What is Sarcopenia?
Sacropenia is a disease associated with loss of muscle mass as one gets older.
Sarcopenia is a condition which involves the progressive loss of muscle mass accompanied by loss of physical function and muscle weakness which occurs with aging. However, there is no widely accepted definition of sarcopenia that has been accepted by the scientific and medical community (Cruz-Jentoft, 2014). The condition is linked to poor health and premature death.
“Are you over 65 years old and experiencing muscle weakness? You might be suffering from sarcopenia.”
As Sarcopenia can affect anybody as we grow older, it is important to be aware of the disease as it can significantly affect one's quality of life. In addition to the personal consequences on the individual, sarcopenia has a great effect on society as a public health issue. Even though the disease is so widespread, there is no consensus in the medical community regarding how to best define and measure the condition.
A Little History!
Loss of muscle mass in extreme old age was first observed and recorded by Critchely in 1931 but the term sarcopenia was first used in 1984 by Rosenberg. Many other scientists and physicians used this definition. However, researchers started noticing that loss of muscle mass was not always associated with loss of muscle function and that the degree of functional loss varied based on the quality rather than the quantity of the muscle mass. Therefore, the definition of sarcopenia changed in order to better describe the disability cascade. The disability cascade includes dynapenia (loss of muscle power), keratopenia (loss of muscle force or strength) and sarcopenia (loss of muscle mass) which, when they occur together produce disability or loss of function in the muscles and therefore inability to perform day-to-day activities. Even though the scientific and medical community has made several attempts to unify the definition of sarcopenia, more works needs to be done in order to have a commonly accepted definition which will help study the disease better.
Risk Factors Leading to Sarcopenia
There are both intrinsic and extrinsic factors that can lead to someone developing sarcopenia. Let's look at each of those categories separately.
Intrinsic Risk Factors
Intrinsic risk factors for sarcopenia are factors that cannot be changed by the individual. Usually it is a characteristic that an individual was born with and therefore the individual needs to work with them and understand them but it is difficult to decrease the effects of those risk factors.
Examples of intrinsic risk factors are genetics, sex and other comorbidities, including diabetes, obesity and cardiovascular diseases as well as age. As mentioned in the introduction, the risk of developing sarcopenia increases with age. More about sex differences will be discussed in another blog post. Finally, genetic dispositions to diabetes or cardiovascular diseases can increase the probability of someone developing sarcopenia.
Extrinsic Risk Factors
Extrinsic risk factors include factors such as diet, body composition, use of pharmaceutics and lifestyle habits. As opposed to intrinsic risk factors, the extrinsic risk factors can be more easily changed by modifying lifestyle habits. For example, changing body composition can be done by exercising more and watching one's diet. Those are the factors that should be focused on when someone is diagnosed with sarcopenia as they are very likely to improve the quality of life of affected individuals.
Canadian Sarcopenia Foundation https://www.canadiansarcopeniafoundation.com/
Cruz-Jentoft, A. J., Landi, F., Schneider, S. M., Zúñiga, C., Arai, H., Boirie, Y., . . . Cederholm, T. (2014). Prevalence of and interventions for sarcopenia in ageing adults: A systematic review. Report of the international sarcopenia initiative (EWGSOP and IWGS). Age and Ageing, 43(6), 748-759. doi:10.1093/ageing/afu115.
Dennison, E. M., Sayer, A. A., & Cooper, C. (2017). Epidemiology of sarcopenia and insight into possible therapeutic targets. Nature Reviews. Rheumatology, 13(6), 340-347. doi:10.1038/nrrheum.2017.60
Fuggle, N., Shaw, S., Dennison, E., & Cooper, C. (2017). sarcopenia. Best Practice & Research Clinical Rheumatology, 31(2), 218-242. doi:10.1016/j.berh.2017.11.007