Health Articles

Zinc deficiency, as indicated by plasma zinc levels < 70 μg/dL, occurs in institutionalized, shut-in, and ambulatory elderly persons. Zinc loss in the urine occurs in persons with diabetes, cirrhosis, and alcoholism and in those using a diuretic. Zinc deficiency is associated with poor wound healing, impaired immune function, night blindness, and hypogonadism. High doses of zinc have been reported to slow the progression of age-related macular degeneration.
Selenium deficiency reportedly occurs in patients receiving long-term tube feedings. The major features are muscle weakness and pain.
Copper deficiency is associated with anemia and possibly mild glucose intolerance.
OBESITY
Fat acts as a storage organ for excess calories, providing protection for older persons with acute illnesses. Fat also protects vital organs from injury during falls and plays an important role in maintaining core body temperature.
Persons who weigh 120% to 130% of their desirable weight are considered moderately obese; those who weigh more than 130% of their desirable weight are considered morbidly obese.
In men, the prevalence of obesity peaks during middle age, and then declines to 26% by age 65 to 74. In white American women, the prevalence of obesity peaks at 36% between ages 65 and 74; 60% of African American women are overweight at these ages. In older persons, obesity may cause certain medical complications (see TABLE 2-4). However, low waist-to-hip ratios protect against obesity-associated dis-
eases.
Etiology
In older men, obesity appears to result from a decrease in physical activity; in older women, from the loss of estrogens; and in both sexes, from decreased growth hormone. Genotype appears to account for 25% of visceral body fat. Acquired causes of obesity include hypothyroidism, Cushing’s syndrome, tumors of the ventromedial hypothalamus, glucocorticoid therapy, monoamine oxidase inhibitors, and moderate doses of phenothiazines. Overeating remains the most common cause.
Treatment
Generally, obesity is a less important problem in older persons than in younger persons, and management should involve evaluation of the risk-benefit ratio of any therapeutic intervention.
Since the major identifiable cause of weight gain in older persons is lack of physical activity, an exercise program represents the most reasonable approach to weight reduction. Walking 1 mile burns about 100 calories. Thus, a mall-walking program in which a person walks 2 to 3 miles four times a week may produce gradual weight loss. For persons with osteoarthritis, an upper body exercise program is recommended.
Diets in older persons should provide at least 800 kcal/day and should always be supplemented with vitamins and trace elements. Older persons on a diet should drink at least 1 L of fluid daily. Any dietary program should be associated with a behavior modification program because in many cases starting a diet is an attempt to change lifetime habits.
Drugs such as fenfluramine or fluoxetine are not recommended for weight loss in older persons because they are associated with irreversible malnutrition, and the possible benefits do not outweigh the side effects. Similarly, any operation that decreases stomach size is contra-indicated in older persons unless obesity is associated with sleep apnea.

Noninstitutionalized older persons in Newfoundland who took a daily vitamin and trace mineral supplement had improved immune function compared to a control group who did not take a supplement. Older men who took Vitamin C were shown to live longer than those who did not; older women had no such advantage. Increasing evidence indicates that free radical damage may play a role in the pathogenesis of many diseases in older persons, including atherosclerosis, cancer, arthritis, and Parkinson’s disease. This has reopened the question of the pharmacologic use of free radical scavengers (vitamins and minerals) to prevent a diverse group of degenerative diseases.
About 25% of older Americans take a vitamin and mineral supplement, with women more likely to do so than men. Vitamin deficiencies are common in institutionalized older persons, but vitamin replacement studies have failed to show any major effects except for a decreased hip fracture rate with vitamin D replacement.
Vitamin A deficiency is rarely a problem in older persons. This vitamin should be avoided because it can produce hypercalcemia, liver dysfunction, and pseudotumor cerebri.
Thiamine (vitamin Bi) deficiency occurs mainly in alcoholics. Thiamine replacement can result in hypoglycemia in persons with liver dysfunction because they have inadequate glycogen reserves. Glucose administration can precipitate acute thiamine deficiency with delirium, ataxia, and bilateral sixth nerve palsies (Wernicke’s syndrome). Thus, in alcoholics, thiamine and glucose should always be administered together.
