The comparative study of bone mineral density between premenopausal women receiving long term suppressive doses of levothyroxine for well-differentiated thyroid cancer with healthy premenopausal women.

OBJECTIVE

To compare bone mineral density (BMD) of lumbar spines (LS) and femoral neck (FN) by Dual energy X-ray absorptiometry (DEXA) in premenopausal well-differentiated thyroid carcinoma women S/P total or near total thyroidectomy with a control group and the effect of Levothyroxine (LT4) to BMD between short term and long term treatment.

MATERIAL AND METHOD

DEXA were performed at LS (L1-L4) and FN in 22 premenopausal thyroid carcinoma women S/P total or near total thyroidectomy followed by 1-131 ablation and long term suppressive dose LT4 and 22 healthy premenopausal women.

RESULTS

Mean BMD of LS and FN were not significantly different between thyroid cancer group and control (LS 1.023 +/- 0.088 VS 0.980 +/- 0.075 g/cm2, p > 0.05, FN 0.800 +/- 0.068 VS 0.770 +/ - 0.061 g/cm2, p > 0.05). Period of time taking suppressive doses LT4 was divided into 3 groups (2-5 6-10 yrs and 11-14 yrs). Mean LS BMD +/- S.D of 2-5 yrs, 6-10 yrs and 11-14 yrs therapy are 1.042 +/- 0.135, 1.004 +/- 0.044 and 1.042 +/- 0.055 respectively (p > 0.05). Mean FN BMD +/- S.D of 2-5 yrs, 6-10 yrs and 11-14 yrs therapy are 0.808 +/- 0.084, 0.781 +/- 0.067 and 0.816 +/- 0.013 respectively (p > 0.05).

CONCLUSION

The suppressive doses LT was not the risk factor of osteoporosis. Although, there was no 4 statistically significant difference of BMD between short and long-term suppressive doses LT groups, the present sample size was not enough to conclude that long-term suppressive doses LT did not decrease BMD.