In this study, we evaluated the effect of thyroxine treatment on bone mineral density in premenopausal women with thyroid nodules. Twenty women were accepted for this study. L-thyroxine was started at a dose of 100 g/day by oral route for a 6-month period. Before and after the treatment bone mineral densities of the femur neck and AP spine were measured. Paired-t test and ANOVA were used in statistical analysis. Serum TSH levels of the patients were found to be within the normal range at the 1st, 2nd, 3rd, 4th , 5th and 6th months. But serum TSH levels at these months decreased with the treatment when compared to basal levels (Basal 1.96±0.77, 6 th month 0.23±0.05 and p=0.0001). On the contrary, bone mineral density (BMD) and Z-scores of the femur neck and vertebra of the patients did not show any significant change (basal BMD is 1.02±0.10 in femur neck and 1.11±0.11 in vertebra. Bone mineral density was 1.10±0.08 in femur neck and 1.14±0.12 in vertebra at 6 th month). Conclusions; treatment of benign thyroid nodules with L-thyroxine leads to hyperthyroidism. L-thyroxine treatment affected neither BMD nor Z-score.
Keywords: Bone mineral density, thyroxine, TSH and benign thyroid nodule