Table 1. Baseline characteristics categorized by 24h sodium excretion.
| 24h urinary sodium excretion | |||||||
|---|---|---|---|---|---|---|---|
| Variable | Overall | <3.0 g/day | 3.0–4.0 g/day | 4.0–5.0 g/day | 5.0–6.0 g/day | >6.0 g/day | P-value |
| Number of patients | 1230 | 220 | 274 | 333 | 222 | 181 | |
| 24h urinary sodium excretion, g/day | 4.50 (1.64) | 2.46 (0.48) | 3.52 (0.27) | 4.47 (0.30) | 5.45 (0.29) | 7.36 (1.35) | <0.001 |
| Age, years | 62.2 (10.9) | 65.2 (9.9) | 63.6 (10.3) | 61.9 (10.6) | 60.8 (11.7) | 58.4 (11.1) | <0.001 |
| Male, n (%) | 651 (52.9) | 92 (41.8) | 133 (48.5) | 169 (50.8) | 127 (57.2) | 130 (71.8) | <0.001 |
| Height, cm | 159.0 (9.1) | 155.8 (8.5) | 157.7 (9.2) | 158.7 (8.6) | 160.4 (8.6) | 163.7 (9.3) | <0.001 |
| Weight, kg | 61.5 (11.6) | 56.8 (9.8) | 59.5 (11.1) | 60.6 (10.0) | 64.2 (11.3) | 68.8 (13.6) | <0.001 |
| BMI, kg/m2 | 24.2 (3.6) | 23.3 (3.4) | 23.8 (3.5) | 24.0 (3.5) | 24.9 (3.6) | 25.5 (3.8) | <0.001 |
| Systolic BP, mmHg | 131.7 (17.5) | 130.5 (18.6) | 132.2 (18.0) | 131.3 (17.4) | 131.9 (16.9) | 133.3 (16.3) | 0.570 |
| Diastolic BP, mmHg | 72.6 (12.2) | 71.0 (12.5) | 71.5 (11.5) | 72.2 (11.6) | 73.0 (12.4) | 76.7 (12.7) | <0.001 |
| Type 2 diabetes, n (%) | 1112 (90.4) | 191 (86.8) | 247 (90.1) | 300 (90.1) | 206 (92.8) | 168 (92.8) | 0.199 |
| Diabetes duration, years | 12.0 (8.0) | 13.4 (8.6) | 11.9 (8.0) | 12.2 (8.3) | 11.3 (7.3) | 11.0 (7.5) | 0.022 |
| Diabetic retinopathy, n (%) | 479 (38.9) | 91 (41.4) | 104 (38.0) | 127 (38.1) | 92 (41.4) | 65 (35.9) | 0.731 |
| History of CVD, n (%) | 250 (20.3) | 64 (29.1) | 57 (20.8) | 59 (17.7) | 45 (20.3) | 25 (13.8) | 0.002 |
| Oral hypoglycemic agent, n (%) | 818 (66.5) | 132 (60.0) | 180 (65.7) | 225 (67.6) | 150 (67.6) | 131 (72.4) | 0.119 |
| Insulin, n (%) | 408 (33.2) | 88 (40.0) | 87 (31.8) | 110 (33.0) | 73 (32.9) | 50 (27.6) | 0.116 |
| RAAS blockade, n (%) | 611 (49.7) | 114 (51.8) | 141 (51.5) | 161 (48.3) | 109 (49.1) | 86 (47.5) | 0.852 |
| Calcium channel blocker, n (%) | 456 (37.1) | 93 (42.3) | 108 (39.4) | 112 (33.6) | 81 (36.5) | 62 (34.3) | 0.237 |
| Diuretics, n (%) | 137 (11.1) | 23 (10.5) | 35 (12.8) | 39 (11.7) | 21 (9.5) | 19 (10.5) | 0.798 |
| Statin, n (%) | 440 (35.8) | 81 (36.8) | 106 (38.7) | 119 (35.7) | 73 (32.9) | 61 (33.7) | 0.688 |
| Total protein, g/dl | 7.48 (0.45) | 7.51 (0.41) | 7.50 (0.46) | 7.45 (0.44) | 7.50 (0.47) | 7.46 (0.44) | 0.434 |
| Albumin, g/dl | 4.39 (0.26) | 4.37 (0.25) | 4.40 (0.26) | 4.38 (0.27) | 4.40 (0.28) | 4.43 (0.27) | 0.138 |
| Uric acid, mg/dl | 5.07 (1.37) | 5.21 (1.35) | 5.08 (1.40) | 4.93 (1.38) | 5.07 (1.34) | 5.14 (1.38) | 0.171 |
| Creatinine, mg/dl | 0.72 (0.19) | 0.74 (0.20) | 0.72 (0.19) | 0.72 (0.20) | 0.71 (0.18) | 0.72 (0.15) | 0.422 |
| eGFR, ml/min/1.73m2 | 78.6 (19.5) | 73.1 (18.3) | 76.9 (18.6) | 78.6 (19.5) | 82.1 (19.9) | 83.6 (19.7) | <0.001 |
| HbA1c, % | 7.26 (0.95) | 7.21 (0.92) | 7.25 (0.99) | 7.25 (0.93) | 7.29 (0.96) | 7.28 (0.97) | 0.927 |
| Serum sodium, mEq/l | 139.6 (1.8) | 139.7 (2.0) | 139.7 (2.0) | 139.6 (1.8) | 139.50 (1.7) | 139.4 (1.6) | 0.376 |
| Serum potassium, mEq/l | 4.44 (0.37) | 4.42 (0.38) | 4.42 (0.36) | 4.43 (0.39) | 4.46 (0.38) | 4.46 (0.34) | 0.547 |
| Serum chloride, mEq/l | 104.3 (2.4) | 104.6 (2.4) | 104.4 (2.5) | 104.4 (2.4) | 104.1 (2.1) | 103.9 (2.2) | 0.028 |
| Total cholesterol, mg/dl | 198.8 (34.7) | 199.4 (34.1) | 199.5 (34.0) | 199.0 (36.4) | 197.8 (34.1) | 198.2 (34.3) | 0.980 |
| HDL cholesterol, mg/dl | 53.3 (14.0) | 54.2 (15.0) | 53.9 (12.9) | 53.8 (14.3) | 52.7 (14.6) | 51.3 (12.6) | 0.198 |
| 24h urinary albumin excretion, mg/day | 44.4 (117.9) | 38.5 (86.7) | 40.1 (149.7) | 48.5 (132.2) | 51.1 (99.4) | 42.6 (85.4) | 0.719 |
| 24h urinary potassium excretion, g/day | 2.14 (0.77) | 1.71 (0.65) | 1.97 (0.61) | 2.11 (0.65) | 2.35 (0.72) | 2.74 (0.91) | <0.001 |
Categorical variables are expressed as the number (%) and continuous variables are expressed as the mean (SD).
BMI, body mass index; BP, blood pressure; CVD, cardiovascular disease; RAAS, renin-angiotensin-aldosterone system; eGFR, estimated glomerular filtration rate; HbA1c, glycated hemoglobin; HDL, high-density lipoprotein