Osteosarcopenia
The Silent Geriatric Giant
“It takes a child one year to acquire independent movement and ten years to acquire independent mobility. An old person can lose both in a day.” — Professor Bernard Issacs
The term “geriatric giants” was coined by Professor Bernard Issacs in 1965 to describe a group of conditions
- immobility
- incontinence
- instability and
- impaired intellect.
These conditions are considered “giants” due to their high prevalence and the immense burden of suffering they impose on the geriatric population, necessitating medical and social intervention.
Over the years, extensive research has focused on these giants, making them a primary target for geriatricians.
Recently, Professor Duque and colleagues from the Australian Institute for Musculoskeletal Sciences identified an even larger giant: Osteosarcopenia.
In a 2021 article published in the Journal of Nutrition, Health & Aging, they highlighted the twin problem of Osteosarcopenia. On one hand, it is highly prevalent, and its impact is profound. On the other hand, it has not received the equal recognition and precedence in clinical practice.
During the first decade of our life, we develop a high level of independence and mobility, strongly associated with progressive increases in muscle and bone mass. However, by the third decade, this peak begins to decline. In a significant proportion of older individuals, several risk factors contribute to both Osteoporosis (decreased bone mass with micro-architectural deterioration) and Sarcopenia (loss of muscle mass, strength, and function).
Emerging evidence suggests that these two pathological conditions can coexist.
The term "Sarco-osteopenia" was proposed by Binkley and Buehring in 2009 to describe a subset of frail older individuals with osteopenia/osteoporosis and sarcopenia.
These individuals face a higher risk of falls, fractures, frailty, and morbidity. Later, the term evolved into “Osteosarcopenia”.
Prevalence estimates for osteosarcopenia range from 5% to 37% among community-dwelling older individuals in various studies conducted in Japan, Iran, Germany, Australia, and China. Unfortunately, there are no published studies from India yet, specifically addressing the prevalence of this condition among the geriatric population.
Advancing age is a well-established risk factor for Osteosarcopenia. Other potential risk factors include malnutrition, high body fat, diabetes, depression, physical inactivity, and low educational levels. Researchers propose that short leukocyte telomere length (Kirk et al.) and intermuscular fat infiltration (Al Saedi et al.) contribute to the coexistence of Osteosarcopenia and serve as predictors of falls and fractures.
Why is Osteosarcopenia relevant?
Without early and prompt interventions, it predisposes older individuals to falls, fractures, disability, frailty, and premature mortality. The Canadian Longitudinal Study on Aging (CLSA), which included 30,097 males and females aged 45-85, concluded that osteosarcopenia was associated with falls, fractures, worse life satisfaction, and limitations in activities of daily living (ADL). In 2010 alone, the European Union had 27.5 million people living with osteoporosis, resulting in approximately 3.5 million fragility fractures and a cost exceeding 37 billion euros. These numbers are projected to increase by 25% by 2025. The Hertfordshire trial estimated an annual cost of £2,707 per person, with an overall cost of £2.5 billion in 2018.
Despite the prevalence of osteoporosis being estimated at 8-62% among Indian women, as reported in a 2023 narrative review by Agarwal et al., there is a noticeable lack of studies from India that describe the prevalence and socioeconomic impact of Osteosarcopenia.
Gap in research
This gap in research urgently needs to be addressed. Furthermore, the development and application of accurate diagnostic methods for identifying Osteosarcopenia and predicting associated falls and fractures are of paramount importance.
Diagnosis
There are no screening or risk calculation tools validated for osteosarcopenia. However, numerous tools are available to diagnose both osteoporosis and sarcopenia.
SARC-F
A 5-point sarcopenia questionnaire recommended in the most recent international consensus guidelines, has limited use as a screening tool due to moderate sensitivity. However, validated tools are available for screening and risk stratification in those with osteoporosis which include the FRAX, widely used and cited.
Bone Mineral Density testing
DEXA is a specific tool for the diagnosis of osteopenia and osteoporosis. According to WHO diagnostic criteria, a t-score of -1 or less classifies the individual as having osteopenia, and -2.5 or less as osteoporosis.
The European Working Group on Sarcopenia in Old People (EWG-SOP 2)
They have established cut-off points for the definitive diagnosis of sarcopenia:
- Appendicular Skeletal Mass Index (ASMI) < 7.0 kg/m2 in males and <5.5 kg/m2 in females;
- Muscle strength < 27kgf for men and <16 kgf in women.
Other tests
Serum 25(OH) vitamin D, calcium, parathyroid hormone, and serum testosterone (in men) can help in detecting most secondary causes of pathology leading to falls and fractures.
Treatment
Treatment of osteosarcopenia is not well defined. Randomized controlled trials have demonstrated the efficacy of progressive resistance and balance exercises to prevent osteosarcopenia.
Whey protein, Vitamin D, and Calcium are nutritional supplements that may help in preventing osteosarcopenia.
Pharmacotherapy specifically for osteosarcopenia has not yet been developed. Denosumab, a RANK ligand inhibitor, has shown promising effects on bone and muscle.
In summary, osteosarcopenia should be identified as a new geriatric giant of our time due to its high prevalence and vast burden of sufferers. Awareness of this condition as a geriatric syndrome should increase, and its prevention, identification, and treatment should become a priority. It should act as a unifier in a set of fragmented fields in which osteoporosis, sarcopenia, falls, and frailty are identified and managed by various specialists. Focused research in this direction could finally improve care for this silent killer.