Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, 100730, China.
Department of Endocrinology, Key Laboratory of Endocrinology of Ministry of Health; Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Shuaifuyuan No. 1, Dongcheng District, Beijing, 100730, China.
Osteoporos Int. 2017 Aug;28(8):2383-2390. doi: 10.1007/s00198-017-4041-0. Epub 2017 Apr 24.
Myasthenia gravis (MG) patients had low proximal hip BMD, which could be explained by reduced muscle strength, elevated bone resorption markers, vitamin D deficiency, and increased PTH levels in those with MG compared to controls.
Muscle strength is closely correlated with bone mineral density (BMD) and vitamin D status. Here, we evaluated muscle strength, BMD, and vitamin D status in a large sample of Chinese patients with MG.
In this cross-sectional survey, 86 patients with MG without glucocorticoid treatment and 86 healthy controls were included. Serum levels of 25-hydroxyvitamin D [25OHD], parathyroid hormone (PTH), bone turnover markers (BTMs), and BMD were measured and compared between the two groups. Grip strength and one-leg standing time (OLST) were also assessed in MG patients.
Low grip strength and short OLST were found in 11 (12.8%) and 12 (14.0%) MG patients, respectively. There were 3 (3.5%) MG patients with low bone mass for chronological age. Serum beta C-terminal telopeptide and PTH levels were higher (p < 0.001 and p = 0.001, respectively), and BMD at the femoral neck and trochanter were lower in MG patients (p < 0.001 and p < 0.001, respectively) compared to healthy controls. In patients with MG, grip strength was positively correlated with BMD. Serum 25OHD levels were lower in MG patients than in healthy controls (17.36 ± 6.64 vs. 22.11 ± 7.28 ng/ml, p < 0.001).
Grip strength was positively correlated with BMD in Chinese patients with MG. MG patients tended to have low proximal hip BMD, which may partially be explained by reduced muscle strength, vitamin D deficiency, increased PTH levels, and elevated bone resorption markers compared to controls.
重症肌无力（MG）患者的髋关节近端骨密度较低，这可能是由于与对照组相比，MG 患者的肌肉力量下降、骨吸收标志物升高、维生素 D 缺乏和甲状旁腺激素（PTH）水平升高所致。
在这项横断面研究中，纳入了 86 例未经糖皮质激素治疗的 MG 患者和 86 名健康对照者。比较两组患者的血清 25-羟维生素 D [25OHD]、甲状旁腺激素（PTH）、骨转换标志物（BTMs）和骨密度。同时评估 MG 患者的握力和单腿站立时间（OLST）。
11 例（12.8%）和 12 例（14.0%）MG 患者的握力较低和 OLST 较短。3 例（3.5%）MG 患者的骨量低于年龄。与健康对照组相比，MG 患者的血清β C 端肽和 PTH 水平较高（p<0.001 和 p=0.001），股骨颈和转子间区骨密度较低（p<0.001 和 p<0.001）。在 MG 患者中，握力与骨密度呈正相关。MG 患者的血清 25OHD 水平低于健康对照组（17.36±6.64 vs. 22.11±7.28 ng/ml，p<0.001）。
在中国人 MG 患者中，握力与骨密度呈正相关。与对照组相比，MG 患者髋关节近端骨密度较低，这可能部分归因于肌肉力量下降、维生素 D 缺乏、PTH 水平升高和骨吸收标志物升高。
