The effect of thyroid suppression therapy (TST) on trabecular bone scores (TBS) and bone mineral density (BMD) in thyroidectomized women with differentiated thyroid carcinoma (DTC) on long-term follow-up is presently not conclusive.
Patients and methods: We carried out a study in 61 premenopausal and 84 postmenopausal Caucasian women with DTC. Serum biochemistry, bone markers, TBS, BMD, and bone fractures were evaluated 1-3 months post surgery and after a median follow-up of 10 years.
Results: In the final study, patients belonged to Group I Premenopausal (n = 14) who remained in this status; Group II Premenopausal who became postmenopausal (n = 47); Group III patients who were and continued as postmenopausal (n = 84). Baseline premenopausal patients had a normal TBS mean value of 1.39 ± 0.14 significantly higher than that found in postmenopausal 1.31 ± 0.12 (p = 001). In the final study, premenopausal patients continued to have a normal TBS of 1.46 ± 0.08 compared to the significantly lower value of postmenopausal patients 1.25 ± 0.11 (p = 0.0009). Lumbar BMD (L-BMD) loss after the long-term study was significant in Group II (0.99 g/cm2 ± 0.13 vs. 0.91 ± 0.12 g/cm2, p < 0.0001) and there was a slight, but not significant, bone loss in Group I (1.00 ± 0.12 vs. 0.98 ± 0.11, p = 0.1936) and in Group III (0.86 ± 0.12 vs. 0.84 ± 0.15, p = 0.1924) compared with baseline values.
Conclusion: Longer-term suppression therapy in female patients with DTC did not increase significantly the risk of bone loss, although we found in postmenopausal patients deterioration of bone microarchitecture. TBS study should be considered in the evaluation of postmenopausal DTC patients on long-term DTC for the evaluation of the risk of fractures.
Keywords: Bone mineral density; Differentiated thyroid cancer; TSH suppression therapy; Trabecular bone score.