Table 3.
Baseline characteristics of study participants in the pulse wave velocity ancillary study by tertile of serum sodium level
| Variable | Tertile 1 (≤138 mmol/L) (n = 134) | Tertile 2 (139–140 mmol/L) (n = 184) | Tertile 3 (≥141 mmol/L) (n = 273) | P value |
|---|---|---|---|---|
| Age, years | 73 ± 9 | 71 ± 10 | 72 ± 10 | 0.46 |
| Sex, n (%) male | 75 (56) | 113 (61) | 169 (62) | 0.49 |
| Race, n (%) white | 103 (77) | 124 (67) | 168 (62) | 0.008 |
| Study randomization group, n (%) intensive treatment group | 69 (52) | 97 (53) | 129 (47) | 0.48 |
| Prevalent CVD, n (%) | 16 (12) | 23 (13) | 41 (15) | 0.61 |
| Prevalent CHF, n (%) | 4 (3) | 2 (1) | 5 (2) | 0.42 |
| Prevalent CKD, n (%) | 46 (34) | 71 (39) | 94 (34) | 0.62 |
| Smoking status, n (%) | 0.76 | |||
| Never smoked | 55 (41) | 89 (48) | 128 (47) | |
| Former smoker | 69 (52) | 82 (45) | 125 (46) | |
| Current smoker | 10 (8) | 13 (7) | 20 (7) | |
| MAP, mm Hg | 95 ± 10 | 97 ± 12 | 98 ± 12 | 0.09 |
| Heart rate, bpm | 64 ± 11 | 66 ± 11 | 67 ± 21 | 0.28 |
| Body mass index, kg/m2 | 27.0 ± 4.8 | 28.5 ± 5.3 | 28.2 ± 5.0 | 0.02 |
| eGFR, ml/minute/1.73 m2 | 69.2 ± 21.0 | 67.1 ± 19.1 | 67.1 ± 21.3 | 0.60 |
| Urinary albumin to creatinine ratio | 11.8 (6.6, 25.4) | 9.6 (6.1, 22.6) | 12.1 (6.3, 39.7) | 0.01 |
| Antihypertensive agents, no./patient, n (%) | 0.12 | |||
| 0 | 6 (5) | 19 (10) | 24 (9) | |
| 1 | 43 (32) | 70 (38) | 108 (40) | |
| 2 | 48 (36) | 65 (35) | 75 (28) | |
| 3 | 24 (18) | 20 (11) | 44 (16) | |
| 4 | 13 (10) | 10 (5) | 22 (8) | |
| Diuretic use, n (%) | 76 (57) | 81 (44) | 116 (43) | 0.020 |
| Serum sodium, mmol/L | 136 ± 2 | 140 ± 1 | 142 ± 1 | <0.0001 |
| CFPWV, m/s | 10.8 ± 2.8 | 10.4 ± 2.6 | 11.0± 2.8 | 0.14 |
| Pulse pressure, mm Hg | 67 ±15 | 64 ± 14 | 66 ± 14 | 0.20 |
Data are mean ± SD, median (interquartile range), or n (%).Comparisons across tertiles were made using a Chi-square test for categorical data and ANOVA for continuous variables. Abbreviations: CFPWV, carotid–femoral pulse wave velocity; CKD, chronic kidney disease; CVD, cardiovascular disease; eGFR, estimated glomerular filtration rate (Modification of Diet in Renal Disease equation); MAP, mean arterial pressure.