Online Medical Reference

Aging and Preventive Health

Ronan Factora

Published: May 2013

Role of Frailty in Preventive Health

Health maintenance and preventive measures contribute to the maintenance of independent function and quality of life in the elderly individual. As with younger adults, optimization of management of chronic and acute disease processes helps to maintain optimal health in elderly patients. Numerous chapters in this text are devoted to management of specific disease processes pertinent to this population. These include the following:

  • Cardiology: Atrial Fibrillation, Cardiac Arrhythmias, Heart Failure, Peripheral Arterial Disease, Preventative Cardiology, Syncope
  • Dermatology: Photo Aging
  • Endocrinology: Erectile Dysfunction, Diabetes, Osteoporosis, Male Hypogonadism
  • Gastroenterology: Colorectal Neoplasia
  • Hematology/Oncology: Anemia, Multiple Myeloma, Breast Cancer Screening, Prostate Cancer
  • Infectious Disease: Immunization for Adults
  • Nephrology: Slowing Progression of Renal Disease
  • Neurology: Alzheimer's Disease, Antiplatelet Agents in Secondary Stroke Prevention, Carotid Vascular Disease, Dizziness, Low Back Pain, Parkinson's Disease, Stroke, Tremors
  • Psychiatry and Psychology: Delirium, Depression, and Other Mood Disorders
  • Pulmonary Disease: Chronic Obstructive Pulmonary Disease
  • Rheumatology: Gout, Osteoarthritis
  • Women's Health: Breast Cancer Risk Assessment and Prevention, Cervical Cancer Screening and Prevention, Menopause, Osteoporosis, Urinary Tract Infections in Adults

Beyond this, other factors contribute to this goal: physical activity, nutritional status, and cognitive and social stimulation. The idea of modifying these factors to foster the process of successful aging has been discussed in detail, and continues to be the focus of research.1 In the elderly population, addressing these issues helps to maintain physical health, independence, and quality of life.

The concept and definition of frailty continue to evolve. Despite recent conventions and definitions, physicians usually say “they know frailty when they see it.” Frailty has been characterized as an interaction between loss of muscle mass (sarcopenia), presence of multiple chronic illnesses, and loss of functional independence
(Fig. 1).2 Factors that have been identified as comprising the frailty phenotype include the loss of muscle mass, muscle weakness, poor endurance or energy, slowness, and low physical activity.

With normal aging and accumulation of chronic diseases, the risks for functional decline and loss of independence increase. Decline is especially marked in individuals with multiple chronic illnesses who experience multiple exacerbations of chronic illness or acute illnesses. Typically, these individuals tend to be less physically active. Lean muscle mass declines as a result of inactivity. This leads to a reduction in resting energy expenditure, reduction in caloric intake, and weight loss (lean muscle mass along with fat). Sarcopenia increases, tolerance of physical activity decreases, and the cycle repeats itself.

Homeostatic reserve is defined as the redundancy of physiologic functions present in human systems that is used to overcome acute and chronic health insults. The frailty phenotype can be used as a marker indicating a critical threshold in decline of homeostatic reserve. It also has been hypothesized to be a contributing factor to progression of chronic disease states, development and worsening of geriatric syndromes, and decline in ability to perform activities of daily living (see Fig. 1).

Decline in cognitive abilities contributes to decline in functional independence. With normal aging, processing speed of the brain declines and recall time increases. Risk of developing Alzheimer's disease increases each year after age 60. Comorbid illnesses such as stroke, diabetes, hypertension, and hyperlipidemia may also increase the risk of dementia. Current research has been focused on treating the consequences of dementia, but no treatment modality is currently available to reverse the process or halt its progression. Loss of cognitive reserve and the development of dementia have been associated with a greater risk of developing delirium, which is associated with increased morbidity and mortality in the context of acute illness.

Loss of homeostatic reserve puts the individual in a vulnerable position, whereby acute health events may lead to loss of function and independence and reduction in quality of life. An example of such an outcome is the admission of an elderly person into the hospital for a urinary tract infection. The patient, already having problems maintaining independent function at home (because of mobility issues and cognitive impairment), experiences various hospitalization insults, including delirium related to medications, immobility (from restraints and bed rest), and deconditioning. Such individuals are typically discharged to a rehabilitation facility. Delirium and underlying cognitive impairment lead to poor recovery of independent ambulatory function; eventually this patient is transferred to a nursing home. The patient never regains independence to a level that is safe to be at home.

