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

Objectives: 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. Methods: 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. Results: 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). Discussion: 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.