VIII.111 - Protein-Energy Malnutrition

Summary

Protein-energy malnutrition (PEM) or, as it is still sometimes called, protein-calorie malnutrition (PCM), is a term of convenience that refers to a range of syndromes among infants and children of preschool age in whom manifestations of growth failure occur because of protein and energy deficiencies. In most instances this condition besets those in the less developed world of Asia, Africa, and Latin America, where dietary factors are thought to be a crucial part of the etiology. PEM thereby tends to exclude what is conventionally known as “failure to thrive” in Europe and North America, in which the vast majority of cases result from organic disorders such as cystic fibrosis or congenital heart disease problems and are not so directly associated with diet as such.

PEM is best described in its two clinical versions of kwashiorkor and marasmus. In the former, edema is always present, whereas extreme wasting (commonly defined as below 60 percent that of normal weight for height) identifies the latter. Much of the research in the 1950s and 1960s focused on differentiating between the symptoms and etiologies of kwashiorkor and marasmus, but since then it has become evident that cases purely of one or the other are the exception rather than the rule. The majority display both edema and extreme wasting, plus a variable mix of other symptoms, that have earned them the rather inelegant designation of marasmic kwashiorkor. In addition, far more common than all of the three put together are numerous subclinical syndromes, usually referred to as mild-to-moderate PEM.