Vitamin D Status in Kidney Transplant Recipients, a Single Center Study

Abstract

Background: Vitamin D deficiency is a well-known complication of chronic kidney disease patients and with kidney transplants. In addition to its effect on bone heath, vitamin D has an additional effect in kidney transplant recipients including immunodulatory and antimicrobial effects.

Aim of the study:To evaluate vitamin D level in kidney transplant recipients, and to determine any correlation between vitamin D level and kidney graft function and  duration, steroid dose ,type of  calcineurin inhibitors  and  important biochemical parameters (PTH,calcium,phosphorus and to talalkaline Phosphatase levels).

Patients and methods: This is across sectional study was performed at Kidney diseases and Transplantation Center, Medical City Teaching Hospital Baghdad,Iraq, from 1^st of March 2018–1^stof April 2019. Fifty one kidney transplant recipients were enrolled in the study, Clinical data of patients were collected included age, gender, duration of transplantation, steroid dose, on cyclosporine or tacrolimus , serum creatinine,Serum intact parathyroid hormone (iPTH), 25(OH)D, serum calcium phosphorus, and total alkaline Phosphatase were measured. The patients classified to deficient, insufficient and sufficient vitamin D groups according to their serum vitamin D level.

Statistical analysis:All data were analyzed using SPSS20 software package for statistical analysis, p value was<0.05 considered significance.

Results:   Mean age of patients was 33.94 (± 10.33)   years. Mean time after transplantation was17.7(±13.84)months,35(68.6%)ofthepatientsweremalesand16(31.4%)werefemales.Mean25(OH)Dlevel forpatientswas15.18(±8.28)ng/mL,only4(8%)patientshadsufficientvitaminD,while26(51%)patientshad deficiency and 21(41%) had insufficiency in vitamin D. There was no significant difference between the genders in regard to distribution of vitamin D level. Vitamin D insufficiency and sufficiency were higher in older than younger age groups (p value 0.006). Vitamin D level did not show significant correlation with the duration of transplant whether above or below 1 year (p value 0.278).  Vitamin D level had inverse correlation withPTH (r=-0.329, p value 0.018), steroid dose (r =-0.52 p value<0.001) and total alkaline Phosphatase (r= -0.503,p value<0.001.Graftfunction(serumcreatinine), calcium and phosphorus not correlated significantly with vitamin D level. The use of either tacrolimusorcyclosporine did not associated with significant effect on vitamin D level.

Conclusion: There was a high prevalence of vitamin D deficiency and insufficiency in renaltransplantrecipients and the measurement of serum vitamin D level is highly recommending in all kidney transplant recipients.