Table 1.
Baseline characteristics of 83,994 study subjects.
| Characteristics | Total Subjects (n = 83,994) | Men (n = 30,499) | Women (n = 53,495) |
|---|---|---|---|
| Age, years (median, IQR) | 46 (30–61) | 48 (31–62) | 45 (29–60) |
| Age group (n, %) | |||
| 0–9 years | 8986 (10.7) | 3329 (10.9) | 5657 (10.6) |
| 10–19 years | 5085 (6.1) | 1874 (6.1) | 3211 (6.0) |
| 20–29 years | 6614 (7.9) | 1962 (6.4) | 4652 (8.7) |
| 30–39 years | 11,493 (13.7) | 3872 (12.7) | 7621 (14.2) |
| 40–49 years | 15,313 (18.2) | 4940 (16.2) | 10,373 (19.4) |
| 50–59 years | 14,089 (16.8) | 5491(18.0) | 8598 (16.1) |
| 60–69 years | 10,850 (12.9) | 4617 (15.1) | 6233 (11.7) |
| 70–79 years | 7096 (8.4) | 2862 (9.4) | 4234 (7.9) |
| ≥80 years | 4468 (5.3) | 1552 (5.1) | 2916 (5.5) |
| Follow-up, number (median, IQR, min–max) | 1 (1–1, 1–40) | 1 (1–1, 1–40) | 1 (1–1, 1–36) |
| Baseline laboratory test result | |||
| Hb, g/dL (median, IQR) | 13.1 (11.9–14.3) | 14.4 (12.4–15.6) | 12.8 (11.7–13.6) |
| Serum ferritin, ng/mL (median, IQR) | 89 (43–192) | 184 (86–319) | 65 (32–119) |
| Serum iron, ug/dL (median, IQR) | 93 (64–123) | 100 (71–132) | 89 (61–117) |
| UIBC, ug/dL (median, IQR) | 215 (171–264) | 197 (155–242) | 224 (181–278) |
| TIBC, ug/dL (median, IQR) | 316 (280–356) | 307 (270–343) | 322 (286–363) |
| TSAT, % (median, IQR) | 29.8 (21.1–39.6) | 32.8 (24.1–43.3) | 28.21 (19.3–37.4) |
| Serum creatinine, mg/dL (median, IQR) | 0.7 (0.6–0.9) | 0.9 (0.8–1.1) | 0.7 (0.6–0.8) |
| eGFR, mL/min/1.73 m2, (median, IQR) | 104.8 (88.5–119.5) | 99.44 (79.4–115.5) | 107.74 (92.5–121.1) |
| Patients with anemia with Hb ≤ 11 g/dL (n, %) | 13,827 (16.5) | 4594 (15.1) | 9233 (17.3) |
| Patients with anemia with Hb ≤ 10 g/dL (n, %) | 7845 (9.3) | 2700 (8.9) | 5145 (9.6) |
| Possible CKD with eGFR < 60 mL/min/1.73 m2 (n, %) | 9587 (11.4) | 5165 (16.9) | 4422 (8.3) |
Abbreviations: CKD, chronic kidney disease; eGFR, estimated glomerular filtration rate; IQR, interquartile range; TIBC, total iron-binding capacity; TSAT, transferrin saturation; UIBC, unsaturated iron-binding capacity. Possible CKD patients were defined as eGFR < 60 mL/min/1.73 m2 (n, %).