Evaluation of bone mineral density in hyperthyroid patients before and after medical therapy

Osteoporosis is a common complication of hyperthyroidism, but it is not often evaluated. The aim of this study is to examine bone mineral density (BMD) (dual energy X-ray absorptiometry: DEXA) in lumbar spine (L1-L4), femoral neck (FN) and Ward's triangle (TW) in 45 hyperthyroid patients (group A: n 25 active hyperthyroidism, group B: n 20 controlled hyperthyroidism on medical therapy, after a mean of 7 months of euthyroidism), compared to control group (group C: n 22). These 3 groups are adjusted by age, sex, menopausal status and BMI. In hyperthyroid patients (group A), as compared to the control group, we noticed a significant reduction of BMD (z score) in different sites, more markedly in the lumbar spine (p L1-L4: 0,005; p FN: 0,011; p TW: 0,019). In group A, no differences were found between BMD values after adjustment for Z score whatever the menopausal status (p L: 0.12; p FN: 0.33; p TW: 0.09) and degree ofhyperthyroidism (p L: 0.48; p FN: 0.41; p TW: 0.21). The degree of BMD in group B patients was different from that of patients in group A (p L: 0.37; p FN: 0.28; p TW: 0.31). and was significantly lower than in those of group C except for the TW (p L: 0.009; p CF: 0.038; p TW: 0.068). We conclude that it is important to consider that after reaching euthyroidism hyperthyroidism patients present a bone risk.