Relation of ankle-brachial index to the rate of decline of residual renal function in peritoneal dialysis patients

Aim: The aim of this study was to determine whether ankle‐brachial index (ABI) predicts the rate of decline of residual renal function (RRF) in peritoneal dialysis (PD) patients. Previous studies demonstrated the importance of loss of RRF in predicting all‐cause risk and cardiovascular mortality in PD patients. It is also known that patients with a low ABI value have a greater risk for deteriorating renal function in the general population. The relationship between ABI and the declining rate of RRF in PD patients with an additional dialysis‐specific risk factor is uncertain. Methods: Seventy‐four PD patients with RRF of more than 1 mL/min per 1.73 m² were analyzed. ABI was used as the surrogate measure of pre‐existing cardiovascular disease and atherosclerosis burden to further determine the outcome of RRF in this study. The slope of decline of RRF was used to determine the outcome. Results: Based on the multivariate analysis, only ABI (P < 0.001), diabetes (P = 0.02) and baseline RRF (P = 0.009) independently predicted a faster decline in RRF. A stepwise multiple linear regression analysis demonstrated that ABI was an independent predictor for the slope of decline of RRF (P < 0.001). Conclusion: A low ABI is an independent predictor of not only the known atherosclerotic events, but also of the rate of decline of RRF over time in PD patients.