Baseline characteristics of new and regular male donors
| Characteristics . | New donors . | Regular donors . | P* . |
|---|---|---|---|
| n | 24 | 25 | |
| Age, y | 39.5 (7.1) | 43.5 (5.8) | .034 |
| Number of previous donations† | 1 (1-2) | 33 (24-52) | <.001 |
| Days since previous donation | 131 (45) | 237 (138) | <.001 |
| Blood volume (L) | 5.7 (0.6) | 5.7 (0.5) | .760 |
| Blood group‡ | .413 | ||
| Type A− | 2 (8.3) | 0 (0) | |
| Type A+ | 10 (41.7) | 8 (32.0) | |
| Type B+ | 4 (16.7) | 5 (20.0) | |
| Type AB+ | 8 (33.3) | 12 (48.0) | |
| Type B−, AB−, O−,§ or O+ | 0 (0) | 0 (0) | |
| Smoking‡ | .704 | ||
| Current smoker | 4 (17) | 2 (8) | |
| Former smoker | 6 (25) | 6 (24) | |
| Never smoker | 14 (58) | 17 (68) | |
| Results of FFQ | |||
| Total iron (mg) | 31.3 (18.7) | 33.5 (15.3) | .67 |
| Heme iron (mg) | 0.9 (0.5) | 0.9 (0.4) | .81 |
| Nonheme iron (mg) | 30.4 (18.6) | 32.6 (15.2) | .66 |
| Calcium (mg) | 1221 (876) | 1402 (457) | .37 |
| Characteristics . | New donors . | Regular donors . | P* . |
|---|---|---|---|
| n | 24 | 25 | |
| Age, y | 39.5 (7.1) | 43.5 (5.8) | .034 |
| Number of previous donations† | 1 (1-2) | 33 (24-52) | <.001 |
| Days since previous donation | 131 (45) | 237 (138) | <.001 |
| Blood volume (L) | 5.7 (0.6) | 5.7 (0.5) | .760 |
| Blood group‡ | .413 | ||
| Type A− | 2 (8.3) | 0 (0) | |
| Type A+ | 10 (41.7) | 8 (32.0) | |
| Type B+ | 4 (16.7) | 5 (20.0) | |
| Type AB+ | 8 (33.3) | 12 (48.0) | |
| Type B−, AB−, O−,§ or O+ | 0 (0) | 0 (0) | |
| Smoking‡ | .704 | ||
| Current smoker | 4 (17) | 2 (8) | |
| Former smoker | 6 (25) | 6 (24) | |
| Never smoker | 14 (58) | 17 (68) | |
| Results of FFQ | |||
| Total iron (mg) | 31.3 (18.7) | 33.5 (15.3) | .67 |
| Heme iron (mg) | 0.9 (0.5) | 0.9 (0.4) | .81 |
| Nonheme iron (mg) | 30.4 (18.6) | 32.6 (15.2) | .66 |
| Calcium (mg) | 1221 (876) | 1402 (457) | .37 |
Values are given in mean (SD), unless otherwise stated.
FFQ, Food Frequency Questionnaire.
Difference between new and regular donors by Student t tests, Mann-Whitney U test, or Fisher exact test when there were fewer than 5 observations in any cell.
Median (p25-p75), in their whole donor career, but at least once in the 2 y preceding the start of the study.
n (%).
Donors with blood group O− were intentionally excluded because their donation frequency is higher than that of the other blood groups and therefore not representative for the (regular) donor population.