Table 3. Unadjusted geometric means (GMs) (95% confidence intervals) and fully adjusted geometric mean ratios (GMRs) (95% confidence intervals) of urinary arsenic (As) and uranium (U) across categories of community water system (CWS, µg/L) As and U in the Strong Heart Family Study (SHFS) and the Multi-Ethnic Study of Atherosclerosis (MESA).
Urine iAs = inorganic arsenic, arsenite and arsenate (µg/L). Urine sumAs = sum of iAs, monomethyl arsonate (MMA), and dimethylarsinate (DMA) (µg/L). Urine U = uranium (µg/L).
| Urine iAs1 | Urine sumAs1 | ||||
|---|---|---|---|---|---|
|
| |||||
| SHFS | N | GM | GMR | GM | GMR |
| ≤ 1 µg As/L water | 170 | 0.24 (0.21, 0.27) | 1.00 (ref) | 3.39 (3.04, 3.77) | 1.00 (ref) |
| > 1–5 µg As/L water | 827 | 0.43 (0.40, 0.45) | 1.50 (1.22, 1.85) | 5.02 (4.79, 5.27) | 1.22 (1.02, 1.46) |
| > 5 µg As/L water | 281 | 0.65 (0.57, 0.74) | 2.56 (1.98, 3.30) | 7.40 (6.74, 8.14) | 1.88 (1.51, 2.34) |
| P-trend2 | 1,278 | -- | <0.001 | -- | <0.001 |
|
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| MESA | N | GM | GMR | GM | GMR |
|
| |||||
| ≤ 1 µg As/L water | 5,850 | 0.27 (0.27, 0.28) | 1.00 (ref) | 5.93 (5.77–6.08) | 1.00 (ref) |
| > 1 µg As/L water | 872 | 0.56 (0.53, 0.59) | 1.32 (1.20, 1.46) | 10.65 (10.07, 11.27) | 1.18 (1.08, 1.28) |
| P-trend2 | 6,722 | -- | <0.001 | -- | <0.001 |
|
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| Urine U 3 | |||||
|
| |||||
| SHFS | N | GM | GMR | ||
|
| |||||
| ≤ 1 µg U/L water | 1,094 | 0.027 (0.025, 0.029) | 1.00 (ref) | ||
| > 1–10 µg U/L water | 153 | 0.030 (0.025, 0.035) | 1.21 (0.95, 1.52) | ||
| > 10 µg U/L water | 238 | 0.111 (0.096, 0.129) | 3.53 (2.51, 4.96) | ||
| P-trend2 | 1,485 | -- | <0.001 | ||
|
| |||||
| MESA | N | GM | GMR | ||
|
| |||||
| ≤ 1 µg U/L water | 1,054 | 0.004 (0.004, 0.005) | 1.00 (ref) | ||
| > 1–5 µg U/L water | 1,643 | 0.005 (0.005, 0.006) | 2.17 (1.81, 2.62) | ||
| > 5 µg U/L water | 935 | 0.023 (0.022, 0.024) | 5.05 (4.23, 6.02) | ||
| P-trend2 | 3,632 | -- | <0.001 | ||
Model for SHFS includes random effects for zip code identifier and family identifier, and adjustment for natural log transformed creatinine, natural log transformed arsenobetaine, sex, age, body mass index (BMI), smoking status, pack years (the number of cigarettes smoked per day multiplied by the number of years smoking), and natural log transformed dietary intake (g) of rice, organ meat, processed meat, and fish. Model for MESA includes random effects for zip code identifier and participant identifier, and adjustment for natural log transformed creatinine, natural log transformed arsenobetaine, sex, age, BMI, smoking status, pack years, number of weekly servings of rice, and natural log transformed dietary intake (g) of red meat, and fish.
Statistical significance evaluated using the Mantel test for trend.
Model for SHFS includes random effects for zip code identifier and family identifier, and adjustment for natural log transformed creatinine, sex, age, BMI, smoking status, pack years, and natural log transformed dietary intake (g) of organ meat. Model for MESA includes random effects for zip code identifier and participant identifier, and adjustment for natural log transformed creatinine, age, BMI, smoking status, pack years, natural log transformed creatinine, and natural log transformed dietary intake (g) of red meat.