Association Between Thyroid Hormone Sensitivity and Dyslipidemia in Elderly Women

Context: This study investigates the relationship between thyroid hormone sensitivity indices and dyslipidemia in elderly Chinese women. Given the potential impact of thyroid hormones on lipid metabolism, understanding this relationship could improve dyslipidemia management in this population. Materials and Methods We conducted a retrospective case-control study involving 1,312 elderly women who underwent health examinations at the Health Examination Center of the 305 Hospital of the Chinese PLA. Thyroid hormone sensitivity indices, including Thyroid Feedback Quantile-based Index (TFQI), Thyroid-stimulating Hormone Index (TSHI), Thyrotroph Thyroxine Resistance Index (TT4RI), and Free Triiodothyronine/Free Thyroxine ratio (FT3/FT4), were assessed alongside dyslipidemia markers. Statistical analyses included logistic regression and restricted cubic spline models to evaluate the associations and dose-response relationships between these indices and dyslipidemia. Results The study found a U-shaped dose-response relationship between TFQI, TSHI, and TT4RI levels and dyslipidemia risk, indicating that both very high and very low levels of these indices were associated with increased risk. The FT3/FT4 ratio was positively correlated with dyslipidemia risk but lost significance when adjusting for additional confounders. Conclusions Elevated and reduced thyroid hormone sensitivity indices are associated with a higher risk of dyslipidemia in elderly women, while moderate levels may be protective. These findings suggest that a comprehensive approach to thyroid function assessment, incorporating sensitivity indices, could enhance the management of dyslipidemia in older women. Further research is needed to confirm these results and explore the underlying mechanisms.