Malnutrition and Electrolyte Metabolism

Abnormal total body and serum electrolyte concentrations are common in protein-energy malnutrition (PEM). The subject of electrolyte metabolism in PEM was studied in depth in the 1960s and early 1970s but has seldom been investigated in the past decade. Electrolyte status has been assessed by a variety of methods, including electrolyte concentrations in serum, urine, or muscle tissue; external electrolyte balances during recovery; and isotopic techniques. Although there is general agreement that total body water and sodium are increased and total body potassium and magnesium are decreased (1), many uncertainties persist about the importance, prognostic significance, or therapeutic implications of such findings, especially with regard to potassium depletion. Some of the discrepancies may derive from methodologic differences but also from variations in the type or degree of malnutrition, severity of the associated diarrhea, or differing electrolyte composition of the deficient diet in various parts of the world.