Table 4.

Associations of urinary potassium excretion with CKD progression among a subset of 855 participants with 24-hour urine samples

Urinary Potassium MetricsNo. of ParticipantsNo. of Events (%)Model 1Model 2Model 3Model 4
HR (95% CI)P Value for TrendaHR (95% CI)P Value for TrendaHR (95% CI)P Value for TrendaHR (95% CI)P Value for Trenda
24-h urinary potassium excretion, mEq/d
 Q1: <3720665 (32)4.21 (2.49 to 7.10)<0.0014.60 (2.69 to 7.88)<0.0013.12 (1.59 to 6.09)<0.0013.05 (1.54 to 6.04)0.002
 Q2: 37–4921036 (17)2.10 (1.19 to 3.70)2.62 (1.47 to 4.70)2.41 (1.25 to 4.67)2.30 (1.18 to 4.47)
 Q3: 50–6521833 (15)1.72 (0.97 to 3.06)2.11 (1.18 to 3.78)1.86 (0.99 to 3.51)1.89 (0.99 to 3.59)
 Q4: ≥6622118 (8)1.001.001.001.00
Spot urinary potassium-to-creatinine ratio, mmol/g
 Q1: <35.120858 (28)2.63 (1.61 to 4.30)<0.0013.35 (1.95 to 5.75)<0.0011.96 (1.08 to 3.56)0.021.95 (1.05 to 3.62)0.03
 Q2: 35.1–47.920829 (14)1.36 (0.78 to 2.37)1.80 (1.02 to 3.19)1.21 (0.67 to 2.18)1.23 (0.68 to 2.23)
 Q3: 48.0–63.220838 (18)1.59 (0.94 to 2.70)1.86 (1.09 to 3.18)1.18 (0.67 to 2.07)1.16 (0.65 to 2.07)
 Q4: ≥63.320822 (11)1.001.001.001.00
Spot urinary potassium concentration, mmol/L
 Q1: <30.020557 (28)11.30 (4.87 to 26.22)<0.00110.59 (4.54 to 24.66)<0.0013.44 (1.41 to 8.36)0.033.79 (1.51 to 9.51)0.01
 Q2: 30.0–43.421155 (26)9.46 (4.07 to 21.99)9.54 (4.09 to 22.28)3.17 (1.31 to 7.65)3.35 (1.38 to 8.15)
 Q3: 43.5–59.920628 (14)5.19 (2.15 to 12.54)4.95 (2.04 to 12.01)3.30 (1.31 to 8.30)3.13 (1.24 to 7.89)
 Q4: ≥60.02107 (3)1.001.001.001.00
  • Model 1: unadjusted crude HR. Model 2: adjusted for age, sex, smoking status, body mass index, and comorbid disease (diabetes and cardiovascular disease). Model 3: model 2 plus mean arterial pressure, eGFR, random urinary protein-to-creatinine ratio (24-hour urinary protein for 24-hour urinary potassium excretion), C-reactive protein level, intact parathyroid hormone level, serum albumin level, serum calcium level, random urinary Na/Cr (24-hour urinary sodium excretion for 24-hour urinary potassium excretion), and LDL cholesterol level. Model 4: model 3 plus renin-angiotensin system blocker, statin, and diuretics usage. In total, 855 patients with available 24-hour urinary data were used in analysis. HR, hazard ratio; 95% CI, 95% confidence interval; Q, quartile.

  • a P values for trend across quartiles of each urinary potassium metric. P values for trend were calculated by treating quartiles as a continuous variable in each model.