The impact of thyroid diseases on bone metabolism and fracture risk.

Osteoporosis is a systemic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue, leading to enhanced bone fragility and a consequent increase in fracture risk. One of the leading causes of secondary osteoporosis are thyroid diseases; this fact carries special importance for Georgia because of thyroid disease prevalence in Georgian population. In the present article we discuss the mechanisms, by which thyroid hormones and thyroid stimulating hormone (TSH) act on bone. We also present the data of meta-analysis of large studies, which demonstrate the complex relationship between the thyroid diseases and bone mineral density as well as the fracture risk; namely by overt and subclinical thyrotoxicosis, hypothyroidism and the treatment with the suppressive doses of levothyroxine. Beside that, we review the related data and the possible reasons, why different treatment regimens of Grave's disease: conservative, operative and radioiodine are related to different fracture risks. Finally, we discuss briefly the practical aspects of the treatment of secondary osteoporosis, related with thyroid diseases.