Catecholamine and thyroid hormones in traumatic injury

During hyperthyroidism, hypothyroidism, and severe stress there is often an inverse relationship between plasma norepinephrine (NE) and thyroid hormones. We evaluated this relationship in patients who were severely burned, patients who had injury to both brain and body, patients with head injury, and patients receiving high dose barbiturates for head injury. Head-injured patients had a low thyroxine (T4), low triiodothyronine (T3), and high reverse T3. Phenytoin for control of seizures lowered T3 and T4 and increased thyroid-stimulating hormone. Burned patients had a strong negative correlation between NE and T3 (r = -.88, p < .001). Patients with injury to both brain and body had a weak negative correlation between NE and T3 (r = -.5, p = .06). Patients with head injury showed no correlation between NE and T3. Severely injured patients had a close inverse relationship between elevated NE levels and depressed T3 levels. This relationship appears to depend on an intact CNS, as the relationship was disrupted by head injury and barbiturates.