The ageing Asian population and the health implications of frailty
Frailty is a significant health problem in the elderly, including in Asia, where the number of elderly people is increasing rapidly. Therefore, physicians need to be actively assessing elderly for the presence and severity of frailty in order to provide the best possible care for them. The physiological development of frailty and sarcopenia is a continuum, highlighting the importance of identifying ways to prevent the development of frailty, and the transition from prefrailty to frailty among elderly people.
Southeast Asia is undergoing rapid demographic transition, with a reduction in fertility, an ageing population and rural-to-urban migration. These trends have a significant impact on health in the region, with a shift from primarily infectious diseases to non-communicable chronic diseases (including hypertension, diabetes, cardiovascular/cerebrovascular disease, cancer, osteoporosis, dementia). (1)
An important aspect of this transition is the growing proportion of the population in Asia aged ≥65 years. In fact, across Asia, the number of elderly people is expected to treble by the year 2050, and there will be a marked increase in the number of people in the oldest age groups (75 years and above).(2)
Elderly people have unique health and social needs associated with declining functional capacity and increasing dependency. Because of declines in fertility, the elderly in Asia will have fewer adult children to support them in coming years, and the changing social and economic environment means that fewer elderly Asian people will live with extended family (2). Therefore, in addition to increasing physical health needs, many older Asian people must care for themselves in relative social isolation, and any physical health concerns can be exacerbated by psychological, economic and nutritional deprivations.
A key determinant of health outcomes in elderly people is frailty. Frail elderly people are more vulnerable to stresses, such that a small event has a disproportionately large effect on their physical and mental status. (3)
What is frailty?
Frailty is a result of physiological decline in multiple body systems (3):
These systems are intricately linked, ie, decline in one area can trigger worsening in another, and the cumulative effect of dysfunction in multiple physiological systems results in frailty. For example, because of the link between the brain and the endocrine system, physiological changes in the ageing brain affect the endocrine control of metabolism and energy use. One theory suggests that the accumulation of deficits within a number of systems determines the onset of frailty. (3) What is known is that frail people often have multiple impairments, including low bodyweight, cognitive impairment, fatigue, impaired mobility and problems with balance (4).
Five key clinical manifestations predict poor outcomes (Table 1) (5). These five clinical indicators, known as the Fried criteria, are commonly used to define frailty and prefrailty states in research on the impact of frailty, although other criteria exist. For example, the Frailty Risk Index (FRI) is a validated tool developed by Singapore researchers from the Singapore Longitudinal Ageing Studies, and it includes both risk factors and manifestations of frailty. (6).
TABLE 1 Fried criteria for defining frailty
|Not frail = 0 clinical manifestations
Pre-frail = 1 or 2 clinical manifestations
Frail = 3+ clinical manifestations
Source: Fried et al (2001)
Frailty is a dynamic process – individuals can transition between non-frail, pre-frail and frail states. However, it is much more common for them to progress to worse states than to transition to a less impaired state. (7)
Elderly people can be frail without having additional chronic disease, but chronic illness and frailty frequently overlap. This highlights the importance of carefully assessing frail elderly for early signs of comorbidity in order to implement preventive strategies. (3)
What causes frailty?
Frailty develops as a result of multiple physiological processes (Figure 1) (4). A common hypothesis is that the lifelong accumulation of molecular and cellular damage causes organ dysfunction (3). The organ dysfunction disrupts physiological homeostasis, and once the impairment exceeds the body’s capacity to compensate, the person begins to show signs and symptoms of frailty.
FIGURE 1 Hypothesized molecular, physiological and clinical pathway to frailty (4)
Source: Walston et al (2006).
Sarcopenia (loss of muscle mass) is an important contributor to frailty, and this is related to both anorexia (reduced food intake) and increased muscle protein breakdown. (8,9). Weight loss contributes to muscle wasting, and exacerbates some of the physiological changes associated with ageing, such as increased oxidative stress and worsening tissue damage (8). This perpetuates the cycle of physical decline by contributing to low energy and fatigue, reducing exercise capacity and the inherent effects of exercise on muscle building.
In addition to maintaining exercise, adequate nutrition is an important component of delaying or reversing the changes associated with frailty. Elderly people need to ensure that their caloric intake, and the essential nutrient content of their food, is adequate to maintain their declining systems. Poor nutrition is a key risk factor for frailty development. (6).
How common is frailty?
In Caucasian populations, the prevalence of frailty and prefrailty (as defined by the criteria in Table 1) is about 13.6% and 33.5%, respectively, in community-dwelling people aged ≥65 years (10).
In Asia, the prevalence of frailty (using Fried criteria), varies widely from 2% in Chinese adults in Singapore to 17.4% in a rural area of South Korea (Table 2) (11-18). However, it should be noted that these prevalence data are not all based on comparable populations (some were aged <65 years, and there was a mix of rural and urban dwelling people). The lowest rates of frailty are seen in studies from Taiwan or Singapore where the studied populations included individuals aged ≥50 or 55 years, respectively (13-14,18). In Asian populations aged ≥65 years, the prevalence varies between 7.4% and 17.4% (11-12,15-17),similar to the rates reported in Western populations (10).
