Table 1.
Participants baseline characteristics according to ferritin serum levels (n= 1,063)
| Variables | Low ferritin n=153 |
Normal ferritin n=663 |
High ferritin n=247 |
|---|---|---|---|
| Ferritin (ng/mL) | 14 (6–22) | 109 (67–163) | 358 (301–477) |
| Age-years | 50 ± 5* | 53 ± 6 | 53 ± 5 |
| Male (%) | 23 (15)* | 262 (40) | 117 (47)† |
| Race – black (%) | 65 (43) | 287 (43) | 130 (53)† |
| Heart rate (bpm) | 69 ± 9* | 66 ± 10 | 65 ± 10 |
| Systolic blood pressure (mmHg) | 121 ± 17 | 122 ± 17 | 125 ± 17† |
| Diastolic blood pressure (mmHg) | 75 ± 8 | 75 ± 11 | 77 ± 11† |
| BMI (Kg/m2) | 28 (24.5–33.2) | 27.5 (24.7–31.7) | 29.5 (26.3–32.7) † |
| Hypertension (%) | 48 (31) | 251 (38) | 107 (43) |
| Current smokers (%) | 27 (18) | 152 (23) | 56 (23) |
| Current drinkers (%) | 66 (43) | 338 (51) | 131 (53) |
| Iron intake (mg/day) | 10.1 ± 3.7* | 11.2 ± 5.0 | 10.9 ± 4.3 |
| Hemoglobin (g/dL) | 12.7 (11.8–13.6)* | 13.6 (12.7–14.5) | 13.9 (12.8–15.0) |
| CRP (mg/mL) | 2.1 (0.7–4.6) | 2.0 (0.9–4.4) | 2.3 (1.0–4.9) |
| Albumin (mg/dL) | 3.8 ± 0.2* | 3.9 ± 0.2 | 3.9 ± 0.2† |
| GFR (ml/min/1.73m2) | 110 (101–121)* | 107 (97–117) | 105 (96–117) |
| Glucose (mg/dL) | 99 (93–107) | 101 (95–109) | 104 (97–113)† |
| LDL (mg/dL) | 132 (108–155) | 132 (110–160) | 135 (107–163) |
| Use of NSAID (%) | 14 (9) | 69 (10) | 27 (11) |
| Postmenopausal status (%)‡ | 39/130 (30)* | 307/401 (75) | 123/130 (95) |
| High education level (%) | 61 (40) | 241 (36) | 74 (30) |
BMI: body mass index; CRP: C reactive protein; GFR: glomerular filtration ratio; LDL: low density lipids cholesterol; NSAID: non-steroidal anti-inflammatory drugs.
‡
Proportion among women in each group.
*
p<0.05 low vs. normal ferritin and
†
p<0.05 high vs. normal ferritin