Association Between the Blood Copper-Zinc (Cu/Zn) Ratio and Anemia in Patients Undergoing Maintenance Hemodialysis.

Copper (Cu) and zinc (Zn) imbalances are common in dialysis patients. This study aimed to investigate the relationship between the blood Cu/Zn ratio and anemia in patients undergoing maintenance hemodialysis (MHD) treatment. This cross-sectional study included patients undergoing MHD at our center in September 2019. Clinical and demographic data and blood samples were collected before the hemodialysis sessions, and the blood levels of Zn and Cu were measured by inductively coupled plasma mass spectrometry. Multivariable linear and binary logistic regression analyses were performed to study the relationship between blood Cu/Zn ratio and anemia. A total of 144 MHD patients were enrolled in this study. The patients had a mean age of 64.33 ± 13.39 years, a median dialysis vintage of 33.50 (16.25-57.50) months, with 66 being females (45.8%). The median blood Cu/Zn ratio was 15.55 (interquartile range: 12.47-20.31). Anemia was present in 99 patients (68.8%). Groups with higher hemoglobin levels had decreased blood Cu/Zn ratios (p < 0.05). After adjustments for confounding factors, higher blood Cu/Zn ratios were independently associated with lower hemoglobin levels and anemia in MHD patients based on multivariate linear and multivariate binary logistic regression, respectively, in different models. Our study found that the blood Cu/Zn ratio is independently associated with anemia in MHD patients, but prospective multicenter studies with larger sample sizes are still needed to determine the appropriate cutoff values for blood zinc, blood copper, and blood Cu/Zn levels in this patient population.