Demographic and clinical data (age, sex, marital status, education level, monthly income, duration of dialysis, and primary renal disease) were collected. The Charlson comorbidity index (CCI) was used to score the patients’ comorbidities. The CCI includes 19 comorbidities, which are weighted according to the severity of the corresponding chronic disease [16 (link)]. Lin et al [17 (link)] found that the CCI is a strong predictor of outcomes in patients on MHD and correlates with hospitalization. Fasting blood samples before dialysis and biochemistry data (albumin [Alb], hemoglobin, blood urea nitrogen, serum creatinine [Scr], calcium, phosphorus, intact parathyroid hormone, total cholesterol, and triglycerides) were analyzed using an automatic chemistry analyzer (Beckman Coulter, Brea, CA, USA).