Many people who are living longer after a sedentary lifestyle are paying the price. The diseases osteoporosis and sarcopenia are on the rise, and their underlying biological similarities and common risk factors are creating a new syndrome: osteosarcopenia.
This syndrome exacerbates each disease’s associations with high risk of frailty, falls, fractures, hospitalisation and mortality; indeed, a study confirmed that osteosarcopenia is linked with poorer physical function than sarcopenia alone.
Early diagnosis and intervention for this “hazardous duet” are imperative, so here’s what to know.
Osteosarcopenia broken down
Osteoporosis affects more than 60% of Australians over 50 years. It happens with aging when bone tissue starts deteriorating, resulting in porous bones and increased risk of fracture – even with minor falls. It can be diagnosed with a bone mineral density scan.
Sarcopenia, on the other hand, refers to accelerated loss of skeletal muscle mass and strength with aging. Affecting around one in three older adults, it can be harder to detect – especially if a person is overweight. Handgrip is typically used to measure muscle strength and gait to assess physical performance.
Sarcopenia has far-reaching effects beyond just muscles. This includes bones. Muscles help maintain bone mass by producing hormones and prevent falls by providing support and assisting balance.
Bones and muscles both release hormones that impact the metabolism and functions of other tissues, and crosstalk with fat cells – together these three groups are the biggest constituent of connective tissue.
When muscle and bone tissues break down, they are typically infiltrated with fat cells which creates toxicity and inflammation and interferes with the crosstalk between them.
The only way to diagnose osteosarcopenia is with combined detection of each disease.
A history of falls and/or fractures should sound warning bells. Shortened stature is also a clue to fractures of the vertebrae due to osteoporosis. Muscle weakness and wasting can point to sarcopenia, and genetics play a role in both conditions.
People with these risk factors should be regularly screened for each disease, and experts agree that all postmenopausal women over 65 should have bone mineral density scans regardless.
Factors that lead to high risk of osteosarcopenia include older age, being female, endocrine disorders, sex steroids, low protein intake, smoking, inadequate dietary calcium intake, low vitamin D levels, and minimal mobility and function.
Prevention and treatment
It is better to treat osteosarcopenia as one condition, using an integrated approach, rather than the two contributing diseases separately.
Inactivity is a primary, modifiable cause of muscle wasting and bone density loss, as the health of both bones and muscles relies on mechanical stimulus. Resistance training – increasing muscle strength – is most important.
Regular weight-bearing and muscle-strengthening exercises that target agility, strength, posture and balance have demonstrated benefits and are recommended at least three times a week for 20 minutes or more.
Protein is vital for bone and muscle and is recommended at more than 0.8 mg/kg body weight per day. Calcium and vitamin D also have dual benefits for bone and muscle; together with protein they can help reduce falls, fractures and disability.
Regular activity and a healthy diet with adequate nutrition are also the most effective ways to prevent age-related deterioration of bone and muscle and retain independence and optimal quality of life.
References
https://www.racgp.org.au/afp/2017/november/osteosarcopenia-a-new-geriatric-syndrome/
http://www.ageingmuscle.be/sites/ageingmuscle.be/files/Osteosarcopenia%20-%20where%20bone%2C%20muscle%2C%20and%20fat%20collide.pdf
https://academic.oup.com/innovateage/article/2/suppl_1/304/5169225
https://journals.lww.com/co-clinicalnutrition/FullText/2017/11000/Vitamin_D_and_osteosarcopenia___an_update_from.12.aspx
https://pdfs.semanticscholar.org/a290/14f8fcbd70b97a16cc9c393a9cdb3ec3a808.pdf
