Szulc Pawel, Feyt Clément, Chapurlat Roland
INSERM UMR 1033 Hôpital Edouard Herriot University of Lyon Lyon France.
J Cachexia Sarcopenia Muscle. 2016 Jun;7(3):299-311. doi: 10.1002/jcsm.12066. Epub 2015 Nov 19.
Several studies assessed the association of prevalent fractures with muscle mass, strength, and physical capacity in men. Clinical impact of these associations is not clear, and they could be influenced by confounders. Our aim was to assess the association of the prevalent fractures with muscle strength, physical function, and the risk of subsequent falls in older men after adjustment for muscle mass and potential confounders.
In a cohort of 890 men aged 50 and older, we assessed appendicular skeletal muscle mass (ASM) by DXA, grip strength, physical function (chair stands, static, and dynamic balance). Relative ASM (RASM) was calculated as ASM / (height)(2). Then, 813 men aged 60 and over were followed up prospectively for 5 years and 144 sustained >1 incident falls. All the analyses were adjusted for lifestyle factors, co-morbidities, and hormones known to influence muscle and physical function.
Low leisure physical activity, very high occupational physical activity, Parkinson's disease, diabetes mellitus, low apparent free testosterone concentration (AFTC), as well as Grade 2 and 3 vertebral fractures and multiple fractures were associated with lower grip strength when adjusted for confounders including upper limb RASM. Low leisure physical activity, very high occupational physical activity, diabetes mellitus, prior stroke, low AFTC and 25-hydroxycholecalciferol, high C-reactive protein, vertebral fractures, and non-vertebral fractures were associated with poor physical function (lowest quintile of the score of tests) when adjusted for confounders including lower limb RASM. Grade 2 and 3 and multiple vertebral fractures were associated with twofold higher risk of multiple falls after adjustment for confounders. Men having multiple fractures had a twofold higher risk of multiple falls after adjusting for confounders. In multivariable models, risk of falls increased proportionally to the increasing severity and number of vertebral fractures as well as to the increasing number of all fractures.
In older men, Grade 2 and 3 vertebral fractures and multiple vertebral and non-vertebral fractures are associated with lower grip strength, poor physical function, and higher risk of multiple falls after adjustment for multiple confounders. This suggests a real direct association. One fracture can initiate a vicious circle leading to another fracture; thus, patients with fractures need physical therapy regardless of their general health status.
多项研究评估了男性现患骨折与肌肉质量、力量及身体功能之间的关联。这些关联的临床影响尚不清楚，且可能受到混杂因素的影响。我们的目的是在对肌肉质量和潜在混杂因素进行调整后，评估老年男性现患骨折与肌肉力量、身体功能及后续跌倒风险之间的关联。
在一个由890名50岁及以上男性组成的队列中，我们通过双能X线吸收法（DXA）评估了四肢骨骼肌质量（ASM）、握力、身体功能（从椅子上站起、静态和动态平衡）。相对ASM（RASM）计算为ASM /（身高）²。然后，对813名60岁及以上的男性进行了为期5年的前瞻性随访，其中144人发生了>1次跌倒事件。所有分析均针对已知会影响肌肉和身体功能的生活方式因素、合并症和激素进行了调整。
在对包括上肢RASM在内的混杂因素进行调整后，低休闲体力活动、极高职业体力活动、帕金森病、糖尿病、低表观游离睾酮浓度（AFTC）以及2级和3级椎体骨折和多发性骨折与较低的握力相关。在对包括下肢RASM在内的混杂因素进行调整后，低休闲体力活动、极高职业体力活动、糖尿病、既往中风、低AFTC和25-羟基胆钙化醇、高C反应蛋白、椎体骨折和非椎体骨折与身体功能较差（测试分数最低五分位数）相关。在对混杂因素进行调整后，2级和3级及多发性椎体骨折与多次跌倒风险增加两倍相关。在调整混杂因素后，发生多发性骨折的男性多次跌倒的风险增加两倍。在多变量模型中，跌倒风险与椎体骨折的严重程度和数量增加以及所有骨折数量的增加成比例增加。
在老年男性中，在对多种混杂因素进行调整后，2级和3级椎体骨折以及多发性椎体和非椎体骨折与较低的握力、较差的身体功能以及多次跌倒的较高风险相关。这表明存在真正的直接关联。一次骨折可能引发恶性循环导致另一次骨折；因此，骨折患者无论其总体健康状况如何都需要物理治疗。
