Table 1 Sample characteristics of Chinese adults aged ≥55 years old at the first cognitive function test by quartiles of iron related dietary pattern (N = 4685)
From: Iron-related dietary pattern increases the risk of poor cognition
| Â | Q1 | Q2 | Q3 | Q4 | p-value |
|---|---|---|---|---|---|
N = 1150 | N = 1128 | N = 1161 | N = 1246 |  | |
Energy intake (kcal/d) | 1625.8 (440.6) | 2028.5 (1057.2) | 2196.2 (552.1) | 2516.4 (799.3) | < 0.001 |
Fat intake (g/d) | 56.5 (30.3) | 71.0 (112.6) | 70.7 (36.2) | 72.8 (58.6) | < 0.001 |
Protein intake (g/d) | 47.1 (14.6) | 60.0 (17.2) | 67.1 (20.5) | 78.4 (28.5) | < 0.001 |
Carbohydrate intake (g/d) | 229.1 (69.9) | 282.3 (80.1) | 316.2 (88.9) | 377.5 (121.5) | < 0.001 |
Most recent iron intake (mg/d) | 13.8 (7.2) | 18.1 (7.3) | 21.2 (11.0) | 26.8 (15.2) | < 0.001 |
Cumulative iron intake (mg/d) | 15.8 (6.2) | 21.2 (6.6) | 24.5 (9.4) | 31.0 (12.2) | < 0.001 |
Intake of fruit (g/d) | 22.6 (69.4) | 23.8 (73.8) | 23.9 (83.9) | 22.7 (90.2) | 0.97 |
Intake of fresh vegetable (g/d) | 183.8 (103.5) | 254.4 (132.4) | 298.4 (155.6) | 352.3 (234.9) | < 0.001 |
Intake of rice (g/d) | 190.9 (116.7) | 232.1 (140.5) | 252.9 (163.5) | 237.7 (207.9) | < 0.001 |
Intake of wheat (g/d) | 84.4 (90.9) | 107.9 (110.8) | 140.3 (138.3) | 227.8 (226.3) | < 0.001 |
Intake of meat (g/d) | 56.0 (58.1) | 77.8 (74.4) | 80.6 (83.4) | 77.1 (102.3) | < 0.001 |
Age (years) | 67.8 (9.0) | 63.1 (7.3) | 62.0 (6.8) | 60.9 (6.1) | < 0.001 |
Sex |  |  |  |  | < 0.001 |
 Men | 356 (31.0%) | 499 (44.2%) | 594 (51.2%) | 799 (64.1%) |  |
 Women | 794 (69.0%) | 629 (55.8%) | 567 (48.8%) | 447 (35.9%) |  |
Education | Â | Â | Â | Â | 0.002 |
 Low | 727 (77.5%) | 735 (70.7%) | 773 (71.8%) | 832 (70.7%) |  |
 Medium | 105 (11.2%) | 158 (15.2%) | 163 (15.1%) | 202 (17.2%) |  |
 High | 106 (11.3%) | 146 (14.1%) | 141 (13.1%) | 142 (12.1%) |  |
Urbanization |  |  |  |  | < 0.001 |
 Low | 224 (19.5%) | 218 (19.3%) | 282 (24.3%) | 468 (37.6%) |  |
 Medium | 274 (23.8%) | 325 (28.8%) | 368 (31.7%) | 352 (28.3%) |  |
 High | 652 (56.7%) | 585 (51.9%) | 511 (44.0%) | 426 (34.2%) |  |
Smoking |  |  |  |  | < 0.001 |
 Non-smoker | 879 (76.8%) | 796 (70.7%) | 765 (65.9%) | 709 (57.0%) |  |
 Ex-smokers | 42 (3.7%) | 33 (2.9%) | 36 (3.1%) | 66 (5.3%) |  |
 Current smokers | 224 (19.6%) | 297 (26.4%) | 359 (30.9%) | 469 (37.7%) |  |
Survey year |  |  |  |  | < 0.001 |
 1997 | 561 (48.8%) | 537 (47.6%) | 500 (43.1%) | 514 (41.3%) |  |
 2000 | 210 (18.3%) | 171 (15.2%) | 186 (16.0%) | 207 (16.6%) |  |
 2004 | 246 (21.4%) | 239 (21.2%) | 284 (24.5%) | 324 (26.0%) |  |
 2006 | 133 (11.6%) | 181 (16.0%) | 191 (16.5%) | 201 (16.1%) |  |
Alcohol drinking (yes) | 241 (21.4%) | 305 (27.6%) | 390 (34.0%) | 498 (40.7%) | < 0.001 |
Physical activity (MET, hours/week) | 58.1 (75.9) | 87.2 (101.0) | 91.3 (98.8) | 111.9 (109.5) | < 0.001 |
BMI (kg/m2) | 22.8 (3.8) | 23.2 (3.7) | 23.1 (3.5) | 23.1 (3.4) | 0.075 |
BMI ≥ 24 kg/m2 | 367 (34.9%) | 408 (39.2%) | 412 (37.9%) | 407 (35.8%) | 0.15 |
Hypertension (yes) | 447 (41.2%) | 375 (35.5%) | 363 (32.8%) | 375 (32.3%) | < 0.001 |
Diabetes (yes) | 45 (4.0%) | 36 (3.2%) | 29 (2.6%) | 39 (3.2%) | 0.29 |
Stroke (yes) | 34 (3.0%) | 19 (1.7%) | 18 (1.6%) | 28 (2.3%) | 0.082 |