Department of Orthopedic Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Gumi-ro 173, 82 Beon-gil, Bundang-gu, Seoungnam-si, Gyeonggi-do, 13620, South Korea.
Department of Rehabilitation Medicine, Seoul National University Bundang Hospital, Gumi-ro 173, 82 Beon-gil, Bundang-gu, Seoungnam-si, 13620, Gyeonggi-do, South Korea.
Osteoporos Int. 2021 Jul;32(7):1387-1393. doi: 10.1007/s00198-020-05809-y. Epub 2021 Jan 16.
We investigated the effect of vitamin D supplementation on the expression of muscle vitamin D receptor (VDR) and cross-sectional area (CSA) in patients with a distal radius fracture (DRF). Significant increases in VDR expression and CSA were observed, especially in vitamin D-deficient patients.
Vitamin D supplementation is known to enhance muscle mass and function, but whether the VDR is essential in this process remains unknown. We evaluated the change in VDR expression and CSA in the forearm muscles following vitamin D supplementation in patients with a DRF.
We prospectively recruited 18 women with a median age of 63.5 years who have a DRF. We obtained two biopsies of the forearm muscle, first at the time of fracture repair and then during hardware removal. We supplemented 1000 IU of vitamin D per day during a median interval of 8 months. We examined the changes in VDR expression and CSA by immunohistochemistry.
The median serum 25-hydroxyvitamin D [25(OH)D] increased from 14.3 to 32.1 ng/mL (P = 0.001). The median VDR expression increased from 0.72 to 0.78 (P = 0.002), and the median CSA increased from 1290.0 to 1685.8 μm (P = 0.022). Significant increases in VDR expression and CSA were observed in vitamin D-deficient patients [25(OH)D] < 20 ng/mL, but not in vitamin D-non-deficient patients. The changes in VDR expression and CSA were in the same direction in 13 patients, but in the opposite direction in 5 patients.
Vitamin D supplementation may increase muscle VDR expression and CSA in patients with a DRF, especially in vitamin D-deficient patients. The increase in CSA without an increase in VDR expression in some patients indicates that the effect of vitamin D supplementation on muscle mass could be mediated by indirect effect of serum vitamin D restoration and by VDR.
维生素 D 补充已知可以增强肌肉质量和功能，但 VDR 是否是这一过程的关键尚不清楚。我们评估了维生素 D 缺乏症患者桡骨远端骨折 (DRF) 后维生素 D 补充对前臂肌肉 VDR 表达和 CSA 的变化。
我们前瞻性招募了 18 名中位年龄为 63.5 岁的女性，均患有 DRF。我们在骨折修复时和取内固定物时，分别获取前臂肌肉的两个活检标本。在中位 8 个月期间，我们每天补充 1000IU 的维生素 D。我们通过免疫组化检查 VDR 表达和 CSA 的变化。
中位血清 25-羟维生素 D [25(OH)D] 从 14.3 增加到 32.1ng/ml（P=0.001）。中位 VDR 表达从 0.72 增加到 0.78（P=0.002），中位 CSA 从 1290.0 增加到 1685.8μm（P=0.022）。在维生素 D 缺乏症患者 [25(OH)D] < 20ng/ml 中观察到 VDR 表达和 CSA 的显著增加，但在维生素 D 非缺乏症患者中则没有。13 名患者的 VDR 表达和 CSA 的变化方向相同，但在 5 名患者中则相反。
维生素 D 补充可能会增加 DRF 患者的肌肉 VDR 表达和 CSA，尤其是在维生素 D 缺乏症患者中。在一些患者中 CSA 的增加而 VDR 表达没有增加表明，维生素 D 补充对肌肉质量的影响可能是通过血清维生素 D 恢复的间接作用和 VDR 介导的。
