Observational Study
Copyright ©The Author(s) 2021.
World J Gastroenterol. May 7, 2021; 27(17): 2039-2053
Published online May 7, 2021. doi: 10.3748/wjg.v27.i17.2039
Table 1 Descriptive data for laboratory parameters at baseline, at week 2 and at week 6
Analysis
High-dose intravenous iron
Baseline, mean ± SD
Week 2, mean ± SD
Difference from baseline at week 2
Difference between FCM and FDI at week 2 (95%CI)
P value
Week 6, mean ± SD
Difference from baseline at week 6
Difference between FCM and FDI at week 6 (95%CI)
P value
Serum phosphate, mmol/L (ref. value 0.8-1.65)FCM1.07 ± 0.20.65 ± 0.2-0.417-0.344 (-0.427 to -0.260)< 0.0011.00 ± 0.3-0.072-0.070 (-0.144 to 0.004)0.064
FDI1.15 ± 0.21.07 ± 0.2-0.0731.14 ± 0.2-0.002
Intact FGF23, pg/mL (ref. value 11.50-48.90)FCM43.42 ± 14.291.61 ± 63.849.20545.312 (25.982 to 64.697)< 0.00144.79 ± 23.11.7181.559 (-6.407 to 9.525)0.698
FDI43.88 ± 14.547.77 ± 22.13.89244.04 ± 16.60.159
C-terminal FGF23, pmol/L (ref. value 0.30-3.00)FCM2.46 ± 3.21.68 ± 1.3-0.7566.783 (-1.319 to 14.885)0.0990.94 ± 1.2-1.5075.124 (-1.310 to 11.558)0.116
FDI8.87 ± 30.61.33 ± 1.4-7.5392.24 ± 7.6-6.632
FEPO4, % (ref. value N/A)FCM9.95 ± 5.818.70 ± 10.89.9465.375 (1.801 to 8.95)0.00413.68 ± 11.34.2103.326 (-0.309 to 6.96)0.072
FDI12.55 ± 5.917.03 ± 8.64.57013.37 ± 6.00.884
PTH, pmol/L (ref. value 1.5-7.0)FCM5.46 ± 2.67.02 ± 3.41.6080.442 (-0.561 to 1.445)0.3845.97 ± 3.30.7670.590 (-0.358 to 1.539)0.220
FDI5.51 ± 2.66.72 ± 3.41.1665.69 ± 2.30.176
Ionised calcium, mmol/L (ref. value 1.16-1.32)FCM1.21 ± 0.01.20 ± 0.0-0.015-0.020 (-0.035 to -0.004)0.0121.21 ± 0.00.000-0.018 (-0.036 to -0.001)0.044
FDI1.23 ± 0.01.23 ± 0.10.0051.25 ± 0.00.018
25-hydroxyvitamin D, nmol/L (ref. value 50-125)FCM58.35 ± 24.457.13 ± 23.1-1.212-2.133 (-6.238 to 1.972)0.30557.48 ± 20.8-0.865-0.160 (-7.078 to 6.759)0.964
FDI63.51 ± 21.964.63 ± 20.00.92262.75 ± 21.1-0.706
1,25-dihydroxyvitamin D, ng/L (ref. value 20-79)FCM51.10 ± 19.228.77 ± 17.9-21.074-16.463 (-24.487 to -8.438)< 0.00153.78 ± 20.23.2185.357 (-3.164 to 13.878)0.215
FDI52.85 ± 20.448.24 ± 17.7-4.61150.71 ± 19.8-2.139
Table 2 Laboratory parameters for patients stratified by hypophosphatemia status (with/without) at week 2 and at week 6
Analysis
High-dose intravenous iron
Week 2 serum phosphate 0.8 mmol/L, mean ± SD
Week 2 serum phosphate < 0.8 mmol/L, mean ± SD
Difference
P value
Week 6 serum phosphate 0.8 mmol/L, mean ± SD
Week 6 serum phosphate < 0.8 mmol/L, mean ± SD
Difference
P value
Intact FGF23, pg/mL (ref. value 11.50-48.90)FCM33.71 ± 10.56 (n = 14/51)114.33 ± 62.22 (n = 37/51)80.62< 0.00139.30 ± 16.79) (n = 40/51)66.86 ± 30.05 (n = 11/51)27.560.013
