Serum Lipids are Novel Predictors for Thyroid Autoimmunity in the General Population with Normal TSH Levels From A Cross-Sectional Study

Serum lipids have been shown to regulate inflammatory and immune processes, but little is known about their association with thyroid autoimmunity. This study aimed to investigate the association of serum lipids with thyroid autoantibody positivity in the general population with normal thyroid-stimulating hormone (TSH) levels. Data regarding the 7688 subjects’ baseline characteristics were retrospectively collected. All subjects were categorized into four groups according to thyroid autoantibodies against thyroglobulin (TgAb) and thyroid peroxidase (TPOAb) positivity and serum lipid levels were compared. Binary logistic regression models were used to evaluate the risk of TgAb or TPOAb positivity with increasing serum lipid levels. In 6456 included subjects, after adjusting for confounders, the risk of TgAb positivity was positively associated with increasing low-density lipoprotein cholesterol (LDL-C) levels (OR 1.14, 95% CI 1.03–1.27, P = 0.011) and negatively correlated with the increasing high-density lipoprotein cholesterol (HDL-C) levels (OR 0.77, 95% CI 0.61–0.98, P = 0.035). In female subjects, the association between increasing LDL-C (OR 1.16, 95% CI 1.04–1.28, P = 0.007) or HDL-C levels (OR 0.77, 95% CI 0.61–0.99, P = 0.037) and TgAb positivity become more pronounced. We have shown the associations of HDL-C and LDL-C with TgAb positivity in the general population with normal TSH levels in a gender-dependent manner. This study highlights that serum lipids may be new predictors of thyroid autoimmunity even when TSH is within the reference range.