Table 1.
Baseline Characteristics of the Study Population by Categories of 24-Hour Urinary Sodium Excretion
| Characteristics | Tertiles of 24-hour urinary sodium excretion (mmol/day) | p-value* | ||
|---|---|---|---|---|
| T1 (n=3,345) | T2 (n=3,345) | T3 (n=3,345) | ||
| 24-Hour urinary sodium, mmol/day | 106.1±16.4 | 142.1±8.7† | 184.3±22.3†,‡ | <0.001 |
| Daily energy intake, kcal | 1,863±819 | 1,907±785 | 1,875±763 | 0.085 |
| Age, yr | 45.6±16.3 | 49.5±15.3† | 53.1±15.0†,‡ | <0.001 |
| Male sex | 1,301 (38.9) | 1,335 (39.9) | 1,358 (40.6) | 0.157 |
| Waist circumference, cm | 78.1±10.0 | 80.4±9.3† | 83.8±9.3†,‡ | <0.001 |
| Body mass index, kg/m2 | 22.9±3.3 | 23.5±3.1† | 24.5±3.3†,‡ | <0.001 |
| Appendicular muscle mass, kg | 18.1±4.9 | 18.4±4.9† | 19.0±4.8†,‡ | <0.001 |
| Systolic blood pressure, mm Hg | 115.9±16.0 | 119.8±17.1† | 124.5±18.2†,‡ | <0.001 |
| Diastolic blood pressure, mm Hg | 75.5±10.0 | 77.2±10.3† | 79.2±10.7†,‡ | <0.001 |
| Fasting plasma glucose, mg/dL | 95.6±23.3 | 96.5±19.7 | 99.0±22.8† | <0.001 |
| Total cholesterol, mg/dL | 187.0±35.1 | 188.6±35.9 | 191.7±35.7†,‡ | <0.001 |
| HDL cholesterol, mg/dL§ | 52.8±12.5 | 51.7±12.4† | 50.8±11.8†,‡ | <0.001 |
| Triglycerides, mg/dL§ | 115.0±81.1 | 126.3±91.9† | 141.0±95.8†,‡ | <0.001 |
| LDL cholesterol, mg/dL§ | 114.9±31.5 | 115.8±31.4 | 117.3±31.2† | 0.012 |
| eGFR, CKD-EPI, mL/min/1.73 m2 | 98.2±15.6 | 96.8±15.2† | 96.1±14.4† | <0.001 |
| Platelet, 109/L§ | 258.4±55.5 | 255.0±58.0† | 256.9±58.9 | 0.113 |
| Insulin, μU/mL§ | 9.6±5.2 | 10.1±6.4† | 10.6±5.6†,‡ | <0.001 |
| HOMA-IR§ | 2.3±1.6 | 2.5±2.5† | 2.7±2.4†,‡ | <0.001 |
| AST, IU/dL | 20.9±8.7 | 21.3±10.2† | 22.4±9.1†,‡ | <0.001 |
| ALT, IU/dL | 20.1±15.1 | 20.7±15.0† | 22.2±16.2†,‡ | <0.001 |
| GGT, IU/dL | 27.4±35.8 | 27.0±30.9 | 29.3±32.3†,‡ | <0.001 |
| Vitamin D, ng/mL | 17.1±6.5 | 17.7±6.5† | 18.2±6.5†,‡ | <0.001 |
| FLI | 23.2±22.9 | 27.0±22.9† | 33.9±24.7†,‡ | <0.001 |
| FLI ≥30 | 965 (28.8) | 1,213 (36.3)† | 1,606 (48.0)†,‡ | <0.001 |
| Sarcopenia | 447 (13.4) | 492 (14.7) | 618 (18.5)†,‡ | <0.001 |
| Current smoking | 686 (20.5) | 554 (16.6)† | 473 (14.1)†,‡ | <0.001 |
| Moderate-intensity exercise | 496 (14.8) | 504 (15.1) | 497 (14.9) | 0.977 |
| Hypertension | 768 (23.0) | 878 (26.2)† | 1,144 (34.2)†,‡ | <0.001 |
| Diabetes | 273 (8.2) | 276 (8.3) | 400 (12.0)†,‡ | <0.001 |
| Metabolic syndrome | 744 (22.2) | 907 (27.1)† | 1,275 (38.1)†,‡ | <0.001 |
Data are presented as mean±SD or number (%).
T1, lowest tertile, T2, middle tertile; T3, highest tertile; HDL, high-density lipoprotein; LDL, low density lipoprotein; eGFR, estimated glomerular filtration rate; CKD-EPI, Chronic Kidney Disease Epidemiology Collaboration; HOMA-IR, homeostasis model assessment of insulin resistance; AST, aspartate aminotransferase; ALT, alanine aminotransferase; GGT, gamma glutamyl transpeptidase; FLI, fatty liver index.
*Chi-square tests for qualitative variables and analysis of variance tests for quantitative variables; †p<0.05 by post hoc analyses when compared with the lowest tertile; ‡p<0.05 by post hoc analyses when compared with the middle tertile; §Log-transformed.