Identifying Malnutrition

Physical findings of malnutrition include weight loss, decreased muscle mass and subcutaneous fat, localized or generalized fluid accumulation (edema and ascites), compromised functional status, poor wound healing, loose clothes or jewelry, dry and sallow skin, and fatigue.2,5,21 Laboratory tests used to help measure nutritional status include albumin, prealbumin, transferrin, retinal binding protein, insulin-like growth factor-1, and fibronectin.5,21 Other laboratory tests such as C-reactive protein, white blood cell count, and blood glucose levels may aid in diagnosing a specific etiology of malnutrition.21 If a patient’s signs and symptoms indicate malnutrition, a formal nutritional assessment using approved screening tools should be performed by a healthcare professional with nutritional expertise (Table 1).5,6

Significant advances in the ability to detect malnutrition through the use of screening tests have occurred in the last 30 years.5,6The Mini Nutritional Assessment (MNA) was created by Vellas and Guigoz in 1989 and has become the best validated and most widely used tool to assess malnutrition.2,5 It is composed of 18 questions that are graded numerically based on an individual’s response, with scores between 17 and 23 reflecting the individual to be considered at risk for malnutrition and scores <17 representing protein energy malnutrition.5 The advantage of the MNA over other screening tests is that it does not rely on laboratory testing, making it more accessible and easier to perform.5

A shorter form of the MNA (MNA-SF) is designed especially for the elderly and consists of 6 questions that address weight loss, appetite, mobility, psychologic stress, neuropsychologic problems, and body mass index (BMI).5 It is often used as an initial screening tool that can be combined with the MNA for a more detailed nutritional assessment when warranted.6 The MNA and MNA-SF are not useful for patients who are unable to provide accurate and reliable information about themselves.5,6

Although the MNA is the most widely used screening tool, several other validated tests are available to identify malnutrition.5 The Malnutrition Universal Screening Tool (MUST) uses BMI, weight loss, and acute disease effect. It is validated for all adult patients in any healthcare setting.5,6 The Nutritional Risk Index (NRI) and the Geriatric Nutritional Risk Index (GNRI) use albumin and another nutrition indicator such as weight loss to assess nutritional status.6 These values are then plugged into an equation that varies slightly between the NRI and GNRI, giving a score that can be categorized into well nourished, mildly malnourished, moderately malnourished, and severely malnourished.6

The Subjective Global Assessment gives a grade of malnutrition based on questions asked about weight loss, dietary intake changes, gastrointestinal tract symptoms, physical function, and parameters of physical examination. Grade A refers to normally nourished patients, grade B refers to moderate malnutrition, and grade C is used for severely malnourished patients. Some disadvantages to this test are that it must be administered by a physician and it is subjectively based on the patient’s answers.6

Despite the availability of screening tests that have been developed to detect malnutrition, the condition remains underdiagnosed.2,5,6

Consequences of Malnutrition

Malnourishment is often referred to as “a cause and consequence of adverse outcomes” andaffects almost every organ system in the body.1 When the body is not receiving adequate nutrient intake, it relies on nutritional stores to provide fuel and energy for normal functions.1 When these stores run out, the body starts to metabolize protein into a usable energy source, resulting in depleted muscle mass. The patient then becomes more susceptible to disease.1,2

Impaired immune response as a result of malnutrition makes the elderly more susceptible to infection and diminishes the ability to mount a response if infected, which can be life threatening.1,2,4 Because protein in muscles is broken down for energy in a malnourished state, overall muscle strength is decreased, leading to an increase in falls, reduced respiratory function, and the inability to perform tasks such as shopping, cooking, and food preparation, contributing to further nutrient deficit.2

Malnourished patients often lack energy, resulting in decreased activity.2 This sedentary lifestyle increases the risk for pressure ulcers and deep vein thrombosis.2,8 Malnutrition can lead to temperature, salt, and fluid regulatory mechanisms being lost or impaired, which can result in hypothermia, dehydration, or overhydration.2 Inadequate intake of nutrient-dense foods can cause nutrient deficiencies in vitamin C, vitamin B12, folate, vitamin A, potassium, and iron. Inadequate levels of these nutrients may lead to impairment in homeostasis, increasing the risk of mortality if left untreated.2,8,18 Psychosocial function may also be affected, increasing the risk for depression, apathy, introversion, loneliness, and hypochondriasis, which can further contribute to poor nutrition in the patient.2,15

Malnutrition has been identified as a preventable risk factor that leads to unnecessary hospital visits and expenditures.3,7 Elderly adults are at high risk for repeat hospitalizations and readmissions, and reducing these occurrences has become a major goal of hospitals and insurance companies.3,7 In hospitalized patients, multiple factors such as disease, trauma, sepsis, and fever can contribute to malnutrition even if adequate oral intake is achieved.7

A retrospective study analyzed whether malnutrition at hospital admission helped predict the clinical outcomes of 2076 patients aged 65 years and older during an 18-month follow-up.1 Nutritional status was determined using the MNA within 72 hours of admission: 30% of patients were malnourished, and 53% were at risk for malnutrition.1 The authors found that malnourished patients had a longer median hospital stay (34 days), at-risk patients’ median stay was 26 days, and well-nourished patients had the shortest stay with a 20-day median.1 The number of readmissions was not significantly associated with malnutrition in this study; however, it should be noted that compared with well-nourished patients, malnourished patients had 6 times the rate of discharge to a high-level care facility.1 Analysis of the survival rate in this study when controlling for age, sex, disease, morbidity, and length of stay revealed that the hazard ratio for death in the malnourished group was 3.4 times that of the well-nourished group.1

A Canadian study evaluating 1022 patients found that malnutrition, as determined by Subjective Global Assessment, was independently associated with prolonged length of hospital stay and readmission.7 Several similar studies investigating the role of malnutrition on clinical outcomes had results consistent with these findings.1,3,7