College of Physical Education, University of Brasília, Brasília, Distrito Federal, Brazil.
College of Physical Education, University of Brasília, Brasília, Distrito Federal, Brazil.
Exp Gerontol. 2018 Sep;110:241-246. doi: 10.1016/j.exger.2018.06.018. Epub 2018 Jun 21.
Important components that might mediate the relationship between aging and falls are reduced muscle strength and mass. Although muscle-related phenotypes have been linked to falls in older people, the role of muscle quality has yet to be examined.
To investigate the relationship between muscle quality and incidence of falls over an 18-month follow-up in older community-dwelling women.
A total of 167 women (68.1 ± 6.2 years) underwent quadriceps isometric peak torque and thigh-muscle thickness assessments using isokinetic dynamometer and ultrasound, respectively. Muscle quality was considered as the ratio between maximal strength and muscle thickness. Participants were tracked by phone calls for ascertainment of falls during the follow-up period. Cox proportional regressions and X tests were performed, with statistical significance set at P < 0.05.
A total of 139 volunteers were successful tracked over the follow-up period. The overall incidence of fall was 23.4% (95% CI: 16.5-31.0). Rate of fallers among individuals with low-muscle quality (57.7%) was higher than in those with normal muscle quality (15.3%) (X = 21.132; P < 0.001). The proportion of multiple fallers was also significantly higher (X = 11.029; P < 0.001) among volunteers with low-muscle quality when compared to those with normal muscle quality (14.8% and 3.6%, respectively). The presence of low-muscle quality was associated with a significantly greater risk of falls over the follow-up (hazard ratio: 4.619; 95% CI: 2.302-9.269).
Low-muscle quality is associated with a higher incidence of falls in older women. These findings provide support for the concept that muscle quality is a clinically meaningful assessment among older people.
可能介导衰老与跌倒之间关系的重要因素是肌肉力量和质量的下降。尽管肌肉相关表型与老年人跌倒有关，但肌肉质量的作用尚未得到检验。
调查 18 个月随访期间肌肉质量与老年社区居住女性跌倒发生率之间的关系。
共有 167 名女性（68.1±6.2 岁）接受了等速测力计的股四头肌等长峰值扭矩和超声的大腿肌肉厚度评估。肌肉质量被认为是最大力量与肌肉厚度之间的比率。在随访期间，通过电话随访确定参与者是否跌倒。使用 Cox 比例风险回归和 X 检验进行统计分析，以 P<0.05 为统计学显著性标准。
共有 139 名志愿者在随访期间成功跟踪。总跌倒发生率为 23.4%（95%CI：16.5-31.0）。肌肉质量低的个体（57.7%）的跌倒率高于肌肉质量正常的个体（15.3%）（X²=21.132；P<0.001）。肌肉质量低的志愿者中多次跌倒的比例也明显更高（X²=11.029；P<0.001），而肌肉质量正常的志愿者中分别为 14.8%和 3.6%。肌肉质量低与随访期间跌倒的风险显著增加相关（风险比：4.619；95%CI：2.302-9.269）。
肌肉质量低与老年女性跌倒发生率增加相关。这些发现为肌肉质量是老年人具有临床意义的评估这一概念提供了支持。
