Muscle mass, quality, and the menopause: sex-specific strategies to mitigate sarcopenia in aging populations

随着年龄的增长，我们的肌肉会变得更小、更虚弱(骨质疏松症)，这会使我们更难完成日常活动，并可能增加我们对医疗保健系统的依赖。英国人口日益老龄化，因此，骨质疏松症是一个主要的医疗问题(例如，2016年英国医疗体系的估计成本为25亿GB)。目前迫切需要制定预防石棺减少症的策略。然而，这些策略需要有针对性，有证据表明，老年男性和女性患石棺减少的情况不同。例如，与男性相比，女性出现骨质疏松症的时间更早，导致身体残疾的程度更高。年龄增长的潜在性别差异尚不清楚，但女性石棺减少的早期流行与更年期不谋而合。更年期是性激素环境的变化，这是正常女性衰老的一部分，与身体成分的变化有关，包括肌肉减少和身体脂肪增加。这种增加的身体脂肪可能会位于肌肉中，进一步加速肌肉力量的丧失和健康状况的恶化。对于身体成分的这些变化是如何发生的，人们缺乏了解。然而，为了让肌肉变小，在我们去除肌肉蛋白质的速度和制造新的肌肉蛋白质的速度之间肯定存在不平衡。我们最近开发了先进的生物化学技术来测量我们制造和去除肌肉蛋白质的速度。通过将这些技术应用于绝经前和绝经后的女性，我们将第一次能够更好地了解肌肉蛋白质在衰老过程中的平衡。通过将这些技术与磁共振成像(MRI)相结合，我们将开发新的方法来定位新脂肪在体内的沉积位置和速度。这些方法结合在一起，将为如何最好地针对未来针对女性石棺减少症的干预提供重要的见解。抵抗运动疗法(RET)目前提供了最有效的策略，以促进肌肉质量和力量的老化。然而，与年轻女性相比，老年女性对阻力运动的反应迟钝。我们将测量更年期是否对运动产生新的肌肉蛋白质的速度产生影响，并使用我们的MRI成像技术，监测RET是否改变了体内脂肪沉积的速度。总而言之，这些措施将决定RET在减缓绝经后妇女石棺减少和改善身体成分方面的有效性。利用我们的研究结果，我们将创建循证资源和信息，并通过现有的联系将这些建议落实到更年期干预计划中，途径是与英格兰体育积极伙伴关系(共同活跃在莱斯特郡和体育诺茨)、诺丁汉大学和莱斯特大学的运动医学系、拉夫堡的国家运动和运动医学中心、以及国家医生“运动医学”网站、莱斯特综合医院的运动医学诊所、以及莱斯特和诺丁汉的更年期诊所。

As we grow older, our muscles become smaller and weaker (sarcopenia), which can make it more difficult to complete daily activities and can increase our reliance on healthcare systems. The UK has a growing ageing population, and, therefore, sarcopenia represents a major healthcare concern, (for example, its estimated cost to the UK healthcare system in 2016 was £2.5 billion). There is an urgent need to develop strategies to prevent sarcopenia. However, these strategies need to be targeted, with evidence suggesting that older men and women develop sarcopenia differently. For instance, sarcopenia develops earlier in women, resulting in greater levels of physical disability compared with men. The underlying sex differences with ageing are unclear, yet the earlier prevalence of sarcopenia in women coincides with the menopause. The menopause is a change in the sex hormone environment that is a part of normal female ageing and is associated with changes in body composition including muscle loss and increased body fat. This increase in body fat can become located within muscle, further accelerating the loss of muscle strength and poor health. There is a lack of understanding of how these changes in body composition occur. However, for muscle to decrease in size, there must be an imbalance between how quickly we remove muscle proteins and how quickly we make new muscle proteins. We have recently developed advanced biochemistry techniques to measure how quickly we make and remove muscle proteins. By applying these techniques to pre- and post-menopausal women, we will be able to better understand muscle protein balance during ageing for the first time. By combining these techniques with magnetic resonance imaging (MRI), we will develop new methods to locate where, and how quickly, new fat is deposited in the body. Combined, these approaches will provide vital insights on how best to target future interventions against sarcopenia in women. Resistance exercise therapy (RET) currently offers the most effective strategy to promote muscle mass and strength in ageing. However, responses to resistance exercise are blunted in older women compared to younger women. We will measure whether the menopause has an impact on how quickly new muscle proteins are made in response to exercise, and, using our MRI imaging techniques, we will monitor whether RET alters the rate of fat deposition in the body. Together, these measures will determine the effectiveness of RET at slowing sarcopenia and improving body composition in post-menopausal women. Using our results, we will create evidence-based resources and information, and implement these recommendations into menopause intervention programmes through existing connections with Sport England Active Partnerships (Active Together in Leicestershire and Sport Notts), Sports Exercise Medicine departments at the Universities of Nottingham and Leicester and the National Centre for Sport and Exercise Medicine in Loughborough, as well as the national "Moving Medicine" website for doctors, the Exercise Medicine clinic at Leicester General Hospital, and menopause clinics in Leicester and Nottingham.