Association Between Residual Kidney Function and Frailty in End-Stage Renal Disease Patients Undergoing Hemodialysis: A Cross-Sectional Study

Residual kidney function (RKF) plays a crucial role in maintaining biochemical balance in hemodialysis patients. Frailty, commonly observed in end-stage renal disease (ESRD) patients, is associated with metabolic derangements, inflammation, and fluid overload. However, the relationship between RKF and frailty in this population remains unclear. This study aimed to investigate the association between RKF and frailty in ESRD patients undergoing hemodialysis. Secondary objectives included assessing the prevalence of frailty and sarcopenia, and identifying clinical correlates. A cross-sectional study was conducted involving 110 adult ESRD patients undergoing maintenance hemodialysis for ≥6 months at an urban teaching hospital in Bangkok, Thailand between October 2023 and February 2024. RKF was assessed by 24-hour urine volume, with <100 mL defined as absent RKF. Frailty was evaluated using the Thai version of the FRAIL scale, and sarcopenia was diagnosed based on the 2019 Asian Working Group for Sarcopenia (AWGS) criteria. Demographic, clinical, and laboratory data were analyzed using chi-squared tests, logistic regression, and multivariable models. Among 110 participants, 78 (70.91%) had no RKF. Frailty prevalence was 13.64%, and sarcopenia prevalence was 65.45%. Frailty was associated with a history of cerebrovascular accident [adjusted odds ratio (OR) 10.303; P = 0.036] and lower total iron-binding capacity (TIBC) (adjusted OR 0.972; P = 0.047). Sarcopenia was linked to advanced age (adjusted OR 1.054; P = 0.020) and lower Kt/V values (adjusted OR 0.417; P = 0.002). RKF was not significantly associated with frailty. While RKF was not directly associated with frailty, this study highlights other significant factors, such as cerebrovascular accidents and low TIBC, contributing to frailty and advanced age associated with sarcopenia. These findings emphasize the need for comprehensive frailty screening and tailored interventions to improve outcomes in ESRD patients.