Protein-Energy Malnutrition

Basics

Protein–energy malnutrition (PEM) is present when sufficient energy and/or protein is not available to meet metabolic demands, leading to impairment in normal physiologic processes. In adults, it is highly associated with systemic inflammation.
Commonly seen in children in resource-limited countries, where it is estimated to contribute to 45% of all child deaths globally
Malnutrition in children is a major underlying factor in ~5 million preventable deaths annually, with two distinct phenotypes.
- Marasmus (wasting syndrome): a wasting condition due to deficiency of calories and protein
- Kwashiorkor: generalized edema and ascites, associated with low protein relative to caloric intake
System(s) affected: immunologic, gastrointestinal (GI), endocrine/metabolic, hematologic, musculoskeletal, integumentary, neurologic

Children
- Most commonly <5 years of age
- Prevalent sex: males = females
- Globally, malnutrition increases morbidity and mortality from other common childhood diseases.
- In the United States, clinical perspective and description has evolved during the past 3 decades, although older studies suggest up to 25% of all hospitalized children experienced acute PEM, and approximately 27% experience chronic food insecurity.
- Common causes:
  - Illness—acute or chronic
  - Adverse environmental factors
  - Behavioral conditions
  - Injury
  - Congenital anomalies
Older patients
- Intake reduction is one of the main causes of chronic malnutrition in the elderly.
- Highest risk group age >75 years, affecting 5–10% of nursing home residents and up to 50% of older patients on hospital discharge
- Increased mortality and morbidity, including pressure ulcers, infection, and cognitive status changes
- Common causes:
  - Geriatric anorexia
  - Alterations in taste and smell
  - Hormone changes regulating gastric/intestinal motility
  - Mood alterations (dementia, depression)
Malnutrition may be common, but it is difficult to recognize in hospital populations.

Prevalence

Worldwide, >70 million children suffer from moderate and severe acute malnutrition.
Prevalence in older patients is between 29% and 61%.

Conditions that predispose the patient to cachexia also increase the risk of PEM.
Starvation-related malnutrition
- Prolonged and severe reduction of intake
- Anorexia nervosa
Chronic inflammatory states (rheumatoid arthritis, chronic cardiac or lung disease, and cancer)
Metabolic disorders (diabetes, hyperthyroidism)
Malabsorptive and maldigestive states (celiac disease and pancreatic insufficiency)
Protein-losing enteropathy, liver cirrhosis, chronic kidney disease, nephrotic syndrome, enteric fistulas
Marked inflammatory conditions: acute disease, fever, infection, trauma, burns, closed head injury
Other states in which caloric requirements are increased: pregnancy and lactation, childhood growth and development

ALERT

Functional, financial, and social factors may limit access to an adequate diet.
Elders with delirium, dementia, or depression or long periods spent NPO or with prolonged hospitalization are at high risk for malnutrition.
Extreme high- or low-BMI individuals are also at increased risk.
Malnutrition can occur in healthy weight or overweight individuals. BMI can be a tool in the identification of chronic malnutrition in patients but should not be used as a sole method of screening or diagnosis.
Cirrhotic patients: PEM is one of the most common complications in liver cirrhosis and is associated with an increased risk of variceal bleeding, ascites, hepatic encephalopathy, and hepatorenal syndrome.

Observation and recording of patients’ nutritional intake and BMI
In children, routine record of anthropomorphic measurements and developmental milestones
Early recognition of increased nutritional requirements during stress, infection, and other medical illness
Emphasis on food security and nutritional education

Infection: weakened immune system, predisposing to bacterial, viral, and parasitic infections
Electrolyte disturbances: loss of cellular integrity, diminished transmembrane pump activity, renal dysfunction
Hypoglycemia: decreased glycogen stores, increased glucose use (as in infection or trauma)
Micronutrient deficiencies: vitamins, including B complex, folic acid, iron, magnesium (1)
Wounds: pressure ulcers in older patients (increased incidence if reduced mobility)

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