Table 1. Basic characteristics.
| Controls | Donors | P-value | ||
|---|---|---|---|---|
| N | 276 | 277 | – | |
| Total number of donation | – | 107 (54.5,196.5) | – | |
| Questionnaire information | ||||
| Sex male (n, %) | 177 (63.9%) | 100 (36.1%) | 0.77 | |
| Age (year, mean ± SD) | 52.74 ± 2.13 | 53.64 ± 2.78 | <0.001 | |
| BMI (kg/m 2, mean ± SD) | 25.73 ± 5.50 | 25.39 ± 3.40 | 0.38 | |
| Annual household income | Low | 8 (2.90%) | 41 (14.80%) | <0.001 |
| Medium | 78 (28.30%) | 199 (71.80%) | ||
| High | 190 (68.80%) | 37 (13.40%) | ||
| Physical activity (IPAQ) | Low | 64 (23.20%) | 52 (18.80%) | <0.001 |
| Medium | 174 (63.00%) | 221 (79.80%) | ||
| High | 38 (13.80%) | 4 (1.40%) | ||
| Protein intake | Rarely | 25 (9.10%) | 2 (0.70%) | <0.001 |
| Often | 44 (15.90%) | 175 (63.20%) | ||
| Daily | 207 (75.00%) | 100 (36.10%) | ||
| Calcium supplementation | Rarely | 258 (93.50%) | 270 (97.50%) | 0.02 |
| Often | 18 (6.50%) | 7 (2.50%) | ||
| Daily | 0 (0.00%) | 0 (0.00%) | ||
| Vitamin D supplementation | Rarely | 276 (100.00%) | 277 (100.00%) | - |
| Often | 0 (0.00%) | 0 (0.00%) | ||
| Daily | 0 (0.00%) | 0 (0.00%) | ||
| Bone metabolism indicators | ||||
| 25OHD (ng/mL) | 17.24 ± 8.37 | 13.02 ± 7.09 | <0.001 | |
| P1NP (ng/mL) | 64.31 ± 24.16 | 70.98 ± 44.94 | 0.03 | |
| β-CTX (ng/mL) | 0.34 ± 0.20 | 0.30 ± 0.15 | <0.001 | |
| PTH (pg/mL) | 40.73 ± 17.72 | 49.01 ± 22.02 | <0.001 | |
| Total Ca (mmol/L) | 2.33 ± 0.08 | 2.34 ± 0.06 | 0.62 |