Health + Wellness

Sarcopenia as a silent killer: what can we do to protect the elderly today?

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Sarcopenia is the age-related loss of muscle mass and strength and/or physical performance. While it is known that a large proportion of the elderly are affected by age-related diseases such as cancer and neurodegenerative disease (e.g. Alzheimer’s disease), sarcopenia is not so well known among the public as an ageing condition. Nonetheless, while sarcopenia usually occurs much earlier in life, it can precede and contribute to the detrimental effects of ageing.

Sarcopenia causes a gradual decrease in muscle mass, from as early as age 40 [1], with severe effects at advanced age. In the elderly, sarcopenia is associated with a decline in muscular strength and function, such as negative effects on balance and gait. This may impact on a person’s ability to perform everyday activities, such as walking, climbing stairs, and lifting objects. Sarcopenia occurrence is thought to lead to frailty, increasing the risk of fall and disability [2]. Loss of independence due to physical disability may result in financial burden on the families of those affected as well as stress on healthcare systems. Both the prevalence and the severity of sarcopenia increase with age, which may affect up to 50% of people by age 80 [3], shedding light on its widespread debilitating effects.

Aside from affecting physical function, sarcopenia increases the risk of all-cause mortality [4]. Loss of skeletal muscle as a metabolic organ increases the risk of diabetes and age-related obesity [5,6]. Other negative impacts of sarcopenia include increased incidence of hospitalisation and reduced recovery following surgery, chemotherapy, and infection [7]. Moreover, muscle mass and strength are lost at an accelerated rate during a hospital stay [8]. Thus, sarcopenia may prevent an elderly patient from returning to their previously independent lives quickly if at all. Therefore, while the research is still ongoing to uncover precise events leading to sarcopenia, there are many striking negative health consequences associated.

Sarcopenia prevalence in Singapore

Since the ageing population is known to be on the rise in Singapore and that sarcopenia most severely affects the elderly, sarcopenia prevalence is likely to increase in future years. For example, the Ministry of Health reported the prevalence of adults aged over 65 as 12.6% in 2016 [9], which is expected to double by 2030 [2]. Sarcopenia can be diagnosed based on the presence of low muscle mass and impaired muscular function, which can be measured in the clinic using a low-X-ray body scan (DXA) to determine muscle mass, with physical tests for handgrip strength and gait speed [10]. A study at Tan Tock Seng Hospital reported that of the independently living elderly people in Singapore aged 50-99, 25% exhibited sarcopenia as assessed by DXA and hand grip strength [11]. Furthermore, by screening patients over 65 years old in medical specialist outpatient clinics at NUH by questionnaire, 44.3% exhibited sarcopenia and sarcopenia occurrence was associated with frailty [12]. However, since there is variation in current methods of diagnosing sarcopenia and populations assessed, the exact local prevalence of sarcopenia cannot yet be determined. Thus, it is important to define clinical guidelines that are sex- and ethnicity-specific so that sarcopenia can be diagnosed across different age groups in Singapore.

Lifestyle modifications to counteract and prevent sarcopenia

To date, there are no approved drugs for the treatment or prevention of sarcopenia. Currently, it is recommended for sarcopenia to be treated through a combination of physical activities and nutritional supplementation.

Both endurance exercise training (e.g. running or cycling) and resistance exercise training (e.g. weight training) have been demonstrated to significantly increase muscle mass and strength in sarcopenic older people. At minimum, an increase in daily activity is likely to provide some countermeasure, since a sedentary lifestyle increases the loss of muscle mass associated with sarcopenia [13]. Furthermore, exercise has shown positive effects on conditions related to sarcopenia including cardiovascular disease, cancer and response to treatment, diabetes, obesity, as well as Alzheimer’s and Parkinson’s disease [14,15]. For specific exercises that can help elderly patients, it is best to consult with a physiotherapist or healthcare professional, especially if there are concurrent mobility issues or comorbidities such as bone/joint issues or diabetes.

It is known that as people get older voluntary food intake decreases, increasing the risk of malnutrition [16]. Since malnutrition is known to accelerate sarcopenia [17], nutrition must be monitored and balanced as we age, especially by ensuring that we consume the recommended daily allowance of protein (amino acids). Other nutrients that are shown to be related to muscle mass regulation and sarcopenia are vitamin D, antioxidant nutrients, and long-chain polyunsaturated fatty acids, all of which should be maintained at healthy levels [18]. Further research into beneficial nutritional supplements for sarcopenia may revel new compounds to help affected individuals.

Amino acid supplementation together with resistance exercise training has been considered to be the most effective way to slow down muscle loss and functional decline. Some studies have shown that amino acid intake increases muscle protein synthesis in the elderly and could increase muscle mass [19]; however, larger effects are associated with the concurrent intake of amino acids following resistance exercise training [20]. Therefore, exercise is considered as being the primary effective countermeasure to sarcopenia with additional benefits from amino acid intake.

Importance of sarcopenia research

Clinically, the exact nature of exercise prescription for sarcopenia has not yet been determined. For the effective implementation of exercise to improve sarcopenia as a therapy, a consensus must be reached by healthcare professionals regarding the content of the prescribed exercise and the most optimal frequency and intensity. Further research should be focused on the development of suitable exercise prescription, especially for older people at risk of functional decline or sarcopenia. Moreover, investigation is warranted to reveal precise mechanisms by which exercise and nutrition can ameliorate sarcopenia severity, and importantly, to uncover novel therapeutic targets.


Article contributed by Elisa Marie Crombie.

Elisa is a researcher with the Ageing and Metabolism Laboratory within the Department of Physiology at the Yong Loo Lin School of Medicine. She was recently awarded a grant by Mitsui Sumitomo Insurance Welfare Foundation (MSIWF), the non-profit arm of Mitsui Sumitomo Insurance Group (MSIG), for her research to identify the role of muscle stem cells in age-related muscle wasting and how it contributes to muscle functional decline. This year marks the 12th year of this MSIWF grant since its inception in Singapore. To date, the Foundation has supported a total of 46 projects with a value of over SGD440,000.

Founded in 1975 by Mitsui Sumitomo Insurance in Japan, Mitsui Sumitomo Insurance Welfare Foundation (MSIWF) advocates for budding and inter-disciplinary research focused on the growing ageing population and the rising concerns over traffic safety in Asia.

Photo credit: Mitsui Sumitomo Insurance Welfare Foundation (MSIWF)


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