Effects of L-thyroxine supressive therapy in patients with euthyroid goiter

L-thyroxine suppressive therapy for euthyroid nodular goiter is still a treatment of choice. Many conceptions have been reported about efficacy of this therapy on thyroid nodule size, and bone mineral density. In addition, we could not encounter any study, related with thyroxin suppressive therapy and serum lipoproteins, and body mass index. In this prospective study, 20 euthyroid nodular goiter patients given L-thyroxine suppressive therapy were followed for changes in nodule size; bone mineral density, and serum lipids for 18-20 months. The thyroid nodule size was measured by thyroid ultrasound, and bone mineral density assessed with DEXA (Dual Energy X-Ray Absorptiometry) in the regions of hip and lumbar spine. Other laboratory studies were performed with auto-analyser devices. At the end of the study, nodule size, bone mineral density, and serum lipid levels did not show any significant changes before and after suppressive therapy (p>0.05). In conclusion, levothyroxine suppressive therapy did not cause any significant changes in thyroid nodule size, bone mineral density, serum lipid levels, and body mass index. However, when considered with the studies in literature, further studies are necessary. Key Words: L-thyroxine suppressive therapy, nodular goiter, bone mineral density, serum lipid profile.