P269
VITAMIN D LEVELS IN A MULTI-ETHNIC, RENAL TRANSPLANT POPULATION
ALL IS NOT EQUAL.
Dreyer, G, Badri, M, Mirza, A, Fan, S, Raftery, M, Yaqoob, M
Renal Department, Royal London Hospital
INTRODUCTION: Vitamin D deficiency is highly prevalent in renal transplant patients
potentially increasing the already high background risk of osteoporosis, malignancy and
infection in this patient group. The effect of ethnicity on 25 (OH) vitamin D levels in this
population group has never been studied.
METHODS: 244 consecutive renal transplant recipients from a total transplant population of
802 had a serum 25 (OH) vitamin D measurement between 1/1/08 and 1/5/09 in addition to
routine blood tests and clinical evaluation. Ethnicity (self reported) was simplified into 4
groups: white (n=150), black (n=21), south Asian (n=38), other (n=35). The 4 variable MDRD
equation was used to generate eGFR values, corrected for ethnicity. Episodes of biopsy proven
rejection were obtained from hospital records. Analysis is based on the last values from the
study period.
RESULTS: Vitamin D deficiency (< 30 nmol/L) was highly prevalent in south Asian (52.6%)
and black (38%) patients compared to white patients (26%) and other ethnicities (22.4%).
69.2% of patients received cholecalciferol 800 IU/day, 16% received calcitriol (dose range 0.251.5 mcg per day) and 14.8% received no vitamin D compounds. Vitamin D medication use did
not differ significantly between ethnic groups. Mean (+/- SD) 25 (OH) vitamin D levels were
significantly higher in patients taking cholecalciferol (57 nmol/l, 28.1) compared to calcitriol
(42 nmol/L, 26.8) or no treatment (37 nmol/L, 21.9) (p<0.001). There was no significant
difference in PTH, calcium, phosphate or alkaline phosphatase between ethnic groups. Mean
blood pressure did not vary significantly between ethnic groups or in different strata of 25 (OH)
vitamin D (< or > 30 nmol/L). Mean 25 (OH) vitamin D levels were significantly lower in
diabetic patients (39.7 vs 50.9 nmol/L, p=0.03) and patients with a shorter duration post
transplantation - < 12 months post transplant: 42.1 nmol/L, > 12 months post transplant: 52.0
nmol/L (p=0.013). Rates of rejection did not significantly differ between pre defined vitamin D
strata or ethnic groups.
Table 1: Ethnicity and vitamin D levels
Mean 25 (OH)
Mean
Mean
Mean eGFR
Mean systolic
Ethnicity
vitamin D level
PTH
diastolic BP
(ml/min/1.73m2)
BP (mmHg)
(nmol/L)
(pmol/L)
(mmHg)
53.3
42.0
11.9
127.4
77.5
White
41.2
45.7
13.8
127.2
79.4
South Asian
43.0
56.9
13.2
127.1
79.6
Black
50.0
42.4
11.0
132.0
78.5
Other
p value for
0.035
< 0.001
ns
ns
ns
difference
between groups
CONCLUSION: Vitamin D deficiency is highly prevalent in south Asian and Afro-Caribbean
patients after renal transplantation despite equivalent use of vitamin D medications. Other high
risk transplant groups for low 25 (OH) vitamin D levels include diabetic patients and those in
the first year post transplant. The clinical significance of these findings needs further study by a
randomised controlled trial with an emphasis on the correct dose of vitamin D replacement in
this population group.