P1002EFFECT OF VITAMIN D ON URINARY ANGIOTENSIOGEN LEVEL IN EARLY DIABETIC NEPHROPATHY
Abstract Background and Aims UrinaryAngiotensinogen (UAGT) is supposed to be a marker of activation of intrarenalreninangiotensin system (RAS) system in early Diabetic Nephropathy (DN). Vitamin D has been studied as a negative regulator of the circulating and tissue RAS activity; so its supplementation may prevent progression of DN. This study was planned to assess the RAS activation and effect of vitamin D supplementation in early diabetic nephropathy progression by estimatingUAGT level. Method A total of 730 Diabetic subjects were screened for early DN based on Inclusion criteria(eGFR ≥ 120ml/min/1.73m2 with unrestricted ACR value eGFR of 60- 120 mL/min/1.73m2 and ACR 30-300mg) and Exclusion criteria(on ACE I or ARB, eGFR<60ml/min/1.73m2, Hypercalcemia (>11.5mg%), UTI, Pregnancy, Hypertension, HbA1c (>8.0 %), vitamin D supplementation during the last 6 month).Of them 103 included subjects were underwent randomization to receive either Cholecalciferol(54) or matching Placebo(49) in a double blind method. All were subjected to routine investigations, urinary albumin: creatinine (UACR), UAGT, serum 25(OH)vitamin D, and intact parathyroid hormone (iPTH) at the zero and six months. A total 40 healthy controls without any comorbidity were also includedfor assessment of same investigations at zero month. Comparative results at zero months of all three groups were analyzed. Results The change in levels of UACR (mg/g), UAGT (ng/ml), vitamin D (ng/ml) and iPTH(pg/ml)in Cholecalciferol group from zero to six month were [Median (IQR)] : 12.50 (-24.82 to -5.95); p<0.001, -6.60 (-20.91 to -2.63);p<0.001, 5.75 (2.07-9.70); p<0.001, -5.35 (-11.55 to -3.67) ;p<0.001, respectively. After six months, median (IQR) of UAGT and UACR levels were significantly lower in the Cholecalciferol group as compared to Placebo group (p<0.001 and p= 0.04 respectively).Significant reduction of UACR (mg/g) and UAGT (ng/ml) level corroborating with increase in 25(OH) vitamin D(ng/ml) levelfrom zero to six months (all three p<0.001). There was significant correlation of vitamin D3 level with UAGT (r value: -0.255 & p value: 0.009) and UACR level (r value: -0.28& p value: <0.01). The median UAGT level was significantly higher in patients with early DN (Cholecalciferol&Placebo Group) than Control Group at zero month (p =0.001). Conclusion Significantly higher UAGT levels in early DN supports role of intrarenal RAS activation. Significant decrease in UAGT level in cholecalciferol group supports beneficial role of vitamin D supplementation in progression of early DN.