Table 1.
Sample characteristics according to ferritin status (mean values and standard deviations; numbers and percentages).
| Total | Low ferritin < 10.0 ng/mL | Normal ferritin = 10.0 − 299.9 ng/mL | High ferritin ≥ 300.0 ng/mL | P value | |
|---|---|---|---|---|---|
| Variables | (n = 8163) | (n = 431) | (n = 6951) | (n = 781) | |
| Age (years) | 50.9 ± 15.1 | 41.8 ± 12.0 | 51.4 ± 15.2 | 51.5 ± 14.0 | <0.0001 |
| ≥60 years | 2275 (27.9) | 33 (7.7) | 2033 (29.3) | 209 (26.8) | <0.0001 |
| Risk factors | |||||
| Systolic pressure (mmHg) | 124.9 ± 19.0 | 117.0 ± 15.9 | 125.1 ± 19.2 | 127.7 ± 17.7 | <0.0001 |
| Diastolic pressure (mmHg) | 80.3 ± 11.2 | 76.3 ± 10.1 | 80.1 ± 11.2 | 83.2 ± 11.4 | <0.0001 |
| Myocardial infarction | 81 (0.99) | 2 (0.47) | 75 (1.08) | 4 (0.51) | 0.6651 |
| Cardiovascular stroke | 114 (1.4) | 2 (0.47) | 100 (1.44) | 12 (1.54) | 0.2080 |
| BMI (kg/m2) | 23.4 ± 3.5 | 22.6 ± 3.2 | 23.3 ± 3.5 | 24.6 ± 3.3 | <0.0001 |
| Obesity (BMI ≥ 30 kg/m2) | 338 (4.14) | 7 (1.62) | 278 (4.00) | 53 (6.79) | <0.0001 |
| Waist circumference (cm) | |||||
| Men | 84.4 ± 10.2 | 82.1 ± 9.1 | 83.8 ± 10.2 | 87.7 ± 10.0 | <0.0001 |
| Women | 81.3 ± 10.3 | 77.9 ± 9.6 | 81.4 ± 10.3 | 87.3 ± 10.1 | <0.0001 |
| Central obesity | 3135 (38.4) | 154 (35.7) | 2634 (37.9) | 347 (44.4) | 0.0005 |
| Diabetes (%) | 679 (8.32) | 12 (2.78) | 519 (7.47) | 148 (18.95) | <0.0001 |
| Diabetes (men) (%) | 327 (8.63) | 6 (11.76) | 215 (6.91) | 106 (16.85) | <0.0001 |
| Diabetes (women) (%) | 342 (7.92) | 6 (1.59) | 295 (7.78) | 41 (27.33) | <0.0001 |
| High CRP level (0-3.0 mg/L) | 1394 (17.08) | 32 (7.42) | 1185 (17.05) | 177 (22.66) | <0.0001 |
| Dietary factors | |||||
| Energy intake (kcal/day) | 2141.3 ± 658.7 | 2011.3 ± 569.0 | 2133.6 ± 661.1 | 2265.3 ± 665.4 | <0.0001 |
| Fat intake (g/day) | 75.4 ± 39.7 | 68.9 ± 30.0 | 75.1 ± 40.0 | 81.3 ± 41.1 | <0.0001 |
| Protein intake (g/day) | 65.8 ± 22.9 | 62.1 ± 21.0 | 65.4 ± 22.8 | 71.0 ± 23.5 | <0.0001 |
| Carbohydrate intake (g/day) | 295.1 ± 101.4 | 284.3 ± 95.3 | 294.5 ± 101.4 | 303.5 ± 104.3 | 0.006 |
| Analytical values | |||||
| HbA1c (%) | 5.6 ± 0.9 | 5.5 ± 0.6 | 5.6 ± 0.9 | 6.0 ± 1.4 | <0.0001 |
| Urea (mmol/L) | 5.5 ± 1.6 | 4.7 ± 1.4 | 5.5 ± 1.6 | 5.8 ± 1.6 | <0.0001 |
| Uric acid (mg/dL) | 308.3 ± 106.3 | 239.3 ± 70.8 | 304.7 ± 99.9 | 379.1 ± 136.2 | <0.0001 |
| Apolipoprotein A-1 (g/L) | 1.2 ± 0.4 | 1.2 ± 0.3 | 1.2 ± 0.4 | 1.1 ± 0.3 | <0.0001 |
| Apolipoprotein B (g/L) | 0.9 ± 0.3 | 0.8 ± 0.3 | 0.9 ± 0.3 | 1.0 ± 0.3 | <0.0001 |
| Lipoprotein (mg/dL) | 15.6 ± 22.9 | 15.3 ± 21.9 | 15.8 ± 23.1 | 13.9 ± 20.2 | 0.0799 |
| Creatinine (μmol/L) | 87.4 ± 22.5 | 78.9 ± 16.5 | 87.1 ± 20.3 | 94.8 ± 37.2 | <0.0001 |
| Insulin (μIU/mL) | 14.4 ± 22.4 | 11.6 ± 8.9 | 14.3 ± 23.1 | 16.9 ± 21.2 | 0.0003 |
| Insulin (men) (μIU/mL) | 14.6 ± 23.7 | 10.0 ± 6.96 | 14.4 ± 25.0 | 16.1 ± 16.7 | 0.1149 |
| Insulin (women) (μIU/mL) | 14.1 ± 20.6 | 11.8 ± 9.1 | 14.1 ± 21.5 | 17.7 ± 17.2 | 0.0113 |
| Antidiabetic drugs | |||||
| Oral drugs | 182 (2.2) | 0 (0) | 146 (2.10) | 36 (4.61) | <0.0001 |
| CRP (mg/L) | 2.6 ± 9.0 | 1.3 ± 2.9 | 2.5 ± 8.6 | 4.0 ± 13.8 | <0.0001 |
| Insulin injection | 51 (0.62) | 0 (0.0) | 42 (0.60) | 9 (1.15) | 0.0125 |
Data are given as the mean ± SD or n (%).