Description

Control Group: Received routine hemodialysis treatment. Sports Group: Received pre-dialysis resistance training in addition to routine treatment.

Combined Intervention Group: Received mindfulness meditation training during dialysis in addition to exercise therapy.

The study was designed as a single-blind trial. The outcome assessors were blinded to group allocation to reduce assessment bias, particularly in the evaluation of subjective measures such as sleep quality, anxiety, and depression.

Interventions and Methods: Including 4 parts: Part 1 comprehensive assessment and preliminary education; Part 2 testing of one repetition maximum (1RM); Part 3 pre-dialysis resistance training; Part 4 mindfulness meditation training during dialysis.

Comprehensive Assessment and Preliminary Education: Collection of general information (including gender, age, dialysis age, primary disease, etc.). Health education, dietary guidance (calorie intake 30-35kj/kg/d; protein intake 1.0-1.2g/kg/d; maintain weight gain during dialysis within 3%-5% of dry weight). Establishment of a joint intervention team (including 2 meditation instructors, 1 rehabilitation therapist, 2 specialists, and 2 nurses). One week before the trial, patients were introduced to the theoretical knowledge, specific methods, and precautions of mindfulness meditation and PRT training. According to the "Expert Consensus on Exercise Rehabilitation for Chinese Adult Patients with Chronic Kidney Disease" , all participants had no serious complications or comorbidities and were all medium-low risk patients who could undergo incremental moderate-high intensity RT (1 RM 70-85% exercise load).

1RM Assessment: First, perform 5-10 minutes of warm-up exercises for the relevant muscle groups. Choose a weight close to the individual's maximum effort to overcome and begin testing, requiring the completion of 2 squatting movements. Gradually increase the barbell weight in the order of 5kg, 2kg, and 1kg until only one squat can be completed. This weight is recorded as 1RM. Rest for 2-3 minutes between each squat attempt.

Resistance Training: Patients underwent resistance training in the hemodialysis center's gym under the guidance of a rehabilitation therapist 1-2 hours before each dialysis session. The RT prescription was formulated with reference to "the American College of Sports Medicine, ACSM Guidelines for Exercise Testing and Prescription (9th Edition)" and the 2020 KDIGO Clinical Practice Guidelines to develop individualized exercise programs . The control group received routine dialysis treatment.

Mindfulness Meditation Training: After starting dialysis and once blood pressure and heart rate stabilized (approximately 10 minutes), MHD patients were intervened upon using mindfulness hemodialysis meditation audio developed by Lihuili Hospital [20].

Observation Indicators and Methods:

Exercise Capacity: CS-30, HGS, 6MWT, 22StairsUpDownTime, TT10SU. The 30-second chair stand test was used to assess lower limb muscle strength in the "sit-to-stand" state before and after 12 weeks of intervention. Patients crossed their arms over their chest and then performed rapid, continuous "stand up, sit down" movements for a limited time of 30 seconds. The fewer the number of movements within 30 seconds, the worse the lower limb muscle strength. HGS: Measured 3 times using a T.K.K 5001GRIP-A grip strength meter (HKBG., Ltd, Sweden), and the average value was taken. 6MWT, time to climb up and down 22 stairs, and time to stand up and sit down 10 times were measured before and after 12 weeks of intervention. 6MWT: Performed according to the method reported by A.T.S . Subjects walked back and forth in a quiet and ventilated dialysis room corridor with a length of 30m, and the final 6MWT was measured. Time to climb up and down 22 stairs: Subjects continuously climbed up and down 22 stairs (vertical height of approximately 3.3m) and the time taken was recorded. Time to stand up and sit down 10 times: Subjects repeatedly stood up and sat down from a standard-height chair, and the time taken to stand up and sit down 10 times was recorded, and the average value was taken.

Dynamic Balance Function (Timed Up and Go Test, TUGT): The "stand-up and walk" test was used. After the "start" command was issued, the subject stood up from a seated position (on a chair with a backrest), then walked forward 3m as quickly as possible, then turned 180° around the 3m marker and quickly walked back to the chair and sat down with their back against the backrest. The time taken for the entire process was recorded. The longer the time taken, the worse the patient's dynamic balance function .

Ultrasound Examination of the Quadriceps Femoris : The patient was placed in a supine position with the upper body elevated 30°, and both legs were kept relaxed and straight while avoiding internal and external rotation of the hip and knee joints. The linear array probe was placed vertically at approximately the lower 1/3 of the line connecting the anterior superior iliac spine and the upper edge of the patella, keeping the sound beam perpendicular to the femoral body and the probe pointing dorsally. The probe position was adjusted to examine each muscle of the quadriceps femoris (including the cross-sectional area of the rectus femoris, the thickness of the rectus femoris, and the thickness of the vastus intermedius) on the right thigh. The values of each parameter of the quadriceps femoris on the right thigh were measured three times at W0, W4, W8, and W12, and the average value was taken.

5.4 Sleep, Anxiety, and Depression Scores: The Pittsburgh Sleep Quality Index (PSQI) , Self-Rating Anxiety Scale (SAS), and Self-Rating Depression Scale (SDS) were used for evaluation .

The psychometric properties (validity and reliability) of these scales have been validated in populations similar to the study cohort, as referenced in previous literature. Assessors were trained and underwent consistency checks to ensure reliable application of these scales.

Laboratory Tests (Inflammatory Markers, Nutritional Markers, and Dialysis Adequacy): Fasting elbow venous blood was collected to measure interleukin-6 (IL-6), high-sensitivity C-reactive protein (Hs-CRP), tumor necrosis factor (TNF), albumin (ALB), prealbumin (PA), adequacy index (KT/V), etc., before and after the intervention.

Comparison of the occurrence of adverse reactions: Adverse events were monitored throughout the study. These included physical injuries from exercise, as well as psychological distress related to the mindfulness meditation intervention. Adverse events were classified according to their severity and managed appropriately. A report and monitoring mechanism was established for any serious adverse events.