Prevalence of vitamin D deficiency and persistent hyperparathyroidism in an Egyptian cohort of renal transplant recipients: a cross-sectional study

Abstract

Background Vitamin D metabolism might be influenced by impaired allograft function and by persistently elevated parathyroid hormone (PTH) and fibroblast growth factor 23 levels as well. Hyperparathyroidism is a frequent and sometimes severe complication following renal transplantation. Purpose The primary objective was to measure the prevalence of vitamin D deficiency in renal transplant recipients in a single center (Almowasah Hospital). The secondary objective was to determine predictors of low 25-hydroxyvitamin D levels using patient characteristics to identify patients at a higher risk of vitamin D deficiency. Patients and methods A retrospective cross-sectional study was conducted on 55 renal transplant recipients for whom 25-hydroxyvitamin D was measured. Intact PTH was measured as well and compared with pretransplant values. Results The majority of the patients, representing ∼81.8%, were vitamin D deficient, whereas 14.5% had insufficient serum vitamin D level. A minority of the patients (3.6%) showed sufficient vitamin D level. The mean vitamin D level was 15.13±7.03 ng/ml. Approximately 38.2% of the patients showed evidence of persistent hyperparathyroidism. The median PTH level was higher in the pretransplant period, with a value of 308.0 pg/ml, compared with the posttransplant period (121.0 pg/ml). The difference was statistically significant (P<0.001). Serum PTH level showed a reduction in its level by ∼55.79% after transplantation. Conclusion Vitamin D deficiency is highly prevalent in renal transplant recipients. It is also more prevalent in early than late transplant recipients, and there is a statistically significant inverse correlation between vitamin D and PTH.