Relationship between vitamin D status and immunosuppressive therapy in kidney transplant recipients

Figures & data

Table 1. Basic characteristics of the kidney transplant recipients included in the study.

	Males	Females	Total
n	189	100	289
Age (years)	42.80 ± 13.12	42.47 ± 11.59	42.69 ± 12.59
Time after TR* (months)	92.84 ± 61.42	95.61 ± 63.79	93.80 ± 62.16
eGFR^† (mL/min/1.73 m^2)	63.11 ± 21.37	65.40 ± 26.36	63.90 ± 23.19
BMI^§	24.86 ± 4.79	23.73 ± 4.79	24.44 ± 4.38
Vitamin D concentration^‡ (nmol/L)	63.97 ± 23.31	49.73 ± 21.02	59.04 ± 23.51

*TR – transplantation, ^†eGFR – estimated glomerular filtration rate (CKD-EPI formula), ^§BMI – body mass index, ^‡ total 25(OH)D.

Figure 1. Vitamin D status of the studied kidney transplant recipients (n = 289).

Figure 2. Immunosuppressive agents in the studied cohort of patients (n = 289). CNIs and mTORI (a); cytotoxic agents (b); oral steroids (c).

Table 2. Spearman correlation analysis of 25(OH)D serum level and continuous parameters in kidney transplant recipients (n = 289).

Parameter	Correlation coefficient (r)
Age (years)	−0.071
Time after transplantation (months)	0.126*
BMI	−0.130*
Ca level	0.075
P level	0.003
CsA level	−0.057
Tac level	−0.074
eGFR	0.075
Proteinuria (g/24 h)	−0.024

*Correlation is significant at the 0.05 level (2-tailed).

BMI – body mass index, Ca – serum calcium, P – serum phosphorus, CsA – Cyclosporin A, Tac – tacrolimus, eGFR – estimated glomerular filtration rate.

Table 3. Factors influencing 25-hydroxyvitamin D levels.

	β	SE	P value
Intercept	5.994	0.621	<0.0001
Females	−0.332	0.052	<0.0001
July	0.254	0.101	0.012
August	0.444	0.084	<0.0001
September	0.329	0.079	<0.0001
Diabetes mellitus	−0.181	0.091	0.048
ln BMI	−0.900	0.361	0.013
CNI	−0.177	0.084	0.036
Age (years)	0.0001	0.002	0.963
Proteinuria (g/L)	−0.028	0.028	0.325
ln eGFR	−0.019	0.071	0.791
Oral steroids	0.015	0.066	0.821
Pulse steroids	−0.096	0.086	0.264
Azathioprine	−0.159	0.147	0.279
Mycophenolates	−0.099	0.126	0.435
mTORI	0.124	0.084	0.144

Dependent variable: ln 25-hydroxyvitamin D; adjusted R² = 0.345.

BMI – body mass index, SE – standard error; eGFR – estimated glomerular filtration rate (CKD-EPI), CNI – calcineurin inhibitors, mTORI – mammalian target of Rapamycin inhibitors.