Physical Aspects of Aging

PHYSICAL ASPECTS OF AGING

Cardiovascular System

Heart disease is the leading cause of death in the aged. The heart valves become thicker and stiffer, and the heart muscle and ar-teries lose their elasticity. Calcium and fat deposits accumulate within arterial walls, and veins become increasingly tortuous. Although function is maintained under normal circumstances, the cardiovascular system has less reserve and responds less effi-ciently to stress. The maximum cardiac output decreases by about 25% from age 20 to age 80. Under conditions of stress, both the maximum cardiac output and the maximum HR di-minish gradually. The relationship between maximum HR and age is as follows:

Normal maximum HR for age = 220 − age in years

Hypertension has been shown to be a serious risk factor at all ages for cardiovascular disease and stroke. A diagnosis of hyper-tension is made only after it has been confirmed by at least two subsequent readings. In older people, hypertension is classified as follows:

Isolated systolic hypertension: the systolic reading exceeds140 mm Hg, and the diastolic measurement is normal or near normal (less than 90 mm Hg)

Primary hypertension: the diastolic pressure is greater than orequal to 90 mm Hg regardless of the systolic pressure Secondary hypertension: hypertension that can be attributed toan underlying cause

Cardiovascular dysfunction may manifest as congestive heart failure, coronary artery disease, arteriosclerosis, hypertension, in-termittent claudication (leg pain caused by walking), peripheral vascular disease, orthostatic hypotension, dysrhythmias, cerebro-vascular accidents (strokes), or myocardial infarction (heart attack).

Heart failure (HF) is the number one cause of hospitalization among Medicare recipients and is a major cause of morbidity and mortality among the elderly population in the United States. Older patients often present with different symptoms than those seen in younger patients. Typically, younger persons present for care with the symptoms of exertional dyspnea, or-thopnea, and peripheral edema, whereas older patients typically report fatigue, nausea, and abdominal discomfort. In the younger population, men are more prone to HF, but in the el-derly population far greater numbers of women develop it. De-pending on its cause, HF can require various forms of therapy. The current standard of therapy for HF includes diuretics, angiotensin-converting enzyme inhibitors (ACE inhibitors) and, digoxin. Several large studies have also indicated that carefully monitored, low-dose beta-blockers and spironolactone can de-crease mortality (Rittenhouse, 2001).

Cardiovascular health can be promoted by regular exercise, proper diet, weight control, regular blood pressure measure-ments, stress management, and smoking cessation. To avoid light-headedness, fainting, and possible falls caused by orthostatic hypotension, the older person should be counseled to rise slowly (from a lying, to a sitting, to a standing position); to avoid strain-ing when having a bowel movement; and to consider having five or six small meals each day, rather than three, to minimize the hypotension that can occur after a large meal. Extremes in tem-perature should be avoided, including hot showers and whirlpool baths. Yard work should be limited to no more than 20 minutes on hot summer days. Exposure to wind or cold weather also should be avoided because of the risk of dizziness or falling asso-ciated with slower adjustments of blood pressure. If an individ-ual experiences dependent edema as the day progresses, the use of elastic compression stockings helps to minimize venous pooling.

Respiratory System

Age-related changes in the respiratory system affect lung capacity and function and include increased anteroposterior chest diame-ter, osteoporotic collapse of vertebrae resulting in kyphosis (in-creased convex curvature of the spine), calcification of the costal cartilages and reduced mobility of the ribs, diminished efficiency of the respiratory muscles, increased lung rigidity, and decreased alveolar surface area. Increased rigidity or loss of elastic recoil in the lung results in increased residual lung volume and decreased vital capacity. Gas exchange and diffusing capacity are also di-minished. Decreased cough efficiency, reduced ciliary activity, and increased respiratory dead space make the older person more vulnerable to respiratory infections.

Health promotion activities that help elderly persons maintain adequate respiratory function include regular exercise, appropri-ate fluid intake, pneumococcal vaccination, yearly influenza im-munizations, and avoidance of people who are ill. As with people of all ages, smoking cessation and frequent hand hygiene are pru-dent health practices. Hospitalized older adults should be fre-quently reminded to cough and take deep breaths, particularly postoperatively, because their decreased lung capacity and de-creased cough efficiency predispose them to respiratory infections and atelectasis.

Integumentary System

The functions of the skin include protection, temperature regu-lation, sensation, and excretion. With aging, changes occur that affect the function and appearance of the skin. The epidermis and dermis become thinner. Elastic fibers are reduced in number, and collagen becomes stiffer. Subcutaneous fat diminishes, particu-larly in the extremities. Decreased numbers of capillaries in the skin result in diminished blood supply. These changes cause a loss of resiliency and wrinkling and sagging of the skin. Hair pig-mentation decreases, resulting in gradual graying. The skin be-comes drier and susceptible to irritations because of decreased activity of the sebaceous and sweat glands. These changes in the integument reduce tolerance to extremes of temperature and to exposure to the sun.

