Table 2.
Covariate-unadjusted and -adjusted effect size estimates for associations between measures of As exposure and GSH, GSSG, Cys, and CySS.
| wAs (μg/L) | uAs (μg/L) | bAs (μg/L) | ||||
|---|---|---|---|---|---|---|
| Unadjusted | Adjusteda | Unadjusted | Adjustedb | Unadjusted | Adjusteda | |
| Blood GSH (μmol/L) | ||||||
| Mean change (95% CI)c | –33.8 (–49.3, –18.0) | –25.4 (–45,3, –5.31) | –59.6 (–84.0, –35.3) | –54.0 (–90.8, –17.2) | –46.6 (–72.3, –21.1) | –33.4 (–62.8, –3.9) |
| p-Value | < 0.0001 | 0.01 | < 0.0001 | 0.004 | 0.0004 | 0.03 |
| R2 | 4.6 | 23.5 | 5.8 | 24.8 | 3.3 | 23.3 |
| ∆R2 | 1.3 | 1.8 | 1.1 | |||
| Blood GSSG (μmol/L) | ||||||
| Mean ratio (95% CI)d | 1.00 (0.95, 1.04) | 0.98 (0.95, 1.02) | 1.07 (0.99, 1.14) | 0.95 (0.88, 1.05) | 0.99 (0.92, 1.06) | 0.98 (0.91, 1.04) |
| p-Value | 0.88 | 0.42 | 0.07 | 0.31 | 0.63 | 0.43 |
| R2 | 0.0 | 47.8 | 0.8 | 48.0 | 0.06 | 47.8 |
| ∆R2 | 0.1 | 0.2 | 0.1 | |||
| Blood GSH Eh (mV)e | ||||||
| Mean change (95% CI)c | 1.92 (0.74, 3.11) | 1.19 (–0.25, 2.62) | 4.51 (2.67, 6.35) | 2.72 (0.10, 5.35) | 2.64 (0.70, 4.58) | 1.73 (–0.37, 3.83) |
| p-Value | 0.002 | 0.10 | < 0.0001 | 0.04 | 0.008 | 0.11 |
| R2 | 2.6 | 31.1 | 5.8 | 32.2 | 1.9 | 31.1 |
| ∆R2 | 0.5 | 0.8 | 0.5 | |||
| Plasma Cys (μmol/L) | ||||||
| Mean ratio (95% CI)d | 0.93 (0.88, 0.98) | 1.06 (0.98, 1.14) | 0.98 (0.89, 1.09) | 1.12 (0.99, 1.28) | 0.90 (0.81, 0.99) | 1.05 (0.95, 1.16) |
| p-Value | 0.01 | 0.14 | 0.73 | 0.06 | 0.03 | 0.34 |
| R2 | 1.7 | 39.4 | 0.0 | 40.6 | 1.3 | 39.2 |
| ∆R2 | 0.3 | 0.6 | 0.1 | |||
| Plasma CySS (μmol/L) | ||||||
| Mean change (95% CI)c | –2.94 (–4.19, –1.69) | –3.00 (–4.61, –1.40) | –1.78 (–3.80, 0.25) | –3.56 (–6.47, –0.66) | –4.11 (–6.17, –2.06) | –3.09 (–5.40, –0.79) |
| p-Value | < 0.0001 | 0.0002 | 0.08 | 0.02 | 0.0001 | 0.009 |
| R2 | 5.3 | 29.8 | 0.8 | 28.8 | 4.0 | 28.5 |
| ∆R2 | 2.7 | 1.2 | 1.4 | |||
| Plasma Cys Eh (mV)f | ||||||
| Mean change (95% CI)c | 1.38 (–0.21,2.98) | –2.05 (–3.89, –0.21) | –0.007 (–2.51, 2.49) | –4.04 (–7.34, –0.74) | 1.90 (–0.67, 4.48) | –2.01 (–4.65, 0.64) |
| p-Value | 0.09 | 0.03 | 0.99 | 0.02 | 0.15 | 0.14 |
| R2 | 0.8 | 38.3 | 0.0 | 39.1 | 0.6 | 37.8 |
| ∆R2 | 0.9 | 1.0 | 0.4 | |||
| Abbreviations: bAs, blood As; Cys, cysteine; CySS, cystine; Eh, reduction potential; GSH, glutathione; GSSG, glutathione disulfide; uAs, urinary As; wAs, water As. aAdjusted for log-transformed age, sex, television ownership (yes/no), smoking (ever/never), log-transformed BMI and plasma folate, and GSH/Cys laboratory batch. bAlso adjusted for log urinary creatinine. cRepresents the mean change in the outcome for a change in the exposure from the 25th to the 75th percentile. dRepresents the ratio of the geometric mean in the outcome for a change in the exposure from the 25th to the 75th percentile. eReduction potential of the GSH/GSSG redox pair. fReduction potential of the Cys/CySS redox pair. | ||||||