FDI45.82 ± 16.90 (n = 47/53)57.16 ± 46.35 (n = 6/53)11.430.57743.85 ± 16.83 (n = 52/54)48.93 ± 10.13 (n = 2/54)5.080.604
C-terminal FGF23, pmol/L (ref. value 0.30-3.00)FCM1.03 ± 0.99 (n = 14/51)1.93 ± 1.33 (n = 37/51)0.90.0140.76 ± 0.63 (n = 40/51)1.64 ± 2.14 (n = 11/51)0.880.206
FDI1.36 ± 1.47 (n = 47/53)1.08 ± 0.72 (n = 6/53)-0.280.4652.27 ± 7.79 (n = 52/54)1.31 ± 0.33 (n = 2/54)-0.970.384
FEPO4, % (ref. value N/A)FCM13.35 ± 5.94 (n = 12/46)20.59 ± 11.60 (n = 34/46)7.240.0099.62 ± 6.56 (n = 36/47)26.99 ± 13.38 (n = 11/47)17.370.001
FDI15.97 ± 7.85 (n = 46/52)25.11 ± 10.22 (n = 6/52)9.140.08013.00 ± 5.79 (n = 52/54)22.85 ± 4.41 (n = 2/54)9.850.176
PTH, pmol/L (ref. value 1.5-7.0)FCM5.46 ± 2.83 (n = 14/48)7.46 ± 3.23 (n = 34/48)20.0425.22 ± 2.39 (n = 39/47)9.93 ± 4.43) (n = 8/47)4.710.020
FDI6.28 ± 2.97 (n = 47/53)10.13 ± 4.70 (n = 6/53)3.850.1025.66 ± 2.32 (n = 52/54)6.40 ± 1.70 (n = 2/54)0.740.649
Ionised calcium, mmol/L (ref. value 1.16-1.32)FCM1.21 ± 0.32 (n = 13/50)1.19 ± 0.05 (n = 37/50)-0.020.3361.21 ± 0.05 (n = 40/51)1.22 ± 0.04 (n = 11/51)0.010.496
FDI1.24 ± 0.45 (n = 46/52)1.21 ± 0.09 (n = 6/52)-0.030.4221.25 ± 0.05 (n = 51/53)1.23 ± 0.02 (n = 2/53)-0.020.314
25-hydroxyvitamin D, nmol/L (ref. value 50-125)FCM63.00 ± 30.94 (n = 14/51)54.54 ± 19.69 (n = 37/51)-8.460.35460.05 ± 21.68 (n = 40/51)45.45 ± 10.00 (n = 11/51)-14.60.002
FDI64.16 ± 20.30 (n = 45/51)64.83 ± 18.93 (n = 6/51)0.670.93763.68 ± 20.97 (n = 50/52)39.50 ± 2.12 (n = 2/52)-24.18< 0.001
1,25-dihydroxyvitamin D, ng/L (ref. value 20-79)FCM46.34 ± 19.10 (n = 14/50)21.46 ± 11.63 (n = 36/50)-24.88< 0.00156.76 ± 20.27 (n = 40/50)40.89 ± 15.95 (n = 10/50)-15.870.016
FDI49.05 ± 18.52 (n = 47/53)45.72 ± 7.15 (n = 6/53)-3.330.41450.88 ± 19.92 (n = 52/54)46.45 ± 21.85 (n = 2/54)-4.430.822
Table 3 Descriptive 36-item short form health survey scores for patient groups with/without hypophosphatemia independent of treatment group
SF-36 scale item
Normal phosphate population, baseline, mean ± SD
Hypophosphatemia population, baseline, mean ± SD
Difference1 at baseline, mean (95%CI)
Normal phosphate population, change at week 2, mean ± SD
Hypophosphatemia population, change at week 2, mean ± SD
Difference1 at week 2, mean (95%CI)
Normal phosphate population, change at week 6, mean ± SD
Hypophosphatemia population, change at week 6, mean ± SD
Difference1 at week 6, mean (95%CI)
General health50.91 ± 20.148.50 ± 26.12.4 (-14.5 to 19.4)-0.45 ± 12.90.75 ± 12.2-1.2 (-9.2 to 6.8)3.06 ± 16.33.25 ± 15.1-0.2 (-10.2 to 9.8)
Physical functioning78.72 ± 22.486.11 ± 21.1-7.4 (-21.3 to 6.6)2.63 ± 10.9-0.28 ± 6.32.9 (-1.6 to 7.4)3.97 ± 14.5-0.28 ± 4.74.2 (0.2 to 8.3)
