Arata N, Momotani N, Maruyama H, Saruta T, Tsukatani K, Kubo A, Ikemoto K, Ito K
Department of Medicine, Medical School, Keio University, Tokyo, Japan.
Thyroid. 1997 Aug;7(4):547-54. doi: 10.1089/thy.1997.7.547.
Restoration of bone loss associated with thyrotoxicosis follows normalization of thyroid function. However, the extent of bone loss and restoration remain controversial. To clarify whether bone recovery is complete, we examined lumbar and femoral bone mineral density (BMD) by dual-energy x-ray absorptiometry (DXA) in 14 thyrotoxic premenopausal women with Graves' disease and 31 premenopausal women treated for Graves' disease by subtotal thyroidectomy who had been in remission for at least 3 years. In the remission group, to exclude the influence of subclinical hyperthyroidism, thyrotropin (TSH) levels were followed and subjects with low levels excluded. Thus, all 31 subjects had normal thyroid hormone levels with transiently or persistently elevated TSH levels post-thyroidectomy. Data from the two study groups were compared with those from healthy premenopausal controls matched for age, height and weight. Mean lumbar (anterior-posterior and lateral), femoral neck, and trochanter BMDs were significantly lower in the thyrotoxic group than in controls (p < .05, all four BMDs). Mean lumbar (anterior-posterior), femoral neck and trochanter BMDs were significantly higher in the remission group than in controls (p < 0.05, all three BMDs). At the time of DXA, the 31 remission subjects showed a significant positive correlation between lumbar BMD and TSH (p < 0.05) and a significant negative correlation between femoral neck BMD and free triiodothyronine (FT3) (p < 0.05). These observations suggest: (1) in premenopausal women, bone loss associated with thyrotoxicosis due to Graves' disease is present but is fully restored when remission is reached after subtotal thyroidectomy; (2) subclinical hypothyroidism after subtotal thyroidectomy may result in higher BMD than that of controls.
甲状腺毒症相关的骨质流失会随着甲状腺功能的正常化而恢复。然而，骨质流失和恢复的程度仍存在争议。为了明确骨质恢复是否完全，我们通过双能X线吸收法（DXA）检测了14例患有格雷夫斯病的甲状腺毒症绝经前女性以及31例因格雷夫斯病接受甲状腺次全切除术且已缓解至少3年的绝经前女性的腰椎和股骨骨密度（BMD）。在缓解组中，为排除亚临床甲状腺功能亢进的影响，对促甲状腺激素（TSH）水平进行跟踪，并排除TSH水平低的受试者。因此，所有31名受试者甲状腺激素水平正常，甲状腺切除术后TSH水平短暂或持续升高。将两个研究组的数据与年龄、身高和体重相匹配的健康绝经前对照组的数据进行比较。甲状腺毒症组的平均腰椎（前后位和侧位）、股骨颈和大转子骨密度显著低于对照组（所有四个骨密度，p < 0.05）。缓解组的平均腰椎（前后位）、股骨颈和大转子骨密度显著高于对照组（所有三个骨密度，p < 0.05）。在进行DXA时，31名缓解受试者的腰椎骨密度与TSH之间存在显著正相关（p < 0.05），股骨颈骨密度与游离三碘甲状腺原氨酸（FT3）之间存在显著负相关（p < 0.05）。这些观察结果表明：（1）在绝经前女性中，与格雷夫斯病导致的甲状腺毒症相关的骨质流失存在，但在甲状腺次全切除术后达到缓解时会完全恢复；（2）甲状腺次全切除术后的亚临床甲状腺功能减退可能导致骨密度高于对照组。
