The effect of 12 weeks carnosine supplementation on renal functional integrity and oxidative stress in pediatric patients with diabetic nephropathy: a randomized placebo‐controlled trial

Background and Objectives Oxidative stress is a significant contributor to the pathogenesis of diabetic nephropathy. Carnosine is a natural radical oxygen species scavenger. We investigated the effect of carnosine as an adjuvant therapy on urinary albumin excretion ( UAE ), the tubular damage marker alpha 1‐microglobulin ( A1M ), and oxidative stress in pediatric patients with type 1 diabetes and nephropathy. Methods This randomized placebo‐controlled trial included 90 patients with diabetic nephropathy, despite oral angiotensin‐converting enzyme inhibitors ( ACE ‐Is), who were randomly assigned to receive either 12 weeks of carnosine 1 g/day ( n  = 45), or matching placebo ( n  = 45). Both groups were followed‐up with assessment of hemoglobin A1c ( HbA1c ), UAE , A1M , total antioxidant capacity ( TAC ) and malondialdhyde ( MDA ). Results Baseline clinical and laboratory parameters were consistent between carnosine and placebo groups ( P  > .05). After 12 weeks, carnosine treatment resulted in significant decrease of HbA1c (8.2 ± 2.1% vs 7.4 ± 1.3%), UAE (91.7 vs 38.5 mg/g creatinine), A1M (16.5 ± 6.8 mg/L vs 9.3 ± 6.6 mg/L), MDA levels (25.5 ± 8.1 vs 18.2 ± 7.7 nmol/ mL ) while TAC levels were increased compared with baseline levels ( P  < .001) and compared with placebo ( P  < .001). No adverse reactions due to carnosine supplementation were reported. Baseline TAC was inversely correlated to HbA1c ( r  = −0.58, P  = .04) and A1M ( r  = −0.682, P  = .015) among carnosine group. Conclusions Oral supplementation with L‐Carnosine for 12 weeks resulted in a significant improvement of oxidative stress, glycemic control and renal function. Thus, carnosine could be a safe and effective strategy for treatment of pediatric patients with diabetic nephropathy.