Strategies to promote healthy skin function include avoiding exposure to the sun, using a lubricating skin cream, avoiding long soaks in the tub, and maintaining adequate intake of water (8 to 10 eight-ounce glasses per day).

Reproductive System

Ovarian production of estrogen and progesterone ceases with menopause. Changes occurring in the female reproductive sys-tem include thinning of the vaginal wall, along with a narrowing in size and a loss of elasticity; decreased vaginal secretions, result-ing in vaginal dryness, itching, and decreased acidity; involution (atrophy) of the uterus and ovaries; and decreased pubococcygeal muscle tone, resulting in a relaxed vagina and perineum. These changes contribute to vaginal bleeding and painful intercourse.

In older men, the penis and testes decrease in size, and levels of androgens diminish. Erectile dysfunction may develop with concomitant cardiovascular disease, neurologic disorders, dia-betes, or even respiratory disease, which limits exercise tolerance.

Sexual desire and activity decline but do not disappear. The use of water-based lubricants can help prevent painful intercourse. Local estrogen replacement intravaginally enhances vaginal tissue without the risks and side effects of oral estrogen. Several modal-ities are available for treatment of erectile dysfunction, which is linked to cardiovascular, neurologic, endocrine, or occasionally psychological dysfunction. The use of vacuum penile pumps, local injection or placement of vasostimulating medication into the ure-thral opening, and use of an oral medication, sildenafil citrate (Vi-agra), have all proved effective for some patients. Sildenafil citrate is contraindicated in patients who are taking oral nitrates.

If significant sexual dysfunction is present, referral to a gyne-cologist or urologist is warranted. For both men and women, maintenance of a daily physical exercise routine promotes en-hanced sexual performance.

Genitourinary System

The genitourinary system continues to function adequately in older people, although there is a decrease in kidney mass, pri-marily because of a loss of nephrons. Changes in kidney function include a decreased filtration rate, diminished tubular function with less efficiency in resorbing and concentrating the urine, and a slower restoration of acid–base balance in response to stress. Older women often suffer from stress or urge incontinence, or both. Benign prostatic hyperplasia (enlarged prostate gland), which is a common finding in older men, causes a gradual in-crease in urine retention and overflow incontinence. Prostate can-cer, a slow-growing cancer, is most often seen in men older than

70 years of age. Kidney and bladder cancers are most frequently seen after the age of 50 years. Smoking is known to be a primary causative agent of these carcinomas.

Adequate consumption of fluids is important to reduce the risk of bladder infections and urinary incontinence. Other healthy habits include having ready access to toilet facilities and voiding every 2 to 3 hours while awake. Avoidance of bladder-irritating substances—such as caffeinated, carbonated, and acidic beverages, Nutra-sweet, and alcohol—will greatly reduce urinary urgency and frequency. Water intake should be increased to avoid concentrated urine, which causes urinary urgency.

Pelvic floor exercises, first described by Kegel (1948), can also be extremely useful in reducing the symptoms of stress and urge incontinence. Teaching the patient how to do the exercises be-gins with identifying the pubococcygeus muscle, which is the same muscle used to hold back flatus or to voluntarily stop the flow of urine without contracting the abdomen, buttocks, or inner thigh muscles. The pelvic muscles are first tightened and then relaxed, maintaining a 5-second contraction with 10-second rest intervals. This exercise should be routinely practiced for 30 to 80 repetitions each day; additional repetitions are discouraged because of the risk of fatigue of the muscle. Because achieving bet-ter muscle control takes at least several months to accomplish, the elderly person is encouraged to consistently perform the exercises. To maintain pubococcygeus muscle control, these daily exercises must continue indefinitely. The use of biofeedback to confirm the correct execution of these exercises increases their effective-ness significantly.

As menopause approaches, a woman’s circulating estrogen de-creases, and, as a result, the pelvic floor is deprived of its needed blood supply and nutrients. This causes increasing stress and urge incontinence. Through the use of biofeedback-assisted pelvic muscle exercise, an individual can successfully regain bladder function. These exercises are also recommended for men with dribbling incontinence related to prostatectomy. The nurse in-structs the patient to tighten the rectal sphincter until the penis and testes slightly lift. Frequent repetition produces the desired muscle tone.

