Braz Nayara Felicidade Tomaz, Rocha Natalia Pessoa, Vieira Érica Leandro Marciano, Gomez Rodrigo Santiago, Barbosa Izabela Guimarães, Malheiro Olívio Brito, Kakehasi Adriana Maria, Teixeira Antonio Lucio
Neuroscience Branch, Interdisciplinary Laboratory for Medical Research, Faculty of Medicine, Federal University of Minas Gerais (UFMG), Avenue Alfredo Balena, 190, room 281, Santa Efigenia, Belo Horizonte, MG, 30130-100, Brazil.
Neuromuscular Disease Center, University Hospital, UFMG, Belo Horizonte, Brazil.
Neurol Sci. 2017 Aug;38(8):1405-1413. doi: 10.1007/s10072-017-2964-z. Epub 2017 May 9.
This current study aimed to evaluate the frequency of low bone mass, osteopenia, and osteoporosis in patients with myasthenia gravis (MG) and to investigate the possible association between bone mineral density (BMD) and plasma levels of bone metabolism markers. Eighty patients with MG and 62 controls BMD were measured in the right femoral neck and lumbar spine by dual-energy X-ray absorptiometry. Plasma concentrations of osteocalcin, osteopontin, osteoprotegerin, tumor necrosis factor (TNF-α), interleukin (IL)-1β, IL-6, dickkopf (DKK-1), sclerostin, insulin, leptin, adrenocorticotropic hormone, parathyroid hormone, and fibroblast growth factor (FGF-23) were analyzed by Luminex®. The mean age of patients was 41.9 years, with 13.5 years of length of illness, and a mean cumulative dose of glucocorticoids 38,123 mg. Patients had significant reduction in BMD of the lumbar, the femoral neck, and in the whole body when compared with controls. Fourteen percent MG patients had osteoporosis at the lumbar spine and 2.5% at the femoral neck. In comparison with controls, patients with MG presented lower levels of osteocalcin, adrenocorticotropic hormone, parathyroid hormone, sclerostin, TNF-α, and DKK-1 and higher levels of FGF-23, leptin, and IL-6. There was a significant negative correlation between cumulative glucocorticoid dose and serum calcium, lumbar spine T-score, femoral neck BMD, T-score, and Z-score. After multivariate analysis, higher TNF-α levels increased the likelihood of presenting low bone mass by 2.62. MG patients under corticotherapy presented low BMD and altered levels of bone markers.
本研究旨在评估重症肌无力（MG）患者低骨量、骨质减少和骨质疏松的发生率，并探讨骨矿物质密度（BMD）与骨代谢标志物血浆水平之间的可能关联。采用双能X线吸收法测量了80例MG患者和62例对照者右侧股骨颈和腰椎的BMD。通过Luminex®分析骨钙素、骨桥蛋白、骨保护素、肿瘤坏死因子（TNF-α）、白细胞介素（IL）-1β、IL-6、Dickkopf（DKK-1）、硬化蛋白、胰岛素、瘦素、促肾上腺皮质激素、甲状旁腺激素和成纤维细胞生长因子（FGF-23）的血浆浓度。患者的平均年龄为41.9岁，病程13.5年，糖皮质激素平均累积剂量为38123mg。与对照组相比，患者腰椎、股骨颈和全身的BMD均显著降低。14%的MG患者腰椎有骨质疏松，2.5%的患者股骨颈有骨质疏松。与对照组相比，MG患者的骨钙素、促肾上腺皮质激素、甲状旁腺激素、硬化蛋白、TNF-α和DKK-1水平较低，而FGF-23、瘦素和IL-6水平较高。糖皮质激素累积剂量与血清钙、腰椎T值、股骨颈BMD、T值和Z值之间存在显著负相关。多因素分析后，较高的TNF-α水平使出现低骨量的可能性增加2.62倍。接受皮质激素治疗的MG患者BMD较低，骨标志物水平改变。
