Evaluation of the Effect of Zinc supplementation on the Health Status of Hemodialysis Patients

Abstract

End stage renal disease (ESRD) is a late stage of chronic kidney disease (CKD) in which glomerular filteration rate is less than 15 ml/min or the initiation of renal replacement therapy – either dialysis or renal transplant – is a must for the patient to survive. Although dialysis has improved the life expectancy of End Stage Renal Disease (ESRD) patients, the mortality rate still remains disappointingly high. Oxidative stress and inflammation together with their complications such as cardiovascular diseases, protein-energy wasting and erythropoietin-resistant anemia are prevalent in hemodialysis (HD) patients and increase mortality in these patients. Zinc deficiency is abundant in HD patients (40–78%) and contributes to a lot of uremia symptoms including oxidative stress, inflammation, anemia, anorexia, hypogeusia, hyposmia, and disorders of sexual and immunological functions. Patients undergoing HD have been found to have low serum concentrations of zinc due to zinc removal during HD and decreased serum albumin levels as well as inadequate dietary intake and reduced gastrointestinal absorption of zinc. Serum zinc levels can also be reduced by increased expression of intracellular metallothioneins following oxidative stress. The current study was designed to evaluate the efficacy of oral zinc supplement at a dose of 25 mg/day for 12 weeks compared to placebo in Zn deficient HD patients on oxidative stress, inflammation, anemia and patients’ quality of life. This was accomplished by assessing its effect on serum malondialdehyde (MDA), total antioxidant capacity (TAC), superoxide dismutase (SOD), high sensitivity C-reactive protein (hs-CRP), Interleukin-6 (IL-6), hemoglobin (Hb) and Fatigue Severity Scale (FSS). The study was a prospective, randomized, placebo controlled, single blinded study conducted on 52 adult Zn deficient HD patients. These patients were randomized to one of the two groups: Group 1: 28 patients received 25 mg zinc supplement hard gel capsules once daily. Group 2: 24 patients received Placebo hard gel capsules once daily. The patients received either zinc supplement or Placebo in addition to conventional therapy for 12 weeks. All patients were subjected to a thorough history taking and the following parameters were evaluated at baseline and 12 weeks thereafter for the two groups: a- Serum MDA level, b- Serum TAC level, c- Serum SOD level, d- Serum hs-CRP level, e- Serum IL-6 level, f. Hemoglobin, g. FSS The current study showed that: • Zinc deficiency is highly prevalent in HD patients (66%).

• There was no significant difference between the two groups at baseline regarding all demographics except for gender.

• There was no significant difference between the two groups at baseline regarding all lab investigations and FSS.

• At the end of the study, serum zinc significantly increased in group 1 with a significant difference between both groups.

• Serum MDA significantly decreased and serum TAC significantly increased in group1 after Zn supplementation period with no significant difference between both groups.

• Serum SOD showed no significant difference either within or between groups at the end of the study.

• At the end of the study there were no significant difference either within or between groups regarding serum hs-CRP and IL-6 levels.

• There was a significant increase in Hb level in group 1 at the end of the study with a significant difference between both groups.

• Fatigue severity scale significantly decreased in group1 patients at the end of the study while it was not significantly increased in group 2.

• At the end of the study, Comparison of the percent change in FSS between the two groups showed a significant difference.