Assessment of Risk Factors Associated with Bone and Mineral Disease Post-Renal Transplantation: “The Experiences of Two Centers”

Figures & data

Table 1 Baseline Characteristics of Patients and the Reason for Transplantation (n = 197)

Demographical Characteristics	n (%)
Gender
Male	106 (53.8)
Female	91 (46.2)
Age (in Years)	45.9±14 (18–77)
Body mass index BMI (kg/m^2)	28.4±6.13 (12–49)
Smoking Status
Yes	15 (7.6)
No	182 (92.4)
Diagnosis (reason of transplant)
Unknown origin	103 (52.3)
Diabetic nephropathy	46 (23.4)
Hypertension	23 (11.7)
Focal Segmental Glomerulosclerosis (FSGS)	8 (4.1)
Lupus nephritis	4 (2.0)
Polycystic kidney disease	4 (2.0)
IgA nephropathy	3 (1.5)
Alport syndrome	2(1.0)
Glomerulonephritis	2 (1.0)
Reflux Nephropathy	2 (1.0)
Osteoporosis Risk (FRAX Imaging)
Low	116 (58.9)
Intermediate	8 (4.1)
High	5 (2.5)
Not Done	68 (34.5)
Hip Fracture Risk (FRAX Imaging)
Low	119 (60.4)
High	10 (5.1)
Not Done	68 (34.5)

Table 2 Bone Mineral Density Findings Prior and Post-Transplantation (n = 197)

Question	n	%
Bone Mineral Density tested
Yes	46	23.40
No	151	76.60
Prior BMD interpretation
Osteoporosis	4	2
Osteopenia	15	7.6
Normal	27	13.7
Not done	151	76.6
Findings – 2 Years Post-Transplantation
Bone Mineral Density tested
Yes	53	26.90
No	144	73.10
Post-transplantation BMD interpretation
Osteoporosis	22	11.2
Osteopenia	21	10.7
Normal	10	5.1
Not done	144	73.1

Table 3 Comparison of Mean Between Biochemical Markers Before and After Transplantation

Variables		n	Mean	p-value
Calcium total (mmol/l)	Before	197	2.01 ± 0.40	0.070
	After	197	2.07 ± 0.26
Calcium free (mmol/l)	Before	184	2.19 ± 0.36	0.0001
	After	184	5.24 ± 11.27
Parathyroid hormone (PTH) (pg/mL)	Before	189	50.01 ± 38.54	0.0001
	After	189	24.60 ± 21.31
Vitamin D (ng/mL)	Before	140	28.77 ± 16.10	0.117
	After	140	32.40 ± 22.92
Phosphate (PO4) (mmol/l)	Before	197	1.61 ± 0.49	0.339
	After	197	1.47 ± 2.01

Note: Bolded p-value < 0.05 statistically highly significant.

Figure 1 Distribution of osteoporosis, osteopenia and fracture of before and after transplantation.

