Effect of low dose ionizing radiation on thyroid function in radiation workers:a Meta analysis / 中华放射医学与防护杂志

ABSTRACT

Objective To explore the effect of low dose ionizing radiation on the thyroid of radiation workers in our country. Methods The literatures were searched of domestic and foreign journals from 1996 to 2017. A total of 15 studies involving 6332 participants were included. These studies were screened according to the inclusion and exclusion criteria. Three indicators of the thyroid function were analyzed in radiation workers, including triiodothyronine ( T3 ) , thyroxine ( T4 ) and thyroid stimulating hormone( TSH) . The Meta analysis was performed using Stata 14. 0 software. Results For radiation workers, the standardized mean difference (SMD) of T3 levels was -0. 32[95% CI ( -0. 61,-0. 04), P=0. 03?, lower than that of the control group. Univariate meta - regression analysis of sources of heterogeneity showed that only gender composition was related to heterogeneity of the study [ adjusted R-squared (Adj R2 ) =29. 99%, P =0. 03]. The SMD of T4 levels was -0. 49 [95%CI ( -0. 94,-0. 03), P=0. 04], lower than that of the control group. Only the gender composition was related to heterogeneity of the study[Adj R2 =26. 60%, P=0. 02]. However, the SMD of TSH levels was 1. 10 [95% CI (0. 32,1. 89), P=0. 006], higher than that of the control group. Conclusions The long term exposure of radiation workers to low dose ionizing radiation may lead to negative impact on thyroid. It is important to strengthen radiation protection of thyroid.