Hemodialysis (HD) is the main renal replacement therapy for patients with end-stage renal disease. However, factors such as hemodynamic instability can lead to gradual loss of residual renal function (RRF) in HD patients. The loss of RRF not only affects the adequacy of dialysis and complications control but also impacts the patients' quality of life and survival. Unfortunately, there are currently no effective methods to protect RRF. The purpose of this study is to validate the protective effect of remote ischemic conditioning (RIC) on RRF in HD patients. This will provide evidence for the application of RIC in protecting RRF in HD patients.

Hemodialysis (HD) is the main renal replacement therapy for patients with end-stage renal disease. However, factors such as hemodynamic instability can lead to gradual loss of residual renal function (RRF) in HD patients. The loss of RRF not only affects the adequacy of dialysis and complications control but also impacts the patients' quality of life and survival. Unfortunately, there are currently no effective methods to protect RRF. Remote ischemic conditioning (RIC) is a simple, safe, non-invasive, and non-pharmacological intervention. It induces the remote organs to develop an anti-ischemic injury capacity through repeated and brief ischemic stimuli on limbs, thereby reducing ischemic damage. RIC is a clinically feasible method that is easy to implement and promote. It has been widely used in the treatment and research of cardiovascular and cerebrovascular diseases, as well as in the prevention of acute kidney injury related to thoracoabdominal surgery and contrast agents. Studies have also found that RIC significantly reduces myocardial ischemic injury in HD patients. Theoretically, RIC can also be used to protect the RRF in HD patients. This study aims to validate the protective effect of RIC on RRF in HD patients. This will provide evidence for the application of RIC in protecting RRF in HD patients.

Inclusion Criteria:

• Age ≥ 18 years;
• First-time initiators of hemodialysis treatment for end-stage renal disease patients;
• Urine output > 500ml/day or GFR > 3ml/min/1.72m2;
• Hemodialysis access as a central venous catheter.
• Signed and dated informed consented is obtained;

Exclusion Criteria:

• Active infection;
• Infectious disease;
• Expected dialysis duration < 6 months;
• Presence of vascular access dysfunction (blood flow rate < 180ml/min);
• Patients who had contraindication of remote ischemic conditioning, such as severe soft tissue injury, fracture or vascular injury in the upper extremities, venous thrombosis in the acute or subacute stage of upper extremities;
• Pregnancy or lactation women;
• Patients who are participating in other clinical studies, or who have participated in other clinical studies within 3 months prior to enrollment;
• Unwillingness to be followed up or poor adherence to treatment;
• Other circumstances that the investigator considers unsuitable for enrolment.

Only Research Assistant will be unblinded. Participant, clinical team, PI, etc. will all be blinded to the randomization group.