Constipation can be a major factor contributing to urinary in-continence. The patient is encouraged to eat a high-fiber diet, drink adequate fluids, and increase mobility to promote regular bowel function.

Urinary tract infections are prevalent in older women. The reasons include the effects of decreased estrogen, which shortens the urethral length, allowing easier passage of bacteria into the bladder; less overall fluid consumption, which causes a concen-trated urine in which bacteria can proliferate; and the introduc-tion of bacteria from the rectum as a result of poor bathroom hygiene secondary to impaired mobility and joint changes. Lim-ited range of motion of the arm and limited hand dexterity often result in a woman’s cleansing the perineal area in a back-to-front motion, causing bacteria such as Escherichia coli to be introduced to the urethral meatus and thus into the bladder (Degler, 2000b).

Gastrointestinal System

The older adult is at increased risk for impaired nutrition. Peri-odontal disease leading to tooth decay and loss of teeth is com-mon. Salivary flow diminishes, and the older person may experience a dry mouth. A preference for sweet and salty foods results from a decrease of taste receptors. Major complaints often center on feelings of fullness, heartburn, and indigestion. Gastric motility may decrease, resulting in delayed emptying of stomach contents.

Diminished secretion of acid and pepsin reduces the absorption of iron, calcium, and vitamin B₁₂. Absorption of nutrients in the small intestine also appears to diminish with age. The function of the liver, gallbladder, and pancreas is generally maintained, although absorption and tolerance to fat may decrease. The inci-dence of gallstones and common bile duct stones increases pro-gressively with advancing years.

Difficulty in swallowing, or dysphagia, affects 1 in 17 people, including 6.2 million Americans over the age of 60 years, with 300,000 to 600,000 new cases diagnosed each year. It is a serious condition that can be life-threatening. It results from interrup-tion or dysfunction of neural pathways, such as can occur with stroke. It may also develop from dysfunction of the striated and smooth muscles of the gastrointestinal tract in up to 50% of pa-tients with Parkinson’s disease and in those with conditions such as multiple sclerosis, poliomyelitis, and amyotrophic lateral scle-rosis (Lou Gehrig’s disease). Aspiration of food or fluid is the most serious complication and can occur in the absence of cough-ing or choking (Galvan, 2001).

Constipation is common in aged people. When mild, the symptoms involve abdominal discomfort and flatulence, but more serious consequences include fecal impaction that contributes to diarrhea around the impaction, fecal incontinence, and obstruc-tion. Predisposing factors for constipation include lack of dietary bulk, prolonged use of laxatives, the use of some medications, inactivity, insufficient fluid intake, and excessive dietary fat. Another factor may be ignoring the urge to defecate.

Gastrointestinal health promotion practices include receiving regular dental care; eating small, frequent meals; avoiding heavy activity after eating; eating a high-fiber, low-fat diet; ingesting an adequate amount of fluids; establishing regular bowel habits; and avoiding the use of laxatives and antacids. Understanding that there is a direct correlation between loss of smell and taste per-ception and food intake helps caregivers to intervene to maintain elderly patients’ health.

Nutritional Health

The social, psychological, and physiologic functions of eating in-fluence the dietary habits of the aged person. Decreased physical activity and a slower metabolic rate reduce the number of calo-ries needed by the older adult to maintain an ideal weight. Apathy, immobility, depression, loneliness, poverty, inadequate knowl-edge, lack of oral health, and lack of taste discrimination also con-tribute to suboptimal nutrient intake. Budgetary constraints and physical limitations may impair food shopping and meal prepa-ration. Education regarding healthy versus “empty-calorie” foods is helpful.

Health promotion teaching includes encouraging a diet that is low in sodium and saturated fats and high in vegetables, fruits, and fish. The older adult requires a variety of foods to maintain balanced nutrition. No more than 20% to 25% of dietary calo-ries should be consumed as fat. Reducing salt intake is also advo-cated, because sodium reduction has been shown to correct hypertension in some people. Protein intake should remain the same in later adulthood as in earlier years. Carbohydrates, a major source of energy, should supply the diet with 55% to 60% of the daily calories. Simple sugars should be avoided and complex car-bohydrates encouraged. Potatoes, whole grains, brown rice, and fruit provide the person with minerals, vitamins, and fiber and should be encouraged. Drinking 8 to 10 eight-ounce glasses of water per day is recommended unless contraindicated by a medical condition. A multivitamin each day helps to maintain daily nutritional needs.

