The Protein-Bound Plasma Iodine in Patients with Thyroid Disease1

Endocrine Review: THE CLINICAL SIGNIFICANCE OF THE BLOOD IODINE: A REVIEW*

“…They found this relationship to be valid both before and after treatment with thiouracil. However, since the basal heat production fell more slowly that the PBI, this relationship did not hold for the first two weeks following initiation of treatment (181). In another report on 32 patients they found the PBI directly correlated with heat production regardless of age, sex, thyroid disease, lugolization or thyroidectomy (99).…”

“…Lowenstein and his associates gave thiouracil to 18 patients with hyperthyroidism and caused a reduction of the PBI, beginning in from four to seven days, which reached normal within two weeks. Basal heat production fell more slowly, seldom beginning to decline in less than one week, however, likewise approximating normal after two weeks (181). Riggs also states that a sudden alteration in the level of thyroid activity, such as following subtotal thyroidectomy or in response to thiouracil therapy, is more rapidly reflected in the serum iodine level than in the metabolic rate (100).…”

“…The serum iodine responds more rapidly to alterations in thyroid status than does the BMR (100,181,184). Likewise it is less subject than is the BMR to fluctuations in serial determination (100).…”