The Prevalence of Hypothyroidism among Patients With β-Thalassemia: A Systematic Review and Meta-Analysis of Cross-Sectional Studies

Abstract

As a cause of chronic blood transfusions, iron overload is an important issue in β-thalassemia (β-thal) patients that leads to multiple organ dysfunctions. This is an updated meta-analysis conducted to summarize the existing evidence of the prevalence of hypothyroidism (HT) among patients with transfusion-dependent (TDT) and non transfusion-dependent β-thal (NTDT) and for the first time we meta-analyzed the relationship between ferritin level and HT. This systematic review and meta-analysis were done according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. We searched databases including Web of Science (ISI), Scopus, PubMed, Embase, and Scholar. The quality of the included studies was assessed based on the Newcastle-Ottawa scale (NOS) checklist. Meta-analysis was done using Stata statistical software. The pooled prevalence of total HT, subclinical HT, and overt HT among β-thal patients was 13.25 [95% confidence interval (95% CI): 10.29–16.21; 11.84, 95% CI: 8.43–15.25 and 12.46, 95% CI: 1.05–23.87], respectively. The prevalence of total HT was 16.22% (95% CI: 12.36–20.08) in TDT and 7.22% (95% CI: 3.66–10.78) in NTDT patients. Serum ferritin (SF) levels were significantly lower in euthyroid compared to hypothyroid patients [standard mean difference (SMD) −2.15 (95% CI: −3.08, −1.21, p value <0.001]. The prevalence of HT was higher in TDT compared to NTDT patients. Moreover, our results showed a significant association of high serum ferritin (SF) levels with hypothyroidism in β-thal patients. Both of these findings highlight the importance of prevention measures and timely diagnosis and management of iron overload in β-thal patients.

Keywords:

• β-Thalassemia (β-thal)
• ferritin
• hypothyroidism (HT)
• meta-analysis
• prevalence

Acknowledgments

We would like to thank Shiraz University of Medical Sciences for their approval and support. This study was relevant to the thesis of Mohammad R. Mousavi by grant number 22442. Availability of data and materials: The data presented in this study are available on request from the corresponding author. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results. Author’s Contributions: S. Haghnapah had the idea for the article; S. Haghnapah, M. Hosseini-Bensenjan and M.R. Mousavi performed the literature search; M. Sayadi performed the data analysis; S. Haghnapah and M. Hosseini-Bensenjan prepared the original draft; M. Karimi, M. Ramzi and S. Haghnapah wrote and edited the review; V. de Sanctis proof read the article and was supervised by S. Haghnapah. All authors have read and agreed to the final version of the manuscript and contributed substantially to the reported study.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Additional information

Funding

This research was funded by the Research Vice-Chancellor of Shiraz University of Medical Sciences, Shiraz, Iran.