Table 2.

Hazard ratios and 95% confidence intervals of CKD progression and all-cause mortality according to quartile of 24-hour urinary excretion of sodium and potassium among 3757 patients with CKD (the CRIC Study)

VariableUrinary Sodium Excretion, mmol/24 hUrinary Potassium Excretion, mmol/24 h
<116.8116.8–153.6153.7–194.5≥194.6P Value for Difference<39.439.4–52.152.2–67.0≥67.1P Value for Difference
No. of participants940939938940939940938940
CKD progression
 Events233225234247275242225197
 Person-yr37383940407940493622390840264251
 Hazard ratio (95% CI)
  Multivariable model 11.01.11 (0.92 to 1.34)1.28 (1.05 to 1.56)1.63 (1.32 to 2.01)<0.0011.01.22 (1.01 to 1.47)1.46 (1.19 to 1.79)1.64 (1.29 to 2.07)<0.001
  Multivariable model 21.01.01 (0.83 to 1.23)1.17 (0.95 to 1.43)1.36 (1.09 to 1.70)0.021.00.96 (0.80 to 1.17)1.18 (0.96 to 1.46)1.36 (1.07 to 1.73)0.01
  Multivariable model 31.01.01 (0.83 to 1.23)1.14 (0.93 to 1.40)1.54 (1.23 to 1.92)<0.0011.01.00 (0.83 to 1.21)1.28 (1.04 to 1.59)1.59 (1.25 to 2.03)<0.001
  Multivariable model 41.01.00 (0.82 to 1.22)1.12 (0.91 to 1.37)1.46 (1.16 to 1.82)0.0021.00.97 (0.80 to 1.17)1.21 (0.98 to 1.50)1.46 (1.14 to 1.86)0.002
All-cause mortality
 Events144145123128177150110103
 Person-yr49945080519551965042508851395196
 Hazard ratio (95% CI)
  Multivariable model 11.01.26 (0.99 to 1.59)1.25 (0.96 to 1.62)1.76 (1.34 to 2.32)0.0011.01.12 (0.89 to 1.41)1.00 (0.76 to 1.31)1.12 (0.82 to 1.52)0.70
  Multivariable model 21.01.14 (0.88 to 1.46)1.15 (0.88 to 1.52)1.41 (1.05 to 1.90)0.101.00.95 (0.74 to 1.21)0.86 (0.65 to 1.15)0.93 (0.68 to 1.28)0.80
  Multivariable model 31.01.14 (0.89 to 1.47)1.14 (0.87 to 1.50)1.45 (1.08 to 1.95)0.101.00.97 (0.76 to 1.24)0.87 (0.66 to 1.16)0.98 (0.71 to 1.35)0.80
  Multivariable model 41.01.14 (0.89 to 1.46)1.13 (0.86 to 1.49)1.42 (1.05 to 1.91)0.101.00.92 (0.72 to 1.18)0.81 (0.61 to 1.08)0.89 (0.64 to 1.23)0.60
CKD progression or death
 Events332320311329382342301267
 Person-yr38494050416541263748403041034310
 Hazard ratio (95% CI)
  Multivariable model 11.01.13 (0.96 to 1.32)1.23 (1.04 to 1.45)1.61 (1.35 to 1.93)<0.0011.01.21 (1.04 to 1.41)1.34 (1.13 to 1.60)1.48 (1.21 to 1.81)<0.001
  Multivariable model 21.01.03 (0.87 to 1.21)1.12 (0.94 to 1.34)1.33 (1.10 to 1.61)0.011.00.97 (0.83 to 1.14)1.12 (0.94 to 1.35)1.26 (1.02 to 1.54)0.05
  Multivariable model 31.01.02 (0.86 to 1.20)1.08 (0.91 to 1.29)1.43 (1.18 to 1.73)<0.0011.00.99 (0.85 to 1.17)1.17 (0.98 to 1.41)1.42 (1.15 to 1.74)0.002
  Multivariable model 41.01.01 (0.86 to 1.19)1.06 (0.89 to 1.26)1.36 (1.13 to 1.65)0.0031.00.96 (0.82 to 1.13)1.11 (0.93 to 1.33)1.31 (1.06 to 1.61)0.01
  • Multivariable model 1: adjusted for age, sex, race, urinary creatinine excretion, and clinic site. Multivariable model 2: model 1 plus education, waist circumference, lean body mass, body mass index, cigarette smoking, alcohol drinking, physical activity, history of hypercholesterolemia, history of diabetes, history of CVD, use of diuretics, use of renin-angiotensin system blocking agents, and use of other antihypertensive medications. Model 3: model 2 plus baseline eGFR. Model 4: model 3 plus adjustment for urinary potassium excretion in sodium models and adjustment for urinary sodium excretion in potassium models. 95% CI, 95% confidence interval.