Subtle changes in thyroid hormone levels, even within the normal range, can have a significant effect on the risk of metabolic diseases, including diabetes mellitus, hyperuricaemia, fatty liver, cardiovascular disease and even all‐cause mortality (Ding et al., 2022; Sun et al., 2022; Wan et al., 2024, 2023; Yu et al., 2024). This evidence concerns the gene TG and diabetes mellitus.