Genetic analysis technique finds missing link between thyroid function and lipid profile
Chinese Medical Journal
July 8, 2021 (Medical Xpress) — A recent study published in Chinese Medical Journal reveals an association between thyroid function and serum lipid profiles with the help of a genetic analysis technique known as “Mendelian randomization”
Thyroid hormones are amino acid-based molecules produced by the thyroid gland. Involved in direct or indirect regulation of key metabolic pathways, these molecules play critical roles in the development and normal functioning of the body. The mechanism of how thyroid hormones exert their effect on each other as well as on other metabolic pathways is complex, but a two-way feedback loop is central to their biological activity. Dysregulation of the feedback loop that controls their production affects other biochemical pathways, causing various ailments including those related to the cardiovascular system, liver function, or bone development.
Several clinical studies have shown the effect of thyroid hormones on lipid levels: That treating the patients with thyroid hormone analogs helps to improve their lipid level, for example, or that thyroid hormones are associated with glycolipid metabolism and increased risk of cardiovascular diseases (CVD). These results highlight the possibilities of predicting the risk of lipid-related diseases or designing a CVD treatment strategy based on thyroid hormones. But such efforts would require the base of a biological cause-and-effect relationship between thyroid hormones and lipid profile, an association that has remained unproven thus far.
It is notable that the results of the previously conducted clinical studies, however intriguing, have remained unable to pinpoint thyroid hormones as the probable cause of change in the lipid profile. This is because many confounding factors might have impacted both, blurring the cause-and-effect relationship between thyroid function and lipid profiles. Additionally, the observed relationship between the two could reflect reverse causation, where the change in lipid profile affected the thyroid function. Thus, to leverage the observed association between thyroid function and serum lipid profile for designing treatment strategies for lipid-related diseases, a better understanding of their causal dynamics becomes imperative.