Table III.
Parameter estimates* for CHr (pg), venous haemoglobin (g/l), log10 sTfR (mg/l), log10 Ferritin (μg/l) and log10 ratio of sTfR/Ferrtin
| CHr Model estimate (SE) | Venous Haemoglobin Model estimate (SE) | log10 sTfR Model estimate (SE) | log10 Ferritin Model estimate (SE) | log10 (sTfR/Ferritin) Model estimate (SE) | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Mean** | 31.69 (0.60) | 139.4 (1.5) | 0.45 (0.02) | 1.62 (0.05) | 1.84 (0.06) | |||||
| Intercept*** | 32.72 (0.62) | 146.6 (2.7) | 0.42 (0.03) | 1.67 (0.07) | 1.76 (0.09) | |||||
| Race/Ethnicity | ||||||||||
| p-value | 0.001 | <0.0001 | <0.0001 | 0.007 | 0.06 | |||||
| Asian | −0.39 (0.64) | 0.14 (0.11) | 0.01 (0.02) | 0.12 (0.03) | −0.11 (0.04) | |||||
| Black | −1.39 (0.32) | −0.49 (0.09) | 0.07 (0.01) | 0.03 (0.03) | 0.04 (0.04) | |||||
| Hispanic | −0.76 (0.38) | −0.20 (0.11) | −0.01 (0.02) | −0.04 (0.03) | 0.03 (0.04) | |||||
| White | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | |||||
| Other | −0.64 (0.47) | −0.20 (0.15) | 0.00 (0.02) | 0.03 (0.06) | −0.03 (0.07) | |||||
| Gender | ||||||||||
| p-value | 0.07 | <0.0001 | 0.61 | <0.0001 | 0.001 | |||||
| Female | −0.41(0.35) | −1.66 (0.20) | 0.05 (0.02) | −0.30 (0.05) | 0.34 (0.05) | |||||
| Male | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | |||||
| Age (years) | Male | Female | Male | Female | Male | Female | Male | Female | Male | Female |
| p-value | 0.0001 | 0.002 | <0.0001 | 0.03 | 0.001 | 0.14 | 0.003 | <0.0001 | 0.005 | <0.0001 |
| 16 – 29 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| 30 – 39 | 0.38 (0.28) | 0.42 (0.26) | −0.18 (0.09) | 0.09 (0.08) | 0.00 (0.01) | −0.01 (0.01) | 0.04 (0.03) | 0.11 (0.03) | −0.03 (0.04) | −0.13 (0.03) |
| 40 – 49 | 0.58 (0.22) | 0.88 (0.22) | −0.21 (0.09) | 0.18 (0.08) | −0.01 (0.01) | −0.03 (0.01) | 0.07 (0.03) | 0.19 (0.03) | −0.08 (0.03) | −0.22 (0.03) |
| 50 – 59 | 0.47 (0.21) | 0.69 (0.24) | −0.33 (0.09) | 0.21 (0.09) | 0.00 (0.01) | −0.03 (0.01) | −0.02 (0.03) | 0.23 (0.03) | 0.02 (0.03) | −0.26 (0.04) |
| 60+ | 1.01 (0.22) | 0.63 (0.27) | −0.46 (0.10) | 0.35 (0.11) | −0.04 (0.01) | −0.04 (0.02) | 0.02 (0.03) | 0.27 (0.03) | −0.05 (0.03) | −0.30 (0.04) |
| HFE genotype | ||||||||||
| p-value | <0.0001 | <0.0001 | <0.0001 | 0.003 | <0.0001 | |||||
| Wild Type or Missing | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | |||||
| Heterozygous H63D | 0.40 (0.12) | 0.14 (0.07) | −0.02 (0.01) | 0.02 (0.02) | −0.03 (0.02) | |||||
| Heterozygous C282Y | 0.50 (0.25) | 0.09 (0.12) | 0.00 (0.01) | 0.04 (0.03) | −0.04 (0.04) | |||||
| Double Mutation | 1.76 (0.42) | 0.57 (0.17) | −0.12 (0.02) | 0.13 (0.06) | −0.25 (0.06) | |||||
| Centre | ||||||||||
| p-value | <0.0001 | <0.0001 | <0.0001 | <0.0001 | 0.002 | |||||
| A | 0.77 (0.13) | 0.15 (0.06) | 0.01 (0.01) | 0.01 (0.02) | 0.00 (0.03) | |||||
| B | — | −0.72 (0.07) | −0.02 (0.01) | 0.03 (0.02) | −0.05 (0.03) | |||||
| C | — | 0.02 (0.07) | −0.02 (0.01) | 0.00 (0.02) | −0.01 (0.03) | |||||
| D | −0.66 (0.12) | −0.16 (0.06) | −0.04 (0.01) | −0.02 (0.02) | −0.02 (0.03) | |||||
| E | 0.20 (0.12) | −0.75 (0.06) | −0.01 (0.01) | −0.07 (0.02) | 0.06 (0.03) | |||||
| F | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | |||||
| Smoking | ||||||||||
| p-value | 0.10 | <0.0001 | <0.0001 | 0.005 | <0.0001 | |||||
| Current smoker | 0.22 (0.13) | 0.39 (0.06) | −0.04 (0.01) | 0.05 (0.02) | −0.09 (0.02) | |||||
| Past/Non/Unknown smoker | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | |||||
| Weight (kg) | Male | Female | Male | Female | Male | Female | Male | Female | Male | Female |
