Background: TSH suppression therapy has been associated with hip and vertebral fracture. However, the relationship between TSH suppression and bone mineral density (BMD) remains controversial. The aim of this study was to evaluate the effect of TSH suppression therapy on cortical bone geometry in differentiated thyroid cancer (DTC) patients.
Methods: This study included 122 subjects (19 men, 27 premenopausal women, and 75 postmenopausal women) who have been on TSH-suppressive doses of levothyroxine after thyroidectomy due to DTC during at least 3 years. Patients were matched with 366 healthy controls. Dual-energy X-ray absorptiometry at the hip and lumbar spine was performed and geometry of hip was analysed.
Results: The mean TSH level was 0.23±0.44 μIU/ml and the proportion of calcium/vitamin D supplement was 51.6% in 122 subjects. TSH suppression therapy did not impair the BMD of patients compared with controls. In addition, cortical bone geometry including cortical width of femur neck (5.5±1.9 vs 5.4±1.1, P=0.903 in men, 5.9±1.1 vs 5.0±0.6, P=0.079 in premenopausal women, and 5.0±0.9 vs 5.1±0.7, P=0.563 in postmenopausal women) and buckling ratio (4.0±2.1 vs 4.0±1.4 in male, 3.0±0.8 vs 3.4±0.3 in premenopausal women, and 3.6±0.7 vs 3.5±0.6 in postmenopausal women) showed no significant difference in patients compared to healthy controls.
Conclusions: There was little evidence of adverse effect of TSH suppression on cortical bone geometry in DTC patients.
16 - 20 May 2015
European Society of Endocrinology