Table 1.
Demographic and clinical characteristics of the study participants.
| Salt intake group | < 6 g/day | 6–9 g/day | 9–12 g/day | >12 g/day | P-value |
|---|---|---|---|---|---|
|
Low group
(n = 643) |
Mild group
(n = 989) |
Moderate group
(n = 1,245) |
High group
(n = 933) |
||
| Age, years | 68.89 ± 6.21 | 68.39 ± 5.80 | 68.46 ± 6.03 | 68.46 ± 6.07 | 0.381 |
| Sex, female (%) | 301 (46.8) | 476 (48.1) | 601 (48.2) | 440 (47.1) | 0.908 |
| Smoking, n (%) | 166 (25.8) | 309 (31.2) | 387 (31.0) | 274 (29.3) | 0.074 |
| Drinking, n (%) | 179 (27.8) | 294 (29.7) | 360 (28.9) | 276 (29.5) | 0.865 |
| Exercise, n (%) | 407 (63.2) | 647 (65.4) | 837 (67.2) | 626 (67.0) | 0.311 |
| Myocardial ischemia, n (%) | 181 (28.1) | 297 (30.0) | 413 (33.2)* | 336 (36.0)*† | 0.003 |
| Hypertension, n (%) | 400 (62.2) | 715 (72.2)* | 909 (73.0)* | 685 (73.4)* | < 0.001 |
| Anti-hypertensive medication, n (%) | |||||
| Diuretics, n (%) | 182 (28.3) | 288 (29.1) | 389 (31.2) | 262 (28.1) | 0.358 |
| Beta-blocker, n (%) | 113 (17.6) | 166 (16.8) | 207 (16.6) | 192 (20.6) | 0.078 |
| Calcium channel blocker, n (%) | 147 (22.9) | 271 (27.4) | 302 (24.3) | 210 (22.5) | 0.058 |
| Angiotensin-converting enzyme inhibitor, n (%) | 176 (27.4) | 268 (27.1) | 328 (26.3) | 224 (24.0) | 0.362 |
| Angiotensin receptor blocker, n (%) | 122 (19.0) | 183 (18.5) | 227 (18.2) | 202 (21.7) | 0.198 |
| Diabetes, n (%) | 88 (13.6) | 122 (12.3) | 158 (12.6) | 121 (12.9) | 0.879 |
| Lowering-glucose medication, n (%) | 85 (13.2) | 119 (12.0) | 155 (12.4) | 119 (12.7) | 0.908 |
| Dyslipidemia, n (%) | 333 (51.7) | 518 (52.3) | 682 (54.7) | 519 (55.6) | 0.310 |
| Anti-dyslipidemia medication, n (%) | 111 (17.2) | 167 (16.8) | 199 (15.9) | 161 (17.2) | 0.842 |
| Antiplatelet medication, n (%) | 196 (30.4) | 312 (31.5) | 403 (32.3) | 297 (31.8) | 0.869 |
| BMI, kg/m2 | 25.39 ± 3.24 | 25.64 ± 3.38 | 25.45 ± 3.48 | 25.44 ± 3.54 | 0.424 |
| SBP, mmHg | 144.95 ± 18.18 | 146.62 ± 18.69 | 147.38 ± 19.01* | 148.79 ± 19.36*† | < 0.001 |
| DBP, mmHg | 71.04 ± 9.60 | 71.96 ± 9.65 | 71.32 ± 9.05 | 71.38 ± 9.41 | 0.218 |
| Heart rate, beats/min | 72.13 ± 9.03 | 72.44 ± 9.03 | 72.65 ± 9.27 | 72.74 ± 9.22 | 0.567 |
| FPG, mmol/L | 5.43 ± 1.57 | 5.52 ± 1.60 | 5.53 ± 1.67 | 5.58 ± 1.69 | 0.360 |
| TCHO, mmol/L | 4.78 ± 0.84 | 4.79 ± 0.88 | 4.78 ± 0.93 | 4.74 ± 0.86 | 0.627 |
| TG, mmol/L | 1.62 ± 0.61 | 1.62 ± 0.67 | 1.62 ± 0.68 | 1.64 ± 0.70 | 0.859 |
| HDL-C, mmol/L | 1.20 ± 0.42 | 1.15 ± 0.39 | 1.15 ± 0.41 | 1.13 ± 0.39* | 0.016 |
| LDL-C, mmol/L | 2.84 ± 0.69 | 2.90 ± 0.77 | 2.89 ± 0.83 | 2.86 ± 0.81 | 0.449 |
| hsCRP, mg/dL | 0.37 (0.27 to 0.46) | 0.51 (0.41 to 0.64)* | 0.65 (0.51 to 0.80)*† | 0.82 (0.69 to 0.93)*†‡ | < 0.001 |
The results are presented as the mean ± SD or the median (IQR, the range from the 25th to 75th percentile), or as frequencies and percentages. BMI indicates body mass index; SBP, systolic blood pressure; DBP, diastolic blood pressure; FPG, fasting plasma glucose; TCHO, total cholesterol; TG, triglyceride; HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol; hsCRP, high-sensitivity C-reactive protein. *P < 0.05, compared with low group;†P < 0.05, compared with the mild group;‡P < 0.05, compared with moderate group.