Table 2.
Baseline and change from baseline Hb, transferrin saturation, and total plasma iron, 8‐OHdG, isoprostane, TAS, CRP, AGP, AST, and ALT
| Time point | Placebo (n = 38) | Fe‐B (n = 28) | Fe‐W (n = 29) | p Unadjusteda | p Adjustedb | Fe groups combined (n = 57) | p Unadjustedc | p Adjustedd | |
|---|---|---|---|---|---|---|---|---|---|
| Hb (g/L) | Baseline | 136 (11)e | 133 (11) | 134 (11) | 134 (11) | ||||
| Change | –3.7 (12) | 2.5 (9.6) | 0.4 (11) | 0.070 | 0.034f | 1.4 (10) | 0.028 | 0.010 | |
| Ferritin (ng/ml)g | Baseline | 55.2 (38) | 61.0 (47) | 53.8 (38) | 57.4 (42) | ||||
| Change | –9.17 (34) | –13.1 (55) | 6.12 (30) | 0.088 | 0.091 | –3.33 (44) | 0.070 | 0.056 | |
| Hepcidin (ng/ml) | Baseline | 47.6 (35) | 65.0 (67) | 46.2 (32) | 55.8 (53) | ||||
| Change | 18.8 (51) | 34.2 (88) | 42.2 (73) | 0.700 | 0.291 | 38.2 (80) | 0.406 | 0.139 | |
| Transferrin Saturation (%) | Baseline | 22.3 (11) | 19.6 (8.0) | 19.6 (11) | 19.6 (9.7) | ||||
| Change | –0.78 (9.7) | 6.13 (11) | 1.62 (9.2) | 0.145 | 0.087 | 3.84 (10) | 0.111 | 0.271 | |
| Total plasma iron (μg/dl) | Baseline | 89.6 (44) | 78.1 (31) | 77.2 (42) | 77.6 (36) | ||||
| Change | –15.8 (38) | 10.5 (38) | –4.03 (42) | 0.158 | 0.065 | 3.09 (40) | 0.109 | 0.314 | |
| 8‐OHdG (ng/mg creatinine) | Baseline | 97.3 (37) | 92.3 (36) | 94.8 (39) | 93.5 (37) | ||||
| Change | –2.55 (43) | 1.72 (51) | 8.20 (57) | 0.737 | 0.659 | 5.02 (54) | 0.505 | 0.822 | |
| Isoprostane (pg/mg creatinine) | Baseline | 366 (209) | 406 (239) | 377 (188) | 392 (214) | ||||
| Change | 8.77 (126) | –3.80 (121) | –19.0 (131) | 0.490 | 0.319 | –11.5 (125) | 0.403 | 0.226 | |
| TAS (mmol/L) | Baseline | 1.69 (0.14) | 1.69 (0.12) | 1.65 (0.12) | 1.67 (0.12) | ||||
| Change | –0.01 (0.11) | 0.01 (0.09) | 0.02 (0.11) | 0.504 | 0.754 | 0.02 (0.10) | 0.273 | 0.571 | |
| CRP (mg/L) | Baseline | 9.7 (9.8) | 14.3 (25) | 14.6 (19) | 14.5 (22) | ||||
| Change | –6.42 (11) | –8.89 (10) | –5.23 (12) | 0.056 | 0.061 | –7.0 (11) | 0.610 | 0.642 | |
| AGP (g/L) | Baseline | 1.2 (0.30) | 1.3 (0.31) | 1.3 (0.32) | 1.3 (0.31) | ||||
| Change | –0.33 (0.25) | –0.42 (0.23) | –0.28 (0.26) | 0.237 | 0.094 | –0.34 (0.25) | 0.363 | 0.608 | |
| AST (IU/L) | Baseline | 18.9 (6.0) | 19.0 (7.1) | 18.7 (6.9) | 18.8 (7.0) | ||||
| Change | 0.37 (6.1) | 2.07 (13) | 0.69 (9.9) | 0.656 | 0.489 | 1.37 (11) | 0.458 | 0.367 | |
| ALT (IU/L) | Baseline | 14.5 (8.9) | 5.7 (1.4) | 13.1 (6.2) | 13.1 (5.9) | ||||
| Change | –2.34 (10) | 0.93 (7.9) | –0.52 (8.5) | 0.312 | 0.332 | 0.19 (8.2) | 0.210 | 0.224 |
Note. Change in values from baseline to final study visit. Data for ferritin, hepcidin, TfSat, plasma iron, 8‐OHdG, isoprostane, CRP, and AGP were log transformed before statistical analyses of group‐wise differences were performed.
Unadjusted difference across three randomization groups as evaluated by using ANOVA.
Differences across three randomization groups as evaluated by using ANCOVA. The baseline marker and covariates found to be significantly associated (P < 0.10) with the outcome variable were included in the ANCOVA models. In addition to the baseline value, hemoglobin was also adjusted for BMI and baseline ferritin, hepcidin, CRP, and TAS by including those variables in the model; hepcidin was also adjusted for total school years and baseline Hb and TAS; TfSat was adjusted for total school years and baseline Hb and CRP; total plasma iron was also adjusted for baseline Hb, CRP, and TAS; isoprostane was also adjusted for BMI, number of school years, and menstrual status at the final study visit; TAS was also adjusted for hemoglobin at baseline, CRP at baseline, and MediCal status (state‐sponsored program that provides health coverage for people with low income); CRP was also adjusted for 8‐OHdG at baseline, ferritin at baseline, BMI, number of school years, menstrual status at the final study visit; AST was also adjusted for ferritin at baseline; ALT was also adjusted for 8‐OHdG at baseline and MediCal status.
Unadjusted difference between the iron groups combined and the placebo group as evaluated by ANOVA.
Difference between the iron groups combined and the placebo group as evaluated by ANCOVA. The same adjustments were made as with the 3‐group analysis as described above.
Mean (SD; all such values).
Placebo versus Fe‐B, p = 0.063; Placebo versus Fe‐W, p = 0.114.
There was an interaction between group assignment and baseline CRP in the 2‐group ferritin analyses. Interaction results are presented in Table 3.
AGP = alpha‐1‐acid glycoprotein; ALT = alanine transaminase; AST = aspartate transaminase CRP = C‐reactive protein; Fe‐B = iron supplement consumed between meals; Fe‐W = iron supplement consumed with meals; Hb = hemoglobin; 8‐OHdG = 8‐hydroxy‐2‐deoxyguanosine; TAS = total antioxidant status;.