SAT-151 A DILEMMA OF CALCITRIOL IN PRE-DIALYTIC CHRONIC KIDNEY DISEASE: A 1-YEAR STUDY FOR COMBINATION THERAPY OF CALCITRIOL AND RENIN-ANGIOTENSIN ALDOSTERONE BLOCKER IN CHRONIC KIDNEY DISEASE

Abstract

Renin-angiotensin aldosterone system blockers (RASB) is main stream of management of chronic kidney disease (CKD). Vitamin D (vitD) is known as a potent negative regulator of renin-angiotensin aldosterone system via vitamin D receptor. VitD deficiency often presents, even in early CKD. However, there is no a definite guideline of use of vitD in CKD. In addition, the use of vitD should be given a careful attention due to development of hypercalcemia or vascular calcification in CKD. Now, we report results of a 1-year study for combination therapy of calcitriol and RASB in patients with pre-dialytic CKD and vitD deficiency. Forty five patients with pre-dialytic CKD and proteinuria >500 mg/day despites of RASB during at least 6 months were enrolled. We prescribed calcitriol of 0.5 μg, thrice weekly only in patients with serum calclium <10 mg/dL and 25(OH)vitD of <15 ng/mL. Only a total 27 patients received combination therapy of calcitriol and RASB, and laboratory data were retrospectively analyzed. Urine albumin-creatinine ratio (UACR) at baseline was measured. UACR and serum creatinine were followed with 6-month interval. We also divided the enrolled patients into two groups, early CKD and advanced CKD group, based on eGFR of 60 mL/min/1.73m2. We performed a comparative analysis for impacts of combination therapy on albuminuria and renal function in the groups based on eGFR. Total 27 patients used calcitriol and RASB. Eleven patients among the 27 patients were classified into early CKD group and sixteen patients were classified into advanced CKD group. Total 18 patients used only RASB. Twelve patients among the 18 patients were classified into early CKD group and six patients were classified into advanced CKD group. (Table 1,2: not shown in the abstract) In combination group, UACR were 3.15 g/g ± 3.82 at baseline and fell to 2.28 g/g ± 2.90 and 1.91 g/g ± 2.75 after 6 and 12 months. (p=0.031 and p=0.096, respectively) (Table 3) Moreover, in RASB only group, UACR were 1.05 g/d ± 1.71 at baseline and fell to 0.34 g/g ± 0.37 and 0.74 g/g ± 1.13 after 6 and 12 months. (p=0.039 and p=0.133, respectively) (Table 4) Change of UACR after 6 months from baseline did not show statistical significance in both groups. However, in combination group, when subgroup analyses were performed in early CKD and advanced CKD, UACR were 3.61 g/g ± 4.13 at baseline and significantly fell to 2.44 g/g ± 3.04 and 1.17 g/g ± 1.68 after 6 and 12 months (p=0.005 and p=0.022, respectively) in only early CKD. In addition, change of GFR in early CKD patients received combination therapy did not decrease significantly during 12 months. (p=0.099) (Table 3) Moreover, we performed a comparative analysis between combination and RASB only to identify effect of calcitriol on UACR according to time. The difference of decreasing UACR between combination and RASB only group was not statistically significant in both groups, however, in early CKD patients, the difference based on time between both groups seemed to be significant. (p=0.05) (Table 4 and Figure 1) View Large Image Figure ViewerDownload Hi-res image Download (PPT) Our study didnot show a significant impact on albuminuria of vitD combination therapy compared with only RASB therapy. However, if sample size and study-duration are expanded, combination therapy might show negative impact on albuminuria, particularly in early CKD patients with persistent proteinuria despites of use of RASB.