Lee Su Jin, Kim Kyoung Min, Lee Eun Young, Song Mi Kyung, Kang Dae Ryong, Kim Hyeon Chang, Youm Yoosik, Yun Young Mi, Park Hyun-Young, Kim Chang Oh, Rhee Yumie
1Department of Internal Medicine, Severance Hospital, Endocrine Research Institute, Yonsei University College of Medicine, Seoul, Korea; 2Department of Internal Medicine, National Health Insurance Service Ilsan Hospital, Goyang, Korea.
3Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
Aging Dis. 2016 Dec 1;7(6):734-743. doi: 10.14336/AD.2016.0325. eCollection 2016 Dec.
Subclinical hyperthyroidism is known to be associated with the risk of fractures in elderly people. However, there are few studies assessing whether low normal thyroid-stimulating hormone (TSH) levels affect bone density and geometry. Here, we aimed to assess the influence of the TSH level on bone mineral density (BMD) and geometry in elderly euthyroid subjects. This was a cross-sectional cohort study. A total of 343 men and 674 women with euthyroidism were included and analyzed separately. The subjects were divided into tertiles based on the serum TSH level. The BMD and geometry were measured using dual-energy X-ray absorptiometry and a hip structural analysis program. Multiple regression analysis was used to compute the odds ratios of osteoporosis in the lower TSH tertile group and the association between geometry parameters and the TSH level. We found that the femoral neck and total hip BMDs were lower in the lower TSH tertile group. In women, the cross-sectional area and cortical thickness of the femur were negatively associated with the TSH level in all three regions (the narrow neck, intertrochanter, and femoral shaft); however, in men, these geometry parameters were significantly associated with the TSH level only in the intertrochanter region. The buckling ratio, a bone geometry parameter representing cortical instability, was significantly higher in the lower TSH tertile group in all three regions in women, but not in men. Our results indicated that lower TSH levels in the euthyroid range are related to lower BMD and weaker femoral structure in elderly women.
已知亚临床甲状腺功能亢进与老年人骨折风险相关。然而，评估甲状腺刺激激素（TSH）水平处于低正常范围是否会影响骨密度和骨几何形态的研究较少。在此，我们旨在评估TSH水平对老年甲状腺功能正常受试者骨矿物质密度（BMD）和骨几何形态的影响。这是一项横断面队列研究。共纳入343名男性和674名甲状腺功能正常的女性，并分别进行分析。根据血清TSH水平将受试者分为三分位数组。使用双能X线吸收法和髋部结构分析程序测量BMD和骨几何形态。采用多元回归分析计算TSH较低三分位数组骨质疏松的比值比以及骨几何形态参数与TSH水平之间的关联。我们发现，TSH较低三分位数组的股骨颈和全髋BMD较低。在女性中，股骨的横截面积和皮质厚度在所有三个区域（窄颈、转子间和股骨干）均与TSH水平呈负相关；然而，在男性中，这些骨几何形态参数仅在转子间区域与TSH水平显著相关。屈曲比是代表皮质不稳定性的骨几何形态参数，在女性的所有三个区域中，TSH较低三分位数组的屈曲比均显著较高，但在男性中并非如此。我们的结果表明，甲状腺功能正常范围内较低的TSH水平与老年女性较低的BMD和较弱的股骨结构有关。