| p-value | 0.008 | <0.0001 | 0.08 | 0.57 | 0.08 | 0.0002 | <0.0001 | 0.001 | <0.0001 | 0.23 |
| < 68 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| 68 – 78 | −0.29 (0.31) | −0.20 (0.14) | 0.01 (0.19) | 0.01 (0.05) | 0.04 (0.02) | 0.01 (0.01) | 0.04 (0.04) | 0.04 (0.02) | 0.00 (0.05) | −0.03 (0.02) |
| 79 – 90 | −0.50 (0.30) | −0.63 (0.16) | 0.04 (0.19) | 0.08 (0.07) | 0.05 (0.02) | 0.02 (0.01) | 0.06 (0.04) | 0.05 (0.02) | −0.01 (0.05) | −0.03 (0.03) |
| ≥ 91 | −0.77 (0.29) | −1.21 (0.18) | 0.18 (0.19) | 0.07 (0.08) | 0.05 (0.02) | 0.05 (0.01) | 0.17 (0.04) | 0.11 (0.03) | −0.12 (0.05) | −0.06 (0.03) |
| Iron Supplementation | ||||||||||
| p-value | 0.23 | 0.86 | 0.19 | 0.001 | 0.001 | |||||
| Iron Supplement | 0.11 (0.09) | −0.01 (0.04) | −0.01 (0.01) | 0.04 (0.01) | −0.05 (0.02) | |||||
| No iron Supplement | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | |||||
| Pregnancy Status | ||||||||||
| p-value | 0.04 | 0.12 | 0.04 | 0.009 | 0.01 | |||||
| Ever Pregnant | −0.40 (0.15) | −0.11 (0.06) | 0.02 (0.01) | −0.05 (0.02) | 0.07 (0.03) | |||||
| Female unknown preg status | −1.87 (1.33) | −0.23 (0.22) | 0.03 (0.03) | −0.25 (0.08) | 0.28 (0.09) | |||||
| Male or never pregnant | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | |||||
| Menstrual Cycle (female) | ||||||||||
| p-value | 0.21 | 0.001 | 0.09 | <0.0001 | 0.01 | |||||
| Periods have stopped | 0.21 (0.17) | 0.22 (0.07) | 0.02 (0.01) | 0.09 (0.02) | −0.08 (0.03) | |||||
| Still having periods | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | |||||
| TF G277S Genotype | ||||||||||
| p-value | 0.34 | 0.97 | 0.93 | 0.59 | 0.97 | |||||
| Wild Type | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | |||||
| Heterozygous or Homozygous | 0.149 (0.124) | 0.007 (0.061) | −0.006 (0.008) | 0.001 (0.018) | −0.005 (0.023) | |||||
| Missing | −0.565 (0.166) | 0.212 (0.106) | −0.005 (0.010) | −0.003 (0.023) | −0.004 (0.028) | |||||
| Red Cell Donations in the previous 2 years | ||||||||||
| p-value | <0.0001 | <0.0001 | <0.0001 | <0.0001 | <0.0001 | |||||
| 0 donations | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | |||||
| 1–3 donations | −0.60 (0.16) | −0.16 (0.05) | −0.03 (0.01) | −0.15 (0.02) | 0.12 (0.02) | |||||
| 4–9 donations | −0.94 (0.17) | −0.26 (0.06) | 0.01 (0.01) | −0.34 (0.02) | 0.34 (0.02) | |||||
| 10+ donations | −1.42 (0.20) | −0.54 (0.08) | 0.04 (0.01) | −0.44 (0.02) | 0.48 (0.03) | |||||
| Time Since Last Donation | ||||||||||
| p-value | 0.01 | <0.0001 | <0.0001 | <0.0001 | <0.0001 | |||||
| 8–13 weeks | −0.26 (0.10) | −0.25 (0.04) | 0.06 (0.005) | −0.23 (0.01) | 0.29 (0.01) | |||||
| 14–19 weeks | −0.14 (0.10) | −0.08 (0.04) | 0.02 (0.005) | −0.16 (0.01) | 0.19 (0.01) | |||||
| 20–25 weeks | 0.05 (0.12) | −0.13 (0.04) | 0.02 (0.004) | −0.08 (0.01) | 0.10 (0.01) | |||||
| 26+ weeks | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | |||||
| Red Cell Donations in the previous 2 years by HFE genotype | ||||||||||
| p-value | 0.08 | 0.24 | 0.05 | 0.01 | 0.02 | |||||
| See Figure 2, Panel A | See Figure 2, Panel B | See Figure 2, Panel C | See Figure 2, Panel D | See Figure 2, Panel E | ||||||
*
Parameter estimates are from repeated measures regression model with the fixed effects shown in the table and with random effects for within and between donor variation.
**
Mean is model least square mean at 0 donations in past 2 years.
***
Intercept is the model prediction for the reference donor (white, male, aged 16–29 years, no HFE mutation, at centre F, non-smoker, weight less than 68 kg, not taking iron supplements, without the TF G277S genotype, and having made no donations in the previous 2 years).