Left atrial enlargement is associated with a rapid decline in residual renal function in ESRD patients on peritoneal dialysis

Background: Left atrial (LA) volume index (LAVI) has been considered a stable indicator of diastolic dysfunction and an independent predictor of mortality in patients with end-stage renal disease. To date, however, little is known about the relationship between LA enlargement and the changes in residual renal function (RRF). Methods: This study was undertaken to investigate the association between LA enlargement and the decline in RRF in 121 incident peritoneal dialysis patients. Within 2 months after the initiation of peritoneal dialysis, LA enlargement was determined by echocardiography and RRF by 24-hour urine collection. Subsequently, RRF was measured every 6 months. Results: The rates of decline in RRF were significantly greater in patients with LA enlargement (LAVI > 32 mL/m ²) compared with those without LA enlargement (-0.17 ± 0.18 vs -0.07 ± 0.16 mL/min/month/1.73 m ², P = .002). In a linear mixed model, there was a significant difference in the rates of RRF decline over time between patients with and without LA enlargement (P <.001). Pearson's correlation analysis revealed that there were significant inverse correlations between the rates of the decline in RRF and LAVI (r = -0.22, P =.018). In multiple linear regression analysis adjusted for other risk factors, LAVI was found to be an independent determinant of the rates of decline in RRF (β = -0.026, P =.018). Conclusions: This study shows that a higher LAVI is independently associated with a more rapid decline in RRF in patients with end-stage renal disease on peritoneal dialysis.