Ascorbic acid effect on CIN incidence in diabetic patient after coronary angiography

This study aims to investigate the antioxidant effect of vitamin C in preventing contrast-induced nephropathy (CIN) in diabetic patients after catheterization.

In a double blinded, randomized controlled trial, 90 diabetic patients who were referred for cardiac catheterization were randomly allocated into two arms of vitamin C (A) and placebo (B). The treatment arm (A) received 2 g of vitamin C orally 2 h before catheterization and the control group (B) received 2 g of oral placebo. Six hours before catheterization, patients received fluid resuscitation with normal saline (CIN was considered as a 25% rise in creatinine (Cr) level or an increase of 0.5 mg/dL in earlier creatinine). CIN was compared between groups. Before andthree days after catheterization. Serum Bun - Cr was measured and GFR were calculated. The results were compared between the two groups. Six hours before catheterization, patients received fluid resuscitation with normal saline CIN was compare between arms.

Mean GFR in group (A) before procedure was respectively 69.82±19.26 and after the treatment was 81.51±27.40 (P=0.001). But in group (B) it was 74.18±24.41 and 75.20±29.65 (P=0.747). Contrast-induced nephropathy was observed in 10 patients (12.3%) including 3 patients (7.7%) in group (A) and (16.7%, 7 patients) in group (B) (P=0.315).

Ascorbic acid intake in diabetic patients prior to use of contrast agents can be effective in maintaining GFR, but the incidence of contrast-induced nephropathy is not associated with the consumption of ascorbic acid.