Background: β-thalassemia major (β-TM) is the most common genetically determined chronic hemolytic anemia. Studies reported that patients with β-thalassemia are zinc deficient due to increased utilization of zinc by oxidative stress, increased urinary zinc excretion and sequestration in the liver.The development of abnormal glucose tolerance in β-TM is associated with alteration in oxidant-antioxidant status. Zinc plays an essential element for insulin synthesis, storage and secretion.
Aim: This study investigated the effect of zinc supplementation on glucose homeostasis in pediatric patients with β-TM complicated with diabetes mellitus (DM) and its relation to clinical and laboratory parameters of these patients.
Methods: Eighty patients with β-TM (aged ≥10 years old) were recruited from the regular attendants of the Pediatric Hematology Clinic. Each of the eligible children was randomly assigned by simple randomization to either; Group I which included 40 patients who received oral zinc in a dose of 40 mg daily for 3 months duration or Group II which included 40 patients who received placebo. All patients were subjected to detailed medical history and thorough clinical examination. Laboratory investigations included complete blood count (CBC), hemoglobin analysis, markers of hemolysis (indirect bilirubin and lactate dehydrogenase [LDH]), serum ferritin, fasting blood glucose (FBG), fructosamine, fasting C peptide, urinary albumin excretion (UAE) and serum zinc levels were assessed. All patients were clinically followed-up for 3 months with assessment of biochemical indices for evaluating the effects and compliance of zinc supplementation and for monitoring signs of any potential adverse effect.
Results: Comparison between baseline clinical and biochemical data among β-TM patients in both groups showed no significant difference. In our study, all the enrolled thalassemia patients had significantly lower zinc levels compared with healthy controls (P<0.001). At 12 weeks, indirect bilirubin, LDH, serum ferritin, FBG,fructosamine and UAE were significantly lower while hemoglobin levels and fasting c peptide were significantly higher after zinc supplementation compared with baseline levels or with placebo group (P<0.05). Baseline serum zinc was negatively correlated to FBG (r=-0.534, P<0.001) and fructosamine (r=-0.555, P<0.001) while positively correlated to fasting C peptide (r=0.777, P=0.002).
Conclusions: Supplementation with zinc was well tolerated with no side effects were reported throughout the study. Zinc intake for 3 months represents a potential therapeutic adjuvant agent decreasing hyperglycemia, improving insulin secretion, glycemic control and increasing the efficacy of iron chelation therapy in reducing hemolysis, iron burden and elevating hemoglobin levels among pediatric patients with β-TM.
19 - 21 Sep 2019
European Society for Paediatric Endocrinology