Table 4 Factors Associated with Post-Transplantation Osteoporosis

Factors	Post-Transplantation Osteoporosis		P-value
	Yes	No
Gender (n, %)			0.477
Male	19 (17.9%)	87 (82.1%)
Female	20 (22%)	71 (78%)
Smoking Status (n, %)			0.171
Yes	5 (33.3%)	10 (66.7%)
No	34 (18.7%)	148 (81.3%)
Diagnosis (reason of transplant) (n, %)			0.790
Diabetic nephropathy	9 (19.6%)	37 (80.4%)
Focal Segmental Glomerulosclerosis (FSGS)	2 (25%)	6 (75%)
Unknown origin	23 (22.3%)	80 (77.7%)
IGA nephropathy	0	3 (100%)
Alport syndrome	0	2 (100%)
Lupus nephritis	0	4 (100%)
Polycystic kidney disease	0	4 (100%)
Glomerulonephritis	0	2 (100%)
Hypertension	4 (17.4%)	19 (82.6%)
Reflux Nephropathy	1 (50%)	1 (50%)
History of Osteoporosis Prior to Transplantation (n, %)			0.022*
Yes	3 (60%)	2 (40%)
No	36 (18.8%)	156 (81.3%)
History of Osteopenia Prior to Transplantation (n, %)			0.896
Yes	6 (20.7%)	23 (79.3%)
No	33 (19.6%)	135 (80.4%)
History of Fracture Prior to Transplantation (n, %)			0.553
Yes	2 (28.6%)	5 (71.4%)
No	37 (19.5%)	153 (80.5%)
History of Osteoarthritis Prior to Transplantation (n, %)			0.991
Yes	1 (20%)	4 (80%)
No	38 (19.8%)	154 (80.2%)
Graft Type (n, %)			0.448
Living	26 (18.4%)	115 (81.6%)
Deceased	13 (23.2%)	43 (76.8%)
Number of Rejection (n, %)			0.047*
0	31 (17.7%)	144 (82.3%)
1	8 (40%)	12 (60%)
2	0	2 (100%)
Vitamin D Level (n, %)			0.335
Deficiency (n, %)	7 (15.9%)	37 (84.1%)
Insufficiency (n, %)	11 (25.6%)	32 (74.4%)
Sufficient (n, %)	15 (28.3%)	38 (71.7%)
Using of Antiepileptic’s Prior to Transplantation (n, %)			0.641
Yes	3 (25%)	9 (75%)
No	36 (19.5%)	149 (80.5%)
Using of Anticoagulant Prior to Transplantation (n, %)			0.553
Yes	2 (28.6%)	5 (71.4%)
No	37 (19.5%)	153 (80.5%)
Using of Proton Pump Inhibitors Prior to Transplantation (n, %)			0.081
Yes	12 (14.1%)	73 (85.9%)
No	27 (24.1%)	85 (75.9%)
Induction Therapy (n, %)			0.862
Antithymoglobulin (ATG)	26 (20.2%)	103 (79.8%)
Basiliximab	13 (19.1%)	55 (80.9%)
Body Mass Index (BMI)	28.49 + 6.25	28.34 + 6.12	0.89
Total Calcium – Prior to Transplantation	2.27 + 0.29	2.14 + 0.031	0.023*
Free Calcium – Prior to Transplantation	2.32 + 0.2	2.15 + 0.39	0.011*
Parathyroid hormone PTH – Prior to Transplantation	35.19 + 31.85	54.06+39.15	0.006*
Phosphate PO4 – Prior to Transplantation	1.6 + 0.45	1.61 + 0.5	0.96

Note:

* Significant at level 0.05.

Table 5 Factors Associated with Post-Transplantation Osteopenia

Factors	Osteopenia		P-value
	Yes	No
Gender (n, %)			0.052
Male	20 (18.9%)	86 (81.1%)
Female	28 (30.8%)	63 (69.2%)
Smoking Status (n, %)			0.300
Yes	2 (13.3%)	13 (86.7%)
No	46 (25.3%)	136 (74.7%)
Diagnosis (reason of transplant) (n, %)			0.660
Diabetic nephropathy	9 (19.6%)	37 (80.4%)
Focal Segmental Glomerulosclerosis (FSGS)	2 (25%)	6 (75%)
Unknown origin	30 (29.1%)	73 (70.9%)
IGA nephropathy	0	3 (100%)
Alport syndrome	1 (50%)	1 (50%)
Lupus nephritis	1 (25%)	3 (75%)
Polycystic kidney disease	0	4 (100%)
Glomerulonephritis	1 (50%)	1 (50%)
Hypertension	4 (17.4%)	19 (82.6%)
Reflux Nephropathy	0	2 (100%)
History of Osteoporosis Prior to Transplantation (n, %)			0.003*
Yes	4 (80%)	1 (20%)
No	44 (22.9%)	148 (77.1%)
History of Osteopenia Prior to Transplantation (n, %)			<0.001*
Yes	21 (72.4%)	8 (27.6%)
No	27 (16.1%)	141 (83.9%)
History of Fracture Prior to Transplantation (n, %)			0.126
Yes	0	7 (100%)
No	48 (25.3%)	142 (74.7%)
History of Osteoarthritis Prior to Transplantation (n, %)			<0.001*
Yes	5 (100%)	0
No	43 (22.4%)	149 (77.6%)
Graft Type (n, %)			0.002*
Living	26 (18.4%)	115 (81.6%)
Deceased	22 (39.3%)	34 (60.7%)
Number of Rejection (n, %)			0.722
0	43 (24.6%)	132 (75.4%)
1	5 (25%)	15 (75%)
2	0	2 (100%)
Vitamin D Level (n, %)			0.127
Deficiency (n, %)	8 (18.2%)	36 (81.8%)
Insufficiency (n, %)	16 (37.2%)	27 (62.8%)
Sufficient (n, %)	17 (32.1%)	36 (67.9%)
Using of Antiepileptic’s Prior to Transplantation (n, %)			0.958
Yes	3 (25%)	9 (75%)
No	45 (24.3%)	140 (75.7%)
Using of Anticoagulant Prior to Transplantation (n, %)			0.003*
Yes	5 (71.4%)	2 (28.6%)
No	43 (22.6%)	147 (77.4%)
Using of Proton Pump Inhibitors Prior to Transplantation (n, %)			0.923
Yes	21 (24.7%)	64 (75.3%)
No	27 (24.1%)	85 (75.9%)
Induction Therapy (n, %)			0.370
Antithymoglobulin (ATG)	34 (26.4%)	95 (73.6%)
Basiliximab	14 (20.6%)	54 (79.4%)
Body Mass Index (BMI)	28.34 + 6.48	28.37 + 6.03	0.97
Total Calcium – Prior to Transplantation	2.25 + 0.274	2.14 + 0.32	0.029*
Free Calcium – Prior to Transplantation	2.29 + 0.22	2.15 + 0.39	0.026*
Parathyroid hormone PTH – Prior to Transplantation	47.96 + 49.9	50.92+ 34.22	0.65
Phosphate PO4 – Prior to Transplantation	1.44 + 0.29	1.66 + 0.53	0.007*

