8-hydroxy-2′-deoxyguanosine, a biomarker of oxidative DNA injury, in diabetic kidney disease
Belinda Spoto, Cristina Politi, Patrizia Pizzini, Rosa Maria Parlongo, A. Testa, Marco Mobrici, Giovanni Luigi Tripepi, Francesca Mallamaci, Carmine Zoccali
Abstract
Background and aims To gain insight into the extent of oxidative stress and DNA damage in diabetic kidney disease (DKD), a serious complication of diabetes, we compared the levels of the oxidative stress-related metabolite 8-hydroxy-2′-deoxyguanosine (8-OHdG) in a case-control study accurately matching diabetic patients with and without renal complications. Methods and results We analyzed serum 8-OHdG in relation to clinical indicators of kidney function in a group of type-2 diabetes patients including 33 patients with DKD and 33 without DKD. Circulating levels of 8-OHdG were higher in patients with DKD than in those without (4.6 ± 0.7 ng/mL vs 4.0 ± 0.8 ng/mL, p=0.002). In a logistic regression analysis adjusting for potential confounders, 8-OHdG was associated with DKD (OR: 2.90, 95%CI:1.15–7.34; p=0.02) and in a linear regression model, a 1 ng/mL increase of this biomarker entailed a reduction of 11.5 mL/min/1.73 m 2 in the renal filtration rate. Furthermore, an interaction analysis showed that glycated hemoglobin was a modifier of the relationship between 8-OHdG and study outcomes (p for effect modification=0.02). Conclusion This study supports the role of oxidative stress in the pathogenesis of diabetic nephropathy and highlights the potential of serum 8-OHdG as a biomarker for assessing oxidative stress and DNA damage in patients with diabetes and renal complications.