The loss of homeostatic reserve and the development of frailty can be manifested in the myriad of syndromes encountered in the elderly. Geriatric syndromes include falls, delirium, malnutrition, urinary incontinence, and deconditioning. These syndromes typically arise out of several contributing factors. Identification of specific risk factors related to these syndromes has been shown to reduce the risk of their development.

Arguably, through interventions to maintain physical and cognitive reserves, it may be possible to prevent, slow, or reverse the development of the frailty phenotype and cognitive decline in healthy elderly individuals, even for those who have already developed loss of homeostatic reserve. As understanding of these relations grows, randomized trials of targeted interventions may more accurately determine the efficacy of therapies to these end points. In the interim, it is worthwhile to look at the available literature and examine which interventions may be of benefit.

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Physical Activity

Engagement in physical activity often declines with increasing age. Benefits of regular exercise have been studied extensively and are myriad, including reduction in risk of heart attack and stroke, improvement of diabetic control, stress reduction, improvement of pulmonary function, reduction of osteoarthritic pain and stiffness, and reduction of depressive symptoms. Beyond the benefits associated with chronic disease processes, physical activity in and of itself helps to maintain pulmonary and cardiac function, as well as musculoskeletal mass and tone.

There is a clear connection between maintenance of muscle strength, cardiovascular tone, and the ability to perform activities of daily living, to engage in leisure activities, and maintain quality of life. Intensity of physical activity and appropriate nutrition contribute to the maintenance of muscle mass. With normal aging, a reduction in muscle mass does occur. Participating in a regular exercise program can help reduce the risk of developing sarcopenia and its consequences.3

Targeted exercise types may also help specific areas of weakness and reduce the risk of functional decline. Exercise types include weight training, cardiovascular fitness, balance training, and flexibility training. Each type has its benefits. Strength training through use of resistance exercises helps to maintain muscle bulk and tone. Exercise of large muscle groups used in weight bearing helps to maintain mobility (for example, quadriceps strength is needed to maintain the ability to stand and properly ambulate). An example of this is in maintaining arm and leg strength to be able to perform light and heavy lifting needed to do housework. Such exercises can also be beneficial in maintaining the ability to participate in leisure (gardening, golfing) and social activities (dancing). With reduced use, slow twitch fibers eventually atrophy and convert to fatty tissue, with consequent reduction in muscle bulk, function, and potential decline in physical functional capacity.

Cardiovascular exercise is beneficial in maintaining physical activity tolerance. Even a simple regimen of walking for at least 30 minutes daily for three or more days of the week has demonstrated benefit. Reduced cardiovascular tone can result from a sedentary lifestyle, but may also be a consequence of comorbid illnesses that affect physical activity (congestive heart failure, peripheral vascular disease, osteoarthritis). Prolonged inactivity leads to a reduction in physical activity tolerance. The individual can become more limited in his or her ability to engage in activities that require some level of physical exertion. Thus, activities previously performed with no difficulty become burdensome. This can potentially lead to social isolation, further inactivity, and a cycle of declining quality of life and depression. One example could be loss of ability to volunteer at a community center because of significant exertional dyspnea related to walking; this can lead to reduction in volunteerism, less time spent socializing, potentially more time spent at home, and greater inactivity.

Along with cardiovascular tone, adequate balance and flexibility contribute to ambulatory ability. Several disease processes can affect these factors, including cerebrovascular disease, osteoarthritis, peripheral neuropathy, joint replacement surgeries, visual impairment, and vestibular dysfunction. A reduction in balance or flexibility because of these factors can increase the risk of falls in the individual (Fig. 2).

A fall is a sentinel event signaling a decline in an individual's physical homeostatic reserve, marking a point of greatest risk for loss of independence. Typically, several factors contribute to this end point and punctuate the multifactorial nature of the development of frailty and loss of functional capacity. Risk of falls is greatest after acute illness. These periods are associated with bed rest, inactivity, and inadequate nutritional intake. The consequence is development of deconditioning. Many hospitalized elderly patients who were initially able to ambulate on admission end up being discharged requiring a walker or wheelchair, all as a result of weakness that developed during acute hospitalization. A decline in the ability to ambulate can lead to a decline in ability to perform activities of daily living independently, increased reliance on others for assistance, and increased risk of social isolation.

