The primary cause of Sarcopenia is aging. We start to lose muscle mass after the age of 30, losing approximately 3 – 8% per decade, and more rapidly after the age of 60. By age 80 approximately 40% of one of our lower major muscle groups, the vastus lateralis has been lost; this muscle group is important for balance and avoiding falls. Hormonal changes associated with aging affect muscle mass. Drops in estrogen in menopausal women, and lower testosterone levels in men as they age contribute to the loss of muscle.  

Other, secondary causes of Sarcopenia include diseases such as cancer, osteoarthritis, and neurological disorders; any condition which might limit mobility.

Inactivity due to bed rest, a sedentary lifestyle, or physical inactivity can contribute to the development of this disorder, and conditions related to nutrition, such as undernutrition, malabsorption, medication related anorexia, or over nutrition can also cause Sarcopenia.

The structural function of muscle is familiar to most people, the role of muscle in movement, balance, posture, and strength is generally well known. Muscle also has other important functions in our body; the average healthy person’s body weight is made up of 40% muscle. In addition to helping us move through the activities of our lives, muscle has metabolic functions such as heat generation, a role in immune function, it contains energy stores, and it is an endocrine organ. Signals sent out from muscles affect other tissues in the body, including bone, helping to heal and repair.

Muscles affect every system in the body, this is why Sarcopenia is related to longevity; frail patients have a higher in hospital mortality rate, and a higher 1-year mortality rate after a fall.

The components of Sarcopenia are low muscle strength, low muscle quality/quantity, and low physical performance. If a person has low muscle strength Sarcopenia may be suspected. The diagnosis would then be confirmed by a combination of diagnostic tests and assessments that indicate low muscle quality or quantity. If someone experiences low physical performance, we can say they have severe Sarcopenia.

Screening may include collecting a patient’s history and completing a screening form called a SARCF. If screening is positive the patient’s health care team may move to the assessment stage which could include grip strength tests, a chair stand test, and a gait speed test.

The loss of muscle and bone are both common with aging. When significant loss of both muscle and bone loss are present it can be referred to as “Osteosarcopenia” or “Sarcoporosis.” This is important to identify because this combination indicates a higher risk of falls and mortality. There are common mechanisms and risk factors for both bone and muscle loss including hormonal changes, inactivity, and malnutrition. These conditions are also related because bone and muscle talk to each other through signaling molecules which help to signal bone and muscle repair. Sarcopenia increases the risk of fragile falls, those that occur when the legs lose strength or simply “give out”, which in turn lead to fractures.

The risks factors of Sarcopenia are not all controllable. Some risk factors such as age and genetics for example, are not modifiable. There are measures you can take, however, to maintain your peak muscle mass and reduce your risk of Sarcopenia. The first tool we have to prevent Sarcopenia is exercise, particularly resistance training. Aim for a routine 2-3 times per week that is progressive, targets major muscle groups, and uses things like free weights, resistance bands, machines, and body weight. Some studies show that combining resistance training with aerobic activity may have better results. The exercise recommendations for Sarcopenia overlap with Osteoporosis Canada’s recommendations regarding exercise. This means that you can find resources on Osteoporosis Canada’s website such as the Too Fit to Fracture sheet, and the exercise video series, which will help you get started on an exercise protocol. You may also seek advice from a professional who is trained in safe movement for bone and muscle health such as a physiotherapist, an exercise physiologist, a kinesiologist, a personal trainer, or from a Bone Fit™ trained professional.

Diet and supplementation can also support muscle mass. Older adults who are at a higher weight should avoid low calorie diets as this is associated with a loss of muscle mass. High protein diets are key to maintaining muscle mass. Protein from supplements can help with strength and mass but may have limited effect on physical performance. Vitamin D is also important as it may improve muscle strength and performance, which decreases fall risks.

Nutrition guidelines for Sarcopenia also overlap with Osteoporosis Canada’s guidelines for bone health, so online resources like the nutrient calculator can help to ensure that nutritional targets are being met.

There are currently no medications approved to treat Sarcopenia, although several studies are in late stages of progress and this is likely to change at some point in the future.

In general, the approach to prevention and treatment of Sarcopenia should be multimodal, and personalized for you by your team of health professionals.