Effects of Zinc Supplementation on Serum Zinc and C-Reactive Protein Concentrations in Hemodialysis Patients

Objective We examined the effects of zinc supplementation on serum zinc and C-reactive protein concentrations in hemodialysis patients. Design This was a randomized, double-blinded, placebo-controlled clinical trial. Setting This study was conducted at the Shahid Faghihi and Namazi Dialysis Centers in Shiraz, Iran. Patients Fifty-five hemodialysis patients (32 men and 23 women) participated after meeting the following criteria: zinc deficiency, treated for a minimum of 6 months; no record of hospitalizations in the preceding 3 months; and hemodialysis treatment 2 to 3 times per week. Intervention Patients were randomly divided into two groups. The zinc supplementation group (n = 28) received a 220-mg zinc sulfate capsule, and the control group (n = 27) received a placebo capsule (220 mg corn starch), for 42 days. Main Outcome Measures Fasting, predialysis serum samples were collected on days 0 and 42 to determine serum zinc and C-reactive protein levels. Results After supplementation, subjects in the zinc-supplemented group showed significant increases in serum zinc concentrations, from 57.4 ± 2.4 μg/dL SEM on day 0 to 88.4 ± 4.8 μg/dL SEM on day 42. Serum C-reactive protein concentrations were initially high among subjects in the control (15.1 ± 3.9 mg/L SEM) and zinc-supplemented (13.5 ± 3.8 mg/L SEM) groups. Serum C-reactive protein concentrations in the control group increased throughout the study period, but did not reach statistical significance. A progressive decrease in serum C-reactive protein concentrations was observed in the zinc-supplemented group from the beginning (13.5 ± 3.8 mg/L SEM) to the end (10.5 ± 3.5 mg/L SEM) of the study, but this event was not significant. Conclusion Zinc supplementation intake may cause an increase in serum zinc concentrations, leading to a decrease of inflammation in hemodialysis patients.