Assessment of trace elements in sera of patients undergoing renal dialysis

To assess the serum levels of copper, zinc, iron, and lead in patients on maintenance dialysis.

This cross-sectional study performed at King Khalid University Hospital, Riyadh, Saudi Arabia between September 2011 and October 2012 included 42 patients with end stage renal disease on hemodialysis (HD), 18 patients on peritoneal dialysis (PD), and 18 normal controls. Serum copper, zinc, and lead levels were determined by atomic absorption spectrophotometry, and serum iron was determined by spectrophotometric determination.

The median serum copper level in HD patients (20.5 nmol/L; 95% confidence interval [CI]: 17.52-22.39; interquartile range [IQR]: 16.40-24.20) was higher (p=0.001) than the controls (14.30 nmol/L; 95% CI: 9.72-16.91; IQR: 9.70-17), and the PD patients (15.60 nmol/L; 95% CI: 14.17-16.66; IQR: 14.10-16.70). Although no different from PD patients` serum levels of zinc in HD patients (9.50 nmol/L; 95% CI: 7.83-12.09; IQR: 7.00-14.40) were lower than controls (13.20 nmol/L; 95% CI: 10.65-15.22; IQR: 10.58-15.35; p=0.03). Copper/zinc ratio in HD patients was 2.4, 2.5 in PD patients, and 0.88 in controls. The serum iron levels in HD patients (10 mmol/L; 95% CI: 8.03-11.96; IQR: 7-14.50; p=0.003), and PD patients (10 mmol/L; 95% CI 6.56-14.43; IQR 5.50-15; p=0.03) were lower than controls. Serum lead levels in PD patients (0.11 umol/L; 95% CI: 0.02-0.14; IQR: 0.02-0.14) were lower than HD patients (0.18 umol/; 95% CI: 0.15-0.21; IQR: 0.13-0.25; p=0.005), and controls (0.15 umol/L; 95% CI: 0.07-0.24; IQR: 0.06-0.25; p=0.04).

Alterations in serum trace elements emphasize the need for monitoring trace elements in patients receiving maintenance dialysis.