Table 4. 

Multivariable-adjusted difference in 24-hour urinary phosphorus excretion and fractional excretion of phosphorus per 10% higher percentage African ancestry among African-American participants in the CRIC study

24-hour urine phosphorus excretionFractional excretion of phosphorus
Model 1Model 2Model 1Model 2
Variablesmg/day (95%CI)P valuemg/day (95%CI)P value% (95%CI)P value% (95%CI)P value
African ancestry, per 10% higher−36.4 (−19.0, −53.7)<0.001−39.6 (−18.2, −60.9)<0.001−1.0 (−0.2, −1.8)0.009−1.1 (−0.2, −2.0)0.01
Age, per 1 year−3.1 (−1.6, −4.7)<0.001−2.4 (−0.4, −4.4)0.02−0.1 (−0.0, −0.2)0.007−0.2 (−0.1, −0.3)<0.001
Female sex−136.3 (−104.3, −168.2)<0.001−147.2 (−105.1, −189.2)<0.001−4.9 (−3.4, −6.3)<0.001−3.9 (−2.2, −5.7)<0.001
eGFR, 1 ml/min per 1.73 m22.7 (1.7,3.7)<0.0012.7 (1.3,3.9)<0.001−0.4 (−0.3, −0.4)<0.001−0.4 (−0.3, −0.5)<0.001
Body mass index, per 1 kg/m26.3 (3.7,8.9)<0.001−0.1 (−0.0, −0.2)0.19
Diabetes11.2 (−31.3,53.6)0.611.3 (−0.4,3.1)0.14
Education < versus ≥ high school diploma28.6 (−22.5,79.7)0.272.7 (0.5,4.9)0.01
Annual income ≤ versus > $20,000/year−73.5 (−30.4, −116.7)<0.001−0.1 (−1.9,1.8)0.95
Dietary phosphorus, per 100 g/day7.4 (3.74,11.1)<0.0010.3 (0.2,0.5)<0.001
Serum phosphorus, per 1 mg/dL45.8 (11.3,80.3)0.01−4.2 (−2.8, −5.7)<0.001
  • Analyses restricted to 1393 African-American participants with plausible 24-hour urine data.