Magnesium excretion and hypomagnesemia in pediatric renal transplant recipients

Figures & data

Table 1. Clinical and biochemical characteristics of patients.

	Patients n = 91
Age (years)	13.6 ± 3.7
Male/Female	48/43
Donor type (cadaveric/living)	20/71
CNI type (cyclosporine/Tacrolimus)	18/73
MMF	91
Prednisolone	77
Oral magnesium replacement (yes/no)	33/58
Mean serum creatinine (mg/dL)	1.03 ± 0.57
Mean cystatin C (mg/L)	1.52 ± 0.67
eGFR (mL/min/1.73m^2)	67 ± 23
Mean serum magnesium (mg/dL)	1.73 ± 0.22
Mean serum calcium (mg/dL)	9.89 ± 0.42
Mean serum phosphorus (mg/dL)	4.38 ± 0.72
Mean serum uric acid (mg/dL)	5.13 ± 1.49
FEMG (%)	5.9 ± 3.7

Note: CNI: calcineurine inhibitor, MMF: mycophenolate mofetil, eGFR: estimated glomerular filtration rate, FEMg: fractional magnesium excretion.

Table 2. The comparison of laboratory measurements between renal transplant recipients with hypomagnesemia and normal magnesium levels.

	Patients with normal magnesium levels N = 38	Patients with hypomagnesemia N = 53	p Value*
Age (years)	13.7 ± 3.8	13.5 ± 3.6	0.704
Transplant duration (months)	23 ± 16	18 ± 15	0.061
Serum creatinine (mg/dl)	1.10 ± 0.57	0.94 ± 0.56	0.051
Cystatin C (mg/L)	1.58 ± 0.69	1.43 ± 0.64	0.097
GFR (mL/min/1.73m^2)	65 ± 23	70 ± 24	0.180
Serum cholesterol (mg/dL)	172 ± 38	163 ± 36	0.224
Serum triglyceride (mg/dL)	133 ± 66	138 ± 69	0.822
Fasting blood glucose (mg/dL)	84 ± 10	86 ± 12	0.293
Systolic blood pressure (mmHg)	110 ± 11	107 ± 20	0.517
Diastolic blood pressure (mmHg)	66 ± 10	67 ± 10	0.786
FEMg (%)	6.47 ± 3.97	5.15 ± 3.22	0.135
Serum magnesium (mg/dL)	1.87 ± 0.14	1.53 ± 0.14	0.000
Serum calcium (mg/dL)	9.82 ± 0.42	9.98 ± 0.42	0.127
Serum phosphorus (mg/dL)	4.39 ± 0.72	4.36 ± 0.70	0.966
Serum uric acid (mg/dL)	5.13 ± 1.29	5.14 ± 1.75	0.623

Note: *Independent samples t test, p < 0.05 is significant.

Table 3. Comparison of mean serum magnesium and FEMg of patients on tacrolimus and cyclosporine.

Variables	Patients on tacrolimus (n = 73)	Patients on cyclosporine (n = 18)	p Value
Serum magnesium (mg/dL)	1.67 ± 0.23	1.71 ± 0.17	0.446
FEMg (%)	5.60 ± 2.80	6.10 ± 3.80	0.952
Rate of hypomagnesemia (%)	32/73 (43%)	6/18(33%)	0.421
Rate of hypermagnesuria (%)	47/73 (64%)	12/18 (66%)	0.857

Table 4. The number of patients with hypomagnesemia and hypermagnesuria.

	Patients with normal FEMg n = 32(35 %)	Patients with high FEMg n = 59(65%)
Patients with normal magnesium  levels n = 53(58%)	16 (17.5%)	37 (40.5%)
Patients with hypomagnesemia  n = 38(42%)	16 (17.5%)	22 (24.5%)