Falls themselves are risk factors for future falls. Development of fear of falling because of feelings of unsteadiness or a fall can prompt an individual to limit physical activity. This may further perpetuate the cycle of inactivity, further reductions in muscular and cardiovascular tone, reduced oral intake, impaired nutritional status, and further decline. Several studies have been conducted confirming the benefit of the exercise Tai Chi in improving balance and reducing the risk of falls.4 Engaging in this or similar activities may improve or enhance balance and flexibility.

With greater amounts of exercise, greater benefits can be derived from it. The maintenance and increase of reserve functional capacity are important concepts in the elderly population. Homeostatic reserve allows an individual to overcome the results of acute insults to health. The presence of a greater amount of homeostatic reserve allows an individual to recover more quickly and more completely from acute declines in health. Decline in homeostatic reserve in all systems as a part of the aging process is generally recognized. This is accelerated by chronic disease processes and acute illness. The consequence is an impaired ability to recover from acute illness, the potential for permanent impairment, and development of a new functional baseline.

Ultimately, the goal in participation of physical activity in the healthy elderly population is maintenance and development of physical functional reserve capacity. For individuals suffering acute illness, appropriate physical activity in the form of physical therapy, rehabilitation, and scheduled exercise can accelerate recovery to a functional baseline.

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Interventions for Nutrition

Normal aging is associated with changes in body composition. Lean muscle mass declines and percentage of body fat increases. Caloric intake has been demonstrated to decline with increasing age in several observational studies. Several factors associated with normal aging contribute to this decline. These include a reduction in the senses of smell and taste, increased cholecystokinin production leading to earlier and more pronounced satiety with small meals, and reduced gastric motility (Box 1).5

Box 1: Age-Related Changes That Affect Appetite
Sensory Changes
  • Decreased odor perception
  • Increase in taste thresholds
  • Decline in taste sensitivity
Gastrointestinal Tract Changes
  • Earlier satiation
  • Reduced fundal compliance
  • Delayed gastric emptying
Hormonal Changes
  • Increased serum leptin
  • Decreased serum testosterone
  • Increased serum cholecystokinin
  • Increased inflammation-mediated cytokines
  • IL-1, TNF-α, IL-6, and ciliary neurotrophic factor
Central Nervous System Changes
  • Decreased opioid receptor activity
  • Reduction in physical activity
  • Decline in resting metabolic rate
IL, interleukin; TNF, tumor necrosis factor.
From Morley JE: Decreased food intake with aging. J GerontolA Biol Sci Med Sci 2001;56(Spec No 2):81-88.


Although many of these factors occur as an inexorable process of normal aging, many other risk factors for nutritional decline and subsequent weight loss can be identified. Several observational studies have demonstrated that significant weight loss, low BMI, and protein energy undernutrition are associated with increased morbidity and mortality in the elderly. In many circumstances, presence of any of these problems is under-recognized.

A full discussion regarding diagnosis of malnutrition and evaluation of weight loss is beyond the scope of this chapter. A pattern of significant weight loss (loss of ≥10 lbs or 10% of baseline body weight within a 6-month period) should prompt evaluation. If a cause, or contributing factors, is identified, intervention may be able to reverse the decline.

Nutritional status and levels of physical activity are inexorably linked. Decreases in physical activity are associated with a reduction in caloric needs, reduction in appetite, and subsequent weight loss. Muscle mass tends to decline in this scenario. With greater levels of activity, caloric needs increase, and a stimulation of appetite develops. In this circumstance, lean muscle mass may also increase as a result of increased physical activity.

Identification of risk factors for undernutrition and malnutrition may provide the opportunity for intervention for those at risk. The “DETERMINE Your Nutritional Status” checklist is useful in identifying these risk factors (Box 2).6 Especially common problems that contribute to weight loss in the elderly include dental problems, social isolation, economic issues, and the presence of depression and cognitive impairment. Timely interventions may prevent development of protein-calorie undernutrition and maintain proper nutrition and weight.

