Gender difference in the association between sensitivity to thyroid hormones with incident high remnant cholesterol levels in euthyroid adults

Abstract

Abstract Background Whether resistance to thyroid hormones affect the atherogenic remnant cholesterol (RC) levels remains unknown. The aim of this study was to explore the association of sensitivity to thyroid hormones with the incident high RC levels in euthyroid Chinese adults and further explore this association was modified by gender differences. Methods We performed a post hoc analysis including eligible participants from the 11223 who underwent at least two health examinations and were with RC < 0.8 at baseline from 2006 to 2010. Central and peripheral sensitivity to thyroid hormones such as thyroid-stimulating hormone index (TSHI) and thyrotrophic thyroxine resistance index (TT4RI), thyroid feedback quantile-based index (TFQI) and free triiodothyronine (FT3)/free thyroxine (FT4) were calculated. Results Participants with RC levels had higher levels of TSHI ,TT4RI and TFQI than participants in the normal RC group in females. However, there were no differences of TSHI, TT4RI, TFQI and FT3/FT4 between the normal RC group and the high RC group in males. In the multi-adjusted models, the highest tertiles (tertiles 3) of TSHI was associated with an increased high RC levels risk compared with the lowest tertiles (tertiles 1) (HR = 1.819, 95%CI 1.268–2.607, P = 0.001) in females. The association was also significant using TT4RI and TFQI as indices of central sensitivity to thyroid hormones in females. In stratified analyses, the relationship between thyroid hormone sensitivity and incident high RC levels was statistically significant in women < 48 years old, but not in ≥ 48 years old. Conclusion High TSHI ,TT4RI and TFQI increase risk of incident high RC levels in euthyroid Chinese adults in females, suggesting that central resistance of thyroid hormones may participant in the pathophysiological process of high RC levels.