抄録
Bone mineral density ( BMD ) decreases in Graves'disease due to the high rate of bone turnover with a predominance of resorption. Studies have evaluated the use of dual energy X-ray absorptiometry (DEXA) for investigating bone metabolism. Bone strength is a function of BMD and bone quality. Quantitative ultrasound (QUS), which involves no radiation exposure and uses portable equipment, assesses both BMD and bone quality. This study investigated the relationship between broadband ultrasound attenuation ( BUA ), speed of sound (SOS), and stiffness to BMD measured at the calcaneus in a closely matched region of interest (ROI) ; and the relationship between BMD and ultrasound parameters to markers of bone metabolism in female patients with Graves' disease. We investigated 9 patients with untreated Graves' disease (group G : mean age, 41.0±7.6 years) and 19 patients in remission from Graves' disease (group RG : mean age, 55.7±5.0 years) . Ultrasound parameters by QUS correlated significantly with calcaneus BMD in the ROI only for group RG, suggesting that bone quality played an additional role. In 8 patients who were in remission for more than 5 years, the Z-scores for ultrasound parameters of the calcaneus assessed by QUS were in the negative range. No significant correlation was found between blood or urine markers and ultrasound parameters or calcaneus BMD. These results show that the lack of a significant correlation between ultrasound parameters and BMD of the calcaneus in our present group G indicates that BUA and SOS are affected by mineral content and by other material and structural properties. In addition, even Graves' disease patients who are in long-term remission may not have had recovery of bone density to normal levels following hyperthyroidism.
