Prevalence of Hypothyroidism, Hypoparathyroidism and theFrequency of Regular Chelation Therapy in Patients with Thalassemia Major in Iran: A Systematic Review and Meta-analysis study

Abstract The present study aimed to determine the prevalence of hypothyroidism, hypoparathyroidism and the frequency of regular chelation therapy in patients with thalassemia major in Iran. Searching process was performed by two independent  researchers using valid keywords in the national and international database, including: Magiran, Iranmedex, SID, Medlib, Scopus, PubMed, Science Direct, Cochrane, Web of Science, Springer, Wiley Online Library and google scholar search engine. All studies were searched until 2016 with no time limit. All articles met inclusion criteria were evaluated and the data were analyzed by using SATA Software Ver.11.1. Twenty-seven studies about hypothyroidism (sample size of 4851, the mean age of 16.36±5.5) and 19 studies related to hypoparathyroidism (sample size of 3219, the mean age of 17.44±6.5) were examined. The prevalence of hypothyroidism was calculated 5.7% (95% CI: 4.7-6.8) in patients with thalassemia major in Iran (P=0.000; I2 index=93.9%). The prevalence of overt and subclinical hypothyroidism was estimated 3.1% (95% CI: 1-4.7) and 6.7% (95% CI: 3.3-10), respectively. The prevalence of hypoparathyroidism was calculated 10% (95% CI: 7-12) in patients with thalassemia major in Iran. In reviewing 5 studies, the frequency of regular chelation therapy was estimated 54.6% (95% CI: 28-81.2) in these patients. The prevalence of hypothyroidism and hypoparathyroidism is high in patients with thalassemia major in Iran. Thus, new planning and supervising seem to be essential to minimize endocrine complications in these patients. There is no connection between serum ferritin level and developing hypoparathyroidism. A high percent of Iranian patients with thalassemia major perform the chelation therapy irregularly. It's been recommended to adopt the necessary measures such as educating and enhancing awareness of the patients about its complications.