Transient and permanent hypothyroidism in Iran: what are the associated factors

Introduction: The prevalence of Permanent and TCH in Iran is reported 1:581 and 1: 628, with cutoff level for TSH of 5 mU/L. This study is going to investigate the prevalence of TCH and PCH in Tehran, Iran and the associated factors.Materials & Methods: This study was carried out as a cross sectional study, evaluating 723 children, from March 2006 to March 2019. all participants were Iranian, resident of Tehran, Iran and were diagnosed with CH by screening program at 3-5 days of age. The reevaluation of these patients was performed at 3 years of age. Following 3-4 weeks of discontinuation of therapy, in case the TSH level was elevated (more than 5mU/L), persistent CH was confirmed and in case it was within the normal range (less than 5 mU/L), TCH is confirmed.Results: Among 723 recruited cases, 323(44.7%) were female. The average TSH level of the initial assessment, second assessment, from heel prick sample and venous sample, were 22.09 (+ 30.43), 15.89 (+20.80) and 37.29 (+41.72) mU/L, respectively. The initial TSH level and second TSH level measured in venous samples in the PCH was significantly higher than TCH (p-value=0.006 ).Conclusion & discussion: Our study showed that the elevated primary TSH level during screening program and also secondary TSH level obtained by venous sample is related to the TCH or PCH; showing PCH had a higher level of them.

کلیدواژه ها:

ongenital hypothyroidism ، transient hypothyroidism ، permanent hypothyroidism ، TSH level