Sarcopenia

WGSOP defines a clinical definition for sarcopenia as an age-related, progressive decline in skeletal muscle mass with decreased muscle strength or lower physical performance.

“Skin ageing”, “joint and organ degeneration” are the terminologies familiar to us. However, have you ever heard of sarcopenia or muscle ageing”? How much do you know about it? Let’s understand more about sarcopenia and how to prevent or improve the condition through diet and exercise.

The European Working Group on Sarcopenia in Older People (EWGSOP) defines a clinical definition for sarcopenia as an age-related, progressive decline in skeletal muscle mass with decreased muscle strength or lower physical performance. Individuals, who are physically inactive, bed-bound, having inadequate intakes of energy and/or protein, having malabsorption or suffering from cancer, are at higher risk to develop sarcopenia. EWGSOP suggests a conceptual staging of sarcopenia as ‘presarcopenia’ , ‘sarcopenia’ and ‘severe sarcopenia’. Differences between three stages are showed in table below. A wide range of techniques can be used to assess muscle mass, strength and physical performance, such as Computed Tomography scan(CT scan), Magnetic, Resonance Imagery (MRI), Dual Energy X-ray Absorptiometry (DXA), Bioimpedance Analysis (BIA) are used to measure muscle mass. Handgrip strength is used to measure muscle strength. Gait speed, grip strength, step climbing and Short Physical Performance Battery (SPPB) are used to assess physical performance.

Why is there a muscle loss?

Skeletal muscle is one of the protein stores in the body. The rate of protein degradation exceeds protein synthesis when ageing resulting in inevitable consequence – skeletal muscle loss. After reaching the peak of the adult years at about age 40, skeletal muscle mass gradually decreases 0.5-1.0% every year until the years of 60, the rate of muscle loss accelerates.. hormonal changes when menopause including decreased level of anabolic hormones such as growth hormone, androgen, estrogen and insulin-like growth factor would hinder protein synthesis, which may accelerate the development of sarcopenia. At the early stage, arms and lower limbs tend to have a gradual loss of muscle. However, it may not be obvious, probably until temporary functional disability or fall is caused, then it is known to suffer from this condition. Long-term adversity may include weakened muscle strength and function, resulting in increased risk of fall which can cause fracture and death. Therefore, it is highly recommended to maintain a healthy lifestyle in order to prevent muscle degeneration.

Older people are highly recommended to have about 15-minutes outdoor activity to obtain vitamin D from the sun every day.

Diet

Total Energy/Protein
sufficient energy intake not only helps maintain body health, but it also delays ageing process. Order people are generally recommended to have 1400-1700 kcal intake per day with 3-5 bowls of carbohydrates including rice, noodles, sweet potatoes and corn, and 4-5 taels of meat per day including eggs and beans. Since malnutrition is a common problem in older people. It can disturb metabolism and hormonal balance, which can further increase muscle loss. For those older people who are frail or having poor appetite, it is recommended to follow small frequent meal pattern to increase energy-dense or protein-rich snacks, such as peanut butter on toast, milk or egg pudding. Protein intake for older people is suggested to be 4-5 taels of meat and 2 portions of milk per day. Vegetarian may consume protein from beans or its products including red kidney beans, soy beans, black beans tofu curd, vegetarian chicken, dried bean curd sheet etc. however, older people may have chewing or swallowing problems. It is recommended to consume meat in soft texture, such as fish, eggs, lean meat and tofu.

Vitamin D

Older people especially who are house-bound are more likely to have vitamin D deficiency. Approximately 50% of 65 years of age or above are having deficiency. A number of studies suggest that vitamin D deficient older people are more likely to have fall, and long-term deficiency can largely weaken skeletal muscle strength. Therefore, older people are recommended to consume vitamin D-rich foods including bony fish, sardine, egg yolk, milk products and cereal breakfast to prevent deficiency. Also, vitamin D can be absorbed from the sum. Order people are highly recommended to have about 15-minutes outdoor activity to obtain vitamin D from the sun every day.

Physical activity

Regular exercise is a must to prevent or improve sarcopenia. It is recommended to have 30-minutes exercise every day such as skeletal muscle strength training, stretching and endurance exercise to strengthen the muscle, improve balance and joint flexibility. Examples of types of exercise for older people are shown in the following table.

Reference:

Cruz-Jentoft AJ. Baeyens JP. Baruer JM. Boirie Y. Cederhholm T. Landi F. Martin FC. Michel JP, Rolland Y, Schneider SM, Topinkova E. Vandewoude M & Zamboni M. (2010) European Working Group on Sarocpenia in Older People Saropenia: European consensus on definition and diagnosis: Report of the European Working Group on sarcopenia in older people. Age Ageing 39(4); 412-423

Kim MK, Baek KH, Song KH, ll Kang M. Park CY & Oh KW. (2011) Vitamin D deficiency is associated with sarcopenia in order Koreans, regardless of obesity: the Fourth Korea National Health and Nutrition Examination

Surveys (KNHANES IV) 2009. J Clin Endocrinol Metab 96(10): 3250-6

Paddon-Jones D & Rasmussen BB. (2009) Dietary protein recommendations and the prevention of sarcopenia. Curr Opin Clin Nutr Metab Care 12(1): 86-90

Paddon-Jones D. short KR, Campbell WW. Volpi E & Wolfe RR. (2008) Role dietary protein in the sarcopenia of ageing. Am J Clin Nutr 87(5) 1562S-1566S

330 Tips provided by:  Dr. Forrest Yau  (Health/ Fitness Specialist, Centre for Nutritional Studies, School of Public Health and Primary Care, Faculty of Medicine, CUHK)

Date: 2014-12-01