Fasting glucagon-like peptide-1 in patients with overt hyperthyroidism and euthyroid congenital hypothyroidism

Aim: To investigate the influence of overt hyperthyroidism and euthyroid congenital hypothyroidism on fasting glucagon-like peptide-1 (GLP-1) levels. Methods: A total of 30 untreated overt hyperthyroidism patients, 17 euthyroid congenital hypothyroidism children, and age-and sex-matched controls were enrolled. Levels of GLP-1, insulin, glucose, and homeostasis model assessment (HOMA-IR) were measured and evaluated. Results: Fasting GLP-1, blood glucose, insulin, and HOMR-IR levels were higher in patients with overt hyperthyroidism than in controls (p =0.030, p=0.008, p=0.004, p=0.037, respectively). These parameters in euthyroid hypothyroidism were similar to the controls. In euthyroid congenital hypothyroidism and overt hyperthyroidism patients, serum GLP-1 levels were not correlated with thyroid hormone, blood glucose, insulin, and HOMR-IR. Conclusions: Fasting GLP-1 levels in the peripheral circulation were significantly increased in overt hyperthyroidism, however, they were no different in euthyroid congenital hypothyroidism.