Isfahan Thyroid Cohort Study (ITCS)


  • 1Isfahan Endocrine and Metabolism Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
  • 2Department of Epidemiology and Biostatistics, Isfahan University of Medical Sciences, Isfahan, Iran.
  • 3Isfahan Clinical Toxicology Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
  • 4Department of Radiology, Isfahan University of Medical Sciences, Iran.
  • 5Department of Engineering and Mathematics, Sheffield Hallam University, Sheffield, UK.
Arch Iran Med

Abstract

Background: The Isfahan Thyroid Cohort Study (ITCS) is one of the few population-based epidemiological studies in Iran that investigates the prevalence and incidence of thyroid disorders including hypothyroidism, hyperthyroidism, goiter, nodule, and iodine status.

Methods: This cohort is located in Isfahan, Iran. The first phase was initiated in 2006 with 2523 participants (1275 males, 1248 females). The participants were selected using multi-stage cluster sampling from the general residents of Isfahan, Iran. The study had two phases (2006 and 2011) and its third stage is planned for 2020-2021.

Results: The prevalence of thyroid function states was euthyroid (89.3%, 95% CI: 88%-90%), overt hypothyroidism (2.8%, 95% CI: 2%‒3%), subclinical hypothyroidism (5.8%, 95% CI: 4%-6%), overt hyperthyroidism (0.8%, 95% CI: 0.4%‒1%), and subclinical hyperthyroidism (0.99%, 95% CI: 0.6%-1%). Hypothyroidism and hyperthyroidism were significantly associated with goiter. The incidence of thyroid dysfunction was reported as follows: overt hypothyroidism (2.7, 95% CI: 1.6-3.7), subclinical hypothyroidism (20.6, 95% CI: 18-23), overt hyperthyroidism (1.9, 95% CI: 1-2.7) and subclinical hyperthyroidism (2.7, 95% CI: 1.6-3.7) per 1000 (person-year).

Conclusion: We assessed the prevalence and incidence of thyroid disorders in Isfahan in the first and second phase, respectively. We are conducting the third phase of the ITCS in order to study the associations between thyroid peroxidase antibody (TPOAb) level and environmental factors such as infection.

Keywords: Cohort studies; Goiter; Hyperthyroidism; Hypothyroidism.

How to Cite

Shahrokh Esfahani S, Tabatabaee A, Aminorroaya A, Amini M, Feizi A, Janghorbani M, Tabatabaei A, Meamar R, Adibi A, Abyar M, Karimifar M, Sajad R, Salehidoost R, Faghih Imani E, Hovsepian S, Sirous M, Aminorroaya Yamini S. Isfahan Thyroid Cohort Study (ITCS). Arch Iran Med. 2021 Nov 1;24(11):788-795. doi: 10.34172/aim.2021.118. PMID: 34841823.