Negative Association between Serum 25 Hydroxy Vitamin D and Serum Uric Acid among Stage 3-5 Chronic Kidney Disease Patients

Author(s):

Ahmed Fayed, Mahmoud M. El-Nokeety, Khaled Marzouk, Ahmed A Heikal, Hany Hammad, Mervat M Naguib, Mona M Salem and Usama A Sharaf El-Din*

Background: The association between serum level of 25 hydroxy vitamin D (25 (OH)D) and serum uric acid (SUA) among non-diabetic chronic kidney disease (CKD) has not been reported so far. Objective: We aimed to study the association of serum 25 (OH)D with SUA among stage 3a-5 CKD patients with and without diabetes mellitus (DM). Cases and Methods: we studied 527 (234 male and 293 female) diabetic (group 1) and 1197 (611 female and 586 male) nondiabetic (group 2) CKD patients. A blood sample was drawn to estimate eGFR, SUA, serum calcium (Ca), phosphorus (P), albumin (Alb), parathormone (PTH), and 25(OH)D. Fasting blood sugar (FBS) and fasting insulin (FI) levels were used to calculate Homeostatic Model Assessment of Insulin Resistance (Homa-IR) in group 2 patients. In addition, a morning urine sample was collected for estimation of urine albumin excretion (UAE). Results: There was no significant difference in SUA or 25 (OH) vit D between the 2 groups or between male and female patients. By univariate analysis, SUA significantly correlated with age, 25(OH) vit D, PTH, Ca, P and UAE (R= 0.05, -0.726, 0.54, -0.087, 0.166, and 0.736 respectively, P= 0.039 for age, and <0.001 in all other associations). Neither SUA nor 25(OH) vit D have significant association with Homa-IR in group 2. SUA was independently related to 25 (OH)D in multivariate linear regression analysis. Conclusion: Vitamin D deficiency is significantly associated with elevated SUA among stage 3a-5 CKD patients. Further studies are needed to confirm this finding and to disclose the underlying mechanism(s).