Department of Endocrinology, Odense University Hospital, Odense, Denmark.
Department of Clinical Research, University of Southern Denmark, Odense, Denmark.
Endocrine. 2021 Feb;71(2):397-406. doi: 10.1007/s12020-020-02398-y. Epub 2020 Jul 4.
Fracture risk in hypothyroid patients is debated, and since the effects of hypothyroidism on bone microarchitecture and strength are unclarified, we investigated these characteristics by high-resolution peripheral quantitative computed tomography (HR-pQCT).
Two approaches were used: a cross-sectional control study, comparing 32 hypothyroid women (mean age; 47 ± 12 years) suffering from Hashimoto's thyroiditis with 32 sex-, age-, and menopause-matched healthy controls; a prospective study, where 27 of the women were reexamined 1 year after restoration of euthyroidism. HR-pQCT of the distal radius and tibia, and dual-energy X-ray absorptiometry (DXA) of the spine and hip were performed. Bone strength was estimated using a finite element analysis (FEA).
Cross-sectional control study: in the radius, total (mean 14.6 ± 29.3% (SD); p = 0.04) and trabecular bone areas (19.8 ± 37.1%, p = 0.04) were higher, and cortical volumetric bone mineral density (vBMD) lower (-2.2 ± 6.5%, p = 0.032) in hypothyroid patients than in controls. All indices of tibia cortical and trabecular vBMD, microarchitecture, and estimated bone strength were similar between groups, as was hip and spine areal BMD (aBMD). Prospective study: in the radius, mean cortical (-0.9 ± 1.8%, p = 0.02) and trabecular (-1.5 ± 4.6%, p = 0.02) vBMD decreased, and cortical porosity increased (18.9 ± 32.7%, p = 0.02). In the tibia, mean total vBMD (-1.1 ± 1.9%, p = 0.01) and cortical vBMD (-0.8 ± 1.4%, p = 0.01) decreased, while cortical porosity (8.2 ± 11.5%, p = 0.002) and trabecular area (0.2 ± 0.6%, p = 0.047) increased. No changes in FEA were detected. Lumbar spine aBMD decreased (-1.3 ± 3.0%, p = 0.04).
Hypothyroidism was associated with an increased trabecular bone area and a lower mineral density of cortical bone in the radius, as assessed by HR-pQCT. Restoration of euthyroidism mainly increased cortical porosity, while estimated bone strength was unaffected.
甲状腺功能减退症患者的骨折风险存在争议，由于甲状腺功能减退症对骨微观结构和强度的影响尚不清楚，我们通过高分辨率外周定量计算机断层扫描（HR-pQCT）来研究这些特征。
采用两种方法：一项横断面对照研究，比较 32 名患有桥本甲状腺炎的甲状腺功能减退症女性（平均年龄 47 ± 12 岁）与 32 名性别、年龄和绝经匹配的健康对照者；一项前瞻性研究，其中 27 名女性在恢复甲状腺功能正常后 1 年接受复查。对桡骨和胫骨进行 HR-pQCT 检查，对脊柱和髋部进行双能 X 线吸收法（DXA）检查。使用有限元分析（FEA）来估计骨强度。
横断面对照研究：在桡骨中，总骨面积（平均 14.6 ± 29.3%（SD）；p = 0.04）和小梁骨面积（19.8 ± 37.1%，p = 0.04）更高，而皮质体积骨矿物质密度（vBMD）更低（-2.2 ± 6.5%，p = 0.032）。甲状腺功能减退症患者与对照组相比，所有胫骨皮质和小梁 vBMD、微观结构和估计的骨强度指数均相似，髋部和脊柱面积 BMD（aBMD）也相似。前瞻性研究：在桡骨中，平均皮质（-0.9 ± 1.8%，p = 0.02）和小梁（-1.5 ± 4.6%，p = 0.02）vBMD 降低，皮质孔隙度增加（18.9 ± 32.7%，p = 0.02）。在胫骨中，总 vBMD（-1.1 ± 1.9%，p = 0.01）和皮质 vBMD（-0.8 ± 1.4%，p = 0.01）降低，而皮质孔隙度（8.2 ± 11.5%，p = 0.002）和小梁面积（0.2 ± 0.6%，p = 0.047）增加。未检测到 FEA 的变化。腰椎 aBMD 降低（-1.3 ± 3.0%，p = 0.04）。
HR-pQCT 评估显示，甲状腺功能减退症与桡骨的小梁骨面积增加和皮质骨矿物质密度降低有关。恢复甲状腺功能正常后主要增加皮质孔隙度，而估计的骨强度不受影响。
