Sarcopaenia in surgical populations: A review
Introduction
Sarcopaenia is defined as loss of lean muscle mass and quality. It is part of the physiological process of ageing. As the population ages the need for pre-operative risk assessment tools to identify frailty, and therefore those at higher risk of adverse surgical outcomes, increases. Sarcopaenia has shown promise as a surrogate marker of frailty and therefore has been the subject of a multitude of recent publications analysing its effect on surgical patients. In this review we aim to summarise the salient points from the literature on this subject.
Section snippets
The aetiology of sarcopaenia
Several theories regarding the cause of sarcopaenia have been proposed; however the precise mechanism of its development remains unclear. The rate of muscle loss within this process is also the subject of debate. Nevertheless, it has been identified as part of the ageing process and is also associated with many chronic diseases.1, 2, 3
Sarcopaenia may be due to impaired muscle protein anabolism in individuals as they age,4 with similar levels of protein ingestion preventing this process from
Diagnosing and defining sarcopaenia
Possibly due to the relative recency of interest in sarcopaenia, the definitions and methods by which it is diagnosed are variable across the literature. This leads to difficulty in undertaking systematic reviews in this subject.8 Direct measures of muscle strength can be assessed on clinical evaluation of patients. Grip strength, skin fold thickness, timed up-and-go tests and walking speed can all be used as markers of physical performance.9 Although these are not direct measures of muscle
Mortality
To date, by far the greatest volume of research into sarcopaenia has been in cancer populations, where it has been found to be a significant independent risk factor for 3-year mortality.20 Sarcopaenia has an impact on outcome following resection of multiple different tumour types. Biliary,21 hepatic,22, 23, 24 gastric,25 renal cell,26 bladder,27 adrenocortical carcinoma,28 Non Small Cell Lung Cancer29 and pancreatic malignancies30 have all been studied to this regard and sarcopaenia has
Sarcopaenia and obesity
Possibly the greatest two challenges facing modern medicine are an aging population and obesity. Sarcopaenia is independent of body habitus. Therefore it is possible to be sarcopaenic and have a reduced, normal or increased body mass index (BMI). Conventional markers of nutritional status are therefore not diagnostic of this condition. In combination, sarcopaenia and obesity appear to have an even greater association with poor outcomes45 than either of these factors in isolation. Sarcopaenic
How can sarcopaenia be used to predict risk?
The complete assessment of older patients with co-morbidities requiring surgical intervention is challenging. Risk assessment is a complex process and can involve subjective testing as well as objective measures. Assessment for the presence of sarcopaenia may aid decision-making and procedural planning. On comparative analysis, sarcopaenia has a greater predictive value than some traditional frailty scores, e.g. modified frailty index, in patients over 65 years of age50 for predicting adverse
Is sarcopaenia modifiable?
Although physiological optimisation of patients in the pre-operative phase (so-called “pre-habilitation”) is not yet universally adopted in clinical practice, treating sarcopaenia is possible and may improve outcomes. Sarcopaenic vascular, general surgery and transplant patients in Michigan who took part in a pre-operative training and support program aimed at optimising sarcopaenia had reduced length of stay and reduced costs compared to those with sarcopaenia who did not undertake this
Conclusions
Sarcopaenia is common and in the setting of an aging population is likely to increase. Traditional markers of nutrition do not appear to adequately predict risk in surgical populations, and in fact those with sarcopaenic obesity are at increased risk of morbidity and mortality. Frailty scoring, which can be subjective, may not give adequate pre-operative information to best plan surgical strategies.
Measuring sarcopaenia on CT imaging is a straightforward procedure which does not add a lot of
Conflicts of interest
There are no conflicts of interest to declare.
Source of funding
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
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