Note:

* Significant at level 0.05.

Table 6 Factors Associated with Post-Transplantation Fracture

Factors	Fracture		P-value
	Yes	No
Gender (n, %)			0.251
Male	5 (4.7%)	101 (95.3%)
Female	8 (8.8%)	83 (91.2%)
Smoking Status (n, %)			0.284
Yes	0	15 (100%)
No	13 (7.1%)	169 (92.9%)
Diagnosis (reason of transplant) (n, %)			0.290
Diabetic nephropathy	0	46 (100%)
Focal Segmental Glomerulosclerosis (FSGS)	1 (12.5%)	7 (87.5%)
Unknown origin	12 (11.7%)	91 (88.3%)
IGA nephropathy	0	3 (100%)
Alport syndrome	0	2 (100%)
Lupus nephritis	0	4 (100%)
Polycystic kidney disease	0	4 (100%)
Glomerulonephritis	0	2 (100%)
Hypertension	0	23 (100%)
Reflux Nephropathy	0	2 (100%)
History of Osteoporosis Prior to Transplantation (n, %)			0.221
Yes	1 (20%)	4 (80%)
No	12 (6.3%)	180 (93.8%)
History of Osteopenia Prior to Transplantation (n, %)			< 0.001*
Yes	7 (24.1%)	22 (75.9%)
No	6 (3.6%)	162 (96.4%)
History of Fracture Prior to Transplantation (n, %)			0.474
Yes	0	7 (100%)
No	13 (6.8%)	17 (93.2%)
History of Osteoarthritis Prior to Transplantation (n, %)			0.547
Yes	0	5 (100%)
No	13 (6.8%)	179 (93.2%)
Graft Type (n, %)			0.001*
Living	4 (2.8%)	137 (97.2%)
Deceased	9 (16.1%)	47 (83.9%)
Number of Rejection (n, %)			0.886
0	12 (6.9%)	163 (93.1%)
1	1 (5%)	19 (95%)
2	0	2 (100%)
Vitamin D Level (n, %)			0.234
Deficiency (n, %)	3 (6.8%)	41 (93.2%)
Insufficiency (n, %)	1 (2.3%)	42 (97.7%)
Sufficient (n, %)	6 (11.3%)	47 (88.7%)
Using of Antiepileptic’s Prior to Transplantation (n, %)			0.342
Yes	0	12 (100%)
No	13 (7%)	172 (93%)
Using of Anticoagulant Prior to Transplantation (n, %)			0.404
Yes	1 (14.3%)	6 (85.7%)
No	12 (6.3%)	178 (93.7%)
Using of Proton Pump Inhibitors Prior to Transplantation (n, %)			0.420
Yes	7 (8.2%)	78 (91.8%)
No	6 (5.4%)	106 (94.6%)
Induction Therapy (n, %)			0.133
Antithymoglobulin (ATG)	11 (8.5%)	118 (91.5%)
Basiliximab	2 (2.9%)	66 (97.1%)
Body Mass Index (BMI)	31.48 + 7.95	28.15 + 5.95	0.06
Total Calcium – Prior to Transplantation	2 + 0.32	2.18 + 0.31	0.039*
Free Calcium – Prior to Transplantation	2.17 + 0.27	2.19 + 0.37	0.88
Parathyroid hormone PTH -Prior to Transplantation	47.42 + 25.71	50.41 + 39.27	0.79
Phosphate PO4 – Prior to Transplantation	1.61 + 0.55	1.61 + 0.49	0.96

Note:

* Significant at level 0.05.