Table 3a.
Selenium dietary, chemical and biochemical biomarkers: longitudinal analysis
| Variable | Quartile* | Week 2 (n = 39) | Week 8 (n = 37) | Week 17 (n = 37) | Week 23 (n = 38) | Mean | P-value† |
|---|---|---|---|---|---|---|---|
| Dietary selenium (μg/d) | 1st | 28 (3)‡ | 35 (9) | 36 (12) | 35 (8) | 34 (4) | NSI |
| 2nd | 40 (4) | 45 (12) | 44 (23) | 49 (17) | 45 (3) | NS | |
| 3rd | 50 (3) | 43 (13) | 58 (22) | 53 (12) | 51 (6) | NS | |
| 4th | 70 (15) | 57 (15) | 61 (10) | 57 (21) | 61 (6) | NS | |
| Mean | 47 (17) | 44 (14) | 49 (20) | 48 (17) | NS | ||
| Dietary selenium (ng/kJ/d) | 1st | 3.93 (0.6) | 5.00 (1.5) | 5.75 (1.9) | 5.53 (1.9) | 5.05 (0.8) | NS |
| 2nd | 4.98 (0.2) | 4.92 (1.2) | 6.17 (2.3) | 5.13 (1.3) | 5.30 (0.6) | NS | |
| 3rd | 5.64 (0.3) | 5.19 (1.8) | 5.51 (1.4) | 6.40 (1.8) | 5.69 (0.5) | NS | |
| 4th | 9.11 (2.8) | 6.38 (1.9) | 6.99 (2.2) | 7.07 (2.4) | 7.39 (1.2) | NS | |
| Mean | 5.83 (2.3) | 5.32 (1.6) | 6.16 (2.0) | 5.99 (1.9) | NS | ||
| Plasma GPX3 activity (EU/g protein) | 1st | 3.65 (0.2) | 4.52 (0.6) | 4.31 (0.7) | 4.13 (0.8) | 4.15 (0.4) | 0.014 |
| 2nd | 4.52 (0.3) | 4.81 (1.0) | 4.42 (1.0) | 4.02 (1.0) | 4.44 (0.3) | NS | |
| 3rd | 5.34 (0.2) | 5.49 (0.6) | 5.13 (0.7) | 4.93 (0.6) | 5.22 (0.2) | NS | |
| 4th | 6.71 (0.8) | 6.37 (0.8) | 6.06 (0.9) | 6.33 (1.0) | 6.37 (0.3) | NS | |
| Mean | 5.01 (1.2) | 5.27 (1.0) | 4.95 (1.0) | 4.82 (1.2) | NS | ||
| n = 20 | n = 20 | ||||||
| Plasma selenium (μmol/l) | 1st | 0.89 (0.05) | 0.93 (0.07) | 0.91 (0.06) | NS | ||
| 2nd | 1.05 (0.05) | 1.24 (0.31) | 1.14 (0.24) | NS | |||
| 3rd | 1.18 (0.05) | 1.12 (0.09) | 1.15 (0.08) | NS | |||
| 4th | 1.33 (0.07) | 1.28 (0.14) | 1.30 (0.11) | NS | |||
| Mean | 1.11 (0.18) | 1.14 (0.05) | NS |
NS = Not significant
*
Quartiles sorted by week 2 values.
†
Significance level P <0.05 by 1-way ANOVA.
‡
Values are mean (SD).