Table 2.
Baseline characteristics of participants according to blood selenium concentration.
| Variables | Blood selenium concentration (μg/L) | p value | |||
|---|---|---|---|---|---|
| Q1 (<168.8) | Q2 (168.8–183.75) | Q3 (183.75–200.55) | Q4 (>200.55) | ||
| N = 1,716 | N = 1,717 | N = 1,718 | N = 1,718 | ||
| Age, year, Mean (SD) | 49.29 (18.08) | 47.50 (17.31) | 47.91 (17.07) | 48.78 (16.63) | 0.014 |
| Gender, N (%) | <0.001 | ||||
| Male | 758 (44.17%) | 820 (47.76%) | 836 (48.66%) | 926 (53.90%) | |
| Female | 958 (55.83%) | 897 (52.24%) | 882 (51.34%) | 792 (46.10%) | |
| Race, N (%) | <0.001 | ||||
| Mexican American | 157 (9.15%) | 212 (12.35%) | 242 (14.09%) | 218 (12.69%) | |
| Other Hispanic | 189 (11.01%) | 185 (10.77%) | 159 (9.25%) | 174 (10.13%) | |
| Non-Hispanic White | 604 (35.20%) | 621 (36.17%) | 666 (38.77%) | 629 (36.61%) | |
| Non-Hispanic Black | 559 (32.58%) | 470 (27.37%) | 367 (21.36%) | 342 (19.91%) | |
| Other race-including multi-racial | 207 (12.06%) | 229 (13.34%) | 284 (16.53%) | 355 (20.66%) | |
| Education level, N (%) | <0.001 | ||||
| Above high school | 916 (53.38%) | 993 (57.83%) | 1,051 (61.18%) | 1,049 (61.06%) | |
| Completed high school | 459 (26.75%) | 430 (25.04%) | 368 (21.42%) | 387 (22.53%) | |
| Less than high school | 341 (19.87%) | 294 (17.12%) | 299 (17.40%) | 282 (16.41%) | |
| Ratio of family income to poverty, Mean (SD) | 3.05 (1.60) | 3.15 (1.54) | 3.16 (1.57) | 3.14 (1.50) | 0.173 |
| BMI, kg/m2, Mean (SD) | 29.65 (7.64) | 29.83 (7.28) | 29.97 (7.01) | 29.87 (7.10) | 0.662 |
| Diabetes, N (%) | 0.444 | ||||
| Yes | 266 (15.50%) | 247 (14.39%) | 249 (14.49%) | 289 (16.82%) | |
| No | 1,407 (81.99%) | 1,419 (82.64%) | 1,418 (82.54%) | 1,375 (80.03%) | |
| Borderline | 43 (2.51%) | 51 (2.97%) | 51 (2.97%) | 54 (3.14%) | |
| Fasting glucose, mg/dL, Mean (SD) | 112.00 (27.17) | 110.48 (18.44) | 110.91 (20.36) | 113.50 (25.04) | <0.001 |
| Drink, N (%) | <0.001 | ||||
| Yes | 728 (42.42%) | 798 (46.48%) | 838 (48.78%) | 773 (44.99%) | |
| No | 988 (57.58%) | 919 (53.52%) | 880 (51.22%) | 945 (55.01%) | |
| Smoke, N (%) | 0.056 | ||||
| Yes | 737 (42.95%) | 726 (42.28%) | 700 (40.75%) | 714 (41.56%) | |
| No | 979 (57.05%) | 991 (57.72%) | 1,018 (59.25%) | 1,004 (58.44%) | |
| Physical activity, N (%) | 0.021 | ||||
| Yes | 741 (43.18%) | 825 (48.05%) | 868 (50.52%) | 859 (50.00%) | |
| No | 975 (56.82%) | 892 (51.95%) | 850 (49.48%) | 859 (50.00%) | |
| ALT, U/L, Mean (SD) | 19.55 (12.01) | 21.81 (15.33) | 23.27 (15.48) | 24.33 (18.20) | <0.001 |
| ALP, U/L, Mean (SD) | 75.93 (28.87) | 74.44 (23.69) | 76.96 (24.17) | 74.07 (22.97) | 0.235 |
| AST, U/L, Mean (SD) | 20.80 (10.00) | 21.30 (11.02) | 21.74 (9.63) | 22.06 (13.11) | <0.001 |
| GGT, U/L, Mean (SD) | 28.75 (45.82) | 27.06 (31.40) | 29.21 (34.06) | 30.49 (34.67) | 0.044 |
| ALT/AST, Mean (SD) | 0.93 (0.32) | 0.99 (0.34) | 1.04 (0.36) | 1.08 (0.37) | <0.001 |
| TC, mmol/L, Mean (SD) | 4.59 (0.93) | 4.83 (1.05) | 4.86 (1.02) | 5.06 (1.09) | <0.001 |
| Dietary selenium intake, μg/day, Mean (SD) | 157.12 (10.20) | 176.47 (4.26) | 191.56 (4.86) | 220.48 (25.55) | <0.001 |
Significant results highlighted in bold. BMI, Body mass index; TC, Total cholesterol; ALT, Alanine aminotransferase; AST, Aspartate aminotransferase; GGT, Gamma-glutamyl transferase; and ALP, Alkaline phosphatase.