Riboflavin (vitamin B2) and pyridoxine (vitamin Bβ) deficiencies are common among nursing home residents. Signs of vitamin B2 deficiency include cheilosis, glossitis, angular stomatitis, seborrheic dermatitis, and a magenta tongue; signs of vitamin Bβ deficiency include sideroblastic anemias. A vitamin B complex is indicated for those with signs of vitamin B2 deficiency; pyridoxine is indicated for those with signs of vitamin B6 deficiency.
Niacin deficiency occurs in older persons who are alcoholics, are receiving isoniazid, or have carcinoid syndrome. Characteristically, the patient develops pellagra, ie, dermatitis on areas exposed to the sun, dementia, and diarrhea or constipation. High doses of nicotinic acid, but not nicotinamide, lower the cholesterol level. Nicotinic acid is com-plexed with chromium to produce glucose tolerance factor and may play a minor role in the hyperglycemia of aging. However, the practice of taking these agents as supplements is not recommended for older persons.
Vitamin B12 deficiency can lead to dementia, megaloblastic anemia, incontinence, orthostatic hypotension, or posterior column disease (loss of position and vibration sense). Up to 5% of persons over age 80 have vitamin B12 deficiency. The most common cause is pernicious anemia, which results from a lack of instrinsic factor. The diagnosis of vitamin B12 deficiency is made by documenting a vitamin B12 level < 200 μg/dL. However, 25% of persons with levels between 200 and 300 μg/dL are deficient, as demonstrated by elevated methylmalonic acid and homocysteine levels in the urine. Thus, patients who are suspected clinically of vitamin B12 deficiency and who have vitamin B12 levels between 200 and 300 μg/dL should have their urine methylmalonic acid and homocysteine levels checked. Traditionally, the Schilling test has been used to diagnose pernicious anemia. However, it is now recognized that when older persons develop gastric achlorhydria, they may be able to absorb vitamin B12 that is not bound to food but cannot liberate vitamin B12 that is bound to food and therefore absorb it. Thus, in most cases, the Schilling test is not clinically useful. Although oral vitamin B12 has been used to treat this deficiency, most authorities recommend vitamin B12 1000 |xg IM every month.
Vitamin C deficiency is associated with increased bruising, poor wound healing, and the development of pressure sores. Ingesting vitamin C at any dose results in false-negative fecal and urinary occult blood tests; ingesting megadoses can interfere with serum and urine glucose tests and may result in oxalate kidney stones, increased serum salicylate levels, and rebound scurvy (bleeding after withdrawal).

Protein-energy undernutrition (malnutrition) results from a deficient supply or absorption of nutrients or an excessive utilization of nutrients by the body. Marasmus and kwashiorkor are two forms of protein-energy undernutrition.
Marasmus is a condition of borderline nutritional compensation in which a patient has a marked depletion of muscle mass and fat stores but normal visceral protein and organ function. Because the patient has depleted nutritional reserves, any additional metabolic stress (eg, surgery, infection, burn) may rapidly lead to kwashiorkor (hypoalbu-minemic protein-energy malnutrition). Characteristically, elderly patients deteriorate to this state more rapidly than young patients; even relatively minor stress may be the cause. Usually, susceptible elderly patients are underweight, but even those who appear to have ample fat and muscle mass are susceptible if they have a recent history of rapid weight loss.
About 16% of elders living in the community consume < 1000 kcal/day, an amount that cannot maintain adequate nutrition. Undernutrition also occurs in 3% to 12% of older outpatients, 17% to 65% of older persons in acute care hospitals, and 26% to 59% of older persons living in long-term care institutions. Studies show that being underweight in middle age and later places a person at greater risk of death than being overweight. As TABLE 2-1 shows, protein-energy undernutrition can lead to many conditions.
Etiology
An elderly person may eat less food for several reasons (see TABLE 2-2). Diminished senses of smell and taste may decrease the pleasure of eating. Changes in taste are variable and are often associated with lifelong cigarette smoking, poor dental hygiene, and disease. Aging is associated with a decrease in the opioid (dynorphin) feeding drive and an increase in the satiety effect of cholecystokinin. Recent studies suggest that the early satiety in older persons may be caused by a nitric oxide deficiency, which decreases the adaptive relaxation of the fundus of the stomach in response to food.
