Excess endogenous and exogenous thyroid hormone has been previously associated with increased bone loss in vivo.1-3 In this issue of the Archives, Coindre et al describe the pathologic changes in the bone of hypothyroid individuals before and after thyroid replacement.4 Their data and those of others5-7 indicate that hypothyroidism results in increased bone mass. They report that subsequent thyroid replacement to the euthyroid state results in loss of both cortical and trabecular bone and osteopenia.4 These provocative findings are supported by a previously reported densitometric study demonstrating significant loss of lumbar bone mass in similar patients.8 These studies are of particular concern as they are the first reports of increased bone loss associated with appropriate thyroid hormone levels.
Thyroid hormones represent one of the most common medications administered,9 particularly to white perimenopausal and postmenopausal women. This group is also specifically at risk to develop symptomatic bone loss.10,11 Any unnecessary medication
Perry HM. Thyroid Replacement and Osteoporosis. Arch Intern Med. 1986;146(1):41-42. doi:10.1001/archinte.1986.00360130051003