Table 4.
Number and percentage of women with oxidative stress, ferritin, hepcidin, Hb, and inflammation values above or below cut‐offs at the final study visit
| Cut‐off value | Placebo (Baseline: n = 41; Final: n = 38) | Fe‐B (Baseline: n = 37; Final: n = 28) | Fe‐W (Baseline: n = 36; Final: n = 29) | p Adjusteda | Fe groups combined (Baseline: n = 73; Final: n = 57) | p Adjustedb | ||
|---|---|---|---|---|---|---|---|---|
| Hb (g/L) | <120 | Baseline | 3 (7)c | 7 (19) | 2 (6) | 9 (12) | ||
| Final | 1 (3) | 0 (0) | 0 (0) | 0.996 | 0 (0) | 0.954 | ||
| Ferritin (ng/ml) | <15 | Baseline | 3 (7) | 4 (11) | 5 (14) | 9 (12) | ||
| Final | 5 (13) | 1 (4) | 2 (7) | 0.194 | 3 (5) | 0.070 | ||
| <30 | Baseline | 12 (29) | 10 (27) | 10 (28) | 20 (27) | |||
| Final | 18 (46) | 8 (29) | 6 (21) | 0.019d | 14 (25) | 0.006 | ||
| Hepcidin (ng/ml) | <8 | Baseline | 6 (15) | 1 (3) | 2 (6) | 3 (4) | ||
| Final | 3 (8) | 0 (0) | 1 (3) | 0.997 | 1 (2) | 0.960 | ||
| <18 | Baseline | 9 (22) | 7 (19) | 7 (19) | 14 (19) | |||
| Final | 4 (10) | 1 (4) | 2 (7) | 0.549 | 3 (5) | 0.409 | ||
| 8‐OHdG (ng/mg creatinine) | >1SD | Baseline | 8 (20) | 6 (16) | 5 (14) | 11 (15) | ||
| Final | 5 (13) | 3 (11) | 9 (31) | 0.043e | 12 (21) | 0.306 | ||
| Isoprostane (pg/mg creatinine) | >1SD | Baseline | 4 (10) | 5 (14) | 4 (11) | 9 (12) | ||
| Final | 7 (18) | 4 (14) | 5 (17) | 0.621 | 9 (16) | 0.430 | ||
| CRP (mg/L) | >5 | Baseline | 23 (56) | 23 (62) | 20 (56) | 43 (59) | ||
| Final | 8 (21) | 6 (21) | 11 (38) | 0.330 | 17 (30) | 0.346 | ||
| AGP (g/L) | >1 | Baseline | 31 (76) | 31 (84) | 27 (75) | 58 (79) | ||
| Final | 12 (31) | 7 (25) | 9 (31) | 0.511 | 16 (28) | 0.251 |
Difference between three study groups in the proportion of women having values above or below the stated cut‐off value adjusted for the baseline category (high or low) as determined by logistic regression modeling. 8‐OHdG was also adjusted for high baseline CRP and AGP (categorical variables); isoprostane was also adjusted for BMI, total number of school years completed, high baseline CRP (categorical variable); ferritin was also adjusted for BMI; hepcidin was also adjusted for BMI and total number of school years completed; CRP was also adjusted for BMI and low baseline ferritin (categorical variable); AGP was also adjusted for BMI, menstrual status at the final study visit, and high baseline 8‐OHdG (categorical variable). Adjustments were made by putting the covariates in the regression models.
Difference between the iron groups combined and the placebo group in the proportion of women having values above or below the stated cut‐off value adjusted for the baseline category (high or low).
n (%;all such values).
Fe‐W versus Placebo, p = 0.147; Fe‐B vs. Placebo, p = 0.050 as determined by Poisson regression.
Fe‐W versus Placebo, p = 0.086; Fe‐W vs. Fe‐B, p = 0.062 as determined by Poisson regression.
AGP = alpha‐1‐acid glycoprotein; CRP = C‐reactive protein; Hb = hemoglobin; Fe‐B = iron supplement consumed between meals; Fe‐W = iron supplement consumed with meals; 8‐OHdG = 8‐hydroxy‐2‐deoxyguanosine.