Certain medications can produce weight loss by causing anorexia (eg, digoxin, quinidine, hydralazine, vitamin A, fluoxetine and other psychoactives); causing nausea (eg, antibiotics, theophylline, aspirin); increasing energy metabolism (eg, thyroxine, theophylline); or causing malabsorption (eg, sorbitol vehicle in theophylline elixir, cholestyramine). Also, withdrawal from certain drugs (eg, alcohol, anxiolytics, other psychoactives) may be associated with weight loss.
Depression is one of the most common reversible causes of weight loss in older persons. When depressed, they are more likely to lose weight than depressed younger persons. Some very old persons may stop eating because of the "unbearable weight of continued life." Management of this condition depends on the patient's ethical beliefs. Alcoholism in late life is often associated with weight loss, squalor syndrome, and depression.
The recurrence of anorexia nervosa in older persons who had an episode in their teens is being increasingly recognized. Abnormal attitudes about food intake and body image are not rare in underweight older persons. When these abnormal attitudes are associated with severe weight loss, the condition is called anorexia tardive. Late-life paranoia and late-life onset of mania may also be associated with weight loss.
Dementia usually produces weight loss because the person forgets to eat. Those who are wanderers can use large amounts of calories in a single day; consuming sufficient calories may be difficult. Demented persons may have a number of picas, including coprophagia. Recent studies show that patients with Alzheimer's disease do not have increased metabolism. On the other hand, persons with Parkinson's disease have a markedly increased metabolic rate, presumably because of their continuous tremors.
Dysphagia from a stroke or another neurologic disorder or from esophageal pain caused by candidiasis may result in decreased food intake. Dental problems may decrease food intake by up to 100 kcal/day. Xerostomia can also decrease food intake.
Medical causes of weight loss include hyperthyroidism, hypercalcemia, pheochromocytoma, and chronic infections (eg, tuberculosis, cancers). Malabsorption syndromes, particularly a late onset of celiac disease, should also be considered. Tremors and other physical problems with eating (eg, an inability to cut food after a stroke) can be corrected with adaptive utensils, such as a heavy-handled spoon or a rocker-bottom knife. Older persons tend to tolerate medically prescribed diets poorly and thus lose weight.
Poverty is a major cause of low food intake. Elders on fixed incomes may have to choose between filling their drug prescriptions or buying food.
Problems with shopping and food preparation may result in insufficient food being available in the home. Loneliness can diminish the desire to prepare meals.
Diagnosis
No screening battery has been shown to have good sensitivity and specificity for identifying persons at risk for undernutrition. One screening device based on the acronym SCALES has been used to identify persons at risk, but it still needs to be validated (see TABLE 2-3).
Weight loss is the single best factor for predicting persons at risk for malnutrition. Adequate height and weight tables for optimum body mass are not available, but a body mass index below 20 kg/m2 (weight/ height2) suggests a problem. Midarm circumference or arm muscle circumference (which corrects for triceps skinfold thickness) can be useful in following muscle mass changes in persons with a fluid retention problem. Skinfold thickness measurements have little diagnostic value.
In persons with marasmus, edema is absent; serum albumin and hemoglobin levels, total iron-binding capacity, and tests of cell-mediated immune function are usually normal.
When hypoalbuminemic protein energy malnutrition occurs, the serum albumin level is < 3.5 gm/dL, and anemia, lymphocytopenia, and hypotransferrinemia (evidenced by a total iron-binding capacity < 250 μg/dL) are likely. Often, anergy and edema are present.
Albumin, which has a 21-day half-life, is an excellent measure of protein status. Normal ambulatory elders should have serum albumin levels > 4 gm/dL; only when a person is recumbent do fluid shifts result in a normal albumin level of 3.5 gm/dL. Albumin levels < 3.2 gm/dL in hospitalized older persons are highly predictive of subsequent mortality. Cholesterol levels < 160 mg/dL in nursing home residents predict mortality, presumably because such levels reflect malnutrition. Acute illness associated with cytokine release can also lower cholesterol levels. Anergy (failure to respond to common antigens, such as mumps, injected into the skin) can occur in healthy as well as malnourished older persons. The combination of anergy and signs of malnutrition correlates more strongly with a poor outcome than either one alone.
