Significance of 8-hydroxy-2'-deoxyguanosine levels in patients with idiopathic dilated cardiomyopathy.

Background: Although oxidative stress mediated by reactive oxygen species plays an important role in the pathogenesis of heart failure (HF), good clinical markers for reactive oxygen species in patients with HF have not been established. 8-Hydroxy-2'-deoxyguanosine (8-OHdG) is formed from deoxyguanosine in DNA by hydroxyl free radicals and might serve as a sensitive biomarker of intracellular oxidative stress in vivo. Thioredoxin (TRX) is known to be induced in cells as a radical scavenger against oxidative stress. The aim of this study is to evaluate the clinical significance of the serum 8-OHdG and TRX of patients with chronic HF with idiopathic dilated cardiomyopathy (DCM).

Methods And Results: We estimated serum 8-OHdG and TRX levels using enzyme-linked immunosorbent assay in 32 patients with DCM and investigated the impact of these markers to the clinical characteristics of these patients. Serum levels of 8-OHdG, but not TRX were significantly correlated with New York Heart Association functional class, left atrial diameters, left ventricular end-diastolic diameters, left ventricular end-systolic diameters, and plasma levels of brain natriuretic peptide.

Conclusion: These data suggest oxidative DNA damage is increased in patients with DCM according to the severity of HF. Serum levels of 8-OHdG may represent clinically useful markers of left ventricular remodeling.