Box 2: DETERMINE Checklist of Risk Factors for Malnutrition
Disease
  • Chronic diseases impairing appetite or ability to eat
  • Mood and cognitive disorders
Eating Poorly
  • Inadequate food or poor food quality/caloric intake
  • Skipping meals; drinking too much alcohol
Tooth Loss or Mouth Pain
  • Missing or rotting teeth
  • Missing or poorly fitting dentures
Economic Hardship
  • Inadequate income to buy food
Reduced Social Contact
  • Single, widowed
  • No family or community supports
Multiple Medicines
  • Causing nausea, taste alterations, constipation, or anorexia
  • Includes dietary supplements, over-the-counter medications, and herbal products
Involuntary Weight Loss or Gain
  • Due to undiagnosed medical conditions such as cancer, malabsorption syndromes, metabolism-altering states
Needs
  • Assistance with self care
  • Problems with transportation for shopping
  • Problems with ambulation or cooking
Elder Years
  • Older than age 80

From Posner BM, Jette AM, Smith KW, Miller DR: Nutrition and health risks in the elderly: The nutrition screening initiative. Am J Public Health 1993;83(7):972-978.

Chronic diseases, specifically disease processes associated with chronic inflammation, affect appetite and accelerate reduction in caloric intake. Cytokines and other inflammatory factors have been identified as contributing factors to the development of anorexia. Additionally, commonly used medications have side effects that reduce appetite, palatability and flavor of food, or cause nausea, diarrhea, or headaches that may affect an individual's ability to eat (Box 3). Many of the chapters in this text address chronic diseases commonly encountered in the elderly population. Optimal management of these conditions can be beneficial in reducing their potential impact on morbidity associated with malnutrition.

Box 3: Commonly Prescribed Medication Classes Associated with Anorexia in the Older Patient
Antidepressants: selective serotonin reuptake inhibitors
Antibiotics
Ferrous sulfate
Furosemide and sulfa medications
Nonsteroidal anti-inflammatory drugs
Angiotensin-converting enzyme inhibitors
Antihistamines
Digoxin

When the underlying condition cannot be quickly or adequately treated (i.e., progressive dementia, depression, dentition issues), boosting caloric intake through dietary modifications can prevent further weight loss. Such interventions may include reduction in size but increased frequency of meals, discontinuation of dietary restrictions, addition of high calorie–content foods to the mealtime regimen, additional of snacks, and provision of dietary supplements. Box 4 lists other simple recommendations that can be made to increase caloric intake of food.

Box 4: Recommendations for Enhancing Caloric Content of Foods
Make an effort to eat regularly; more frequent small meals are an appropriate substitute for fewer larger meals during the day
Provide snacks throughout the day
  • Cheese and crackers
  • Canned, fresh, or dried fruits
  • Cereals, breads, muffins
  • Nuts, peanut butter
  • Yogurt
Eat fresh vegetables such as carrots, broccoli, or celery as a snack; use a dip to increase the calories.
Adjust flavors and textures of foods to increase appeal.
Drink a nutritional supplement such as Boost, Ensure, or Carnation Instant Breakfast cold or add a scoop of ice cream for a great-tasting shake.
Add nonfat powdered milk to foods such as creamed soups, mashed potatoes, gravies, sauces, hot cereal, scrambled eggs, beverages such as milk or Boost, puddings, and custards. (add 2 or more tablespoons (tbl) to each serving; 1 tbl = 25 kcal and 3 g protein).
Add honey, corn syrup, maple syrup, brown sugar (provided you are not diabetic) to foods such as hot or cold cereal, fruit, sweet potatoes, coffee, and winter squash. (1 tbl = 50 kcal)
Add combinations of grated cheese, margarine, gravies, sauces, and cream cheese (depending on your medical condition) to starchy foods, eggs, vegetables, and creamy soups. (1 tbl = 25-100 kcal)

Normal aging is associated with physiologic changes that alter eating habits. Risk factors for malnutrition can be easily identified using widely disseminated screening tools. Interventions in at-risk patients or those patients with malnutrition or observed weight loss may help to reverse these conditions.

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Interventions for Cognitive Function

Cognitive impairment and dementia occur commonly in the elderly population, and increases in incidence with in those older than 65 years. Several studies have analyzed risk factors for development of dementia, specifically Alzheimer's disease. Beyond health risk factors such as diabetes, hypertension, and hyperlipidemia, several lifestyle factors such as economic background, level of education, physical activity, and leisure activities have been studied to determine a link between them and risk for cognitive decline.7

Investigators have long hypothesized the link between leisure activities and risk of developing dementia. One recent observational study did identify links between a reduced risk of developing Alzheimer's disease and participation in specific types of leisure activities.8 The leisure activities associated with a reduced risk included reading, playing board games, playing musical instruments, and dancing. Increased frequency of participation in these activities was also noted to be associated with an increased level of protection.

