Endocrine Abstracts

Background: TSH-suppressive therapy in patients with differentiated thyroid carcinoma (DTC) leads to iatrogenic thyrotoxicosis and may be associated with alterations in body composition and bone mineral density (BMD). Its effects on a sarcopenia in elderly have not been in detail investigated.

Objective: The objective was to compare changes in total and areal lean body mass (LBM), body fat mass (BFM) and BMD in postmenopausal female patients with DTC during the first 5 years of TSH-suppressive therapy and in control subjects.

Subjects and methods: One hundred and forty females with DTC (menopausal <10 years (n=83) or >10 years (n=57)) and 40 control subjects (menopausal <10 years (n=15) or >10 years (n=25)) were included in this retrospective study. Body composition and BMD were measured at 1, 3 and 5 years after initiation of TSH suppressive therapy.

Results: Body composition and BMD were not significantly different at baseline between the study groups. At 5 years, the results showed that women with DTC more than 10 years post menopause have a significantly increased loss of total LBM and leg LBM (P=0.02 and P=0.03) and total BFM (P=0.04).

Conclusion: Lean mass decreases to a greater extent in women with DTC more than 10 years post menopause suggesting that TSH-suppressive therapy may accelerate progression of age-related muscle loss in post-menopausal women.