Sarcopenic dysphagia, which refers to difficulty swallowing caused by muscle loss, is an underrecognized, relatively new disease entity often seen in older adults. In an interview with MIMS Doctor, geriatrician Dr Tung-Wai Au Yeung of the Jockey Club Institute of Ageing, the Chinese University of Hong Kong, and dietitian Dr Terry Ho-Yan Ting in private practice discussed the causes and multidisciplinary approach to diagnosing, preventing and managing sarcopenic dysphagia, including nutritional support with protein supplementation and rehabilitation.
Vicious cycle of dysphagia and sarcopenia
Dysphagia is a highly prevalent condition affecting up to 50 percent of older adults, particularly patients with neurological or neurodegenerative disorders, including Alzheimer’s disease, Parkinson’s disease, and a history of stroke. [Arch Gerontol Geriatr 2023:110:104991; Mayo Clin Proc 2021;96:488-497]
Sarcopenia can be classified into two types, namely, primary sarcopenia (age-related) and secondary sarcopenia (disease-, activity- or nutrition-related). [Age Ageing 2010;39:412-423]
Sarcopenic dysphagia is characterized by swallowing difficulty resulting from a loss of mass and function in whole-body skeletal and swallowing muscles. [Ann Rehabil Med 2023;47:337-347]
“In patients with a history of stroke, for example, neurological deficit leads to diminished strength in muscles involved in swallowing and induces dysphagia,” said Au Yeung. “Dysphagia results in reduced oral intake, which can potentially lead to malnutrition and consequently a worsening of muscle loss, which thereby aggravates sarcopenia. This creates a vicious cycle of dysphagia, malnutrition and sarcopenia.” (Figure 1)
Diagnostic algorithm
Sarcopenic dysphagia is a relatively new concept. Although there have been several reports on the condition, no established diagnostic methods were available before 2017. Therefore, The Japanese Working Group on Sarcopenic Dysphagia developed a five-step diagnostic algorithm, which classified the diagnosis into three categories: probable sarcopenic dysphagia, possible sarcopenic dysphagia, and no sarcopenic dysphagia. (Figure 2) [JCSM Clin Rep 2017;2:1-10]
Why does protein matter?
From around the age of 40 years, muscle mass decreases by about 0.5–1 percent each year. [Nutrients 2016;8:359] Protein plays a crucial role in muscle repair, maintenance and growth, especially when combined with resistance training, which enables muscle mass preservation and limits age-related muscle loss. [Nutrients 2019;11:1136]
“Inadequate protein intake contributes to the loss of muscle mass and strength, which impacts physical function and increases the risks of frailty, falls and fractures, infections, and mortality,” said Ting and Au Yeung. “Apart from limb muscle loss, muscle loss can also occur in the swallowing system, which can lead to the vicious cycle of dysphagia, malnutrition and sarcopenia.” (Figure 1)
Optimal protein intake for older adults: ≥1.2 –1.5 g/kg/day
“To maintain healthy muscles, metabolic function, and normal immune response, I generally recommend a daily protein intake of ≥1.2–1.5 g/kg for healthy older adults,” advised Ting. According to a position paper from the PROT-AGE Study Group, the protein requirement should be even higher — between 1.5 and 2 g/kg/day — in elderly patients with acute or chronic conditions (eg, sarcopenia), severe illness or injury, or marked malnutrition, except for those with chronic kidney disease. [J Am Med Dir Assoc 2013;14:542-559]
≥40 percent of older adults fail to meet protein intake targets
“In my clinical experience, ≥40 percent of older adults in Hong Kong may be unable to reach their protein intake targets,” pointed out Ting.
“Older adults in Hong Kong often prefer carbohydrate-rich meals that provide greater satiety, which may have inadequate protein content,” shared Ting. “Even those who do not have financial constraints often lack knowledge and awareness of the importance of adequate protein intake.”
Chronic health conditions, age-related physiological changes or dental issues can affect appetite and digestive efficiency, making it challenging for older adults to consume adequate protein-rich food. Additionally, patients with dysphagia may need to consume food with modified textures, such as pureed or ground foods. However, the available protein sources for these preparations may be limited, which can lead to inadequate protein content in their meals and, consequently, insufficient protein intake. [Food Res Int 2024:186:114324; Nutrients 2019;11:2898; J Nutr Health Aging 2018;22:916-922]
Multidisciplinary management
“Importantly, sarcopenic dysphagia may be reversible or preventable with appropriate interventions,” highlighted Au Yeung.