Sleep

Sleep disturbances frequently occur in older people, affecting more than 50% of adults 65 years of age or older. The elderly often experience variations in their normal sleep–wake cycles, and the lack of quality sleep at night often creates the need for napping during the day. Laboratory screening can help to rule out disease processes that might be affecting an older person’s ability to sleep at night. If a spouse notes excessive snoring, a sleep study is indi-cated to rule out sleep apnea. The nurse can recommend prudent sleep hygiene behaviors such as avoiding daytime napping, eating a light snack before bedtime, and decreasing the overall time in bed to adjust for the fewer hours of sleep needed than when the patient was younger (Grandjean & Gibbons, 2000).

Musculoskeletal System

A gradual, progressive decrease in bone mass begins before the age of 40 years. Excessive loss of bone density results in osteoporosis, which affects both older men and women but is most prevalent in postmenopausal women. It is also seen in older men who are receiving hormone treatments for prostate cancer. A higher inci-dence is found among northern Europeans and Asians. Its typi-cal form is associated with inactivity, inadequate calcium intake, loss of estrogens, and a history of cigarette smoking. The danger of fracture as a result of bone reabsorption is especially high for the dorsal portion of the vertebra, humerus, radius, femur, and tibia. A loss of height occurs in later life as a result of osteoporotic changes of the spine, kyphosis (excessive convex curvature of the spine), and flexion of the hips and knees. These changes negatively affect mobility, balance, and internal organ function (Fig. 12-2).

The muscles diminish in size and lose strength, flexibility, and endurance with decreased activity and advanced age. Back pain is common. Beginning in middle age, the cartilage of joints pro-gressively deteriorates. Degenerative joint disease is found in everyone past the age of 70 years.

Calcium supplements, vitamin D, fluoride, estrogens, and weight-bearing exercises are often prescribed for the person who is at high risk for or already has osteoporosis. Although osteo-porosis cannot be reversed, the disease process can be slowed. A bone density test is the gold standard to assess for osteoporosis. Once it is diagnosed and treatment begun, yearly follow-up de-terminations of the bone density level are indicated. For skeletal health, the nurse can recommend the following (Scheiber & Torregrosa, 2000):

•          A high calcium intake, 1500 mg/day. Dairy products and dark green vegetables are excellent sources, as are soups and broths made with a soup bone and cooked with added vine-gar to leach calcium from the bone. Calcium supplements can be recommended to ensure that the daily calcium in-take is adequate.

•          A low-phosphorus diet. A calcium-to-phosphorus ratio of 1:1 is ideal; red meats, cola drinks, and processed foods that are low in calcium and high in phosphorus are avoided.

•          Weight-bearing exercise. The pull of muscle insertions on the long bones strengthens the muscles and retards calcium resorption.

•          Reduction of caffeine and alcohol. This assists in stopping further demineralization and renal excretion of calcium.

•          Smoking cessation.

•          Selective estrogen receptor modulators, such as raloxifene (Evista), preserve bone mineral density without estrogenic effects on the uterus. This medication is indicated for both prevention and treatment of osteoporosis. Although hor-mone replacement therapy (HRT) has been the mainstay of therapy for perimenopausal women, recent studies have demonstrated greater risks than previously recognized (Chen, Weiss, Newcomb, Barlow & White, 2002).

•          The bisphosphate drugs (e.g., Fosamax, Actonel). These drugs bind to mineralized bone surfaces to inhibit osteo-clastic activity and promote bone formation.

Muscle strength and flexibility can be enhanced with a pro-gram of regular exercise. The axiom “use it or lose it” is very rel-evant when considering the physical capacity of aged people. The nurse plays an important role by encouraging older adults to participate in a regular exercise program. Regular exercise in-creases the strength and efficiency of heart contractions, im-proves oxygen uptake by cardiac and skeletal muscles, reduces fatigue, increases energy, and reduces cardiovascular risk factors. Muscle endurance, strength, and flexibility—all outcomes of regular exercise—also help to promote independence and psy-chological well-being. Aerobic exercises are the foundation of programs of cardiovascular endurance conditioning. A physical examination by a physician or nurse practitioner is necessary be-fore initiating an exercise program, and older persons should perform exercises in moderation and use short rests to avoid undue fatigue. Swimming and brisk walking are often recom-mended because they are managed easily and usually are enjoyed by the older person.

Information about the nature and time course of menopause-associated bone loss through early markers may be used to help to preserve bone and thus stop the natural sequelae of osteoporosis. A nurse-led research team used frequent sequential serum mark-ers to confirm these changes and found a correlation with elevated alkaline phosphatase (ALP) and concentrations of follicle-stimulating hormone as a marker for vitamin K status. Therefore, perimenopausal women with elevated ALP can be targeted for health promotion to preserve bone density (Lukacs, 2000).

