Correlations between OSA-related parameters and thyroid hormones sensitivity indices were further explored using quadratic prediction plots.<h4>Results</h4>Among females, OSA patients showed higher FT4 and significantly increased TFQI, PTFQI, TSHI, and TT4RI, but lower FT3/FT4 ratio compared with non-OSA. This evidence concerns the gene TG and obstructive sleep apnea syndrome.