Prevalence of Hypovitaminosis D among Renal Transplant Recipients and Its Relation to Graft Interstitial Fibrosis

Abstract

Background:Vitamin D deficiency is not uncommon among kidney transplant recipients which may lead bone diseases, graft aging and vascular disease. We aimed to evaluate the prevalence of hypovitaminosis D among renal transplant recipients and its relation to graft interstial fibrosis in graft biopsies. Methods:We recruited 99 renal transplant recipients with recent graft biopsies performed during the period between 2016 and 2017 in the nephrology department, organ transplant center of Kuwait. We excluded 2 nd transplants, previous rejecters, extremes of ages (<18,>70years), postmenopausal women, and conditions that interfered with vitamin D metabolism as hepatic disease, gastric bypass, cystic fibrosis; extensive burns and chronic diarrhea. Patients were divided the into two groups: recent transplants (<1-year post-transplant, n=49) and older transplants (>1-year post-transplant, n=50). We measured serum 25(OH) vitamin D, iPTH, albumin, creatinine, calcium, phosphorus, cholesterol and uric acid. Graft biopsies were assessed according to Banff classification 2013. Results:Most of patients (81.8%) had hypovitaminosis D with variable degrees' deficiency (48.5 % had insufficiency, 24.2 % had mild deficiency, and 9.1 % had severe deficiency). In our study, both groups were comparable regarding their demographic data except longer dialysis duration and higher number of patients receiving tacrolimus-based therapy in group 1. Vitamin D level was lower in group 1 but did not rank to significance (p>0.05), however, it had significant negative correlation with iPTH and the degree of renal graft interstitial fibrosis and vitamin D deficiency. Conclusion: The prevalence of 25-OH vitamin D deficiency is high post-transplant and it might contribute to the graft interstitial fibrosis.