Abstract: 【Abstract】Objective To investigate the characteristics of maintenance hemodialysis patients with residual renal function (RRF), explore the influencing factors and biomarkers of RRF, and analyze the association of RRF on prognosis. Methods Huashan Residual Kidney Function Cohort Study (HRKCS) enrolled incident hemodialysis patients with RRF in out- patient clinic with a prospective cohort design. The enrollment and follow-up are conducted between January 2016 and December 2026. Questionnaire interview, physical examination, biochemical testing, RRF measurement, biological specimen collection, and outcome are included
in the baseline or follow-up survey. Results Forty-six incident patients were enrolled between January 2016 and January 2020. The average age of enrolled patients was (61±18) years old, with 50% males. 57 % of them were treated with 2 times/week hemodialysis. During a median follow-up of 1.2 years, 46% of patients with 2 time/week hemodialysis changed their hemodialysis frequency from 2 times/week to 3 times/week. All enrolled patients had an average initial urea nitrogen clearance rate of (3.37± 2.16) ml/(min·1.73m2) (Z=-5.924, P＜0.001), which decreased to (1.81±2.05)ml/(min·1.73m2) after onEyear hemodialysis. All patients had stable control of complications in the first year. During the average follow-up period of 1.8 years, the mortality rate was 1.2/100 person-years, and the incidence of cardiovascular events was 8.5/100 person-years. Conclusion 57% of the patients in this cohort initiated with incremental dialysis, which had benefits to delay the decline of residual renal function, control the complications, and decrease the risk of all-cause death. HRKCS establishes a fundamental database and guidance for RRF studies.

Key words: Maintenance Hemodialysis, Residual Renal Function, Cohort Study