Protein-energy malnutrition (PEM) is classically described as 1 of 2 syndromes, marasmus and kwashiorkor, depending on the presence or absence of edema. Each type may be classified as acute or chronic. Additionally, marasmus can precede kwashiorkor. Many patients exhibit symptoms of both disease states.
Marasmus, or PEM without edema, is defined as inadequate intake of all nutrients, but especially energy. Its extreme form is characterized by muscle wasting and depletion of body fat stores. Other findings may include: hypothermia, bradycardia, hypotension, decreased metabolic rate, loss of skin turgor, and constipation.
Kwashiorkor, or PEM with edema, is characterized by muscle atrophy, maintenance or gain of body fat, and peripheral edema. Other characteristics include: anasarca (generalized edema), hepatomegaly, dry and peeling skin, anorexia, hypothermia, and apathy.
The exact pathogenesis of kwashiorkor is unknown. Derived from an African term meaning “the disease that occurs when the next baby is born,” kwashiorkor was initially thought to result from a diet high in calories (mainly carbohydrates, such as maize) yet deficient in protein. However, recent evidence points away from dietary protein deficiency as the primary cause. While many of these patients exhibit hypoalbuminemia, this is thought to be a consequence of the disease and not a trigger. Aflatoxin poisoning, oxidative stress, immune system dysfunction, and the gut microbiota may play causative roles. , , ,
Mixed marasmus-kwashiorkor (edematous malnutrition) can occur in those who have inadequate dietary intake of all nutrients. This condition is typically triggered by an infection or inflammatory state.
PEM affects multiple organ systems and therefore places affected individuals at increased risk of severe illness and death by increasing the likelihood of micronutrient deficiencies, dehydration, infection, and sepsis.
PEM is primarily a problem in resource-limited countries. Worldwide, PEM is the leading cause of death in children under the age of 5. The highest prevalence is in Africa and south-central Asia. Protein-energy malnutrition is also found in developed countries under various circumstances, including anorexia nervosa, cancer, and severe chronic disease states. The condition has also been found in infants placed on severely restricted diets , and in 5% of a population of patients who requested Roux-en-Y gastric bypass surgery to control obesity.
Individuals treated for protein-energy malnutrition are at risk for refeeding syndrome, in which hypophosphatemia, hypokalemia, and hypomagnesemia may lead to disturbances in the cardiac, neurologic, gastrointestinal, respiratory, hematologic, skeletal, and endocrine systems. The World Health Organization has developed guidelines to help prevent these complications and to establish a transition to normalcy. Treatment consists of 3 phases: stabilization, rehabilitation, and follow-up.
The initial (stabilization) phase proceeds from days 1-7. It consists of treatment and prevention of hypoglycemia, hypothermia, dehydration, and infection; correction of electrolyte imbalance and micronutrient deficiencies; and a cautious feeding regimen.
A rehabilitation phase proceeds from weeks 2-6. It consists of achievement of catch-up growth, p rovision of sensory stimulation, and emotional support.
Follow-up is necessary as patients tend to relapse. Provision of nutritional supplements and education on the benefits of breastfeeding and hygiene have been found to be helpful interventions.