Is subclinical hyperthyroidism dangerous?
The answer may depend on age and sex, Dr. Hart said. The first possible consequence of subclinical hyperthyroidism, decreased bone mineral density, has been found in postmenopausal women but not in men or younger women with the same thyroid level. Cardiac dysfunction, the second possible consequence, may be age-related. A recent Framingham study found that a significant number of subjects with thyroid stimulating hormone (TSH) less than 0.1 had developed atrial fibrillation on 10-year follow-up, suggesting low TSH is a risk factor in older patients, as a surrogate measure of subtle hyperthyroidism. • Is iodine 131 (131I) radiation treatment bad for bad eyes? Earlier retrospective studies suggested eye changes following treatment were more related to the development of hyperthyroidism than to the primary mode of therapy, whether the antithyroid drugs favored by Europeans or the 131I more often used by North Americans. However, a more recent two-year prospective study concluded that 131I
