Table 1.
Characteristics of patients with CKD according to quartile of day-to-night ratio of the urinary sodium and potassium excretion rate
|
Variable |
Day-to-night ratio of the urinary sodium excretion |
Day-to-night ratio of the urinary potassium excretion |
||||||
|---|---|---|---|---|---|---|---|---|
| Q1 ≤1.00 (n = 788) |
Q2 1.01–1.52 (n = 788) |
Q3 1.53–2.52 (n = 788) |
Q4 >2.52 (n = 788) |
Q1 ≤1.44 (n = 788) |
Q2 1.45–1.94 (n = 788) |
Q3 1.95–2.62 (n = 787) |
Q4 >2.62 (n = 789) |
|
| D/Na | 0.73 (0.56–0.87) | 1.24 (1.11–1.38) | 1.91 (1.72–2.16) | 3.63 (2.93–5.33) | 1.14 (0.90–1.29) | 1.69 (1.56–1.81) | 2.24 (2.09–2.40) | 3.39 (2.90–4.42) |
| Age (years) | 52.73 ± 13.32 | 49.62 ± 13.85 | 46.08 ± 14.19 | 42.07 ± 14.88 | 49.96 ± 14.53 | 50.18 ± 14.10 | 46.65 ± 14.22 | 43.72 ± 14.66 |
| ≥60 years (%) | 35.41 | 26.27 | 18.15 | 14.47 | 29.82 | 29.19 | 19.82 | 15.46 |
| Men (%) | 59.01 | 57.36 | 56.09 | 54.57 | 61.04 | 57.11 | 56.16 | 52.72 |
| Risk factors | ||||||||
| BMI (kg/m2) | 24.24 (21.87–26.61) | 23.93 (21.48–26.58) | 23.74 (21.16–26.45) | 23.56 (20.98-26.12) | 24.02 (21.57–26.64) | 23.96 (21.41–26.56) | 23.79 (21.50–26.37) | 23.67 (21.00–26.22) |
| Obesity (BMI ≥ 30 kg/m2) | 8.50 | 8.12 | 6.73 | 6.60 | 8.38 | 7.49 | 8.01 | 6.08 |
| Diabetes mellitus (%) | 30.08 | 22.72 | 19.54 | 14.34 | 25.51 | 23.73 | 20.08 | 17.36 |
| Dyslipidemia (%) | 91.50 | 92.51 | 92.26 | 92.64 | 92.01 | 93.15 | 92.63 | 91.00 |
| Cardiovascular disease (%) | 18.02 | 17.39 | 11.29 | 10.66 | 16.62 | 15.99 | 12.71 | 12.04 |
| Antihypertensive medication (%) | 77.79 | 70.81 | 59.52 | 58.88 | 73.73 | 70.30 | 66.20 | 56.78 |
| RAS blocking agents (%) | 31.35 | 35.03 | 34.52 | 37.31 | 32.49 | 32.23 | 36.34 | 37.14 |
| Calcium channel blockers (%) | 58.12 | 45.81 | 33.63 | 28.68 | 52.41 | 47.72 | 39.52 | 26.62 |
| Other antihypertensive medicationsb (%) | 31.35 | 23.73 | 14.47 | 12.06 | 25.63 | 23.48 | 19.44 | 13.05 |
| Immunosuppressive agentsc (%) | 7.23 | 6.85 | 8.38 | 10.53 | 6.85 | 7.49 | 7.62 | 11.03 |
| Current smoking (%) | 3.81 | 2.79 | 1.90 | 3.30 | 3.55 | 3.05 | 2.67 | 2.53 |
| Weekly alcohol drinking (%) | 13.20 | 13.20 | 13.45 | 12.69 | 13.58 | 13.32 | 14.10 | 11.53 |
| BP | ||||||||
| Office SBP (mmHg) | 137.00 (122.00–152.00) | 134.00 (120.00–151.00) | 129.00 (116.00–144.00) | 127.00 (114.00–141.00) | 136.00 (122.00–153.00) | 133.50 (118.00–149.00) | 130.00 (118.00–146.00) | 126.00 (114.00–141.00) |
| Office DBP (mmHg) | 86.00 (76.00–95.00) | 85.00 (76.00–95.00) | 83.00 (75.00–91.00) | 82.00 (74.00–92.00) | 86.00 (76.00–95.00) | 85.00 (76.00–95.00) | 83.00 (76.00–93.00) | 81.00 (74.00–91.00) |
| 24-h SBP (mmHg) | 127.00 (117.00–139.75) | 123.00 (114.00–134.00) | 120.00 (110.25–130.00) | 117.00 (109.00–126.00) | 125.00 (115.00–138.00) | 123.00 (113.25–134.00) | 121.00 (112.00–131.00) | 118.00 (109.00–126.00) |
