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Treatment of endemic goitre due to iodine deficiency with iodine, levothyroxine or both: results of a multicentre trial
Author(s) -
HINTZE G.,
EMRICH D.,
KÖBBERLING J.
Publication year - 1989
Publication title -
european journal of clinical investigation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.164
H-Index - 107
eISSN - 1365-2362
pISSN - 0014-2972
DOI - 10.1111/j.1365-2362.1989.tb00270.x
Subject(s) - euthyroid , levothyroxine , medicine , iodine , group b , iodine deficiency , thyroid , group a , gastroenterology , randomized controlled trial , endocrinology , chemistry , organic chemistry
. Preliminary clinical studies and recent in vitro investigations suggest that iodine administration may be an effective alternative in the treatment of the diffuse euthyroid goitre of iodine deficiency. Therefore a 12‐month multicentre study was initiated in which 166 patients were randomly assigned to take either 150 μg levothyroxine day‐ 1 (group A, n = 61), 400 μg iodine day‐ 1 (group B, n = 50), or a combination of 75 μg levothyroxine and 200 μg iodine day ‐1 (group C, n = 55) for 8 months with follow‐up examinations at 4 and 8 months as well as 4 months after cessation of treatment. Initially, thyroid volume, as determined by ultrasound, was not significantly different in the three groups. In all three groups, during treatment a significant and comparable mean decrease in goitre size was documented (‐32.1% in group A, ‐37.3% in group B, ‐38.7% in group C). After cessation of treatment in group A mean thyroid volume again increased to near the baseline value (‐12.0% compared to the initial investigation), while the therapeutic effect was sustained in group B (‐32.5%). In group C, only a slight rebound effect was observed (‐26.3% vs baseline volume). Total thyroxine (T 4 ) increased sharply and significantly in group A from 7.8 ± 1.9 to 10.9 ± 2.8 μg dl ‐1 after 8 months ( P <0.001), but only slightly, although significantly in group B (from 7.8±1.5 μg dl ‐1 to 8.9 ± 1.6 μg dl ‐1 ; P <0±02). Striking differences between the three groups were evident in the changes of basal and thyrotropin releasing hormone (TRH) stimulated thyrotropin (TSH). After 8 months a sharp and significant decrease of TSH occurred in group A (from 1.2±0.53 to 0.4±0.74 μU ml ‐1 ; P <0001) and in group C (from 1.2 ± 0.97 to 0.5±0.56 μ ml ‐1 ; P <0.001). In group B, TSH was also significantly lower (from 1.3 ± 1.04 to 0.9 ± 0.72 μUml‐ 1 ; P <0.02), but remained significantly higher compared to group A and group C. Similar changes were observed when the TSH after TRH administration was calculated. After cessation of treatment, the values for basal TSH and TRH‐stimulated TSH in the three groups were not significantly different from each other. They had increased to the initial values. Our data clearly show that iodine alone (400 μg day ‐1 ) or a combination of 75 μg levothyroxine and 200 μg iodine day ‐1 are at least equally as effective for goitre reduction as levothyroxine alone (150 μg day ‐1 ) and offers the further benefit of a sustained effect after cessation of therapy.