Table 2.

Overall and GFR-stratified annualized change in mineral metabolites by rate of GFR decline in the AASK trial

Rate of 125I-iothalamate GFR DeclineaP TrendP Interaction
Slow (<1 ml/min per 1.73 m2 per yr; n=127)Moderate (1–3 ml/min per 1.73 m2 per yr; n=176)Rapid (>3 ml/min per 1.73 m2 per yr; n=116)
Percent change in FGF23 (%)
 Overall (n=419b)−1.1 (−4.4, 2.3)3.9 (−0.1, 8.1)14.9 (10.4, 19.7)<0.01
 Stratified by baseline GFR (ml/min per 1.73 m2)
  ≥45 (n=247)−1.5 (−5.4, 2.5)1.3 (−4.2, 7.2)9.1 (4.0, 14.3)0.010.02
  <45 (n=172)0.3 (−5.8, 6.7)8.7 (3.2, 14.6)27.2 (17.9, 37.3)<0.01
Percent change in PTH (%)
 Overall (n=419b)2.0 (0.0, 4.0)6.1 (4.1, 8.2)12.6 (9.2, 16.1)<0.01
 Stratified by baseline GFR (ml/min per 1.73 m2)
  ≥45 (n=247)3.0 (0.7, 5.4)3.6 (1.3, 5.9)9.1 (5.6, 12.8)0.01<0.01
  <45 (n=172)−0.9 (−4.5, 2.8)9.2 (6.0, 12.5)19.1 (12.8, 25.8)<0.01
Change in serum phosphate (mg/dl)
 Overall (n=419b)−0.01 (−0.03, 0.01)0.04 (0.01, 0.06)0.12 (0.08, 0.17)<0.01
 Stratified by baseline GFR  (ml/min per 1.73 m2)
  ≥45 (n=247)−0.01 (−0.03, 0.02)0.01 (−0.02, 0.04)0.06 (0.03, 0.10)<0.01<0.01
  <45 (n=172)−0.01 (−0.06, 0.04)0.07 (0.02, 0.12)0.22 (0.13, 0.31)<0.01
Change in 25-hydroxyvitamin D (ng/dl)
 Overall (n=419b)−0.11 (−0.34, 0.12)−0.28 (−0.49, −0.07)−0.11 (−0.38, 0.15)0.93
 Stratified by baseline GFR (ml/min per 1.73 m2)
  ≥45 (n=247)−0.21 (−0.47, 0.06)−0.12 (−0.44, 0.20)−0.11 (−0.45, 0.22)0.550.39
  <45 (n=172)0.15 (−0.33, 0.63)−0.44 (−0.75, −0.14)−0.13 (−0.55, 0.29)0.48
  • a Measured from 12 months postrandomization to the completion of the trial.

  • b One participant with repeated measures was missing information on GFR decline.