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Brennan et al., Rochester, MI, USA, quantitated muscle strength,
volume, and efficiency in 10 female patients with hyperthyroidism before
and between 6-9 months after achieving a euthyroid state. Treatment of
hyperthyroidism resulted in 10% increase in thigh muscle cross-sectional
area and 12% in total lower extremity muscle volume. Mean thigh muscle
strength increased by 57% and muscle efficiency (defined as force of muscle
per unit of muscle volume) increased by 46%. (Comment: These results show
that muscle force is not only decreased in hyperthyroidism due to a decrease
in muscle volume but also due to a decrease in muscle strength per unit
of volume. In other words, quality of muscle function is decreased in hyperthyroidism,
the mechanism of which has yet to be elucidated.)
Gómez Acotto et al., Buenos Aires, Argentina, studied changes in body lean tissue and body fat 6 and 12 months after antithyroid therapy in 10 women with hyperthyroid Graves' disease, using dual energy X-ray absorbtiometry. They found that lean and fat masses were decreased in untreated patients as compared to matched controls. The diminution was greater in legs than in arms and trunk. Treatment of hyperthyroidism resulted in an increase of fat mass of arms and trunk of 27 and 10% respectively and of lean mass of the arms of 9%. Imseis et al., Memphis, TN, USA, re-evaluated the effects of propylthiouracil (PTU) and methimazole (MMI) or no drug pre-treatment on the subsequent effect of 131 therapy retrospectively in 93 patients treated for hyperthyroidism. They found that cure rates in MMI or no drug pre-treated patients were similar (61% and 66% respectively) but much lower in PTU pre- treated patients (24%). (Comment: The literature with regard to a possible decreased effectiveness of 131 therapy after antithyroid drug treatment, is controversial. This report is the first that compares the effects of PTU and MMI and may be that this explains why some previous studies found a negative effect of antithyroid drugs, while others did not.) Stenlöf et al., Gothenburg, Sweden, measured serum leptin concentrations before and one year after treatment for hyperthyroidism. During the same period serum leptin concentrations increased by about 40%. This increase correlated very well with increase in body fat as after correction for this, serum leptin levels were similar before and after treatment. |
