Table 5.

Subgroup analysis: 6-month changes in primary and secondary outcomes by baseline vitamin 1,25(OH)2D levels

Variable1,25(OH)2D<24 pg/ml (Deficiency), n=641,25(OH)2D=24–65 pg/ml (Reference Range), n=38
Placebo, n=25Treatment, n=39P ValueaPlacebo, n=10Treatment, n=28P Valuea
Primary outcome
 Pulse wave velocity, m/s0.1 (−1.4 to 1.4)−0.1 (−1.0 to 1.2)0.981.7 (0.3 to 3.1)−0.5 (−1.4 to 0.4)0.01
Secondary outcome
 Systolic BP, mmHg−0.5 (−7.0 to 6.0)4.2 (−1.0 to 9.4)0.604.0 (−2.2 to 10.2)−1.0 (−4.7 to 2.7)0.17
 Diastolic BP, mmHg1.9 (−1.9 to 5.8)0.6 (−2.4 to 3.7)0.592.7 (−1.0 to 6.5)1.5 (−0.7 to 3.7)0.58
 Urine ACR, ln(mg/g)0.2 (−0.1 to 0.5)−0.1 (−0.3 to 0.1)0.130.0 (−0.4 to 0.4)−0.1 (−0.3 to 0.2)0.71
 Calcium, mg/dl−0.2 (−0.3 to −0.0)0.1 (0.0 to 0.3)0.003−0.6 (−1.3 to 0.2)0.0 (−0.4 to 0.5)0.16
 Phosphate, mg/dl−0.2 (−0.0 to 0.4)0.2 (0.1 to 0.4)0.700.1 (−0.3 to 0.6)0.1 (−0.1 to 0.4)0.95
 PTH, ln(pg/ml)0.2 (−0.0 to 0.4)−0.4 (−0.6 to −0.3)<0.0010.1 (−0.2 to 0.4)−0.3 (−0.4 to −0.1)0.08
 FGF-23, ln(pg/ml)0.05 (−0.16 to 0.26)0.24 (0.08 to 0.40)0.150.20 (−0.07 to 0.47)0.16 (−0.01 to 0.32)0.79
 CRP, ln(mg/L)−0.11 (−0.44 to 0.21)0.12 (−0.14 to 0.38)0.26−0.14 (−0.53 to 0.24)−0.05 (−0.28 to 0.18)0.69
 Serum vitamin D
 25(OH)D, ng/ml−0.4 (−17.8 to 17.0)35.6 (22.0 to 49.3)0.002−6.3 (−33.4 to 20.7)27.9 (11.4 to 44.3)0.03
 1,25(OH)2D, pg/ml3.2 (−0.2 to 6.6)8.2 (5.5 to 10.9)0.03−4.4 (−13.3 to 4.5)−0.1 (−5.5 to 5.4)0.41
  • Data are displayed as mean change and 95% CI. SI conversion factors: to convert urine ACR to mg/mmol, multiply by 0.113; to convert calcium to mmol/L, multiply by 0.25; to convert phosphate to mmol/L, multiply by 0.323; to convert PTH to pmol/L, multiply by 0.106; to convert 25(OH)D to nmol/L, multiply by 2.496; to convert 1,25(OH)2D to pmol/L, multiply by 2.6. 95% CI, 95% confidence interval; 1,25(OH)2D, 1,25-dihydroxyvitamin D; ACR, albumin-to-creatinine ratio; ln, natural logarithm; PTH, parathyroid hormone; FGF-23, fibroblast growth factor 23; CRP, C-reactive protein; 25(OH)D, 25-hydroxyvitamin D.

  • a Adjusted mean change, 95% CI, and P value for treatment effects, with the respective baseline value as covariate, compared using analysis of covariance.