Treatment
Some evidence indicates that the mortality rate for all hospitalized older persons would decrease if calorie supplements were given. Also, recent studies clearly show that older persons with hip fractures benefit from either oral calorie supplements or, when their albumin level is < 3 gm/dL, from short-term tube feeding. Total parenteral nutrition should be reserved for severely undernourished persons (those with an albumin level < 2 gm/dL) and for those who cannot tolerate enteral feedings. Peripheral vein parenteral nutrition appears to be underused in acutely ill older persons, in part because its role has not been adequately studied.
The use of specific types of nutrient supplements has little scientific basis. High-protein supplements are generally used for persons with infections. High-fat, high-fiber diets may smooth the glycemic response in persons with diabetes. High-fiber diets may reduce tube-feeding diarrhea but may also result in fecal impaction in immobile persons. In most cases, the choice of a supplement should be based on the patient’s preference. For a tube feeding, the choice should be the most cost-effective supplement.
For long-term tube feedings, most patients prefer percutaneous enteral gastrostomy tubes to nasogastric tubes. Demented patients appear to pull out gastrostomy tubes less often than nasogastric tubes. All types of tube feedings carry the risk of aspiration.
When a malnourished older person is fed, food may produce side effects, including electrolyte abnormalities, hyperglycemia, and aspiration pneumonia. Food can cause a significant drop in blood pressure, which is associated with falls. The decrease in blood pressure results from carbohydrate, which releases the vasodilatory gene-related peptide, calcitonin gene-related peptide.
Recently, recombinant growth hormone has been used to retain nitrogen and increase weight in severely malnourished older persons. Medroxyprogesterone acetate has produced weight gain in older persons with lung cancer.
Overall, undernutrition is poorly recognized and treated in older persons. Thorough examination for treatable causes of weight loss is essential. Appropriate use of short-term aggressive food supplementation can save lives.

Body mass increases between ages 20 and 50, then remains stable until about age 65, when weight loss occurs as a result of both lean and adipose tissue loss. The percentage of body fat increases around age 40 and then decreases after age 70. Intra-abdominal and intramuscular fat increases with aging. Older women have a lower waist-to-hip ratio than older men, and these lower ratios indicate a fat distribution that is less likely to be associated with hyperinsulinemia, hypertension, and diabetes.
Compared with younger men, older men experience a 20% decrease in total energy expenditure. Older women, however, experience only a minimal change in total energy expenditure. The explanation for this is that men tend to markedly reduce their physical activity with retirement, while women continue doing the bulk of the housework throughout their life. Resting metabolic rate decreases by 20% in men and 13% in women. These age-related reductions in resting metabolic rate result from a small decrease in triiodothyronine levels, reduced responsiveness to norepinephrine, reduced muscle tone and strength of muscle contraction, and reduced Na+K+ATPase activity. However, the major factor affecting resting metabolic rate is decreased food intake with aging. Nonsmoking women ages 55 to 74 consume 300 kcal/day less than women ages 19 to 29; for men, the decrease is 950 kcal/day. Older persons also have a decreased thermic response to food.

The primary nutritional problems affecting the elderly are protein-energy undernutrition, vitamin deficiencies, trace mineral deficiencies, and obesity. The physiologic changes of aging place older persons at risk for undernutrition. Mild vitamin deficiencies are very common in older persons, particularly those in institutions, and have been associated with cognitive impairment, poor wound healing, anemia, bruising, and an increased propensity for developing infections and some cancers (eg, vitamin A deficiency is associated with lung cancer). Trace mineral deficiencies are associated with immune dysfunction and many other disorders. Though a less serious problem in older persons than protein-energy undernutrition, obesity can impair functional status, increase the risk of pulmonary embolus and pressure sores, and aggravate chronic diseases such as diabetes mellitus and hypertension.