Study shows a higher risk of sarcopenia in older adults with underweight and sedentary lifestyle

Analysis of medical data from approximately 1,800 65-year-old residents of Kobe, a large Japanese city, has shown that at least 3% have possible sarcopenia, indicating that the risks are higher for those who are underweight and too inactive.

This research was supported by project professor Tamori Yoshikazu (Creative Health Promotion Department) et al. at the Medical Faculty of Kobe University. The researchers analyzed the results of each participant’s specific health check, as well as data on their calf circumference and grip strength (the specific health check is offered to all public health insurance subscribers in Japan aged 40-74 and is designed to prevent lifestyle-related illnesses).

In addition, it was found that people with possible sarcopenia had a higher degree of frailty, even though their specific health exam results were normal. Signs of frailty are decreased activity and physical activity, decreased cognitive function, and a tendency to stay indoors. Frailty is an early indicator that the person may become bedridden and may need care in the future.

The results of this study have shown that sarcopenia cannot be diagnosed through the usual health exams in Japan, suggesting that a test to detect sarcopenia from the age of 65 is needed to prevent people from becoming bedridden and bedridden will care in the future.

These results were published in the online edition of Geriatrics and Gerontology International on June 23, 2021.

main points

  • Analyzing the data from about 1,800 residents of Kobe City at the age of 65, it was found that about 3% suffer from sarcopenia.
  • Possible sarcopenia has rarely been found in association with obesity.
  • Compared to those without possible sarcopenia, those with a significant tendency to frailty showed even if their results on the Specific Health Check were more favorable.
  • Underweight and inadequate physical activity are risk factors for sarcopenia.
  • These results suggest that, in addition to regular health checks after 65, muscle strength and muscle mass must also be measured in older people in order to avoid need for care in the future.

Research background

Frailty can be an early sign that a person is becoming dependent and has received attention as an important issue in considering healthy life expectancy in our increasingly aging society. Frailty is associated with a decline in physical and cognitive function and muscle breakdown (sarcopenia) due to age and weight loss.

Nevertheless, there is a lack of detailed information on the prevalence of sarcopenia, as the diagnosis still requires special measuring devices that make it difficult to diagnose in a regular clinic or during a medical examination.

In November 2019, the Japanese Association on Sarcopenia and Frailty (JASF) introduced a new set of diagnostic criteria that makes the diagnosis of possible sarcopenia comparatively easier. To reduce frailty and care needs in the elderly, it is important to understand how many people at the beginning of old age (65 years old) have potential sarcopenia and to shed light on their health.

Research methodology

This study examined data from approximately 1,800 Kobe citizens aged 65 and over who were all members of Japan’s National Health Insurance. By applying the new JASF criteria, the researchers were able to determine the prevalence of possible sarcopenia from data on the calf circumference and grip strength of the participants. At the same time, the researchers were able to use the answers to the questionnaire for the specific health check to assess the physical and cognitive performance in everyday life of participants with possible sarcopenia.

It was found that around 3% had possible sarcopenia, the majority of whom were not obese. It was found that the thinner the participant, the more likely they were to have possible sarcopenia. Those with possible sarcopenia showed better results on the specific health check than those without their answers to the checklist for assessing physical and mental functioning, but showed a decline in the categories relating to everyday activity, resilience, diet, seclusion, and cognitive function.

From the results of a concurrent analysis, the researchers estimated that possible sarcopenia is caused by weight loss and insufficient exercise.

Research meaning and further research

The results of this study, which was carried out in Kobe, a representative city in Japan, showed that even among the young elderly (aged 65 and over) at least 3% suffer from possible sarcopenia. These results provide initial indications that the mental and physical performance of these people is deteriorating in many areas of daily life, even if the results of the Specific Health Check, which was developed to prevent lifestyle diseases, did not give cause for concern.

Early intervention in sarcopenia cases can have beneficial effects. Against this background, it would be desirable for older people to be offered a test to assess sarcopenia in addition to the current specific health check. This would make it possible to reduce the number of people bedridden and in need of care in the future.

Supplementary explanation

1. Sarcopenia: A disease characterized by age-related decline in muscle mass, activity level, and physical function. It decreases the healthy life expectancy of the individual and can lead to falls, broken bones, difficulty walking and immobility. A person’s muscle mass begins to decline after reaching its peak between the ages of 25 and 30, and that decline accelerates after the age of 65. However, it is possible to delay the progression of sarcopenia through exercise.

2. Frailty: Frailty is characterized by an age-related deterioration in mental and physical health and a tendency to be attached to the home and to withdraw from society. It is the phase between being in good health and being in need of care. However, frailty is a reversible condition and can be alleviated through a balanced diet, adequate exercise, and social engagement. Sarcopenia is a major cause of frailty.

Researcher Commentary (Project Professor Tamori Yoshikazu)

The harmful effects of metabolic syndrome such as obesity and increased visceral fat are well known and measures are in place in Japan to assess them such as the specific health check-up and guidelines. On the other hand, age-related diseases such as sarcopenia and frailty are becoming more important as the population of countries like Japan ages. However, these issues are not currently well understood.

In our study, we found that even among 65 year olds, around 3% have possible sarcopenia. From the results, we understood that the causes include low weight and insufficient movement, and that there is a tendency for frailty in patients with possible sarcopenia. Therefore, in addition to regular health checks, tests to measure muscle strength and mass are also required after the age of 65.

It is important that those over 65 years of age eat a balanced diet and do appropriate exercises, not only to avoid being overweight, but also to avoid being underweight. Especially during the current coronavirus pandemic, people have limited opportunities to go outside and spend extended periods of time indoors, but walking and exercising as much as possible is important.


Journal reference:

Miura, H., et al. (2021) Clinical features of 65-year-old people in Japan diagnosed with possible sarcopenia based on the criteria of the Asian Working Group for Sarcopenia 2019. Geriatrics and Gerontology International.

Related Articles