TABLE 2 The prevalence of frailty and prefrailty in Asian studies using the Fried criteria
|Source||N||Prevalence (of studied population)|
|Makizako et al. 201511||4341||3.9%||49.6%|
|Shimada et al. 201312||5104||11.3%|
|Feng et al. 2016 (SLAS)13||2804||2.6%||33.3%|
|Feng et al. 2016 (SLAS)14||1575||2%||32%|
|Jung et al. 201615||382||17.4%||52.6%|
|Jung et al. 2014 (KLoSHA)16||693||13.2%||59.4%|
|Kim et al. 201417||486||7.4%||50.2%|
|Liu et al. 2015 (I-Lan Longitudinal Aging Study)18||1839||3.6%||39.2%|
*Study participants were aged ≥55 years; †Study participants were aged ≥50 year
Source: Fried et al (2001)
Why is frailty important?
Frail people can have a disproportionate and dramatic decline in their health status in response to apparently small insults (e.g. minor infection or minor surgery) (3). The impact of frailty is not just physical – frail elderly often become socially isolated and more susceptible to stressors as a result of their physical impairments (4).
Frailty significantly increases the risk of a number of adverse health outcomes in elderly people, including (3):
- Worsening disability
- Care home admission
Since frailty is at least partially reversible, interventions to reduce the severity or prevalence of frailty can have important benefits, not only for elderly, but for their families and society. This is especially true early in the course of frailty, when interventions are more likely to produce improvements in functional abilities. (3)
Frailty is significant health problem in the elderly, including in Asia, where the number of elderly people is increasing rapidly. Since a mild insult can have dramatic health consequences in a frail person, the presence of frailty can shift the risk:benefit balance of some interventions, such as surgery. Therefore, physicians need to be actively assessing elderly for the presence and severity of frailty in order to provide the best possible care for them. The physiological development of frailty and sarcopenia is a continuum, highlighting the importance of identifying ways to prevent the development of frailty, and the transition from prefrailty to frailty among elderly people.
- Chongsuvivatwong V, et al. (2011). Health and health-care systems in Southeast Asia: diversity and transitions. Lancet 2011;377:429-37.
- East West Center. Asia’s Aging Population. Available from: http://www.eastwestcenter.org/fileadmin/stored/misc/FuturePop08Aging.pdf Accessed Dec 27 2016.
- Clegg A, et al. (2013). Frailty in elderly people. Lancet 2013;381:752-762
- Walston J, et al. (2006). Research agenda for frailty in older adults: toward a better understanding of physiology and etiology: Summary from the American Geriatrics Society/National Institute on Aging Research Conference on Frailty in Older Adults. J Am Geriatr Soc 2006;54:991-1001
- Fried LP, et al. (2001). Frailty in older adults: Evidence for a phenotype. J Gerontol A Biol Sci Med Sci 2001;56A:M1-M11.
- Ng TP, et al. (2014). Frailty in older persons: multisystem risk factors and the Frailty Risk Index (FRI). JAMDA 2014;15:635-642.
- Gill TM, et al. (2006). Transitions between frailty states among community-living older persons. Arch Intern Med 2006;166:418-423.
- Martone AM, et al. (2013). Anorexia of aging: a modifiable risk factor for frailty. Nutrients 2013;5:4126-4133
- Shaw SC et al (2017). Epidemiology of sarcopenia: determinants throughout the lifecourse. Calcif Tissue Int 2017; Apr 18 [Epub ahead of print]
- Collard RM, et al. (2012). Prevalence of frailty in community-dwelling older persons: a systematic review. J Am Geriatr Soc 2012;60:1487-1492.
- Makizako H, et al. (2015) Impact of physical frailty on disability in community-dwelling older adults: a prospective cohort study. BMJ Open 2015;5:e008462.
- Shimada H, et al. (2013). Combined prevalence of frailty and mild cognitive impairment in a population of elderly Japanese people. JAMDA 2013;14:518-524.
- Feng L, et al. (2016). Cognitive frailty and adverse health outcomes: Findings from the Singapore Longitudinal Ageing Studies (SLAS). JAMDA 2016 [Epub ahead of print]
- Feng L, et al. (2017) Physical frailty, cognitive impairment, and the risk of neurocognitive disorder in the Singapore Longitudinal Ageing Studies. J Gerontol A Biol Sci Med Sci 2017;72:369-375
- Jung H-W, et al.(2016)Prevalence of frailty and aging-related health conditions in older Koreans in rural communities: a cross-sectional analysis of the Aging Study of Pyeongchang Rural Area. J Korean Med Sci 2016;31:345-352.
- Kim S, et al. (2014). Correlation between frailty and cognitive function in non-demented community-dwelling older Koreans. Korean J Family Med 2014;35:309-320.
- Jung H-W, et al. (2014) Prevalence and outcomes of frailty in Korean elderly population: comparisons of a multidimensional frailty index with two phenotype models. PLoS One 2014;9:e87958
- Liu L-K, et al. Association between frailty, osteoporosis, falls and hip fractures among community-dwelling people aged 50 years and older in Taiwan: results from I-Lan Longitudinal Aging Study. PLoS One 2015;10:e0136968