Article Archive
September/October 2017

Anorexia of Aging
By Katherine O'Brien, MD, and Lee A. Lindquist, MD, MPH, MBA
Today's Geriatric Medicine
Vol. 10 No. 5 P. 14

Patients may be reluctant to mention unintended weight loss that may be unnoticed by providers. Clinicians must be attuned to potential anorexia of aging and prescribe appropriate interventions.

Lack of appetite or decreased food intake in the elderly, or the "anorexia of aging" as first described by Morley and Silver in 1988, is a common concern in older populations.1 While at times it can be significant, causing weight loss noticeable to the primary care provider, other times it can be subtle and not always readily mentioned by a patient. For these reasons, providers need to be attuned to detect and make recommendations when anorexia of aging is identified.

Identifying Causes
There are many potential causes in older patients; this further obfuscates the matter, as a complete review is time consuming and complicated. Physiological changes of aging, which are less amenable to clinical intervention, include slowed gastric emptying and changing of hormones associated with appetite control (eg, fasting levels of ghrelin are lower, fasting and postprandial levels of cholecystokinin are higher, and baseline levels of leptin are high).

Sensory changes that occur with aging, such as poor dentition, loss of taste buds, decreased vision, and decreased olfactory sense, can also contribute to the anorexia of aging. Some older adults have difficulty preparing and eating meals due to decreased coordination and loss of the ability to easily perform fine motor tasks. A comprehensive social history can provide clues into potential causes of poor appetite. Many elders live alone and, therefore, do not wish to cook only for themselves, or lack the social interaction they formerly had at meal times when their families were present.

A review of mood and memory should be included in the evaluation in an attempt to glean whether there is depression, which can certainly contribute to poor appetite, or memory issues that should be addressed. Chronic medical conditions, such as heart failure, COPD, and malignancies, can all contribute and, if present, should be adequately managed.

Finally, a review of a patient's medication list is an essential component of the evaluation of anorexia of aging. There are myriad medications that can cause anorexia, as well as other symptoms that may lead to anorexia, such as nausea/vomiting, dry mouth, and constipation.

Consequences of Undetected or Untreated Anorexia of Aging
Anorexia of aging can have significant consequences in older patients. It can lead to frailty, increased risk of falls, pressure injury, osteomalacia and osteoporosis, muscle weakness, prolonged hospital stays, impaired wound healing and immune function, and increased mortality.2

One of the more feared geriatric syndromes, frailty can also be a consequence of unintentional weight loss. In a recent study by Tsutsumimoto el al in Japan, the prevalence of the anorexia of aging was found to be 21.2% in patients who were considered to be frail compared with 7.9% of those without a diagnosis of frailty.3

Frailty can create a state in which elders are more susceptible to stressors, namely acute and chronic illnesses, and can prolong recovery time as well. All of the above are detrimental to the lifespan and quality of life of older adults. Each patient of course is different, and how quickly an insufficient diet and weight loss will lead to a clinically relevant impact can vary greatly. Therefore, it is imperative that frailty be recognized and intervention implemented early.

Nonpharmacologic Treatment
Once anorexia of aging has been identified, providers often wonder what can be done to help patients. Any obvious contributing conditions should be treated after a comprehensive examination has been completed. Patients can be counseled on grazing and increased frequency of meals. Encouraging grazing is usually a simple start to treating anorexia of aging.

Small calorie-dense meals are typically easier for older people to manage and can lead to weight gain. Asking family members or friends to buy a patient's favorite foods, such as favorite cookies, and keeping an open package near where the patient spends most of the day can lead to grazing and increased caloric intake. Liberalizing the diet by incorporating some amount of fats, sugars, and salt can lead older adults to eat more by allowing for foods with more appealing taste.

Many older adults who have diabetes or heart disease may have followed the same strict diets for years, but they may no longer require such tight control. For example, many patients and providers are unaware that the tight glycemic control recommended in younger populations has not been shown to be beneficial in older patients and can actually cause harms. A1c targets should be liberalized as well, with a goal of 7% to 7.5% in healthy older adults, 7.5% to 8% in those with a life expectancy of 10 years or less and multiple comorbidities, and 8% to 9% for patients with a short life expectancy.4

For patients whose family members are available and willing to assist, providing company at meals or hand feeding patients who have difficulty feeding themselves can lead to increased caloric intake and weight gain. Nutritional interventions along with physical activity can lead to lasting improvements in energy, physical activity, and ultimately amelioration of frailty.5

