November 2018 Issue

Adult + Senior Wellness: Anorexia of Aging
By Katherine O'Brien, MD, and Lee A. Lindquist, MD, MPH, MBA
Today's Dietitian
Vol. 20, No. 11, P. 10

RDs can help diagnose and treat unintended weight loss in older adults.

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 RDs and other practitioners, other times it can be subtle and not always readily mentioned by patients. For these reasons, RDs must be attuned to detect and make nutrition recommendations to patients and their care teams when anorexia of aging is identified.

Identifying Causes
There are many potential causes of weight loss 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 reduced olfactory sense, also can contribute to 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, don't 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 to glean whether the patient is experiencing depression, which can contribute to poor appetite, or memory issues that should be addressed. Chronic medical conditions, such as heart failure, COPD, and malignancies, all can 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 also can be a consequence of unintentional weight loss. In a recent study by Tsutsumimoto and colleagues 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 a nutrient- and energy-poor diet and weight loss will lead to a clinically relevant impact can vary greatly. Therefore, it's imperative that RDs and other practitioners recognize frailty and implement interventions early.

Nonpharmacologic Treatment
RDs can make numerous recommendations once anorexia of aging has been identified. Any obvious contributing conditions should be treated after a comprehensive examination has been completed. RDs can counsel clients on grazing and increasing frequency of meals. Encouraging grazing is usually a simple start to treating anorexia of aging.

Small, calorie-dense meals typically are 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 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, patients and even some RDs may not be aware that the tight glycemic control recommended in younger populations hasn't been shown to be beneficial in older patients and actually can cause harm. 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% in 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. Nutrition interventions along with physical activity can lead to lasting improvements in energy, physical activity, and ultimately amelioration of frailty.5

Pharmacologic Treatment
Both patients and RDs likely are familiar with 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's 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's fairly well tolerated with the most common side effects being dry mouth, constipation, and fatigue. While it's commonly prescribed for patients with appetite issues and weight loss, the literature doesn't 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. Currently, there are no studies on the effect of mirtazapine on weight in patients without a diagnosis of depression. Moreover, systematic review of the literature doesn't fully support the idea that mirtazapine induces more weight gain than other antidepressants. However, in a patient who's depressed and losing weight, it may be a reasonable option to try.7

Megestrol, a synthetic progestin with antiestrogenic properties, also has 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 evaluated megestrol use in older adults, and most of these are of questionable design (ie, they aren't randomized controlled trials, don't control for confounding variables, or used inconsistent dosing). Many patients in these trials also couldn't 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 reduced overall mortality.8 RDs can consider adding nutritional supplements to a patient's treatment regimen if the patient enjoys drinking them as an addition to regular meals and snacks. However, they shouldn't be given to patients who dislike their taste, as they will be unlikely to use them, and they shouldn't replace regular small meals.

Overall, the literature doesn't 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 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 or nutrition 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.