Some of these deserve further explanation:
Medications associated with malnutrition include digoxin, diuretics, anti-inflammatory agents, antacids, H2-blockers, antidepressants, anticonvulsants, anti-neoplastic agents, hypoglycemic agents and major tranquilizers; they can produce this effect by causing anorexia, nausea, vomiting, diarrhea, cognitive disturbance or increased metabolism. Emotional problems encountered are often reactive depressions. Anorexia can be physiological (reduced energy expenditure), or due to an age-related impaired sense of taste and/or smell. Late-life paranoia and late-life mania are rare causes of malnutrition in the elderly. Swallowing problems occur with oral, pharyngeal or esophageal disorders - teeth loss is common in nursing home residents, and mucosal lesions have been reported in up to a one third. Dysphagia is common in institutionalized patients.
Oral factors have been mentioned above - teeth loss and mucositis. Neoplasia is the single greatest identifiable cause of weight loss in older persons - most tumors are associated with increased metabolic need - so that appropriate diagnostic steps should be undertaken in older patients with unexplained weight loss.
Wandering is a common presenting symptom of Alzheimer disease and other forms of dementia. The malnutrition in dementia can occur in nursing home settings because the patient doesn't recognize the need to eat. There is no evidence that Alzheimer patients have an increased metabolism. Hyperthyroidism, on the other hand, is clearly associated with increased metabolism, as is hyperparathyroidism; hypothyroidism and hypoadrenalism can also cause malnutrition in older persons. Enteric problems (malabsorption) are occasionally seen in the elderly, due to a variety of causes. Eating difficulties also contribute to malnutrition, including those due to physical disability causing inability to self-feed. Low-salt and low-cholesterol diets often result in reduced intake, due to poor palatability. Social problems, although last on this list, may represent the most difficult to resolve; they include poverty, lack of care, conditions leading to reactive depression, as well as the catering problems associated with community living.
In order to treat malnutrition, it is necessary for the health professional to take a structured approach. If this is done, the etiology of most cases of under-nutrition can be determined. As a first step, the social factors should be addressed, if possible. These include poverty, lack of help with meals, shopping and lack of social incentives to eat properly. Community meals and programs such as Meals-On-Wheels offer effective remedial approaches to these social concerns.
Mechanical barriers to adequate intake should be sought. They are often overlooked, but represent potentially reversible conditions. Oral pathology, poor eyesight, inadequate motor coordination or physical disability (e.g. rheumatoid arthritis, Parkinson's disease) should all be adequately treated. If necessary, the diet should be adjusted to become both acceptable and manageable.
The list of medical conditions that can result in malnutrition is long. As a start, the commonest causes should be excluded: neoplasia, acute and chronic infections, endocrine disorders, chronic obstructive pulmonary disease and congestive heart failure. Possible psychiatric causes (depression, dementia, and late-life paranoia) should be also considered.
At the end of this analysis, the physician may still be in doubt. Observation of the patient at a typical mealtime may be extremely helpful in disclosing unexpected causes. Time spent on tackling this problem will be worthwhile in finding the way to remove impediments to adequate nutrition, making the difficult later years in life more acceptable, even enjoyable.
1. Moprley JE, Silver AJ. Nutritional issues in nursing home care. Ann Int Med 1995;123:850-859