Pharmacologic Treatment
Many patients and providers have read about nutritional supplements and medications that have been used to increase appetite and promote weight gain, including such nutritional supplements and appetite stimulants as mirtazapine and megestrol. The American Geriatrics Society in its "Choosing Wisely" campaign recommends avoiding prescription appetite stimulants such as mirtazapine and megestrol or high-calorie supplements, as there is no quality evidence that clinical outcomes such as quality of life or mortality are affected.6

Mirtazapine is an antidepressant whose side effects include weight gain. It is fairly well tolerated, with the most common side effects being dry mouth, constipation, and fatigue. While it is commonly prescribed for patients with appetite issues and weight loss, the literature does not always suggest its use in this setting. Most studies involving mirtazapine use in older patients included patients with a diagnosis of depression or dementia with depression. There are currently no studies on the effect of mirtazapine on weight in patients without a diagnosis of depression. Moreover, systematic review of the literature does not fully support the idea that mirtazapine induces more weight gain than other antidepressants. However, in a patient who is depressed and losing weight, it may be a reasonable option to try.7

Megestrol, a synthetic progestin with antiestrogenic properties, has also been used historically to promote patients' weight gain. Megestrol is less well tolerated than mirtazapine and has significant side effects associated with its use including an increased risk of deep venous thrombosis, adrenal suppression, hyperglycemia, osteoporosis, diarrhea, flatulence, rash, hypertension, nausea, insomnia, and headache. There are few studies in the literature that specifically studied megestrol use in older adults, and most of these are of questionable design (ie, they are not randomized controlled trials, no control for confounding variable, or inconsistent dosing was used). Many patients in these trials were also unable to tolerate the use of megestrol due to side effects.7

The evidence behind the use of nutritional supplements is again somewhat unclear. In a Cochrane review of 62 trials, the use of nutritional supplements did produce a small but consistent weight gain. However, there was no consistent evidence that providing supplementation actually reduced overall mortality.8 Nutritional supplements can be considered if a patient enjoys drinking them as an addition to regular meals and snacks. However, they should not be given to patients who dislike their taste, as they will be unlikely to use them, and they should not replace regular small meals.

Overall the literature does not clearly support the use of megestrol or mirtazapine for weight gain in older patients with anorexia of aging. While mirtazapine is a possible option if a patient also suffers from depression, other strategies such as those reviewed above should be prioritized with family members and caregivers.

In summary, anorexia of aging is a complicated and sometimes underrecognized issue in older patients. Its identification requires a comprehensive evaluation by a health care professional followed by a clear plan of action that ideally involves not only the patient but also the caregivers to achieve success.

— Katherine O'Brien, MD, is a graduating geriatrics fellow at Northwestern University Feinberg School of Medicine in Chicago and will be starting her palliative care fellowship at Northwestern this fall.

— Lee A. Lindquist, MD, MPH, MBA, is section chief of geriatrics at Northwestern University Feinberg School of Medicine.

1. Morley JE, Silver AJ. Anorexia in the elderly. Neurobiol Aging. 1988;9(1):9-16.

2. Landi F, Calvani R, Tosato M, et al. Anorexia of aging: risk factors, consequences, and potential treatments. Nutrients. 2016;8(2):69.

3. Tsutsumimoto K, Doi T, Makizako H, et al. The association between anorexia of aging and physical frailty: results from the National Center for Geriatrics and Gerontology's study of geriatric syndromes. Maturitas. 2017;97:32-37.

4. AGS Choosing Wisely Workgroup. American Geriatrics Society identifies five things that healthcare providers and patients should question. J Am Geriatr Soc. 2013;61(4):622-631.

5. Ng TP, Feng L, Nyunt MS, et al. Nutritional, physical, cognitive, and combination interventions and frailty reversal among older adults: a randomized controlled trial. Am J Med. 2015;128(11):1225-1236.e1.

6. AGS Choosing Wisely Workgroup. American Geriatrics Society identifies another five things that healthcare providers and patients should question. J Am Geriatr Soc. 2014;62(5):950-960.

7. Fox CB, Treadway AK, Blaszczyk AT, Sleeper RB. Megestrol acetate and mirtazapine for the treatment of unplanned weight loss in the elderly. Pharmacotherapy. 2009;29(4):383-397.

8. Milne AC, Potter J, Vivanti A, Avenell A. Protein and energy supplementation in elderly people at risk from malnutrition. Cochrane Database Syst Rev. 2009;(2):CD003288.