|
Hallengren et al., Lund, Sweden, studied the fracture incidence
up to 1993 in 333 patients who were treated for thyrotoxicosis between
1970-1974. For each patient two control patients without thyrotoxicosis
were selected. Comparing all types of fractures, in females there were
fewer fractures in patients than in controls, and the controls had their
fractures at an earlier age than the patients. There were no differences
between male patients and controls. (Comment: There is no doubt that thyrotoxicosis
induces osteoporosis. The results of this study either indicate that thyrotoxicosis
was generally detected at a very early stage without development of significant
osteoporosis and/or that patients were rather young, and still had strong
bones at the time thyrotoxicosis was detected and treated, because especially
the combination of old age and osteoporosis leads to an increased fracture
rate.)
Tielens et al., Rotterdam, The Netherlands, studied cardiovascular status, using multi-gated equilibrium radionuclide ventriculography, in 11 patients with primary hypothyroidism at diagnosis and during substitution when euthyroidism was reached and in 12 patients with hyperthyroidism at diagnosis and at euthyroidism after treatment. The following results were obtained; In hypothyroidism: impaired diastolic function, a decreased afterload independent contractility and maintenance of cardiac output by a compensatory increase in end-diastolic volume. In hyperthyroidism: a markedly increased diastolic function, an augmented systolic cardiac performance and an increased cardiac output due to an increased heart rate. All abnormalities disappeared at the time of euthyroidism. Verhoeven et al., Rotterdam, The Netherlands, studied the effects of calcium channel blockers on T3 uptake in cardiac myocytes of neonatal rats. They found that in the order of Nifedipine > Verapamil > Diltiazem inhibition of both calcium entry and T3 transport in cardiac myocytes was observed. It was concluded that the inhibition of thyroid hormone transport into cardiac myocytes, effected by calcium channel blockers, may thus contribute to the decrease in cardiac output being beneficial in angina pectoris. |
