This study showed that in thalassemic patients hypozincemia is common but there is no copper deficiency. The thalassemia major is the severe form of the beta thalassemia disease and the patients need repeated blood transfusions and chelation therapy to continue their lives. Although by new therapies the patients’ lifespan has increased to 4th
decade, however these patients are subject to a variety of complications such as growth impairment, endocrinopathy, hypogonadism and so on[1
]. Although the role of iron accumulation in appearance of these complications is well documented, there are some reports emphasizing the role of zinc and copper associated with such clinical problems[12
]. Zinc is one of the essential micro-nutrients in human and considered as the most important mineral preceded by iron. It acts as the cofactor of more than 300 enzymes. Zinc deficiency leads to several clinical disorders including the growth impairment, hypogonadism, osteoporosis, osteopenia, immunologic disorders, repeated infections, etc[7
Tabatabei et al reported that 84.8% of thalassemic major patients had zinc deficiency. They emphasized that the cause of zinc deficiency in these patients was due to insufficient zinc of dietary intake[17
]. Yazdiha et al showed that the serum concentration level of zinc in thalassemic patients (37±1.9mg/dl) was lower than in control group (51±1.8) and there was significant difference statistically. They recommended zinc supplement for thalassemic patients[10
Similar reports were provided by other researchers[11
]. Al-Samarrai et al attributed the cause of hypozincemia in thalassemic patients to hyperzincuria resulted from following hemolysis of red blood cells[21
]. Hashemi Poor et al demonstrated that zinc concentration of hair in thalassemic patients (112.7±53.11 ppm) was lower than that in control group (149.6±72.21 ppm). They suggested that the etiology of zinc deficiency is malnutrition and inadequate zinc intake. They advise administration of zinc supplement[24
]. On the other hand, Mehdizadeh et al have reported that mean serum zinc level was significantly higher in thalassemic group. They noted that zinc deficiency is rare in thalassemia[25
]. Report of Reshadat et al showed that 77% of thalassemic patients have normal serum zinc level and remainder greater than normal. They emphasize that medical treatment of these patients is not appropriate, so the value of zinc administration should be more evaluated[26
]. In contrast to the mentioned studies Kosarian et al reported that serum zinc level in major thalassemic patients and control group were within normal limits, thus these patients are not affected by zinc deficiency[27
]. Present study showed that 65% of thalassemic children have hypozincemia. The causes of zinc deficiency in these patients may be related to insufficient amount of zinc in daily meals, abnormality in urinary absorption of zinc, kidney dysfunction, urinary secretion of zinc, disturbance in zinc metabolism and higher level of zinc excretion in sweat[1
Because there was no relationship between serum zinc level and different variables such as age, weight, height, BMI, duration of blood transfusion, desferri-oxamine dose and ferritin level, so it is most likely that other risk factors unrelated to thalassemia disease such as nutritional status may be responsible for hypozincemia.
Copper is also one of the essential micronutrients of human body mainly attached to albumin and ceruloplasmin. This trace element acts as the cofactor for at least 30 enzymes and many manifestations of copper deficiency and toxicity are associated with irregularities in these enzymes[4
]. Some studies showed that there was an increase in serum level of copper in patients experiencing thalassemia major[11
]. Al-Samarrai et al concluded that the etiology of hypercupremia is hemochromatosis, which is a principal complication of thalassemia[21
]. However, reports of Bekheirnia[29
] and Eshghi[22
] revealed reduction in serum level of copper. Although study by Kassab-Chekir showed no change in copper concentration of serum[20
The serum concentration of copper in patients with thalassemia major depends on several factors including the amount of copper intake in daily diet, intestinal uptake of copper, iron accumulation, kidney function, copper to zinc ratio, and administration of Desferal[11
]. Fortunately none of our thalassemic patients had copper deficiency. This shows that the factors that influence copper level are under control.
The limitations of our study were the small group, local investigation and unavailability of data concerning diet regimens. With respect to importance of identification of zinc deficiency in thalassemic patients for prevention of severe complications such as decreased mineral density of bone[12
], we recommend repetition of this study in a larger scale.