17/146 | 14/147 | 14/149 | 13/136 | ||
| Model 1c | 1.00 | 0.83 (0.39, 1.74) | 0.83 (0.39, 1.74) | 0.83 (0.39, 1.77) | 1.01 (0.77, 1.33) | 0.96 |
| Model 2d | 1.00 | 0.81 (0.38, 1.71) | 0.86 (0.40, 1.82) | 0.81 (0.38, 1.76) | 1.02 (0.77, 1.36) | 0.87 |
| Model 3e | 1.00 | 0.82 (0.39, 1.75) | 0.85 (0.40, 1.82) | 0.76 (0.34, 1.69) | 0.99 (0.73, 1.33) | 0.94 |
| Urinary arsenic (µg/g creatinine) | ||||||
| n (cases/noncases) | 18/153 | 13/143 | 14/148 | 13/114 | ||
| Model 1c | 1.00 | 0.77 (0.36, 1.62) | 0.80 (0.39, 1.67) | 1.01 (0.47, 2.14) | 1.00 (0.76, 1.32) | 0.99 |
| Model 2d | 1.00 | 0.74 (0.35, 1.58) | 0.82 (0.39, 1.73) | 1.08 (0.49, 2.39) | 1.05 (0.80, 1.38) | 0.72 |
| Model 3e | 1.00 | 0.76 (0.36, 1.63) | 0.83 (0.39, 1.76) | 1.01 (0.44, 2.36) | 0.86 (0.49, 1.51) | 0.60 |
| Women | ||||||
| Well-water arsenic (µg/L) | ||||||
| n (cases/noncases) | 40/225 | 49/222 | 35/225 | 55/217 | ||
| Model 1c | 1.00 | 1.24 (0.79, 1.96) | 0.88 (0.54, 1.44) | 1.43 (0.91, 2.23) | 1.15 (0.99, 1.34) | 0.06 |
| Model 2d | 1.00 | 1.19 (0.75, 1.88) | 0.87 (0.53, 1.43) | 1.46 (0.93, 2.30) | 1.17 (1.00, 1.37) | 0.05 |
| Model 3e | 1.00 | 1.22 (0.77, 1.93) | 0.89 (0.54, 1.46) | 1.61 (1.00, 2.58) | 1.24 (1.05, 1.47) | 0.01 |
| Urinary arsenic (µg/g creatinine) | ||||||
| n (cases/noncases) | 33/206 | 43/211 | 44/207 | 51/235 | ||
| Model 1c | 1.00 | 1.28 (0.78, 2.10) | 1.32 (0.81, 2.16) | 1.35 (0.84, 2.17) | 1.06 (0.91, 1.25) | 0.46 |
| Model 2d | 1.00 | 1.32 (0.80, 2.17) | 1.39 (0.85, 2.30) | 1.48 (0.90, 2.41) | 1.09 (0.93, 1.28) | 0.30 |
| Model 3e | 1.00 | 1.31 (0.80, 2.16) | 1.43 (0.87, 2.36) | 1.69 (1.00, 2.86) | 1.24 (1.01, 1.53) | 0.04 |
| aMean (range) of quartiles were Q1, 2.8 (0.1–9); Q2, 30.0 (9.5–57); Q3, 95.1 (58–144); and Q4, 254.5 (145–790) for well-water arsenic and Q1, 66.1 (7–101); Q2, 140.8 (102–187); Q3, 249.7 (188–327); and Q4, 606.3 (328–4306) for urinary arsenic. bORs for a 1-SD increase in well-water arsenic (108.7 µg/L) and urinary arsenic (270.7 µg/g creatinine). cAdjusted for sex and age (years); or for age in the subgroups of men and women. dAdjusted for model 1 variables plus BMI, smoking status (never, past, and current), and educational attainment (years). eAdjusted for model 2 variables plus changes in urinary arsenic (µg/g creatinine) between visits. | ||||||