New horizons in the pathogenesis, diagnosis and management of sarcopenia

Abstract

Sarcopenia is the age-related loss of skeletal muscle mass and function. It is now recognised as a major clinical problem for older people and research in the area is expanding exponentially. One of the most important recent developments has been convergence in the operational definition of sarcopenia combining measures of muscle mass and strength or physical performance. This has been accompanied by considerable progress in understanding of pathogenesis from animal models of sarcopenia. Well-described risk factors include age, gender and levels of physical activity and this knowledge is now being translated into effective management strategies including resistance exercise with recent interest in the additional role of nutritional intervention. Sarcopenia is currently a major focus for drug discovery and development although there remains debate about the best primary outcome measure for trials, and various promising avenues to date have proved unsatisfactory. The concept of 'new tricks for old drugs' is, however, promising, for example, there is some evidence that the angiotensin-converting enzyme inhibitors may improve physical performance. Future directions will include a deeper understanding of the molecular and cellular mechanisms of sarcopenia and the application of a lifecourse approach to understanding aetiology as well as to informing the optimal timing of interventions.

Figure 1.

Mice as a model for sarcopenia: changes in (a) body mass and (b) weight of quadriceps muscles over the life-span of female C57Bl/6J mice expressed as (c) a sarcopenia index [16]. The loss of quadriceps muscle mass starts sometime after 15 months of age, is evident by 24 months and pronounced by 29 months. Statistically significant differences between ages (P < 0.05) are shown as A: different from 3 months, B: different from 15 months and C: different from 24 months. The extent of sarcopenia is influenced by gender (being more pronounced in females than males) and may vary between different muscles.

Figure 2.

EWGSOP-suggested algorithm for sarcopenia case finding in older individuals [5].

Figure 3.

A lifecourse approach to sarcopenia [47].