Oxidative stress is associated with decreased heart rate variability in patients with chronic kidney disease

Elevated oxidative stress and reduced heart rate variability (HRV) is prevalent in patients with chronic kidney disease (CKD) and is associated with increased morbidity and mortality. Previous studies have identified a positive association between elevated oxidative stress and autonomic dysfunction, however this relationship has not yet been investigated in the CKD population.

Plasma was collected from 78 patients with stage 3-4 CKD (estimated glomerular filtration rate 25-60 ml/min/1.73 m²) for the assessment of oxidative stress, including plasma total F2-isoprostanes, glutathione peroxidase activity and total antioxidant capacity. Time and frequency HRV parameters were measured from a three lead electrocardiogram.

Participants with elevated F2-isoprostanes had reduced HRV compared to patients with normal levels of F2-isoprostanes. A number of HRV parameters were found to be inversely correlated with F2-isoprostanes in all CKD patients, including SDNN (r = -0.337; P < 0.01), VLF (r = -0.281, P = 0.01), LF (r = -0.315, P < 0.01) and total power (r = -0.288, P = 0.01). Multiple linear regression found F2-isoprostanes to be an independent predictor of SDNN (r² = 0.287, β = -0.272, P = 0.01).

Oxidative stress is significantly and independently associated with HRV in patients with CKD. Identifying oxidative stress in the pathogenesis of autonomic dysfunction may help target therapeutic strategies.