As a chronic age-related disease known as "silent killer" in medical academic circle, osteoporosis is manifested by slow and insidious development, and obvious age-related physiological changes in muscle, bone and fat. There are few studies on the relationship of osteoporosis with muscle, bone, and fat indices.

To assess the relationship of osteoporosis with muscle, bone, and fat indices.

A total of 108 patients with primary osteoporosis were recruited from the Third Affiliated Hospital of Guangzhou University of Chinese Medicine according to the inclusion and exclusion criteria from July 19, 2019 to January 5, 2021. Data were collected, including general data (height, weight and BMI) , T-score, fat mass, muscle mass and bone mineral content measured by the dual-energy X-ray absorptiometry, bone formation indices, such as serum calcium, bone morphogenetic protein-2 (BMP2) and osteoproteintin (OPG) detected by ELISA. Height, weight, BMI, T-score, fat mass, muscle mass, fat percentage and bone mineral content were compared across three age groups. Fat mass, muscle mass, fat percentage, bone mineral contents and bone formation indices were compared across normal group (T-score≥-1.0, n=20) , bone loss group (-2.5<T-score<-1.0, n=38) and osteoporosis group (T-score ≤-2.5, n=50) divided by the T-score.

The T-score varied significantly in three age groups of 49-58, 59-68, and≥69 (P<0.05) , and it was the highest in the 49-58 age group (P<0.01) . Compared with the normal group, bone loss group had decreased bone mineral content, while osteoporosis group had decreased fat mass and bone mineral content (P<0.05) . Compared with the bone loss group, both the muscle mass and bone mineral content in the osteoporosis group were decreased (P<0.05) . Compared with normal group, a significant decrease was found in OPG and BMP2 in osteoporosis group, and in BMP2 in bone loss group (P<0.05) . Compared with bone loss group, a significant decrease was found in OPG and BCL2 in osteoporosis group (P<0.05) .

The abnormality in dynamic balance between muscular and skeletal systems and adipose tissue is closely related to the pathogenesis of osteoporosis. Bone mineral density decreases with age, decrease in serum BMP2, OPG and Bcl2 levels may be related to the failure of apoptosis-regulatory proteins to play a good role in anti-apoptosis and promoting bone formation, resulting in the decrease of osteoblast activity and the weakening of bone formation activity.

骨质疏松症作为一种老年慢性疾病，其发病过程缓慢、隐匿，在学术界素有"沉默杀手"之称，而随着机体衰老，肌肉、骨骼和脂肪的生理变化在表型上较为明显。目前针对"肌-骨-脂"与骨质疏松症发病关系的研究较少。

初步探讨骨质疏松症与肌-骨-脂的关系。

2019-07-19至2021-01-05广州中医药大学第三附属医院招募符合纳入、排除标准的骨质疏松症患者108例，记录其一般资料〔身高、体质量、体质指数（BMI）〕，采用双能X线吸收法（DXA）检测T值、脂肪质量、肌肉质量和骨矿含量，ELISA法检测钙、骨形态发生蛋白-2（BMP2）、骨保护素（OPG）等骨形成相关指标；根据患者的不同年龄分组（49~58岁31例、59~68岁57例、≥69岁20例），比较不同年龄组患者的身高、体质量、BMI、T值、脂肪质量、肌肉质量、脂肪百分比和骨矿含量。根据T值将患者分为正常组（T值≥-1.0，n=20）、骨量减少组（-2.5<T值<-1.0，n=38）、骨质疏松组（T值≤-2.5，n=50），比较不同组别间脂肪质量、肌肉质量、脂肪百分比、骨矿含量和骨形成相关指标。

不同年龄段的患者T值比较，差异有统计学意义（P<0.05）；与49~58岁患者相比，59~68岁、≥69岁患者T值降低（P<0.01）。与正常组相比，骨质疏松组脂肪质量降低，骨量减少组和骨质疏松组骨矿含量降低（P<0.05）。与骨量减少组相比，骨质疏松组肌肉质量、骨矿含量降低（P<0.05）。与正常组相比，骨质疏松组OPG、BMP2降低，骨量减少组BMP2降低（P<0.05）；与骨量减少组相比，骨质疏松组OPG和B淋巴细胞瘤-2基因（BCL2）降低（P<0.05）。

"肌-骨-脂"之间的动态平衡与骨质疏松症发病过程可能相关。随着年龄的增大，骨质疏松症患者骨密度下降，血清BMP2、OPG和Bcl2含量降低，这可能与凋亡蛋白不能很好地发挥抗凋亡作用和促骨形成作用，使得成骨细胞活性降低、骨形成活动减弱有关。