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THE EFFECT OF IODIZED OIL ON GOITRE SIZE, THYROID FUNCTION AND THE DEVELOPMENT OF THE JOD BASEDOW PHENOMENON *
Author(s) -
MABERLY G. F.,
CORCORAN J. M.,
EASTMAN C. J.
Publication year - 1982
Publication title -
clinical endocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 147
eISSN - 1365-2265
pISSN - 0300-0664
DOI - 10.1111/j.1365-2265.1982.tb01587.x
Subject(s) - medicine , endocrinology , iodine , thyroid function , iodine deficiency , goiter , thyroid , thyroid function tests , chemistry , organic chemistry
SUMMARY In the Lubok Antu district of Sarawak, Malaysia, 240 subjects with 75% prevalence of goitre were studied before and at intervals of 1 and 2 years following iodized oil injection. After 1 year the prevalence of goitre was reduced to 33%, but 2 years after injection, goitres had regrown in fourteen subjects (6%). The mean urinary iodine concentration was low initially at 0±17±0±08 (SD) μmol/l, consistent with iodine deficiency, and rose to a level of 2±6 ± 2±5 μmol/l at 1 year, before falling to 0±46 ± 0±38 μmol/l, again consistent with deficiency. Such a rapid depletion of iodine may be related to the high consumption of cassava. Before injection serum TSH concentrations showed a wide scatter from normal up to 62 mU/l and at 1 year, serum TSH concentrations were undetectable. At 2 years serum TSH was again detectable in 50% of subjects with levels up to 8±6 mu/l. During the 2 years, there was a progressive rise in the mean serum T4 concentration from 92 ± 22 (SD) nmol/l to 110 ± 22 nmol/l ( P < 0±05). Serum T3 concentrations rose serially in all subjects from a pre‐injection mean of 1±9 ± 0±3 nmol/l to 2±5 ± 0±9 nmol/l ( P < 0±001) and then fell significantly below the baseline level to a mean of 1±7 ± 0±6 nmol/l 2 years after injection ( P < 0±01). The mean serum rT3 levels followed the same trend. At 1 or 2 years following injection, eight subjects were clinically hyperthyroid. Four of these consented to venesection and hyperthyroidism was confirmed biochemically. These data reveal that:1 goitres decreased rapidly in size in response to iodized oil injection; 2 2 significant though incomplete depletion of the iodine stores occurred within 2 years of injection; 3 the consistent increase in serum T3 was associated with a fall in serum TSH to undetectable levels; 4 the prevalence of the Jod Basedow phenomenon was l±7%.These data suggest the need for closer biochemical monitoring of subjects receiving massive doses of iodine and a reappraisal of the use of iodized oil in the treatment of endemic goitre.