RESUMEN
Objective: To explore the correlation between fluid load index and cardiovascular events in hemodialysis patients based on repeated body composition analyses. Methods: A prospective cohort study was conducted to collect the clinical data of patients undergoing maintenance hemodialysis (MHD) in the Department of Nephrology, Hangzhou Hospital of Traditional Chinese Medicine from July to September 2020. The pre-dialysis fluid overload (FO) index-overhydration (OH) was measured by bioelectrical impedance method, and the follow-up monitoring was conducted every 6 months. According to the baseline OH value, patients were divided into non-FO group (OH≤2.5 L) and FO group (OH>2.5 L). Moreover, according to the repeated measurements, the patients were divided into continuous non-FO group, continuous FO group and intermittent FO group. All patients were followed up until October 1, 2022, and the outcomes were recorded. The end point of follow-up was cardiovascular events. The cumulative incidence of cardiovascular events was calculated by the Kaplan-Meier method, and the risk factors of cardiovascular events were analyzed by Cox proportional hazards regression model. Results: A total of 289 patients were included, including 88 patients (30.4%) with FO and 201 patients (69.6%) with non-FO. There were 168 males (58.1%) and 121 (41.9%) females, with an average age of (58±13) years and an average follow-up time of (22.0±6.5) months. Kaplan-Meier analysis showed that the incidence of cardiovascular events in the baseline FO group was higher than that in the non-FO group (log-rank χ2=14.44, P<0.001). The incidence of cardiovascular events in both the continuous FO group and the intermittent FO group was higher than that in the continuous non-FO group (log-rank χ2=41.47, P<0.001; log-rank χ2=18.36, P<0.001). After adjustment for gender, age, comorbidities, and biochemical indicators, the incidence of cardiovascular events in the baseline FO group was 1.850 times of the non-FO group (95%CI: 1.046-3.271, P=0.034). The incidence of cardiovascular events in the continuous FO group was 4.679 times of the continuous non-FO group (95%CI: 2.189-10.002, P<0.001). The incidence of cardiovascular events in the intermittent FO group was 3.410 times of the continuous non-FO group (95%CI: 1.696-6.857, P=0.001). Conclusions: OH value measured by bioelectrical impedance can be used as an important reference index for clinical monitoring of cardiovascular events in MHD patients. Continuous chronic and intermittent exposures to FO are risk factors for cardiovascular events in hemodialysis patients.