Table 1.
Main characteristics of study participants according to quintiles of daily protein intake (n = 3404).
| Quintiles of Daily Protein Intake (g/kg of Body Weight) | |||||
|---|---|---|---|---|---|
| ≤0.42 (n = 681) | 0.43−0.52 (n = 680) | 0.53−0.60 (n = 682) | 0.61−0.70 (n = 680) | ≥0.71 (n = 681) | |
| Age, years | 72.1 ± 5.4 | 72.6 ± 5.8 | 72.7 ± 5.7 | 73.1 ± 5.6 a | 73.1 ± 5.7 a |
| Weight, kg | 79.3 ± 13.4 | 74.7 ± 12.6 a | 71.3 ± 10.9 ab | 67.9 ± 10.5 abc | 60.6 ± 9.8 abcd |
| Height, m | 1.66 ± 0.9 | 1.65 ± 0.9 | 1.63 ± 0.8 ab | 1.61 ± 0.9 abc | 1.58 ± 0.8 abcd |
| BMI, kg/m2 | 28.6 ± 4.4 | 27.1 ± 4.1 a | 26.5 ± 3.6 ab | 25.9 ± 3.5 abc | 24.0 ± 3.2 abcd |
| Sex, female | 295, 43.3 | 290, 42.6 | 357, 52.3 | 405, 59.5 | 528, 77.5 * |
| Energy intake, kcal | 388.1 ± 104.6 | 492.2 ± 95.2 a | 546.7 ± 98.3 ab | 612.2 ± 103.9 abc | 688.4 ± 124.8 abcd |
| Protein, g | 27.2 ± 6.3 | 35.0 ± 5.9 a | 39.7 ± 6.0 ab | 44.6 ± 7.0 abc | 51.9 ± 8.6 abcd |
| Protein, g/kg | 0.34 ± 0.06 | 0.47 ± 0.02 a | 0.56 ± 0.02 ab | 0.65 ± 0.02 abc | 0.85 ± 0.14 abcd |
| Calcium, mg | 178.3 ± 100.9 | 235.0 ± 107.6 a | 284.0 ± 116.2 ab | 331.7 ± 120.7 abc | 383.5 ± 126.4 abcd |
| Magnesium, mg | 32.6 ± 10.0 | 39.6 ± 10.0 a | 44.0 ± 9.8 ab | 48.3 ± 10.3 abc | 54.3 ± 11.2 abcd |
| Sodium, mg | 417.2 ± 195.4 | 559.1 ± 217.3 a | 619.7 ± 230.9 ab | 722.7 ± 251.5 abc | 825.9 ± 317.1 abcd |
| Potassium, mg | 356.9 ± 100.4 | 449.4 ± 102.6 a | 503.7 ± 104.3 ab | 555.9 ± 118.1 abc | 641.6 ± 144.3 abcd |
| SBP, mmHg | 130.9 ± 15.0 | 130.4 ± 14.9 | 131.7 ± 17.0 | 130.2 ± 16.0 | 130.0 ± 17.2 |
| DBP, mmHg | 76.4 ± 9.3 | 76.5 ± 9.8 | 76.3 ± 9.5 | 75.6 ± 9.4 | 74.6 ± 9.7 abc |
| Total blood cholesterol, mg/dL | 199.3 ± 34.3 | 196.8 ± 33.2 | 196.9 ± 31.4 | 201.3 ± 31.5 | 205.4 ± 33.8 abc |
| Blood glucose, mg/dL | 107.7 ± 27.0 | 107.7 ± 26.0 | 107.2 ± 25.5 | 105.5 ± 22.5 | 105.4 ± 24.8 |
| Smoking, yes | 105, 15.4 | 101, 14.8 | 84, 12.3 | 88, 12.4 | 71, 10.4 * |
| Physical activity, yes | 135, 19.8 | 167, 24.5 | 182, 26.6 | 165, 24.2 | 164, 24.0 * |
| Antihypertensive drug(s), yes | 405, 12.0 | 377, 11.2 | 373, 11.1 | 355, 10.5 | 310, 9.2 * |
| Cholesterol-lowering drug(s), yes | 235, 34.5 | 230, 33.8 | 232, 34.0 | 218, 32.0 | 209, 30.6 |
| Antidiabetic drug(s), yes | 65, 9.5 | 63, 9.2 | 53, 7.7 | 58, 8.5 | 40, 5.8 |
Data are shown as mean ± standard deviation or absolute number, percentage. a p < 0.05 vs. p ≤ 0.42, b p < 0.05 vs. 0.43–0.52, c p < 0.05 vs. 0.53−0.60, d p < 0.05 vs. 0.61–0.70. * p < 0.05 according to chi-square tests. Abbreviations: BMI, body mass index, DBP, diastolic blood pressure, SPB, systolic blood pressure.