Table 2.
Baseline characteristics of study participants (n = 2582) according to 24-h urinary sodium excretion.
| Characteristics | Tertiles of 24-Hour Urinary Sodium Excretion (mmol/Day) | p-Value | ||
|---|---|---|---|---|
| T1 (n = 861) | T2 (n = 861) | T3 (n = 860) | ||
| 24-h urinary sodium, mmol/day | 129.11 (115.53–138.63) |
160.42 (152.95–167.25) |
192.76 (182.63–208.43) |
<0.001 † |
| Age, yr | 49 (43–59) | 51 (44–61) | 53 (45–61) | <0.001 † |
| Gender (females), n (%) | 529 (61.44) | 531 (61.67) | 511 (59.42) | 0.574 |
| BMI, kg/m2 | 22.91 (21.41–24.61) |
23.53 (21.90–25.01) |
23.89 (22.39–25.34) |
<0.001 † |
| Drinking status, n (%) | 0.783 | |||
| Never | 489 (56.79) | 472 (54.82) | 487 (56.63) | |
| Former | 58 (6.74) | 66 (7.67) | 54 (6.28) | |
| Current | 314 (36.47) | 323 (37.51) | 319 (37.09) | |
| Smoking status, n (%) | 0.002 | |||
| Never | 555 (64.46) | 585 (67.94) | 602 (70.00) | |
| Former | 82 (9.52) | 93 (10.80) | 102 (11.86) | |
| Current | 224 (26.02) | 183 (21.25) | 156 (18.14) | |
| Physical activity, MET-h/week | 17.00 (9.37–30.37) |
18.37 (9.62–34.25) |
19.12 (10.50–35.00) |
0.016 † |
| AST, IU/L | 21 (18–25) | 21 (18–25) | 21 (17–25) | 0.488 † |
| ALT, IU/L | 16 (12–21) | 16 (13–21) | 17 (13–21)) | 0.078 † |
| TG, mg/dL | 106 (77–151) | 111 (82–160) | 120 (86.5–176.5) | <0.001 † |
| T-Chol, mg/dL | 189 (167–214) | 192 (170–215) | 191 (171–214) | 0.097 † |
| Albumin, g/dL | 4.4 (4.2–4.6) | 4.4 (4.3–4.6)) | 4.4 (4.2–4.6) | 0.221 † |
| Urine potassium, mmol/L | 55 (35–82) | 43 (30–64) | 39 (27–55) | <0.001 † |
| HOMA-IR | 1.38 (1.02–1.95) | 1.45 (1.03–2.06) | 1.48 (1.05–2.08) | 0.005 † |
| eGFR, CKD-EPI, mL/min/1.73 m2 | 102.69 (93.11–110.03) |
103.37 (94.73–110.51) |
103.46 (95.80–109.84) |
0.053 † |
| Hypertension, n (%) | 202 (23.46) | 237 (27.53) | 296 (34.42) | <0.001 |
| Diabetes mellitus, n (%) | 30 (3.48) | 28 (3.25) | 42 (4.88) | 0.165 |
| Hyperlipidaemia, n (%) | 262 (29.31) | 257 (28.78) | 294 (32.92) | 0.117 |
| Postmenopausal, n (%) | 290 (33.68) | 312 (36.24) | 350 (40.70) | 0.005 |
| Total energy, kcal | 1796.7 (1484.2–2186.2) |
1883.9 (1515.9–2325.8) |
1930.1 (1592.8–2367.4) |
<0.001 † |
| Protein, g | 58.92 (45.77–75.72) |
62.08 (46.54–78.76) |
63.77 (50.29–81.96) |
<0.001 † |
| Fat, g | 27.04 (18.12–38.19) |
27.57 (17.89–38.91) |
29.05 (19.12–41.19) |
0.002 † |
| Carbohydrate, g | 325.75 (273.96–388.04) |
334.77 (280.48–405.66) |
343.05 (290.38–422.54) |
<0.001 † |
Continuous variables are presented as medians (interquartile ranges). Categorical variables are presented as numbers (%). Analysis of variance tests were used for continuous variables and Chi-squared test for categorical variables that were normally distributed. † Kruskal–Wallis test was performed for continuous variables. T1, lowest tertile, T2, middle tertile; T3, highest tertile; BMI, body mass index; eGFR, estimated glomerular filtration rate; CKD-EPI, chronic kidney disease epidemiology collaboration; HOMA-IR, homeostasis model assessment of insulin resistance; MET, metabolic equivalent of task; AST, aspartate aminotransferase; ALT, alanine aminotransferase; TG, triglyceride; T-Chol, total cholesterol.