Table 1. Baseline characteristics of the included studies in this review.

AITD: autoimmune thyroid disorders, HT: Hashimoto's thyroiditis, GD: Graves disease

Reference	Year	Country	design	Sample size	case	control present	AITD
Chao et al. [12]	2020	China	Observational study	5262	373	Yes	HT
Cvek et al. [13]	2021	Italy	Observational study	637	461	Yes	HT
Sulejmanovic et al. [14]	2020	Tuzla	Observational study	150	50	Yes	Autoimmune Hypothyroidism
Botelho et al. [15]	2018	Brazil	Observational study	159	88	Yes	HT
Planck et al. [16]	2018	Sweden	Case-control	2597	292	Yes	GD
Ma et al. [17]	2015	China	Case-control	210	140	Yes	HT, GD
Unal et al. [18]	2014	Turkey	Case-control	405	281	Yes	HT, GD
Mackawy et al. [19]	2013	Saudi Arabia	Case-control	60	30	Yes	HT
Yasuda et al. [20]	2012	Japan	Case-control	72	26	Yes	GD
Kivity et al. [21]	2011	Hungary	Case-control	92	50	Yes	HT, GD
Tamer et al. [22]	2011	Turkey	Case-control	323	161	Yes	HT