Poor nutritional status is a core characteristic of sarcopenic dysphagia. Intensive nutrition therapy and rehabilitation can help break the vicious cycle. (Figure 1) Maintaining energy (≥30 kcal/kg/day) and protein intake (≥1.2 g/kg/day) helps preserve muscle mass and may improve swallowing and lead to clinically meaningful functional outcomes in patients with sarcopenic dysphagia. [Nutrients 2021;13:4043; Nutrients 2021;13:596]
“It is important to increase both energy and protein intake. Loss of muscle mass will still occur in the presence of adequate protein intake but inadequate intake of energy or other nutrients, and the same applies in reverse,” said Ting.
Whey protein supplementation
“In older adults who fail to achieve their protein targets through dietary intake, such as patients with sarcopenic dysphagia, I recommend using high-quality protein supplements,” said Ting.
Whey protein is a consumer-friendly and readily available source of high-quality protein. “Whey protein is beneficial for enhancing muscle mass and strength and is recommended as part of sarcopenia treatment based on the 2019 consensus update of The Asian Working Group for Sarcopenia,” added Ting and Au Yeung. [J Anim Sci 2021;99:skab060; J Am Med Dir Assoc 2020;21:300-307.e2]
“The benefits of protein supplementation for treatment of sarcopenia are well established. However, clinical evidence of its effects on sarcopenic dysphagia is limited,” commented Au Yeung. “Nonetheless, I think the same approach should be considered, as both conditions share similar pathophysiology due to loss of muscle mass. With protein supplementation, we may be able to break the vicious cycle of sarcopenia, malnutrition and dysphagia.” (Figure 1)
25–30 g of high-quality protein per meal
Evenly distributed protein consumption throughout the day provides a framework that allows older adults to benefit from the synergistic anabolic effect of protein and physical activity, which results from enhanced muscle protein synthesis response. [Am J Clin Nutr 2015;101:1339S-1345S; Nutrients 2019;11:1136] “To prevent or delay sarcopenic muscle loss, I recommend a dietary plan that includes 25–30 g of high-quality protein per meal,” suggested Ting.
Additionally, pre-sleep protein intake is associated with increased mitochondrial and myofibrillar protein synthesis rates during overnight recovery from exercise. [Sports Med 2023;53:1445-1455] “I generally recommended a glass of steamed milk or high-protein soy milk before bed to boost protein level,” added Ting.
Certain protein supplements are tasteless and odourless, easily mixed, and dissolve quickly, with each serving containing about 6 g of protein. [www.nestlehealthscience.com.hk/en/brands/beneprotein] “They are designed to be added to hot or cold beverages and food, making them excellent options for older adults who struggle to meet their protein targets, including those with dysphagia or poor appetite,” said Ting. “We usually prefer protein supplements without added sugar as comorbidities such as diabetes, overweight and dental problems are common in older adults.”
Rehabilitation
Management of sarcopenic dysphagia requires a multidisciplinary approach involving geriatricians, nurses, dietitians, speech therapists, physiotherapists, and occupational therapists. Patients’ and their caregivers’ collaboration is crucial for achieving optimal outcomes. [J Rural Med 2023;18:21-27; J Frailty Sarcopenia Falls 2018;3:1-7]
Rehabilitation for sarcopenic dysphagia focuses on re-establishing effective and efficient swallowing. Tongue pressure resistance training (TPRT) is commonly used by speech therapists to strengthen swallowing muscles. Postural adjustments, Shaker exercises, Mendelsohn manoeuvre, jaw opening exercises, and lingual exercises are possible rehabilitation procedures provided by occupational therapists and physiotherapists for whole-body muscle strengthening. (Figure 3) [Nutrients 2021;13:4043; Nutrients 2022;14:778]
Rethinking prolonged use of feeding tube: Is it necessary?
“Due to lack of awareness, clinicians often overlook the diagnosis of sarcopenic dysphagia, misattributing swallowing difficulties to stroke or other conditions solely, and they assume that patients may require permanent or long-term use of feeding tubes,” commented Au Yeung.
“While feeding tubes enhance nutrition intake, many patients may not need prolonged tube feeding if they are effectively trained with swallowing exercises to rebuild swallowing muscles and receive adequate protein supplementation,” shared Au Yeung. “Even for patients on tube feeding, we encourage oral feeding as much and as safely as possible. Even small quantities of oral intake are beneficial for initiating chewing and swallowing manoeuvres, which may facilitate recovery alongside the use of protein supplements.”
Conclusion
Protein plays a vital role in muscle repair, maintenance and growth. Yet, many older adults struggle to meet their daily protein intake requirements, which can contribute to increased muscle loss. Older adults should ensure adequate protein and energy intake without exceeding recommended levels. Sarcopenic dysphagia may be reversible with multidisciplinary management involving early rehabilitation, resistance training exercise and nutritional support.
This special report is supported by an education grant from the industry.
