The prevalence of thyroid disorders in the general population is 7%. Among type 2 diabetics, this rate rises to 12%, and among type 1 diabetics, it increases further to 33%. This means one-third of type 1 diabetics may have thyroid disease.Clinically, type 1 diabetes is more likely to be associated with hyperthyroidism, hypothyroidism, and thyroiditis, while type 2 diabetes is more commonly linked to hypothyroidism and subclinical hypothyroidism. Therefore, individuals with diabetes should prioritize thyroid function screening.
The reasons for the increased susceptibility to thyroid disorders in people with diabetes may include several factors: 1. Both autoimmune thyroid diseases and type 1 diabetes are organ-specific T-cell-mediated autoimmune disorders, sharing common immunopathological mechanisms.Additionally, the catabolic state in people with diabetes may impair energy utilization in thyroid follicular cells, leading to iodine pump dysfunction. This reduces thyroid iodine uptake and decreases thyroid responsiveness to thyroid-stimulating hormone (TSH), both of which affect thyroid hormone synthesis.
2. Metabolic disturbances in diabetes can cause decreased levels of thyroid hormones T3 and T4, along with elevated TSH levels.Some studies indicate that elevated insulin levels in diabetes may stimulate thyroid tissue hyperplasia, leading to thyroid enlargement and nodule formation.
Notably, thyroid dysfunction can reciprocally affect metabolic balance in individuals with diabetes. For instance, hyperthyroidism may exacerbate glucose metabolism disorders in diabetic patients, while hypothyroidism increases the risk of hypoglycemia. Both conditions may elevate cardiovascular disease risk.
Therefore, individuals with diabetes should undergo regular thyroid function testing to detect issues promptly and receive appropriate treatment. Both conditions are catabolic diseases characterized by elevated basal metabolic rates and increased catabolism. When hyperthyroidism is uncontrolled, dietary restrictions should not be overly stringent. Calorie intake should be increased by 5–10 kcal/kg of body weight compared to individuals with diabetes alone, and foods rich in protein, trace elements, and vitamins should be prioritized.Regarding blood sugar management, for significantly emaciated patients, even if oral hypoglycemic agents control the condition, short-term insulin therapy is recommended. Once the hypermetabolic symptoms of hyperthyroidism subside, insulin dosage can be gradually reduced.