Nervous System

The structure and function of the nervous system change with ad-vanced age, and a reduction in cerebral blood flow accompanies nervous system changes. The loss of nerve cells contributes to a progressive loss of brain mass, and the synthesis and metabolism of the major neurotransmitters are also reduced. Because nerve impulses are conducted more slowly, older people take longer to respond and react. The autonomic nervous system performs less efficiently, and postural hypotension, which causes the person to lose consciousness or feel lightheaded on standing up quickly, may occur. Cerebral ischemia with related lightheadedness may interfere with mobility and safety. The nurse advises the person to allow a longer time to respond to a stimulus and to move more deliberately. Homeostasis is more difficult to maintain, but in the absence of pathologic changes, the older person functions ade-quately and retains cognitive and intellectual abilities.

Mental function is threatened by physical or emotional stresses. A sudden onset of confusion may be the first symptom of an in-fection or change in physical condition (pneumonia, urinary tract infection, medication interactions, dehydration, and others).

A slowed reaction time places the older person at risk for falls and injuries, including driving errors. Compared with the per-mile fatality rate for drivers aged 25 to 69 years, that for drivers 70 years of age and older is nine times as high. When an elderly person has been witnessed driving unsafely, he or she should re-ceive a driving fitness evaluation; this is often administered by an occupational therapist in conjunction with a neuropsychologist, who can help with the more detailed cognitive testing (Dolinar, McQuillen, & Ranseen, 2001).

Sensory System

Sensory losses with old age affect all sensory organs and can be devastating to the person who cannot see to read or watch televi-sion, hear conversation well enough to communicate, or dis-criminate taste well enough to enjoy food.

SENSORY LOSSES VERSUS SENSORY DEPRIVATION

Sensory losses can often be helped by assistive devices such as glasses and hearing aids. In contrast, sensory deprivation is the ab-sence of stimuli in the environment or the inability to interpret existing stimuli (perhaps as a result of a sensory loss). This depri-vation can lead to boredom, confusion, irritability, disorienta-tion, and anxiety. Meaningful sensory stimulation offered to the older person is often helpful in correcting this problem. One sense can substitute for another in observing and interpreting stimuli. The nurse can enhance sensory stimulation in the envi-ronment with colors, pictures, textures, tastes, smells, and sounds. The stimuli are most meaningful if they are interpreted to the older person and if they are changed often. Cognitively impaired persons respond well to touch and to familiar music.

VISION

As new cells form on the outside surface of the lens of the eye, the older central cells accumulate and become yellow, rigid, dense, and cloudy, leaving only the outer portion of the lens elas-tic enough to change shape (accommodate) and focus at near and far distances. As the lens becomes less flexible, the near point of focus gets farther away. This condition, presbyopia, usually begins in the fifth decade of life, and requires the wearing of reading glasses to magnify objects. In addition, the yellowing, cloudy lens causes light to scatter and makes the older person sensitive to glare. The ability to discern blue from green de-creases. The pupil dilates slowly and less completely because of increased stiffness of the muscles of the iris, so the older person takes longer to adjust when going to and from light and dark en-vironments or settings and needs brighter light for close vision. Although pathologic visual conditions are not part of normal aging, the incidence of eye disease (most commonly cataracts, glaucoma, diabetic retinopathy, and age-related macular degen-eration) increases in older people.

Age-related macular degeneration, in its most severe forms, is the most common cause of blindness in adults older than 55 years of age in the United States, and it is estimated to affect more than 10 million Americans. Risk factors include sunlight exposure, cig-arette smoking, and heredity, and people with fair skin and blue eyes are much more prone to the disease. Sunglasses and hats with visors provide some protection. Yearly eye checkups ensure early detection, which makes surgical correction much more success-ful. Optical aids to magnify print and printed objects may help those already suffering from the effects of macular degeneration to continue to read (Friberg, 2000).

HEARING

Presbycusis, a loss of the ability to hear high-frequency tones at-tributed to irreversible inner ear changes, occurs in midlife. Older people are often unable to follow conversation because tones of high-frequency consonants (letters f, s, th, ch, sh, b, t, p) all sound alike. Hearing loss may cause the older person to re-spond inappropriately, misunderstand conversation, and avoid social interaction. This behavior may be erroneously interpreted as confusion. Wax buildup or other correctable problems may also be responsible for major hearing difficulties. A properly pre-scribed and fitted hearing aid may be useful in reducing hearing deficits.

TASTE AND SMELL

Of the four basic tastes (sweet, sour, salty, and bitter), sweet tastes are particularly dulled in older people. Blunted taste may con-tribute to the preference for salty, highly seasoned foods, but herbs, onions, garlic, and lemon should be encouraged as substi-tutes for salt to flavor food.