What to watch with FT4 and Blutzucker?

FT4 (free thyroxine) and blood glucose are metabolically linked. Thyroid hormones stimulate gluconeogenesis and glycogenolysis; thus hyperthyroidism can raise fasting glucose or worsen glucose tolerance, while hypothyroidism reduces hepatic glucose output and may increase hypoglycemia risk, especially in diabetics on insulin or sulfonylureas. Thyroid hormones also affect insulin secretion and sensitivity. When interpreting FT4 and blood glucose together, consider medications (e.g., metformin, glucocorticoids, beta-blockers) and comorbidities (e.g., liver or kidney function). An isolated high FT4 without TSH suppression may indicate euthyroid sick syndrome or TBG abnormalities. Evidence is based on clinical practice and endocrine guidelines. Caveat: Individual assessment by a physician is essential because interactions vary.