Thyroid stimulating hormone (TSH) suppression therapy in differentiated thyroid carcinoma (DTC) has been reported to increase fracture risk and reduce bone mineral density (BMD). However, there are few studies analyzing serial BMD data of a patient over 3 years. Also, the relationship of TSH suppression and trabecular bone score (TBS) is still unclear. The aim of this study is to investigate the effect of TSH suppression therapy on BMD and TBS through serial follow-up data over 3 years.
We conducted a retrospective cohort study including 110 postmenopausal women with DTC who had received TSH suppression therapy and 30 control subjects matched for age, sex, and type of thyroidectomy. BMD in the spine and hip area and TBS were measured by dual energy X-ray absorptiometry (DXA). Data of BMD and TBS was checked at within a year from surgery, 1 year, 2 years, and 4 years after the surgery. All patients had the data at within a year from surgery and at least one follow-up DXA was conducted.
The % difference over time was calculated for BMD of L spine and hip, and TBS. TSH suppression group showed significant % reduction in BMD of L spine and hip earlier than control group. For TBS, control group had no significant change over time, but TSH suppression group showed significant change from 2 years after the surgery. With mixed linear regression analysis, there was significant difference in TBS over time between control and suppression group.
TSH suppression in postmenopausal DTC patient showed earlier reduction in BMD of L spine and hip and TBS.