Ongoing clinical trials continue to evaluate the value of such activities in the prevention of cognitive impairment. Even in patients who already have some level of cognitive impairment, benefit can still be garnered by encouraging participation in cognitively stimulating activities.

Despite encouragement to participate in such activities, barriers preventing the individual to do so may exist. Identifying these may lead to interventions and greater participation. Simple screening for visual and hearing impairments may lead to correction of previously unidentified deficits. Even if medical management is optimized and visual deficits can no longer be corrected, adaptive equipment to assist in performing activities of daily living or participating in leisure activities can be made available and consequently increase the patient's quality of life. Referral to a local sight center or blindness clinic may be useful in achieving this goal. Hearing aids are expensive (the individual is typically left to cover the entire cost) and can be unobtainable because of financial constraints for many elderly individuals. Less costly but still effective hearing augmentative devices may be more readily available; contacting an audiologist may be helpful. These devices may improve an individual's ability to engage in social activities.

Assessment of gait may reveal previously unreported pain issues and instability. Appropriate evaluation and management, including analgesic therapy (when indicated), may increase the individual's willingness to ambulate. A physical therapy evaluation can be useful in assessing reasons for gait instability and recommending appropriate assistive devices to improve the patient's safety and promote greater independence with walking.

Physical and cognitive limitations may also limit the individual's ability to drive or arrange alternative modes of transportation. Social isolation further limits available options for travel. Enlisting the assistance of available family and friends of the patient may be a way to overcome this. By contacting the local Alzheimer's Association or community agency on aging, nearby adult daycare facilities, senior centers, and community centers may be identified that may be able to provide transportation; they may also be able to provide listings for transportation services that could be made available for a nominal fee. Local churches or religious organizations as well as the Veterans Administration facilities may also be able to provide appropriate services.

Optimization of chronic illnesses associated with increased risk of developing dementia, and increased participation in leisure activities can be protective against the development of dementia (specifically Alzheimer's disease). A dose relation exists between amount of participation in leisure activities and reduction in risk of developing dementia. Encouraging elderly individuals to participate in such activities and addressing barriers that may impair their participation can be beneficial.

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Summary

  • Frailty as a syndrome occurs in the elderly and is a result of several contributing factors. This phenotype has been described in detail, and interventions addressing the hypothesized risk factors for frailty continue to be studied. By addressing the specific components related to frailty, functional decline may be prevented to some degree.
  • Promotion of physical activity has been demonstrated to be helpful in maintaining physical functioning in the areas of strength, flexibility, and balance. Monitoring nutritional intake and avoiding or reversing significant weight loss can also reduce associated morbidity and mortality and may lead to maintenance of independence.
  • Management of chronic comorbid illnesses should focus on limiting their impact on function (especially sensory impairments).
  • Elderly individuals should also be encouraged to participate in social and cognitively stimulating activities to help maintain cognition and physical functioning.

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References

  1. Rowe JW, Kahn RL. Human aging: Usual and successful. Science. 1987, 237: (4811): 143-149.
  2. Fried LP, Tangen CM, Walston J, et al: Frailty in older adults: Evidence for a phenotype. J Gerontol A Biol Sci Med Sci. 2001, 56: (3): M146-M156.
  3. Singh MA. Exercise comes of age: Rationale and recommendations for a geriatric exercise prescription. J Gerontol A Biol Sci Med Sci. 2002, 57: (5): M262-M282.
  4. Province MA, Hadley EC, Hornbrook MC, et al: The effects of exercise on falls in elderly patients. A preplanned meta-analysis of the FICSIT Trials. Frailty and Injuries: Cooperative Studies of Intervention Techniques. JAMA. 1995, 273: (17): 1341-1347.
  5. Morley JE. Decreased food intake with aging. J Gerontol A Biol Sci Med Sci. 2001, 56: (Spec No 2): 81-88.
  6. Posner BM, Jette AM, Smith KW, Miller DR. Nutrition and health risks in the elderly: The nutrition screening initiative. Am J Public Health. 1993, 83: (7): 972-978.
  7. Snowdon DA, Nun S. Healthy aging and dementia: Findings from the Nun Study. Ann Int Med. 2003, 139: (5 Pt 2): 450-454.
  8. Verghese J, Lipton RB, Katz MJ, et al: Leisure activities and the risk of dementia in the elderly. N Engl J Med. 2003, 348: (25): 2508-2516.

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