Table 3.
Hematology and iron status measures (n = 43).
| Variable * | Baseline | Midpoint (week 8) | Endpoint (week 16) | Absolute change (endpoint-baseline) | P value Main effect time | P value Main effect baseline measure | P value time × baseline measure | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Beef | Non-beef | Beef | Non-beef | Beef | Non-beef | Beef | Non-beef | ||||
| Hb (g/L) † | 143.4 ± 2.4 | 138.5 ± 0.3 | 145.6 ± 0.2 | 141.5 ± 0.2 | 146.2 ± 0.2 | 140.7 ± 0.2 | 2.8 ± 1.8 | 2.1 ± 1.9 | <0.0001 | <0.0001 | <0.0001 |
| Hct (%) | 41.6 ± 0.7 | 40.2 ± 0.7 | 42.5 ± 0.6 | 40.8 ± 0.5 | 42.4 ± 0.5 | 40.9 ± 0.5 | 0.8 ± 0.5 | 0.8 ± 0.7 | <0.0001 | <0.0001 | <0.0001 |
| RBC (millions/mm3) | 4.7 ± 0.1 | 4.7 ± 0.1 | 4.8 ± 0.1 | 4.7 ± 0.1 | 4.8 ± 0.1 | 4.7 ± 0.1 | 0.1 ± 0.1 | 0.0 ± 0.1 | <0.0001 | <0.0001 | <0.0001 |
| MCV (µm3) | 88.2 ± 0.7 | 87.1 ± 1.1 | 88.2 ± 0.8 | 86.9 ± 1.0 | 88.1 ± 0.8 | 87.3 ± 1.0 | −0.1 ± 0.3 | 0.2 ± 0.6 | <0.05 | <0.0001 | <0.05 |
| MCH (pg) | 30.4 ± 0.3 | 30.0 ± 0.5 | 30.3 ± 0.4 | 30.1 ± 0.5 | 30.4 ± 0.4 | 30.1 ± 0.5 | 0.0 ± 0.2 | 0.0 ± 0.3 | NS | <0.0001 | NS |
| MCHC (%) | 34.5 ± 0.2 | 34.4 ± 0.2 | 34.3 ± 0.3 | 34.6 ± 0.2 | 34.5 ± 0.2 | 34.4 ± 0.3 | 0.0 ± 0.2 | 0.0 ± 0.3 | <0.05 | <0.0001 | <0.05 |
| Body iron (mg/kg) †† | 6.5 ± 0.6 | 5.2 ± 0.8 | 6.5 ± 0.7 | 5.0 ± 3.8 | 7.0 ± 0.6 | 6.0 ± 0.5 | 0.5 ± 0.4 | 0.9 ± 0.5 | <0.001 | <0.0001 | <0.0001 |
| Serum ferritin (ng/mL) | 33.6 ± 4.8 | 28.3 ± 4.2 | 34.0 ± 4.8 | 28.5 ± 4.6 | 41.6 ± 6.8 | 29.2 ± 3.0 | 8.0 ± 3.9 | 0.9 ± 2.7 | <0.0001 | <0.0001 | <0.0001 |
| TfR (mg/L) † †† | 3.1 ± 0.2 | 3.8 ± 0.4 | 3.1 ± 0.2 | 3.8 ± 0.3 | 3.2 ± 0.2 | 3.4 ± 0.2 | 0.1 ± 0.1 | −0.4 ± 0.2 | <0.0001 | <0.0001 | <0.0001 |
| Serum iron (µg/L) | 1027.8 ± 89.1 | 1034.7 ± 115.8 | 921.8 ± 57.6 | 915.2 ± 94.0 | 955.5 ± 66.2 | 1064.8 ± 73.6 | −72.0 ± 97.5 | 30.0 ± 112.9 | <0.0001 | <0.0001 | <0.0001 |
| Tf (mg/dL) | 285.2 ± 9.0 | 290.0 ± 9.5 | 285.5 ± 9.6 | 297.4 ± 9.8 | 285.5 ± 10.5 | 288.3± 10.8 | 0.3 ± 6.2 | −15.5 ± 16.7 | NS | NS | NS |
| Tf saturation (%) | 31.4 ± 3.3 | 31.5 ± 3.9 | 27.6 ± 2.4 | 26.7 ± 3.3 | 28.8 ± 2.5 | 31.1 ± 2.8 | −2.6 ± 2.9 | −0.4 ± 3.2 | <0.0001 | <0.0001 | <0.0001 |
Beef group, n = 22; Non-beef group, n = 21. * Hb = hemoglobin; Hct = hematocrit; RBC = Red Blood Cell count; TfR = transferrin receptor; Tf = transferrin. Values are means ± SE. NS = Not statistically significant. Mixed Models ANOVA with repeated measures was used to determine main effects of time, lunch group, baseline measure, and interactions on baseline, midpoint, and endpoint blood measures; † Effect of lunch group, p < 0.05; †† Effect of lunch group × baseline measurement, p < 0.05.