Role limitations due to physical problems47.61 ± 42.866.67 ± 40.4-19.1 (-45.7 to 7.6)-4.08 ± 28.1-6.25 ± 18.82.2 (-10.8 to 15.1)11.32 ± 39.22.08 ± 16.79.2 (-3.7 to 22.1)
Bodily pain65.65 ± 25.167.17 ± 27.6-1.5 (-19.6 to 16.5)0.68 ± 18.94.42 ± 12.2-3.7 (-12.2 to 4.7)3.40 ± 19.810.83 ± 19.1-7.4 (-20.0 to 5.2)
Vitality37.98 ± 22.040.00 ± 22.4-2.0 (-16.7 to 12.7)4.05 ± 13.17.50 ± 15.9-3.4 (-13.8 to 6.9)10.89 ± 18.012.92 ± 16.0-2.0 (-12.7 to 8.6)
Mental health71.72 ± 18.970.33 ± 16.91.4 (-9.9 to 12.6)3.37 ± 9.04.33 ± 5.0-1.0 (-4.5 to 2.6)4.89 ± 13.21.67 ± 11.13.2 (-4.2 to 10.7)
Social functioning68.35 ± 26.368.75 ± 30.4-0.4 (-20.2 to 19.4)3.86 ± 16.77.29 ± 13.5-3.4 (-12.5 to 5.6)8.70 ± 20.77.29 ± 15.51.4 (-9.1 to 11.9)
Role limitations due to emotional problems67.91 ± 41.572.22 ± 42.2-4.3 (-32.1 to 23.4)-2.66 ± 34.8-8.33 ± 37.95.7 (-19.1 to 30.5)6.52 ± 38.0-2.78 ± 26.49.3 (-8.8 to 27.4)
Table 4 Descriptive visual analogue scale score for patient groups with/without hypophosphatemia independent of treatment group
VAS item
Normal phosphate group, baseline, mean ± SD
Hypophosphatemia group, baseline, mean ± SD
Difference1 at baseline, mean (95%CI)
P value
Normal phosphate group, change at week 2, mean ± SD
Hypophosphatemia group, change at week 2, mean ± SD
Difference1 at week 2, mean (95%CI)
P value
Normal phosphate group, change at week 6, mean ± SD
Hypophosphatemia group, change at week 6, mean ± SD
Difference1 at week 6, mean (95%CI)
P value
General weakness43.54 ± 28.731.17 ± 30.512.4 (-7.6 to 32.4)0.205-4.98 ± 14.9-1.50 ± 17.2-3.5 (-14.7 to 7.7)0.515-10.64 ± 21.9)-6.33 ± 25.7-4.3 (-21.1 to 12.5)0.589
Fatigue37.53 ± 30.029.58 ± 30.17.9 (-11.8 to 27.7)0.403-3.31 ± 19.4-1.33 ± 17.9-2.0 (-13.9 to 9.9)0.728-8.93 ± 22.0-5.17 ± 26.7-3.8 (-21.2 to 13.6)0.648
Joint pain17.30 ± 23.38.25 ± 14.89.1 (-1.2 to 19.3)0.0810.32 ± 14.3-3.09 ± 6.93.4 (-1.9 to 8.7)0.1972.17 ± 18.00.17 ± 7.42.0 (-3.8 to 7.8)0..489
Joint stiffness13.31 ± 22.31.42 ± 3.411.9 (6.9 to 16.8)< 0.001-0.57 ± 18.1-0.64 (2.1)0.1 (-3.9 to 4.0)0.9720.99 ± 17.71.75 ± 8.5-0.8 (-7.1 to 5.6)0.807
Muscle pain15.35 ± 23.15.83 ± 14.59.5 (-0.5 to 19.6)0.062-1.71 ± 14.62.45 (8.9)-4.2 (-10.7 to 2.3)0.194-0.50 ± 20.6-0.17 ± 11.0-0.3 (-8.3 to 7.6)0.932
Bone and skeletal pain7.24 ± 19.41.92 ± 6.65.3 (-0.3 to 10.9)0.0611.85 ± 20.22.64 (8.7)-0.8 (-7.7 to 6.1)0.8173.42 ± 18.7-1.67 ± 6.85.1 (-0.5 to 10.7)0.076
Difficulties performing daily activities34.38 ± 28.529.67 ± 29.74.7 (-14.8 to 24.2)0.611-3.80 ± 14.9-2.17 (23.5)-1.6 (-16.8 to 13.5)0.819-9.45 ± 20.0-11.00 ± 24.81.6 (-14.6 to 17.7)0.839