Table 1.
Baseline characteristics of the study population by quartile (Q) of serum selenium concentrations (n = 5452)1
| Q1 (<113.7 ng/mL) |
Q2 (113.7–123.6 ng/mL) |
Q3 (123.7–134.6 ng/mL) |
Q4 (≥134.7 ng/mL) |
P for trend | |
|---|---|---|---|---|---|
| Age (y) | 42.8 ± 0.92 | 42.5 ± 0.6 | 43.2 ± 0.9 | 43.5 ± 0.9 | 0.46 |
| Sex, male (%) | 41.0 (2.2)3 | 43.7 (1.9) | 52.2 (2.0) | 54.2 (1.7) | <0.001 |
| Race (%) | |||||
| Non-Hispanic white | 68.3 (2.7) | 76.4 (2.2) | 78.9 (1.4) | 83.3 (2.4) | <0.001 |
| Non-Hispanic black | 16.9 (1.1) | 10.4 (0.8) | 7.8 (0.7) | 6.8 (1.0) | <0.001 |
| Mexican American | 5.3 (0.8) | 5.5 (0.5) | 5.8 (0.7) | 4.4 (0.8) | 0.50 |
| High school education (%) | 74.7 (1.9) | 77.1 (1.8) | 79.9 (1.8) | 80.5 (1.7) | <0.001 |
| Body mass index (kg/m2) | 27.0 ± 0.3 | 26.4 ± 0.3 | 26.4 ± 0.2 | 25.9 ± 0.2 | 0.01 |
| Current smoking (%) | 33.8 (2.0) | 30.6 (2.2) | 27.1 (1.8) | 20.9 (1.8) | <0.001 |
| Current alcohol consumption (%) | 62.8 (2.5) | 62.7 (2.3) | 67.7 (2.1) | 66.0 (3.4) | 0.28 |
| Hypertension (%) | 27.6 (1.9) | 25.2 (1.5) | 27.3 (1.4) | 28.9 (2.1) | 0.45 |
| Diabetes (%) | 4.6 (0.6) | 5.6 (0.9) | 4.9 (0.6) | 5.7 (0.9) | 0.44 |
| Vitamin-mineral supplement users (%) | 41.7 (2.6) | 41.3 (2.2) | 40.5 (2.1) | 42.1 (2.8) | 0.97 |
| C-reactive protein <0.03 mg/dL (%) | 69.3 (2.4) | 75.1 (2.0) | 77.5 (1.9) | 78.1 (2.2) | 0.008 |
| Serum selenium (ng/mL) | 105.9 ± 0.4 | 118.9 ± 0.1 | 128.9 ± 0.2 | 147.0 ± 0.9 | — |
1
Adjusted for age, sex, and race-ethnicity.
2
x̄ ± SE (all such values).
3
SE in parentheses (all such values).