| Objective To observe the effect of TSH suppressive therapy on bone mineral density (BMD) and bone metabolism in a six-month follow-up in patients with differentiated thyroid carcinoma (DTC). Methods According to follow-up time, gender, menstruation, and calcium supplementation, 30 DTC patients were divided into different groups. BMD of the lumbar and hip and bone turnover markers (β-collagen specific sequences and procollagen I N-terminal peptide) were examined in the preoperative and the end of follow-up time, respectively. Results After the treatment, β-crosslaps significantly decreased, but PINP significantly increased, comparing to that before the treatment (P <0.05). The follow-up time was positively correlated with BMD of the L3 segment and the whole lumbar vertebrae，but was negatively correlated with BMD of the hip (P < 0. 05). In one-year of follow-up after the treatment, β-crosslaps significantly decreased comparing to that before the treatment (P<0. 05). β-crosslaps significantly decreased in calcium group comparing to that in non-calcium (P < 0. 05). In the less than one-year of follow-up group，BMD and Z value of L3 was significantly lower in premenopausal women than that in male patients (P < 0. 05). In one-year of follow-up group, BMD and Z value of L3 was significantly lower in in males than that in females (P < 0. 05). Changes in BMD of all lumbar spine was positively correlated with TSH, while changes in BMD of overall hip was negatively correlated with TSH. Conclusion The longer time the TSH suppression therapy uses, the lower BMD of the hip and the higher BMD of the lumbar vertebra are. The correlation analysis shows that TSH suppression therapy is not associated with BMD of the lumbar vertebrae, but is closely associated with BMD of the hip，which is most obviously in postmenopausal women. TSH suppression therapy affects bone turnover indexes. |