Decreased Serum Antibodies Against Oxidized Low-Density Lipoprotein Levels Are Associated with Peripheral Arterial...

Background and Objectives: Peripheral arterial disease (PAD) is highly prevalent in patients with end-stage renal disease and is associated with adverse cardiovascular outcomes. Although the ankle-brachial index (ABI) is widely used to identify PAD, it may not fully reflect the complex vascular pathophysiology in patients undergoing peritoneal dialysis (PD). Antibodies against oxidized low-density lipoprotein (anti-oxLDL Ab) have been implicated in atherogenesis; however, their clinical relevance in PD populations remains unclear. Materials and Methods: In this cross-sectional investigation, 90 patients receiving maintenance PD were included. PAD was defined by an ABI below 0.90, and serum anti-oxLDL antibody concentrations were quantified using an enzyme-linked immunosorbent assay. Results: Patients with PAD were older (p = 0.006), had a higher prevalence of diabetes (p = 0.010), and exhibited higher levels of triglycerides (p = 0.008), fasting glucose (p < 0.001), and C-reactive protein (CRP, p < 0.001), but lower anti-oxLDL Ab levels (p = 0.008). Multivariable logistic regression demonstrated that reduced anti-oxLDL Ab levels (per 10 mU/mL increase, odds ratio [OR]: 0.803, 95% confidence interval [CI]: 0.648-0.995, p = 0.045) and increased CRP levels (per 0.1 mg/dL increase, OR: 1.662, 95% CI: 1.152-2.398, p = 0.007) were independently associated with PAD, with consistent results across penalized regression models. Log-transformed anti-oxLDL Ab levels were positively correlated with both left and right ABI values (p = 0.005 and p = 0.017, respectively). Decision curve analysis indicated that the anti-oxLDL Ab-based model provided greater net benefit compared with the treat-all and treat-none strategies across a range of threshold probabilities. Conclusions: Reduced serum anti-oxLDL Ab levels are independently associated with PAD in patients undergoing PD. Serum anti-oxLDL Ab levels are positively associated with ABI values. These findings suggest that impaired immunity against oxidized LDL may contribute to vascular disease in PD patients.