A Study of Compound Amino Acid Capsule on Maintenance Hemodialysis Patients

The goal of this retrospective cohort study is to investigate the effects of compound amino acid capsule on nutrition, calcium and phosphorus metabolism in maintenance hemodialysis(MHD) patients. The main questions it aims to answer are: 1. Can compound amino acid capsule improve the nutritional status of MHD patients? 2. Can compound amino acid capsule help to correct the calcium and phosphorus metabolism imbalance of MHD patients? 3. Is compound amino acid capsule safe for MHD patients? We will collect the medical history and laboratory data of MHD patients who regularly took compound amino acid capsule for 9 months or did not use the same preparation in previous medical experience. We focus on the difference of serum albumin level between the treatment group and the control group within 9 months, as well as prealbumin, hemoglobin, ferritin, calcium, phosphorus, 1,25-OH 2-D3 and intact parathyroid hormone (iPTH).