| 24-h DBP (mmHg) | 83.00 (75.25–91.00) | 81.00 (74.00–89.00) | 79.00 (71.00–87.00) | 76.00 (70.00–84.00) | 82.00 (74.00–90.00) | 81.00 (74.00–89.00) | 80.00 (72.00–88.00) | 77.00 (70.00–84.00) |
| eGFR by CKD-EPId (ml/min per 1.73 m2) | 47.00 (23.00–80.00) | 57.00 (28.00–90.89) | 75.00 (41.00–104.00) | 94.03 (61.36–112.00) | 53.21 (23.44–92.00) | 54.13 (27.87–89.13) | 72.00 (40.00–100.00) | 91.00 (59.00–109.00) |
| eGFR by CKD-EPI <60 (ml/min per 1.73 m2) | 61.17 | 51.65 | 37.82 | 23.10 | 54.82 | 54.57 | 38.63 | 25.73 |
| 24-h V (L) | 1.75 (1.33–2.24) | 1.86 (1.41–2.38) | 1.79 (1.36–2.35) | 1.78 (1.27–2.37) | 1.67 (1.18–2.14) | 1.83 (1.4–2.31) | 1.88 (1.45–2.4) | 1.84 (1.33–2.41) |
| Na excretion (mmol/24h) | 121.75 (80.77–164.58) | 125.18 (88.04–177.04) | 128.32 (88.88–176.89) | 119.11 (78.11–168.88) | 117.39 (76.34–163.20) | 124.78 (84.50–166.97) | 126.59 (88.46–179.73) | 126.57 (87.15–178.05) |
| K excretion (mmol/24h) | 31.08 (23.40–41.58) | 32.50 (24.86–40.81) | 33.62 (26.02–42.14) | 32.48 (23.87–41.44) | 29.69 (21.66–39.21) | 31.62 (24.89–40.77) | 33.25 (26.44–40.94) | 33.94 (25.94–44.94) |
| Plasma Na (mmol/l) | 141.00 (139.00–142.60) | 141.00 (139.00–142.30) | 141.00 (139.00–142.65) | 141.00 (139.00–142.30) | 141.00 (139.00–142.70) | 141.00 (139.00–142.60) | 141.00 (139.00–142.20) | 141.00 (139.00–142.40) |
| Plasma K (mmol/l) | 3.90 (3.60–4.30) | 3.90 (3.60–4.22) | 3.81 (3.60–4.15) | 3.79 (3.51–4.00) | 3.90 (3.57–4.30) | 3.90 (3.60–4.20) | 3.81 (3.59–4.10) | 3.80 (3.60–4.10) |
| Albuminuria category (%) | ||||||||
| A1 (normal to mildly increased) | 13.20 | 18.02 | 24.27 | 23.60 | 15.61 | 16.12 | 21.50 | 25.86 |
| A2 (moderately increased) | 21.83 | 26.27 | 23.00 | 26.90 | 22.72 | 25.13 | 24.05 | 26.11 |
| A3 (severely increased) | 64.97 | 55.71 | 52.73 | 49.49 | 61.68 | 58.76 | 54.45 | 48.04 |
ABPM, ambulatory blood pressure monitoring; BP, blood pressure; BMI, body mass index; CKD-EPI, Chronic Kidney Disease Epidemiology Collaboration equation; DBP, diastolic blood pressure; eGFR, estimated glomerular filtration rate; Na, sodium; K, potassium; RAS, renin-angiotensin system; SBP, systolic blood pressure.
Results are medians (interquartile range) or percentage unless otherwise specified.
Missing values for the following variables: plasma Na (n = 9), plasma K (n = 11).
D/N indicates day/night ratio of urinary sodium or potassium excretion rate; This day-to-night ratio was used to divide the 3152 subjects into 4 quartiles.
Other hypertension medications include a-blockers, b-blockers, and vasodilator (only 12 patients routinely used diuretics).
Any exposure to glucocorticoids or immunosuppressive agents within 12 weeks.
GFR was evaluated using EPI equation.