What Is Age Related Sarcopenia?

Having problems walking long distances, up a slope, or climbing stairs?

The tired old legs are usually the first to warn that we are no longer young ……

If you don’t have other health problems, that feeling of low energy and decreasing physical strength is likely due to sarcopenia.

What is age-related sarcopenia?

Sarcopenia is a progressive loss of skeletal muscle mass and strength or function. It is associated with ageing but can also be due to long-term illness, bed rest and malnutrition.¹

Our muscles begin to atrophy or shrink around age 40. Muscle mass loss after 50 is estimated to be 0.5-1% yearly. That rate can accelerate to 15% every ten years from age 70.

The muscles shrink because there is a reduction in muscle fibres and a decrease in their size. This, in turn, leads to poorer physical strength and functional ability.

Even top athletes, such as marathon runners and weight lifters, experience a decline in performance after about 40 because of lower muscle strength.

So, what is the cause of age-related sarcopenia?

The pathophysiology of sarcopenia is quite complex and is still not fully understood. However, the following contributing factors have been suggested.

• Age-related hormonal changes. The decreasing testosterone levels and insulin-like growth factor (IGF-1) affect muscle growth and mass.
• Older people’s ability to produce the proteins which make up muscle fibres has decreased.
• Poor nutrition. Older people’s diets may not contain enough proteins, essential amino acids and vital nutrients such as Vitamin D. There might be malabsorption problems due to chronic diseases.
• Many older people lead a sedentary lifestyle and do not do enough exercise. Some need bed rest or hospitalization because of one or more health problems. Even healthy people suffer significant muscle wasting following a period of bed rest.

We can see that some of these causative factors are modifiable. We may be able to prevent sarcopenia or improve its outcome by changing our lifestyle, doing more exercise, improving our diet, and so on.

The diagnosis of sarcopenia

According to The European Working Group on Sarcopenia in Older People, a

diagnosis of sarcopenia is confirmed if a person has low muscle mass, muscle strength, or physical function.¹

Research and clinical practices have used the following measurement methods and techniques to diagnose sarcopenia. Some equipment is expensive and may not be available for every situation.

Measurement of muscle mass

• Body imaging techniques have been used to estimate muscle or lean body mass. They are computed tomography (CT), magnetic resonance imaging (MRI) and Dual-energy x-ray absorptiometry (DXA). CT and MRI are gold standards for estimating muscle mass in research. However, DXA is the preferred alternative because it exposes the patient to minimal radiation.
• Bioimpedance analysis (BIA) estimates the volume of fat and lean body mass. It is an easy and inexpensive method suitable for ambulatory and bedridden patients. BIA results under standard conditions have been found to correlate well with MRI predictions.

Measurement of muscle strength

Handgrip strength measured with a handheld dynamometer is a simple and widely used measure of muscle strength. When employed with population references, it correlates well with leg strength.

Measurement of physical performance

Several physical performance tests are available for evaluating balance, gait, strength and endurance. For example, short physical performance battery (SPPB), timed get-up-and-go (TGUG), and the stair climb power test.

How does sarcopenia affect our life?

Age-related sarcopenia is recognized as a geriatric syndrome and is linked to several adverse health outcomes.

• When muscles are weak, simple tasks such as getting dressed, lifting objects, using the bathroom, and walking can become difficult.
• It can become more challenging to maintain balance.
• The walking speed will slow, and the risk of falls and broken bones increases.
• The older person will lose his or her ability to live independently and needs institutional care.
• Sarcopenia is also associated with various other chronic diseases and earlier death.

Studies on the prevalence of sarcopenia had inconsistent results because of different choices of definitions and measuring methods. Nevertheless, the numbers are significant and alarming.

A review of past research showed that prevalence in the 60–70 years olds ranged from 5–13%. For elderly aged above 80 years, 11 to 50% of them were found to be sarcopenic¹. It is a worldwide problem affecting both men and women.

However, it is not all groom and doom.  You can take steps to maintain muscle mass and strength. We shall look into that in the next post.

It is never too young or old to look after your muscle health.

References:

1. Cruz-Jentoft J, Baeyens J,  Bauer J,  Boirie Y,  Cederholm T et al (2010). “Sarcopenia: European consensus on definition and diagnosis: Report of the European Working Group on Sarcopenia in Older People”. Age and Ageing, Volume 39, Issue 4, 1 July 2010, Pages 412–423 https://doi.org/10.1093/ageing/afq034

2. “What Is Sarcopenia?” International Osteoporosis Foundation. https://www.iofbonehealth.org/what-sarcopenia

3. “Sarcopenia with Aging”. https://www.webmd.com/healthy-aging/guide/sarcopenia-with-aging

4. “The Facts about Sarcopenia”. Aging in Motion. http://www.aginginmotion.org/wp-content/uploads/2011/04/sarcopenia_fact_sheet.pdf